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https://gitlab.com/veloren/veloren.git
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597bb3c526
- soil production (currently disabled). - debris flow erosion (combined with regular stream power law). - flow computation using multiple receivers. - filling strategy during drainage network calculations. Also tweaks a variety of other aspects of erosion.
3395 lines
171 KiB
Rust
3395 lines
171 KiB
Rust
use super::{
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diffusion, downhill, neighbors, uniform_idx_as_vec2, uphill, vec2_as_uniform_idx,
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NEIGHBOR_DELTA, WORLD_SIZE,
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};
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use crate::{config::CONFIG, util::RandomField};
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use arr_macro::arr;
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use bitvec::prelude::{bitbox, bitvec, BitBox};
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use common::{terrain::TerrainChunkSize, vol::RectVolSize};
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use faster::*;
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use noise::{NoiseFn, Point3};
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use num::{Float, FromPrimitive, One, Zero};
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use ordered_float::NotNan;
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use packed_simd::{/*f32x8, f64x8,*/ m32, m64};
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use rayon::prelude::*;
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use std::{
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cmp::{Ordering, Reverse},
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collections::BinaryHeap,
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f32, f64, fmt, mem,
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path::PathBuf,
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time::Instant,
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u32,
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};
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use vek::*;
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pub type Alt = f64;
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// pub type Altx8 = /*f64x8*/f32x8;
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pub type Compute = f64;
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pub type Computex8 = [Compute; 8];
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/// Compute the water flux at all chunks, given a list of chunk indices sorted by increasing
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/// height.
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pub fn get_drainage(newh: &[u32], downhill: &[isize], _boundary_len: usize) -> Box<[f32]> {
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// FIXME: Make the below work. For now, we just use constant flux.
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// Initially, flux is determined by rainfall. We currently treat this as the same as humidity,
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// so we just use humidity as a proxy. The total flux across the whole map is normalize to
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// 1.0, and we expect the average flux to be 0.5. To figure out how far from normal any given
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// chunk is, we use its logit.
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// NOTE: If there are no non-boundary chunks, we just set base_flux to 1.0; this should still
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// work fine because in that case there's no erosion anyway.
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// let base_flux = 1.0 / ((WORLD_SIZE.x * WORLD_SIZE.y) as f32);
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let base_flux = 1.0;
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let mut flux = vec![base_flux; WORLD_SIZE.x * WORLD_SIZE.y].into_boxed_slice();
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for &chunk_idx in newh.into_iter().rev() {
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let chunk_idx = chunk_idx as usize;
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let downhill_idx = downhill[chunk_idx];
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if downhill_idx >= 0 {
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flux[downhill_idx as usize] += flux[chunk_idx];
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}
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}
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flux
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}
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/// Compute the water flux at all chunks for multiple receivers, given a list of chunk indices
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/// sorted by increasing height and weights for each receiver.
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pub fn get_multi_drainage(
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mstack: &[u32],
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mrec: &[u8],
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mwrec: &[Computex8],
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_boundary_len: usize,
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) -> Box<[Compute]> {
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// FIXME: Make the below work. For now, we just use constant flux.
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// Initially, flux is determined by rainfall. We currently treat this as the same as humidity,
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// so we just use humidity as a proxy. The total flux across the whole map is normalize to
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// 1.0, and we expect the average flux to be 0.5. To figure out how far from normal any given
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// chunk is, we use its logit.
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// NOTE: If there are no non-boundary chunks, we just set base_flux to 1.0; this should still
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// work fine because in that case there's no erosion anyway.
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// let base_flux = 1.0 / ((WORLD_SIZE.x * WORLD_SIZE.y) as f32);
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let base_area = 1.0;
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let mut area = vec![base_area; WORLD_SIZE.x * WORLD_SIZE.y].into_boxed_slice();
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for &ij in mstack {
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let ij = ij as usize;
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let wrec_ij = &mwrec[ij];
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let area_ij = area[ij];
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// debug_assert!(area_ij >= 0.0);
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for (k, ijr) in mrec_downhill(mrec, ij) {
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/* if area_ij != 1.0 {
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println!("ij={:?} wrec_ij={:?} k={:?} ijr={:?} area_ij={:?} wrec_ij={:?}", ij, wrec_ij, k, ijr, area_ij, wrec_ij[k]);
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} */
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area[ijr] += area_ij * /*wrec_ij.extract(k);*/wrec_ij[k];
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}
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}
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area
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/*
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a=dx*dy*precip
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do ij=1,nn
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ijk=mstack(ij)
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do k =1,mnrec(ijk)
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a(mrec(k,ijk))=a(mrec(k,ijk))+a(ijk)*mwrec(k,ijk)
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enddo
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enddo
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*/
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}
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/// Kind of water on this tile.
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#[derive(Clone, Copy, Debug, PartialEq)]
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pub enum RiverKind {
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Ocean,
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Lake {
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/// In addition to a downhill node (pointing to, eventually, the bottom of the lake), each
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/// lake also has a "pass" that identifies the direction out of which water should flow
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/// from this lake if it is minimally flooded. While some lakes may be too full for this
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/// to be the actual pass used by their enclosing lake, we still use this as a way to make
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/// sure that lake connections to rivers flow in the correct direction.
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neighbor_pass_pos: Vec2<i32>,
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},
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/// River should be maximal.
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River {
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/// Dimensions of the river's cross-sectional area, as m × m (rivers are approximated
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/// as an open rectangular prism in the direction of the velocity vector).
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cross_section: Vec2<f32>,
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},
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}
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impl RiverKind {
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pub fn is_river(&self) -> bool {
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if let RiverKind::River { .. } = *self {
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true
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} else {
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false
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}
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}
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pub fn is_lake(&self) -> bool {
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if let RiverKind::Lake { .. } = *self {
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true
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} else {
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false
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}
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}
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}
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impl PartialOrd for RiverKind {
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fn partial_cmp(&self, other: &Self) -> Option<Ordering> {
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match (*self, *other) {
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(RiverKind::Ocean, RiverKind::Ocean) => Some(Ordering::Equal),
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(RiverKind::Ocean, _) => Some(Ordering::Less),
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(_, RiverKind::Ocean) => Some(Ordering::Greater),
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(RiverKind::Lake { .. }, RiverKind::Lake { .. }) => None,
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(RiverKind::Lake { .. }, _) => Some(Ordering::Less),
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(_, RiverKind::Lake { .. }) => Some(Ordering::Greater),
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(RiverKind::River { .. }, RiverKind::River { .. }) => None,
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}
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}
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}
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/// From velocity and cross_section we can calculate the volumetric flow rate, as the
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/// cross-sectional area times the velocity.
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///
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/// TODO: we might choose to include a curve for the river, as long as it didn't allow it to
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/// cross more than one neighboring chunk away. For now we defer this to rendering time.
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///
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/// NOTE: This structure is 57 (or more likely 64) bytes, which is kind of big.
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#[derive(Clone, Debug, Default)]
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pub struct RiverData {
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/// A velocity vector (in m / minute, i.e. voxels / second from a game perspective).
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///
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/// TODO: To represent this in a better-packed way, use u8s instead (as "f8s").
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pub(crate) velocity: Vec3<f32>,
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/// The computed derivative for the segment of river starting at this chunk (and flowing
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/// downhill). Should be 0 at endpoints. For rivers with more than one incoming segment, we
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/// weight the derivatives by flux (cross-sectional area times velocity) which is correlated
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/// with mass / second; treating the derivative as "velocity" with respect to length along the
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/// river, we treat the weighted sum of incoming splines as the "momentum", and can divide it
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/// by the total incoming mass as a way to find the velocity of the center of mass. We can
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/// then use this derivative to find a "tangent" for the incoming river segment at this point,
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/// and as the linear part of the interpolating spline at this point.
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///
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/// Note that we aren't going to have completely smooth curves here anyway, so we will probably
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/// end up applying a dampening factor as well (maybe based on the length?) to prevent
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/// extremely wild oscillations.
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pub(crate) spline_derivative: Vec2<f32>,
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/// If this chunk is part of a river, this should be true. We can't just compute this from the
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/// cross section because once a river becomes visible, we want it to stay visible until it
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/// reaches its sink.
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pub river_kind: Option<RiverKind>,
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/// We also have a second record for recording any rivers in nearby chunks that manage to
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/// intersect this chunk, though this is unlikely to happen in current gameplay. This is
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/// because river areas are allowed to cross arbitrarily many chunk boundaries, if they are
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/// wide enough. In such cases we may choose to render the rivers as particularly deep in
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/// those places.
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pub(crate) neighbor_rivers: Vec<u32>,
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}
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impl RiverData {
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pub fn is_river(&self) -> bool {
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self.river_kind
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.as_ref()
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.map(RiverKind::is_river)
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.unwrap_or(false)
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}
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pub fn is_lake(&self) -> bool {
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self.river_kind
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.as_ref()
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.map(RiverKind::is_lake)
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.unwrap_or(false)
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}
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}
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/// Draw rivers and assign them heights, widths, and velocities. Take some liberties with the
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/// constant factors etc. in order to make it more likely that we draw rivers at all.
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pub fn get_rivers<F: fmt::Debug + Float + Into<f64>, G: Float + Into<f64>>(
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newh: &[u32],
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water_alt: &[F],
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downhill: &[isize],
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indirection: &[i32],
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drainage: &[G],
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) -> Box<[RiverData]> {
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// For continuity-preserving quadratic spline interpolation, we (appear to) need to build
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// up the derivatives from the top down. Fortunately this computation seems tractable.
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let mut rivers = vec![RiverData::default(); WORLD_SIZE.x * WORLD_SIZE.y].into_boxed_slice();
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let neighbor_coef = TerrainChunkSize::RECT_SIZE.map(|e| e as f64);
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// (Roughly) area of a chunk, times minutes per second.
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let mins_per_sec = /*64.0*/1.0; //1.0 / 64.0;
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let chunk_area_factor = neighbor_coef.x * neighbor_coef.y / mins_per_sec;
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// NOTE: This technically makes us discontinuous, so we should be cautious about using this.
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let derivative_divisor = 1.0;
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let height_scale = 1.0; // 1.0 / CONFIG.mountain_scale as f64;
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for &chunk_idx in newh.into_iter().rev() {
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let chunk_idx = chunk_idx as usize;
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let downhill_idx = downhill[chunk_idx];
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if downhill_idx < 0 {
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// We are in the ocean.
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debug_assert!(downhill_idx == -2);
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rivers[chunk_idx].river_kind = Some(RiverKind::Ocean);
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continue;
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}
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let downhill_idx = downhill_idx as usize;
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let downhill_pos = uniform_idx_as_vec2(downhill_idx);
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let dxy = (downhill_pos - uniform_idx_as_vec2(chunk_idx)).map(|e| e as f64);
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let neighbor_dim = neighbor_coef * dxy;
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// First, we calculate the river's volumetric flow rate.
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let chunk_drainage = drainage[chunk_idx].into();
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// Volumetric flow rate is just the total drainage area to this chunk, times rainfall
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// height per chunk per minute, times minutes per second
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// (needed in order to use this as a m³ volume).
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// TODO: consider having different rainfall rates (and including this information in the
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// computation of drainage).
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let volumetric_flow_rate =
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chunk_drainage * chunk_area_factor * CONFIG.rainfall_chunk_rate as f64;
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let downhill_drainage = drainage[downhill_idx].into();
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// We know the drainage to the downhill node is just chunk_drainage - 1.0 (the amount of
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// rainfall this chunk is said to get), so we don't need to explicitly remember the
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// incoming mass. How do we find a slope for endpoints where there is no incoming data?
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// Currently, we just assume it's set to 0.0.
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// TODO: Fix this when we add differing amounts of rainfall.
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let incoming_drainage = downhill_drainage - 1.0;
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let get_river_spline_derivative =
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|neighbor_dim: Vec2<f64>, spline_derivative: Vec2<f32>| {
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/*if incoming_drainage == 0.0 {
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Vec2::zero()
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} else */
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{
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// "Velocity of center of mass" of splines of incoming flows.
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let river_prev_slope = spline_derivative.map(|e| e as f64)/* / incoming_drainage*/;
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// NOTE: We need to make sure the slope doesn't get *too* crazy.
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// ((dpx - cx) - 4 * MAX).abs() = bx
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// NOTE: This will fail if the distance between chunks in any direction
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// is exactly TerrainChunkSize::RECT * 4.0, but hopefully this should not be possible.
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// NOTE: This isn't measuring actual distance, you can go farther on diagonals.
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// let max_deriv = neighbor_dim - neighbor_coef * 4.0;
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let max_deriv = neighbor_dim - neighbor_coef * 2.0 * 2.0.sqrt();
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let extra_divisor = river_prev_slope
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.map2(max_deriv, |e, f| (e / f).abs())
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.reduce_partial_max();
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// Set up the river's spline derivative. For each incoming river at pos with
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// river_spline_derivative bx, we can compute our interpolated slope as:
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// d_x = 2 * (chunk_pos - pos - bx) + bx
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// = 2 * (chunk_pos - pos) - bx
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//
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// which is exactly twice what was weighted by uphill nodes to get our
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// river_spline_derivative in the first place.
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//
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// NOTE: this probably implies that the distance shouldn't be normalized, since the
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// distances aren't actually equal between x and y... we'll see what happens.
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(if extra_divisor > 1.0 {
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river_prev_slope / extra_divisor
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} else {
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river_prev_slope
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})
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.map(|e| e as f32)
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}
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};
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let river = &rivers[chunk_idx];
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let river_spline_derivative =
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get_river_spline_derivative(neighbor_dim, river.spline_derivative);
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let indirection_idx = indirection[chunk_idx];
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// Find the lake we are flowing into.
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let lake_idx = if indirection_idx < 0 {
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// If we're a lake bottom, our own indirection is negative.
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/* let mut lake = &mut rivers[chunk_idx];
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let neighbor_pass_idx = downhill_idx;
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// Mass flow from this lake is treated as a weighting factor (this is currently
|
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// considered proportional to drainage, but in the direction of "lake side of pass to
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// pass.").
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let neighbor_pass_pos = downhill_pos;
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lake.river_kind = Some(RiverKind::Lake {
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neighbor_pass_pos: neighbor_pass_pos
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* TerrainChunkSize::RECT_SIZE.map(|e| e as i32),
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});
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lake.spline_derivative = Vec2::zero()/*river_spline_derivative*/; */
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let pass_idx = (-indirection_idx) as usize;
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/* let pass_pos = uniform_idx_as_vec2(pass_idx);
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let lake_direction = neighbor_coef * (neighbor_pass_pos - pass_pos).map(|e| e as f64); */
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let pass = &rivers[pass_idx];
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/* // Our side of the pass must have already been traversed (even if our side of the pass
|
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// is the lake bottom), so we acquire its computed river_spline_derivative.
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debug_assert!(pass.is_lake()); */
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// NOTE: Must exist since this lake had a downhill in the first place.
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let neighbor_pass_idx = downhill[pass_idx] as usize/*downhill_idx*/;
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/* let pass_spline_derivative = pass.spline_derivative.map(|e| e as f64)/*Vec2::zero()*/;
|
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// Normally we want to not normalize, but for the lake we don't want to generate a
|
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// super long edge since it could lead to a lot of oscillation... this is another
|
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// reason why we shouldn't use the lake bottom.
|
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// lake_direction.normalize();
|
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// We want to assign the drained node from any lake to be a river.
|
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let lake_drainage = /*drainage[chunk_idx]*/chunk_drainage;
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let lake_neighbor_pass_incoming_drainage = incoming_drainage;
|
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let weighted_flow = (lake_direction * 2.0 - pass_spline_derivative)
|
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/ derivative_divisor
|
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* lake_drainage
|
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/ lake_neighbor_pass_incoming_drainage; */
|
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let mut lake_neighbor_pass = &mut rivers[neighbor_pass_idx];
|
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// We definitely shouldn't have encountered this yet!
|
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debug_assert!(lake_neighbor_pass.velocity == Vec3::zero());
|
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// TODO: Rethink making the lake neighbor pass always a river or lake, no matter how
|
||
// much incoming water there is? Sometimes it looks weird having a river emerge from a
|
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// tiny pool.
|
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lake_neighbor_pass.river_kind = Some(RiverKind::River {
|
||
cross_section: Vec2::default(),
|
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});
|
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/* // We also want to add to the out-flow side of the pass a (flux-weighted)
|
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// derivative coming from the lake center.
|
||
//
|
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// NOTE: Maybe consider utilizing 3D component of spline somehow? Currently this is
|
||
// basically a flat vector, but that might be okay from lake to other side of pass.
|
||
lake_neighbor_pass.spline_derivative += /*Vec2::new(weighted_flow.x, weighted_flow.y)*/
|
||
weighted_flow.map(|e| e as f32);
|
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continue; */
|
||
chunk_idx
|
||
} else {
|
||
indirection_idx as usize
|
||
};
|
||
|
||
// Find the pass this lake is flowing into (i.e. water at the lake bottom gets
|
||
// pushed towards the point identified by pass_idx).
|
||
let pass_idx = if downhill[lake_idx] < 0 {
|
||
// Flows into nothing, so this lake is its own pass.
|
||
lake_idx
|
||
} else {
|
||
(-indirection[lake_idx]) as usize
|
||
};
|
||
|
||
// Add our spline derivative to the downhill river (weighted by the chunk's drainage).
|
||
// NOTE: Don't add the spline derivative to the lake side of the pass for our own lake,
|
||
// because we don't want to preserve weird curvature from before we hit the lake in the
|
||
// outflowing river (this will not apply to one-chunk lakes, which are their own pass).
|
||
if pass_idx != downhill_idx {
|
||
// TODO: consider utilizing height difference component of flux as well; currently we
|
||
// just discard it in figuring out the spline's slope.
|
||
let downhill_river = &mut rivers[downhill_idx];
|
||
let weighted_flow = (neighbor_dim * 2.0 - river_spline_derivative.map(|e| e as f64))
|
||
/ derivative_divisor
|
||
* chunk_drainage
|
||
/ incoming_drainage;
|
||
downhill_river.spline_derivative += weighted_flow.map(|e| e as f32);
|
||
}
|
||
|
||
let neighbor_pass_idx = downhill[pass_idx/*lake_idx*/];
|
||
// Find our own water height.
|
||
let chunk_water_alt = water_alt[chunk_idx];
|
||
if neighbor_pass_idx >= 0 {
|
||
// We may be a river. But we're not sure yet, since we still could be
|
||
// underwater. Check the lake height and see if our own water height is within ε of
|
||
// it.
|
||
// let pass_idx = (-indirection[lake_idx]) as usize;
|
||
let lake_water_alt = water_alt[lake_idx];
|
||
if chunk_water_alt == lake_water_alt {
|
||
// Not a river.
|
||
// Check whether we we are the lake side of the pass.
|
||
// NOTE: Safe because this is a lake.
|
||
let (neighbor_pass_pos, river_spline_derivative) = if pass_idx == chunk_idx
|
||
/*true*/
|
||
{
|
||
// This is a pass, so set our flow direction to point to the neighbor pass
|
||
// rather than downhill.
|
||
// NOTE: Safe because neighbor_pass_idx >= 0.
|
||
(
|
||
uniform_idx_as_vec2(downhill_idx),
|
||
// uniform_idx_as_vec2(neighbor_pass_idx as usize),
|
||
river_spline_derivative,
|
||
)
|
||
} else {
|
||
// Try pointing towards the lake side of the pass.
|
||
(uniform_idx_as_vec2(pass_idx), river_spline_derivative)
|
||
};
|
||
let mut lake = &mut rivers[chunk_idx];
|
||
lake.spline_derivative = river_spline_derivative;
|
||
lake.river_kind = Some(RiverKind::Lake {
|
||
neighbor_pass_pos: neighbor_pass_pos
|
||
* TerrainChunkSize::RECT_SIZE.map(|e| e as i32),
|
||
});
|
||
continue;
|
||
}
|
||
// Otherwise, we must be a river.
|
||
} else {
|
||
// We are flowing into the ocean.
|
||
debug_assert!(neighbor_pass_idx == -2);
|
||
// But we are not the ocean, so we must be a river.
|
||
}
|
||
// Now, we know we are a river *candidate*. We still don't know whether we are actually a
|
||
// river, though. There are two ways for that to happen:
|
||
// (i) We are already a river.
|
||
// (ii) Using the Gauckler–Manning–Strickler formula for cross-sectional average velocity
|
||
// of water, we establish that the river can be "big enough" to appear on the Veloren
|
||
// map.
|
||
//
|
||
// This is very imprecise, of course, and (ii) may (and almost certainly will) change over
|
||
// time.
|
||
//
|
||
// In both cases, we preemptively set our child to be a river, to make sure we have an
|
||
// unbroken stream. Also in both cases, we go to the effort of computing an effective
|
||
// water velocity vector and cross-sectional dimensions, as well as figuring out the
|
||
// derivative of our interpolating spline (since this percolates through the whole river
|
||
// network).
|
||
let downhill_water_alt = water_alt[downhill_idx];
|
||
let neighbor_distance = neighbor_dim.magnitude();
|
||
let dz = (downhill_water_alt - chunk_water_alt).into()/* / height_scale as f32*/; // * CONFIG.mountain_scale;
|
||
let slope = dz.abs() / neighbor_distance;
|
||
if slope == 0.0 {
|
||
// This is not a river--how did this even happen?
|
||
let pass_idx = (-indirection_idx) as usize;
|
||
log::error!("Our chunk (and downhill, lake, pass, neighbor_pass): {:?} (to {:?}, in {:?} via {:?} to {:?}), chunk water alt: {:?}, lake water alt: {:?}",
|
||
uniform_idx_as_vec2(chunk_idx),
|
||
uniform_idx_as_vec2(downhill_idx),
|
||
uniform_idx_as_vec2(lake_idx),
|
||
uniform_idx_as_vec2(pass_idx),
|
||
if neighbor_pass_idx >= 0 { Some(uniform_idx_as_vec2(neighbor_pass_idx as usize)) } else { None },
|
||
water_alt[chunk_idx],
|
||
water_alt[lake_idx]);
|
||
panic!("Should this happen at all?");
|
||
}
|
||
let slope_sqrt = slope.sqrt();
|
||
// Now, we compute a quantity that is proportional to the velocity of the chunk, derived
|
||
// from the Manning formula, equal to
|
||
// volumetric_flow_rate / slope_sqrt * CONFIG.river_roughness.
|
||
let almost_velocity = volumetric_flow_rate / slope_sqrt * CONFIG.river_roughness as f64;
|
||
// From this, we can figure out the width of the chunk if we know the height. For now, we
|
||
// hardcode the height to 0.5, but it should almost certainly be much more complicated than
|
||
// this.
|
||
// let mut height = 0.5f32;
|
||
// We approximate the river as a rectangular prism. Theoretically, we need to solve the
|
||
// following quintic equation to determine its width from its height:
|
||
//
|
||
// h^5 * w^5 = almost_velocity^3 * (w + 2 * h)^2.
|
||
//
|
||
// This is because one of the quantities in the Manning formula (the unknown) is R_h =
|
||
// (area of cross-section / h)^(2/3).
|
||
//
|
||
// Unfortunately, quintic equations do not in general have algebraic solutions, and it's
|
||
// not clear (to me anyway) that this one does in all cases.
|
||
//
|
||
// In practice, for high ratios of width to height, we can approximate the rectangular
|
||
// prism's perimeter as equal to its width, so R_h as equal to height. This greatly
|
||
// simplifies the calculation. For simplicity, we do this even for low ratios of width to
|
||
// height--I found that for most real rivers, at least big ones, this approximation is
|
||
// "good enough." We don't need to be *that* realistic :P
|
||
//
|
||
// NOTE: Derived from a paper on estimating river width.
|
||
let mut width = 5.0
|
||
* (CONFIG.river_width_to_depth as f64
|
||
* (CONFIG.river_width_to_depth as f64 + 2.0).powf(2.0 / 3.0))
|
||
.powf(3.0 / 8.0)
|
||
* volumetric_flow_rate.powf(3.0 / 8.0)
|
||
* slope.powf(-3.0 / 16.0)
|
||
* (CONFIG.river_roughness as f64).powf(3.0 / 8.0);
|
||
width = width.max(0.0);
|
||
|
||
let mut height = if width == 0.0 {
|
||
CONFIG.river_min_height as f64
|
||
} else {
|
||
(almost_velocity / width).powf(3.0 / 5.0)
|
||
};
|
||
|
||
// We can now weight the river's drainage by its direction, which we use to help improve
|
||
// the slope of the downhill node.
|
||
let river_direction = Vec3::new(neighbor_dim.x, neighbor_dim.y, dz.signum() * dz);
|
||
|
||
// Now, we can check whether this is "really" a river.
|
||
// Currently, we just check that width and height are at least 0.5 and
|
||
// CONFIG.river_min_height.
|
||
let river = &rivers[chunk_idx];
|
||
let is_river = river.is_river() || width >= 0.5 && height >= CONFIG.river_min_height as f64;
|
||
let mut downhill_river = &mut rivers[downhill_idx];
|
||
|
||
if is_river {
|
||
// Provisionally make the downhill chunk a river as well.
|
||
downhill_river.river_kind = Some(RiverKind::River {
|
||
cross_section: Vec2::default(),
|
||
});
|
||
|
||
// Additionally, if the cross-sectional area for this river exceeds the max river
|
||
// width, the river is overflowing the two chunks adjacent to it, which we'd prefer to
|
||
// avoid since only its two immediate neighbors (orthogonal to the downhill direction)
|
||
// are guaranteed uphill of it.
|
||
// Solving this properly most likely requires modifying the erosion model to
|
||
// take channel width into account, which is a formidable task that likely requires
|
||
// rethinking the current grid-based erosion model (or at least, requires tracking some
|
||
// edges that aren't implied by the grid graph). For now, we will solve this problem
|
||
// by making the river deeper when it hits the max width, until it consumes all the
|
||
// available energy in this part of the river.
|
||
let max_width = TerrainChunkSize::RECT_SIZE.x as f64 * CONFIG.river_max_width as f64;
|
||
if width > max_width {
|
||
width = max_width;
|
||
height = (almost_velocity / width).powf(3.0 / 5.0);
|
||
}
|
||
}
|
||
// Now we can compute the river's approximate velocity magnitude as well, as
|
||
let velocity_magnitude =
|
||
1.0 / CONFIG.river_roughness as f64 * height.powf(2.0 / 3.0) * slope_sqrt;
|
||
|
||
// Set up the river's cross-sectional area.
|
||
let cross_section = Vec2::new(width as f32, height as f32);
|
||
// Set up the river's velocity vector.
|
||
let mut velocity = river_direction;
|
||
velocity.normalize();
|
||
velocity *= velocity_magnitude;
|
||
|
||
let mut river = &mut rivers[chunk_idx];
|
||
// NOTE: Not trying to do this more cleverly because we want to keep the river's neighbors.
|
||
// TODO: Actually put something in the neighbors.
|
||
river.velocity = velocity.map(|e| e as f32);
|
||
river.spline_derivative = river_spline_derivative;
|
||
river.river_kind = if is_river {
|
||
Some(RiverKind::River { cross_section })
|
||
} else {
|
||
None
|
||
};
|
||
}
|
||
rivers
|
||
}
|
||
|
||
/// Precompute the maximum slope at all points.
|
||
///
|
||
/// TODO: See if allocating in advance is worthwhile.
|
||
fn get_max_slope(h: &[Alt], rock_strength_nz: &(impl NoiseFn<Point3<f64>> + Sync)) -> Box<[f64]> {
|
||
let min_max_angle = (15.0/*6.0*//*30.0*//*6.0*//*15.0*/ / 360.0 * 2.0 * f64::consts::PI).tan();
|
||
let max_max_angle =
|
||
(60.0/*54.0*//*50.0*//*54.0*//*45.0*/ / 360.0 * 2.0 * f64::consts::PI).tan();
|
||
let max_angle_range = max_max_angle - min_max_angle;
|
||
let height_scale = 1.0 / 4.0; // 1.0; // 1.0 / CONFIG.mountain_scale as f64;
|
||
h.par_iter()
|
||
.enumerate()
|
||
.map(|(posi, &z)| {
|
||
let wposf = uniform_idx_as_vec2(posi).map(|e| e as f64) * TerrainChunkSize::RECT_SIZE.map(|e| e as f64);
|
||
let wposz = z as f64 / height_scale;// * CONFIG.mountain_scale as f64;
|
||
// Normalized to be between 6 and and 54 degrees.
|
||
let div_factor = /*32.0*//*16.0*//*64.0*//*256.0*//*8.0 / 4.0*//*8.0*/(2.0 * TerrainChunkSize::RECT_SIZE.x as f64) / 8.0/* * 8.0*//*1.0*//*4.0*//* * /*1.0*/16.0/* TerrainChunkSize::RECT_SIZE.x as f64 / 8.0 */*/;
|
||
let rock_strength = rock_strength_nz
|
||
.get([
|
||
wposf.x, /* / div_factor*/
|
||
wposf.y, /* / div_factor*/
|
||
wposz * div_factor,
|
||
]);
|
||
/* if rock_strength < -1.0 || rock_strength > 1.0 {
|
||
println!("Nooooo: {:?}", rock_strength);
|
||
} */
|
||
let rock_strength = rock_strength
|
||
.max(-1.0)
|
||
.min(1.0)
|
||
* 0.5
|
||
+ 0.5;
|
||
// Powering rock_strength^((1.25 - z)^6) means the maximum angle increases with z, but
|
||
// not too fast. At z = 0.25 the angle is not affected at all, below it the angle is
|
||
// lower, and above it the angle is higher.
|
||
//
|
||
// Logistic regression. Make sure x ∈ (0, 1).
|
||
let logit = |x: f64| x.ln() - (-x).ln_1p();
|
||
// 0.5 + 0.5 * tanh(ln(1 / (1 - 0.1) - 1) / (2 * (sqrt(3)/pi)))
|
||
let logistic_2_base = 3.0f64.sqrt() * f64::consts::FRAC_2_PI;
|
||
// Assumes μ = 0, σ = 1
|
||
let logistic_cdf = |x: f64| (x / logistic_2_base).tanh() * 0.5 + 0.5;
|
||
|
||
// We do log-odds against center, so that our log odds are 0 when x = 0.25, lower when x is
|
||
// lower, and higher when x is higher.
|
||
//
|
||
// (NOTE: below sea level, we invert it).
|
||
//
|
||
// TODO: Make all this stuff configurable... but honestly, it's so complicated that I'm not
|
||
// sure anyone would be able to usefully tweak them on a per-map basis? Plus it's just a
|
||
// hacky heuristic anyway.
|
||
let center = /*0.25*//*0.4*//*0.2*/0.4;
|
||
let dmin = center - /*0.15;//0.05*/0.05;
|
||
let dmax = center + /*0.05*//*0.10*/0.05;//0.05;
|
||
let log_odds = |x: f64| logit(x) - logit(center);
|
||
let rock_strength = logistic_cdf(
|
||
1.0 * logit(rock_strength.min(1.0f64 - 1e-7).max(1e-7))
|
||
+ 1.0 * log_odds((wposz / CONFIG.mountain_scale as f64).abs().min(dmax).max(dmin)),
|
||
);
|
||
// let rock_strength = 0.5;
|
||
let max_slope = rock_strength * max_angle_range + min_max_angle;
|
||
// let max_slope = /*30.0.to_radians().tan();*/3.0.sqrt() / 3.0;
|
||
max_slope
|
||
})
|
||
.collect::<Vec<_>>()
|
||
.into_boxed_slice()
|
||
}
|
||
|
||
/// Erode all chunks by amount.
|
||
///
|
||
/// Our equation is:
|
||
///
|
||
/// dh(p) / dt = uplift(p)−k * A(p)^m * slope(p)^n
|
||
///
|
||
/// where A(p) is the drainage area at p, m and n are constants
|
||
/// (we choose m = 0.4 and n = 1), and k is a constant. We choose
|
||
///
|
||
/// k = 2.244 * uplift.max() / (desired_max_height)
|
||
///
|
||
/// since this tends to produce mountains of max height desired_max_height; and we set
|
||
/// desired_max_height = 1.0 to reflect limitations of mountain scale.
|
||
///
|
||
/// This algorithm does this in four steps:
|
||
///
|
||
/// 1. Sort the nodes in h by height (so the lowest node by altitude is first in the
|
||
/// list, and the highest node by altitude is last).
|
||
/// 2. Iterate through the list in *reverse.* For each node, we compute its drainage area as
|
||
/// the sum of the drainage areas of its "children" nodes (i.e. the nodes with directed edges to
|
||
/// this node). To do this efficiently, we start with the "leaves" (the highest nodes), which
|
||
/// have no neighbors higher than them, hence no directed edges to them. We add their area to
|
||
/// themselves, and then to all neighbors that they flow into (their "ancestors" in the flow
|
||
/// graph); currently, this just means the node immediately downhill of this node.
|
||
/// As we go lower, we know that all our "children" already had their areas computed, which
|
||
/// means that we can repeat the process in order to derive all the final areas.
|
||
/// 3. Now, iterate through the list in *order.* Whether we used the filling method to compute a
|
||
/// "filled" version of each depression, or used the lake connection algoirthm described in [1],
|
||
/// each node is guaranteed to have zero or one drainage edges out, representing the direction
|
||
/// of water flow for that node. For nodes i with zero drainage edges out (boundary nodes and
|
||
/// lake bottoms) we set the slope to 0 (so the change in altitude is uplift(i))
|
||
/// For nodes with at least one drainage edge out, we take advantage of the fact that we are
|
||
/// computing new heights in order and rewrite our equation as (letting j = downhill[i], A[i]
|
||
/// be the computed area of point i, p(i) be the x-y position of point i,
|
||
/// flux(i) = k * A[i]^m / ((p(i) - p(j)).magnitude()), and δt = 1):
|
||
///
|
||
/// h[i](t + dt) = h[i](t) + δt * (uplift[i] + flux(i) * h[j](t + δt)) / (1 + flux(i) * δt).
|
||
///
|
||
/// Since we compute heights in ascending order by height, and j is downhill from i, h[j] will
|
||
/// always be the *new* h[j](t + δt), while h[i] will still not have been computed yet, so we
|
||
/// only need to visit each node once.
|
||
///
|
||
/// Afterwards, we also apply a hillslope diffusion process using an ADI (alternating direction
|
||
/// implicit) method:
|
||
///
|
||
/// https://github.com/fastscape-lem/fastscapelib-fortran/blob/master/src/Diffusion.f90
|
||
///
|
||
/// We also borrow the implementation for sediment transport from
|
||
///
|
||
/// https://github.com/fastscape-lem/fastscapelib-fortran/blob/master/src/StreamPowerLaw.f90
|
||
///
|
||
/// The approximate equation for soil production function (predictng the rate at which bedrock
|
||
/// turns into soil, increasing the distance between the basement and altitude) is taken from
|
||
/// equation (11) from [2]. This (among numerous other sources) also includes at least one
|
||
/// prediction that hillslope diffusion should be nonlinear, which we sort of attempt to
|
||
/// approximate.
|
||
///
|
||
/// [1] Guillaume Cordonnier, Jean Braun, Marie-Paule Cani, Bedrich Benes, Eric Galin, et al..
|
||
/// Large Scale Terrain Generation from Tectonic Uplift and Fluvial Erosion.
|
||
/// Computer Graphics Forum, Wiley, 2016, Proc. EUROGRAPHICS 2016, 35 (2), pp.165-175.
|
||
/// ⟨10.1111/cgf.12820⟩. ⟨hal-01262376⟩
|
||
///
|
||
/// [2] William E. Dietrich, Dino G. Bellugi, Leonard S. Sklar, Jonathan D. Stock
|
||
/// Geomorphic Transport Laws for Predicting Landscape Form and Dynamics.
|
||
/// Prediction in Geomorphology, Geophysical Monograph 135.
|
||
/// Copyright 2003 by the American Geophysical Union
|
||
/// 10.1029/135GM09
|
||
fn erode(
|
||
// Height above sea level of topsoil
|
||
h: &mut [Alt],
|
||
// Height above sea level of bedrock
|
||
b: &mut [Alt],
|
||
// Height above topsoil of alluvium (loose rock)
|
||
// a: &mut [Alt],
|
||
// Height above sea level of water
|
||
wh: &mut [Alt],
|
||
is_done: &mut BitBox,
|
||
done_val: bool,
|
||
erosion_base: f32,
|
||
max_uplift: f32,
|
||
max_g: f32,
|
||
kdsed: f64,
|
||
_seed: &RandomField,
|
||
rock_strength_nz: &(impl NoiseFn<Point3<f64>> + Sync),
|
||
uplift: impl Fn(usize) -> f32 + Sync,
|
||
n_f: impl Fn(usize) -> f32 + Sync,
|
||
m_f: impl Fn(usize) -> f32 + Sync,
|
||
kf: impl Fn(usize) -> f64 + Sync,
|
||
kd: impl Fn(usize) -> f64,
|
||
g: impl Fn(usize) -> f32 + Sync,
|
||
epsilon_0: impl Fn(usize) -> f32 + Sync,
|
||
alpha: impl Fn(usize) -> f32 + Sync,
|
||
is_ocean: impl Fn(usize) -> bool + Sync,
|
||
) {
|
||
let compute_stats = true;
|
||
log::debug!("Done draining...");
|
||
let height_scale = 1.0; // 1.0 / CONFIG.mountain_scale as f64;
|
||
let min_erosion_height = 0.0; // -<Alt as Float>::infinity();
|
||
let mmaxh = CONFIG.mountain_scale as f64 * height_scale;
|
||
// Since maximum uplift rate is expected to be 5.010e-4 m * y^-1, and
|
||
// 1.0 height units is 1.0 / height_scale m, whatever the
|
||
// max uplift rate is (in units / y), we can find dt by multiplying by
|
||
// 1.0 / height_scale m / unit and then dividing by 5.010e-4 m / y
|
||
// (to get dt in y / unit). More formally:
|
||
//
|
||
// max_uplift h_unit / dt y = 5.010e-4 m / y
|
||
//
|
||
// 1 h_unit = 1.0 / height_scale m
|
||
//
|
||
// max_uplift h_unit / dt * 1.0 / height_scale m / h_unit =
|
||
// max_uplift / height_scale m / dt =
|
||
// 5.010e-4 m / y
|
||
//
|
||
// max_uplift / height_scale m / dt / (5.010e-4 m / y) = 1
|
||
// (max_uplift / height_scale / 5.010e-4) y = dt
|
||
// 5e-7
|
||
let dt = max_uplift as f64/* / height_scale*/ /* * CONFIG.mountain_scale as f64*/ / /*5.010e-4*/1e-3/*0.2e-3*/;
|
||
log::debug!("dt={:?}", dt);
|
||
// Minimum sediment thickness before we treat erosion as sediment based.
|
||
let sediment_thickness = 1.0e-4 * dt;
|
||
let neighbor_coef = TerrainChunkSize::RECT_SIZE.map(|e| e as f64);
|
||
let chunk_area = neighbor_coef.x * neighbor_coef.y;
|
||
let min_length = neighbor_coef.reduce_partial_min();
|
||
let max_stable = /*max_slope * */min_length * min_length / (dt/* / 2.0*/); //1.0/* + /*max_uplift as f64 / dt*/sed / dt*/;
|
||
// Landslide constant: ideally scaled to 10e-2 m / y^-1
|
||
let l = /*200.0 * max_uplift as f64;*/(1.0e-2 /*/ CONFIG.mountain_scale as f64*/ * height_scale);
|
||
let l_tot = l * dt;
|
||
// Debris flow coefficient (m / year).
|
||
let k_df = 1.0e-4/*0.0*/;
|
||
// Debris flow area coefficient (m^(-2q)).
|
||
let q = 0.2;
|
||
let q_ = 1.5/*1.0*/;
|
||
let k_da = /*5.0*/2.5 * 16.0.powf(q);
|
||
let nx = WORLD_SIZE.x;
|
||
let ny = WORLD_SIZE.y;
|
||
let dx = TerrainChunkSize::RECT_SIZE.x as f64/* * height_scale*//* / CONFIG.mountain_scale as f64*/;
|
||
let dy = TerrainChunkSize::RECT_SIZE.y as f64/* * height_scale*//* / CONFIG.mountain_scale as f64*/;
|
||
|
||
// ε₀ = 0.000268 m/y, α = 0.03 (1/m). This is part of the soil production approximate
|
||
// equation:
|
||
//
|
||
// -∂z_b / ∂t = ε₀ * e^(-αH)
|
||
//
|
||
// where
|
||
// z_b is the elevation of the soil-bedrock interface (i.e. the basement),
|
||
// ε₀ is the production rate of exposed bedrock (H = 0),
|
||
// H is the soil thickness normal to the ground surface,
|
||
// and α is a parameter (units of 1 / length).
|
||
//
|
||
// Note that normal depth at i, for us, will be interpreted as the soil depth vector,
|
||
// sed_i = ((0, 0), h_i - b_i),
|
||
// projected onto the ground surface slope vector,
|
||
// ground_surface_i = ((p_i - p_j), h_i - h_j),
|
||
// yielding the soil depth vector
|
||
// H_i = sed_i - sed_i ⋅ ground_surface_i / (ground_surface_i ⋅ ground_surface_i) * ground_surface_i
|
||
//
|
||
// = ((0, 0), h_i - b_i) -
|
||
// (0 * ||p_i - p_j|| + (h_i - b_i) * (h_i - h_j)) / (||p_i - p_j||^2 + (h_i - h_j)^2)
|
||
// * (p_i - p_j, h_i - h_j)
|
||
// = ((0, 0), h_i - b_i) -
|
||
// ((h_i - b_i) * (h_i - h_j)) / (||p_i - p_j||^2 + (h_i - h_j)^2)
|
||
// * (p_i - p_j, h_i - h_j)
|
||
// = (h_i - b_i) *
|
||
// (((0, 0), 1) - (h_i - h_j) / (||p_i - p_j||^2 + (h_i - h_j)^2) * (p_i - p_j, h_i - h_j))
|
||
// H_i_fact = (h_i - h_j) / (||p_i - p_j||^2 + (h_i - h_j)^2)
|
||
// H_i = (h_i - b_i) * ((((0, 0), 1) - H_i_fact * (p_i - p_j, h_i - h_j)))
|
||
// = (h_i - b_i) * (-H_i_fact * (p_i - p_j), 1 - H_i_fact * (h_i - h_j))
|
||
// ||H_i|| = (h_i - b_i) * √(H_i_fact^2 * ||p_i - p_j||^2 + (1 - H_i_fact * (h_i - h_j))^2)
|
||
// = (h_i - b_i) * √(H_i_fact^2 * ||p_i - p_j||^2 + 1 - 2 * H_i_fact * (h_i - h_j) +
|
||
// H_i_fact^2 * (h_i - h_j)^2)
|
||
// = (h_i - b_i) * √(H_i_fact^2 * (||p_i - p_j||^2 + (h_i - h_j)^2) +
|
||
// 1 - 2 * H_i_fact * (h_i - h_j))
|
||
// = (h_i - b_i) * √((h_i - h_j)^2 / (||p_i - p_j||^2 + (h_i - h_j)^2) * (||p_i - p_j||^2 + (h_i - h_j)^2) +
|
||
// 1 - 2 * (h_i - h_j)^2 / (||p_i - p_j||^2 + (h_i - h_j)^2))
|
||
// = (h_i - b_i) * √((h_i - h_j)^2 - 2(h_i - h_j)^2 / (||p_i - p_j||^2 + (h_i - h_j)^2) + 1)
|
||
//
|
||
// where j is i's receiver and ||p_i - p_j|| is the horizontal displacement between them. The
|
||
// idea here is that we first compute the hypotenuse between the horizontal and vertical
|
||
// displacement of ground (getting the horizontal component of the triangle), and then this is
|
||
// taken as one of the non-hypotenuse sides of the triangle whose other non-hypotenuse side is
|
||
// the normal height H_i, while their square adds up to the vertical displacement (h_i - b_i).
|
||
// If h and b have different slopes, this may not work completely correctly, but this is
|
||
// probably fine as an approximation.
|
||
/* let epsilon_0 = 2.68e-4;
|
||
let alpha = 3e-2;
|
||
let epsilon_0_tot = epsilon_0 * dt; */
|
||
// Net precipitation rate (m / year)
|
||
let p = 1.0 * height_scale;
|
||
/* let n = 2.4;// 1.0;//1.5;//2.4;//1.0;
|
||
let m = n * 0.5;// n * 0.4;// 0.96;// 0.4;//0.6;//0.96;//0.4; */
|
||
// Stream power erosion constant (bedrock), in m^(1-2m) / year (times dt).
|
||
let k_fb = // erosion_base as f64 + 2.244 / mmaxh as f64 * max_uplift as f64;
|
||
// 2.244*(5.010e-4)/512*5- (1.097e-5)
|
||
// 2.244*(5.010e-4)/2048*5- (1.097e-5)
|
||
// 2.244*(5.010e-4)/512- (8e-6)
|
||
// 2.244*(5.010e-4)/512- (2e-6)
|
||
// 2e-6 * dt;
|
||
// 8e-6 * dt
|
||
// 2e-5 * dt;
|
||
// 2.244/2048*5*32/(250000/4)*10^6
|
||
// ln(tan(30/360*2*pi))-ln(tan(6/360*2*pi))*1500 = 3378
|
||
//erosion_base as f64 + 2.244 / mmaxh as f64 * /*10.0*//*5.0*//*9.0*//*7.5*//*5.0*//*2.5*//*1.5*//*5.0*//*1.0*//*1.5*//*2.5*//*3.75*/ * max_uplift as f64;
|
||
// 2.5e-6 * dt;
|
||
2e-5 * dt;
|
||
// see http://geosci.uchicago.edu/~kite/doc/Whipple_and_Tucker_1999.pdf
|
||
//5e-6 * dt; // 2e-5 was designed for steady state uplift of 2mm / y whih would amount to 500 m / 250,000 y.
|
||
// (2.244*(5.010e-4)/512)/(2.244*(5.010e-4)/2500) = 4.88...
|
||
// 2.444 * 5
|
||
// Stream power erosion constant (sediment), in m^(1-2m) / year (times dt).
|
||
let k_fs_mult_sed = /*1.0;*//*2.0*/4.0; /*1.0;*///2.0;/*1.5*/;
|
||
// Stream power erosion constant (underwater).
|
||
let k_fs_mult_water = /*1.0*//*0.5*/0.25;
|
||
let g_fs_mult_sed = 1.0/*0.5*/;
|
||
// let k_fs = k_fb * 1.0/*1.5*//*2.0*//*2.0*//*4.0*/;
|
||
// u = k * h_max / 2.244
|
||
// let uplift_scale = erosion_base as f64 + (k_fb * mmaxh / 2.244 / 5.010e-4 as f64 * mmaxh as f64) * dt;
|
||
let (
|
||
(dh, indirection, newh, maxh, mrec, mstack, mwrec, area),
|
||
(mut max_slopes, /*(ht, at)*/ h_t),
|
||
) = rayon::join(
|
||
|| {
|
||
let mut dh = downhill(
|
||
|posi| h[posi], /* + a[posi].max(0.0)*//* + uplift(posi) as Alt*/
|
||
|posi| {
|
||
is_ocean(posi)
|
||
&& h[posi]/* + a[posi].max(0.0)*//* + uplift(posi) as Alt*/ <= 0.0
|
||
},
|
||
);
|
||
log::debug!("Computed downhill...");
|
||
let (boundary_len, indirection, newh, maxh) = get_lakes(
|
||
|posi| h[posi], /* + a[posi].max(0.0)*//* + uplift(posi) as Alt*/
|
||
&mut dh,
|
||
);
|
||
log::debug!("Got lakes...");
|
||
let (mrec, mstack, mwrec) = get_multi_rec(
|
||
|posi| h[posi],
|
||
&dh,
|
||
&newh,
|
||
wh,
|
||
nx,
|
||
ny,
|
||
dx as Compute,
|
||
dy as Compute,
|
||
maxh,
|
||
);
|
||
log::debug!("Got multiple receivers...");
|
||
// let area = get_drainage(&newh, &dh, boundary_len);
|
||
let area = get_multi_drainage(&mstack, &mrec, &*mwrec, boundary_len);
|
||
log::debug!("Got flux...");
|
||
(dh, indirection, newh, maxh, mrec, mstack, mwrec, area)
|
||
},
|
||
|| {
|
||
rayon::join(
|
||
|| {
|
||
let max_slope = get_max_slope(h, rock_strength_nz);
|
||
log::debug!("Got max slopes...");
|
||
max_slope
|
||
},
|
||
|| {
|
||
h.to_vec().into_boxed_slice()
|
||
/* rayon::join(
|
||
|| {
|
||
// Store the elevation at t
|
||
h.to_vec().into_boxed_slice()
|
||
// h.into_par_iter().map(|e| e as f64).collect::<Vec<_>>().into_boxed_slice()
|
||
},
|
||
|| {
|
||
a.to_vec().into_boxed_slice()
|
||
},
|
||
) */
|
||
},
|
||
)
|
||
},
|
||
);
|
||
|
||
assert!(h.len() == dh.len() && dh.len() == area.len());
|
||
|
||
// max angle of slope depends on rock strength, which is computed from noise function.
|
||
// TODO: Make more principled.
|
||
let mid_slope = (30.0 / 360.0 * 2.0 * f64::consts::PI).tan(); //1.0;
|
||
|
||
type SimdType = f64;
|
||
type MaskType = m64;
|
||
let simd_func = f64s/*f32s*/;
|
||
|
||
// Precompute factors for Stream Power Law.
|
||
let czero = </*Compute*/SimdType as Zero>::zero();
|
||
let (k_fs_fact, /*()*/ k_df_fact) = rayon::join(
|
||
|| {
|
||
dh.par_iter().enumerate()
|
||
.map(|(posi, &posj)| {
|
||
let mut k_tot = /*Computex8::splat(czero);*/[czero; 8];
|
||
if posj < 0 {
|
||
// Egress with no outgoing flows, no stream power.
|
||
k_tot
|
||
} else {
|
||
let old_b_i = b[posi];
|
||
let sed = (h_t[posi] - old_b_i) as f64;
|
||
let k = if sed > sediment_thickness {
|
||
// Sediment
|
||
// k_fs
|
||
k_fs_mult_sed * kf(posi)
|
||
} else {
|
||
// Bedrock
|
||
// k_fb
|
||
kf(posi)
|
||
} * dt;
|
||
let n = n_f(posi) as f64;
|
||
let m = m_f(posi) as f64;
|
||
|
||
let mwrec_i = &mwrec[posi];
|
||
for (kk, posj) in mrec_downhill(&mrec, posi) {
|
||
// let posj = posj as usize;
|
||
let dxy = (uniform_idx_as_vec2(posi) - uniform_idx_as_vec2(posj)).map(|e| e as f64);
|
||
let neighbor_distance = (neighbor_coef * dxy).magnitude();
|
||
let knew = (k * (p * chunk_area * (area[posi] as f64 * mwrec_i[kk] as f64)).powf(m) / neighbor_distance.powf(n)) as /*Compute*/SimdType;
|
||
// let knew = (k * (p * chunk_area * (area[posi] as f64 * mwrec_i.extract(kk) as f64)).powf(m) / neighbor_distance.powf(n)) as Compute;
|
||
k_tot[kk] = knew;
|
||
// k_tot = k_tot.replace(kk, knew);
|
||
}
|
||
k_tot
|
||
}
|
||
})
|
||
.collect::<Vec</*Computex8*/[SimdType; 8]>>()
|
||
},
|
||
|| {
|
||
dh.par_iter().enumerate()
|
||
.map(|(posi, &posj)| {
|
||
let mut k_tot = /*Computex8::splat(czero);*/[czero; 8];
|
||
let uplift_i = uplift(posi) as f64;
|
||
debug_assert!(uplift_i.is_normal() && uplift_i > 0.0 || uplift_i == 0.0);
|
||
if posj < 0 {
|
||
// Egress with no outgoing flows, no stream power.
|
||
k_tot
|
||
} else {
|
||
let area_i = area[posi] as f64;
|
||
let max_slope = max_slopes[posi]/*mid_slope*/;
|
||
let chunk_area_pow = chunk_area.powf(q);
|
||
|
||
let old_b_i = b[posi];
|
||
let sed = (h_t[posi] - old_b_i) as f64;
|
||
/* let k_f = if sed > sediment_thickness {
|
||
// Sediment
|
||
// k_fs
|
||
k_fs_mult_sed * kf(posi)
|
||
} else {
|
||
// Bedrock
|
||
// k_fb
|
||
kf(posi)
|
||
} * dt; */
|
||
// let g_i = g(posi) as f64;
|
||
let g_i = if sed > sediment_thickness {
|
||
g_fs_mult_sed * g(posi) as f64
|
||
} else {
|
||
g(posi) as f64
|
||
};
|
||
|
||
// Higher rock strength tends to lead to higher curvature?
|
||
let kd_factor =
|
||
// 1.0;
|
||
(1.0 / (max_slope / mid_slope/*.sqrt()*//*.powf(0.03125)*/).powf(/*2.0*/2.0))/*.min(kdsed)*/;
|
||
let k_da = k_da / /*max_slope*/kd_factor;
|
||
|
||
// let k_df = /*uplift_i*/0.05e-3 / (1.0 + k_da * /*chunk_area_pow*/(10_000.0).powf(q)) / max_slope.powf(q_);
|
||
// let k = (uplift_i - kf(posi) * dt * (p * chunk_area).powf(m_f(posi) as f64) * max_slope.powf(n_f(posi) as f64)).max(0.0) / (1.0 + k_da * chunk_area_pow) / max_slope.powf(q_);
|
||
// let k = (uplift_i * (1.0 + g_i / p) - k_f * (p * chunk_area).powf(m_f(posi) as f64) * max_slope.powf(n_f(posi) as f64)).max(0.0) / (1.0 + k_da * chunk_area_pow) / max_slope.powf(q_);
|
||
// let k = uplift_i / (1.0/* + k_da * chunk_area_pow*/) / max_slope.powf(q_);
|
||
// let k = uplift_i / (1.0 + k_da * chunk_area_pow) / max_slope.powf(q_);
|
||
// let k = (uplift_i + max_uplift as f64 * g_i / p) / (1.0 + k_da * chunk_area_pow) / max_slope.powf(q_);
|
||
// let k = (uplift_i + max_uplift as f64 * g_i / p) / (1.0 + k_da * (100.0 * 100.0).powf(q)) / max_slope.powf(q_);
|
||
// let k = k_df * dt;
|
||
|
||
let mwrec_i = &mwrec[posi];
|
||
for (kk, posj) in mrec_downhill(&mrec, posi) {
|
||
let mwrec_kk = mwrec_i[kk];
|
||
// let posj = posj as usize;
|
||
|
||
// Working equation:
|
||
// U = uplift per time
|
||
// D = sediment deposition per time
|
||
// E = fluvial erosion per time
|
||
// 0 = U + D - E - k_df * (1 + k_da * (mrec_kk * A)^q) * (∂B/∂p)^(q_)
|
||
//
|
||
// k_df = (U + D - E) / (1 + k_da * (mrec_kk * A)^q) / (∂B/∂p)^(q_)
|
||
//
|
||
// Want: ∂B/∂p = max slope at steady state, i.e.
|
||
// ∂B/∂p = max_slope
|
||
// Then:
|
||
// k_df = (U + D - E) / (1 + k_da * (mrec_kk * A)^q) / max_slope^(q_)
|
||
// Letting
|
||
// k = k_df * Δt
|
||
// we get:
|
||
// k = (U + D - E)Δt / (1 + k_da * (mrec_kk * A)^q) / (ΔB)^(q_)
|
||
//
|
||
// Now ∂B/∂t under constant uplift, without debris flow (U + D - E), is
|
||
// U + D - E = U - E + G/(p̃A) * ∫_A((U - ∂h/∂t) * dA)
|
||
//
|
||
// Observing that at steady state ∂h/∂t should theoretically
|
||
// be 0, we can simplify to:
|
||
// U + D = U + G/(p̃A) * ∫_A(U * dA)
|
||
//
|
||
// Upper bounding this at uplift = max_uplift/∂t for the whole prior
|
||
// drainage area, and assuming we account for just mrec_kk of
|
||
// the combined uplift and deposition, we get:
|
||
//
|
||
// U + D ≤ mrec_kk * U + G/p̃ * max_uplift/∂t
|
||
// (U + D - E)Δt ≤ (mrec_kk * uplift_i + G/p̃ * mrec_kk * max_uplift - EΔt)
|
||
//
|
||
// therefore
|
||
// k * (1 + k_da * (mrec_kk * A)^q) * max_slope^(q_) ≤ (mrec_kk * (uplift_i + G/p̃ * max_uplift) - EΔt)
|
||
// i.e.
|
||
// k ≤ (mrec_kk * (uplift_i + G/p̃ * max_uplift) - EΔt) / (1 + k_da * (mrec_kk * A)^q) / max_slope^q_
|
||
//
|
||
// (eliminating EΔt maintains the sign, but it's somewhat imprecise;
|
||
// we can address this later, e.g. by assigning a debris flow / fluvial erosion ratio).
|
||
let chunk_neutral_area = /*10.0e6*/1.0e6/*0.1e6*//*100.0 * 100.0*/; // 1 km^2 * (1000 m / km)^2 = 1e6 m^2
|
||
let k = (mwrec_kk * (uplift_i + max_uplift as f64 * g_i/* / p*/)) / (1.0 + k_da * (mwrec_kk * chunk_neutral_area).powf(q)) / max_slope.powf(q_);
|
||
|
||
// ∆p = ||chunk_i - rec_i,kk||
|
||
// k = k_df * Δt / (Δp)^(q_)
|
||
// we have
|
||
//
|
||
//
|
||
// ΔB = k * (1 + k_da * (mrec_kk * A)^q) * (∆p)^(q_)
|
||
// k * (1 + k_da * (mrec_kk * A)^q) = ΔB / ∆p^(q_)
|
||
// k = ΔB / (1 + k_da * (mrec_kk * A)^q) / ∆p
|
||
//
|
||
// Now ∂B/∂t under constant uplift, without debris flow, is
|
||
// ∂B/∂t = U - E + G/(p̃A) * ∫_A((U - ∂h/∂t) * dA)
|
||
let dxy = (uniform_idx_as_vec2(posi) - uniform_idx_as_vec2(posj)).map(|e| e as f64);
|
||
let neighbor_distance = (neighbor_coef * dxy).magnitude();
|
||
|
||
let knew = (k * (1.0 + k_da * chunk_area_pow * (area_i * mwrec_kk as f64).powf(q)) / neighbor_distance.powf(q_)) as SimdType/*Compute*/;
|
||
// let knew = (k * (1.0 + k_da * chunk_area_pow * (area_i * mwrec_i.extract(kk) as f64).powf(q)) / neighbor_distance.powf(q_)) as Compute;
|
||
// let knew = 0.0;
|
||
k_tot[kk] = knew;
|
||
// k_tot = k_tot.replace(kk, knew);
|
||
}
|
||
k_tot
|
||
}
|
||
})
|
||
.collect::<Vec</*Computex8*/[SimdType; 8]>>()
|
||
},
|
||
);
|
||
/* h.par_iter_mut().enumerate().for_each(|(posi, h)| {
|
||
*h += uplift(posi) as Alt;
|
||
}); */
|
||
|
||
log::debug!("Computed stream power factors...");
|
||
|
||
let mut lake_water_volume =
|
||
vec![/*-1i32*/0.0 as Compute; WORLD_SIZE.x * WORLD_SIZE.y].into_boxed_slice();
|
||
let mut elev = vec![/*-1i32*/0.0 as Compute; WORLD_SIZE.x * WORLD_SIZE.y].into_boxed_slice();
|
||
let mut h_p = vec![/*-1i32*/0.0 as Compute; WORLD_SIZE.x * WORLD_SIZE.y].into_boxed_slice();
|
||
/* let mut hp = vec![/*-1i32*/0.0 as Compute; WORLD_SIZE.x * WORLD_SIZE.y].into_boxed_slice();
|
||
let mut ap = vec![/*-1i32*/0.0 as Compute; WORLD_SIZE.x * WORLD_SIZE.y].into_boxed_slice(); */
|
||
let mut deltah = vec![/*-1i32*/0.0 as Compute; WORLD_SIZE.x * WORLD_SIZE.y].into_boxed_slice();
|
||
/* let mut deltah_sediment = vec![/*-1i32*/0.0 as Compute; WORLD_SIZE.x * WORLD_SIZE.y].into_boxed_slice();
|
||
let mut deltah_alluvium = vec![/*-1i32*/0.0 as Compute; WORLD_SIZE.x * WORLD_SIZE.y].into_boxed_slice(); */
|
||
|
||
// calculate the elevation / SPL, including sediment flux
|
||
let tol1 = 1.0e-4 as Compute * (maxh as Compute + 1.0);
|
||
let tol2 = 1.0e-3 as Compute * (max_uplift as Compute + 1.0);
|
||
let tol = tol1.max(tol2);
|
||
let mut err = 2.0 * tol;
|
||
|
||
// Some variables for tracking statistics, currently only for debugging purposes.
|
||
let mut minh = <Alt as Float>::infinity();
|
||
let mut maxh = 0.0;
|
||
let mut nland = 0usize;
|
||
let mut ncorr = 0usize;
|
||
let mut sums = 0.0;
|
||
let mut sumh = 0.0;
|
||
let mut suma = 0.0;
|
||
let mut sumsed = 0.0;
|
||
let mut suma_land = 0.0;
|
||
let mut sumsed_land = 0.0;
|
||
let mut ntherm = 0usize;
|
||
// ln of product of actual slopes (only where actual is above critical).
|
||
let mut prods_therm = 0.0;
|
||
// ln of product of critical slopes (only where actual is above critical).
|
||
let mut prodscrit_therm = 0.0;
|
||
let avgz = |x, y: usize| if y == 0 { f64::INFINITY } else { x / y as f64 };
|
||
let geomz = |x: f64, y: usize| {
|
||
if y == 0 {
|
||
f64::INFINITY
|
||
} else {
|
||
(x / y as f64).exp()
|
||
}
|
||
};
|
||
|
||
// Gauss-Seidel iteration
|
||
|
||
let mut lake_silt =
|
||
vec![/*-1i32*/0.0 as Compute; WORLD_SIZE.x * WORLD_SIZE.y].into_boxed_slice();
|
||
/* let mut lake_sediment = vec![/*-1i32*/0.0 as Compute; WORLD_SIZE.x * WORLD_SIZE.y].into_boxed_slice();
|
||
let mut lake_alluvium = vec![/*-1i32*/0.0 as Compute; WORLD_SIZE.x * WORLD_SIZE.y].into_boxed_slice(); */
|
||
let mut lake_sill = vec![/*-1i32*/-1isize; WORLD_SIZE.x * WORLD_SIZE.y].into_boxed_slice();
|
||
/* let mut h_ = (0..WORLD_SIZE.x * WORLD_SIZE.y)
|
||
.into_par_iter()
|
||
.map(|posi| ht[posi] + at[posi].max(0.0))
|
||
.collect::<Vec<_>>()
|
||
.into_boxed_slice(); */
|
||
|
||
let mut n_gs_stream_power_law = 0;
|
||
let max_n_gs_stream_power_law = /*199*/99;
|
||
while err > tol && n_gs_stream_power_law < max_n_gs_stream_power_law {
|
||
log::debug!("Stream power iteration #{:?}", n_gs_stream_power_law);
|
||
|
||
// Reset statistics in each loop.
|
||
maxh = 0.0;
|
||
minh = <Alt as Float>::infinity();
|
||
nland = 0usize;
|
||
ncorr = 0usize;
|
||
sums = 0.0;
|
||
sumh = 0.0;
|
||
sumsed = 0.0;
|
||
suma = 0.0;
|
||
sumsed_land = 0.0;
|
||
suma_land = 0.0;
|
||
ntherm = 0usize;
|
||
prods_therm = 0.0;
|
||
prodscrit_therm = 0.0;
|
||
|
||
// Keep track of how many iterations we've gone to test for convergence.
|
||
n_gs_stream_power_law += 1;
|
||
|
||
rayon::join(
|
||
|| {
|
||
/*rayon::join(
|
||
|| */
|
||
{
|
||
// guess/update the elevation at t+Δt (k)
|
||
h_p.par_iter_mut()
|
||
.zip(/*h_*/ h.par_iter()) /*.zip(wh.par_iter())*/
|
||
.for_each(|((mut h_p, h_)/*, wh_*/)| {
|
||
*h_p = (*h_)/*.max(*wh_)*/ as Compute;
|
||
});
|
||
/* hp.par_iter_mut().zip(h.par_iter()).for_each(|(mut hp, h)| {
|
||
*hp = *h as Compute;
|
||
}); */
|
||
} /*,
|
||
|| {
|
||
// guess/update the alluvium at t+Δt (k)
|
||
ap.par_iter_mut().zip(a.par_iter()).for_each(|(mut ap, a)| {
|
||
*ap = *a as Compute;
|
||
});
|
||
}, */
|
||
/*)*/
|
||
},
|
||
|| {
|
||
/*rayon::join(
|
||
|| */
|
||
{
|
||
// calculate erosion/deposition of sediment at each node
|
||
deltah.par_iter_mut().enumerate().for_each(|(posi, mut deltah)| {
|
||
let uplift_i = uplift(posi) as Alt;
|
||
// h_j(t, FINAL) + U_j * Δt - h_j(t + Δt, k)
|
||
/* debug_assert!(((h[posi] + a[posi].max(0.0)) - h_[posi]).abs() <= 1.0e-6);
|
||
// let foo = (ht[posi] + uplift_i - h[posi] - (at[posi] - a[posi]/*.max(0.0)*/)) as Compute;
|
||
let foo = (ht[posi] + uplift_i - h[posi] - (at[posi] - a[posi].max(0.0)/*.max(0.0)*/)) as Compute;
|
||
// let foo = (ht[posi] + at[posi] + uplift_i - (h[posi] + a[posi].max(0.0))) as Compute;
|
||
let bar = (at[posi]/* + uplift_i*/ - a[posi].max(0.0)/* - (h[posi] - ht[posi]*/)) as Compute; */
|
||
let delta = (/*ht[posi] + at[posi].max(0.0)*/h_t[posi] + uplift_i - /*h_*/h[posi]/*.max(wh[posi])*/) as Compute;
|
||
/* if (delta - (foo + bar)).abs() > 1.0e-6 {
|
||
println!("dh: {:?}, foo: {:?}, bar: {:?}, delta: {:?}, ht: {:?}, at: {:?}, h: {:?}, a: {:?}, h_: {:?}",
|
||
dh[posi], foo, bar, delta,
|
||
ht[posi], at[posi],
|
||
h[posi], a[posi], h_[posi]);
|
||
debug_assert_eq!(delta, foo + bar);
|
||
} */
|
||
|
||
*deltah = delta;
|
||
});
|
||
/* deltah_sediment.par_iter_mut().enumerate().for_each(|(posi, mut deltah)| {
|
||
let uplift_i = uplift(posi) as Alt;
|
||
*deltah = (ht[posi] + uplift_i - h[posi] - (at[posi] - a[posi].max(0.0))) as Compute;
|
||
}); */
|
||
} /*,
|
||
|| {
|
||
// calculate erosion/deposition of alluvium at each node
|
||
deltah_alluvium.par_iter_mut().enumerate().for_each(|(posi, mut deltah)| {
|
||
let uplift_i = uplift(posi) as Alt;
|
||
*deltah = (at[posi]/* + uplift_i*/ - a[posi].max(0.0)/* - (h[posi] - ht[posi])*/) as Compute;
|
||
});
|
||
},
|
||
)*/
|
||
},
|
||
);
|
||
log::debug!("(Done precomputation).");
|
||
// sum the erosion in stack order
|
||
//
|
||
// After:
|
||
// deltah_i = Σ{j ∈ {i} ∪ upstream_i(t)}(h_j(t, FINAL) + U_j * Δt - h_i(t + Δt, k))
|
||
for &posi in /*newh.iter().rev()*/mstack.into_iter() {
|
||
let posi = posi as usize;
|
||
let posj = dh[posi];
|
||
if posj < 0 {
|
||
lake_silt[posi] = deltah[posi];
|
||
/* lake_sediment[posi] = deltah_sediment[posi];
|
||
lake_alluvium[posi] = deltah_alluvium[posi]; */
|
||
} else {
|
||
let uplift_i = uplift(posi) as Alt;
|
||
/* if (deltah[posi] - (deltah_sediment[posi] + deltah_alluvium[posi])).abs() > 1.0e-2 {
|
||
println!("deltah_sediment: {:?}, deltah_alluvium: {:?}, deltah: {:?}, hp: {:?}, ap: {:?}, h_p: {:?}, ht: {:?}, at: {:?}, h: {:?}, a: {:?}, h_: {:?}",
|
||
deltah_sediment[posi], deltah_alluvium[posi], deltah[posi],
|
||
hp[posi], ap[posi], h_p[posi],
|
||
ht[posi], at[posi],
|
||
h[posi], a[posi], h_[posi]);
|
||
debug_assert_eq!(deltah[posi], deltah_sediment[posi] + deltah_alluvium[posi]);
|
||
} */
|
||
deltah[posi] -= ((/*ht[posi] + at[posi].max(0.0)*/h_t[posi] + uplift_i) as Compute - h_p[posi]);
|
||
/* deltah_sediment[posi] -= ((ht[posi] + uplift_i - (at[posi] - ap[posi].max(0.0))) as Compute - hp[posi]);
|
||
deltah_alluvium[posi] -= ((at[posi]/* + uplift_i - (hp[posi] - ht[posi])*/) as Compute - ap[posi].max(0.0)); */
|
||
let lposi = lake_sill[posi];
|
||
if lposi == posi as isize {
|
||
if deltah[posi] <= 0.0 {
|
||
lake_silt[posi] = 0.0;
|
||
} else {
|
||
lake_silt[posi] = deltah[posi];
|
||
}
|
||
/* if deltah_sediment[posi] <= 0.0 {
|
||
lake_sediment[posi] = 0.0;
|
||
} else {
|
||
lake_sediment[posi] = deltah_sediment[posi];
|
||
}
|
||
if deltah_alluvium[posi] <= 0.0 {
|
||
lake_alluvium[posi] = 0.0;
|
||
} else {
|
||
lake_alluvium[posi] = deltah_alluvium[posi];
|
||
} */
|
||
}
|
||
deltah[posi] += (/* ht[posi] + at[posi].max(0.0) */h_t[posi] + uplift_i) as Compute - h_p[posi];
|
||
let mwrec_i = &mwrec[posi];
|
||
for (k, posj) in mrec_downhill(&mrec, posi) {
|
||
deltah[posj] += deltah[posi] * mwrec_i[k]/*mwrec_i.extract(k)*/;
|
||
}
|
||
/* let posj = posj as usize;
|
||
deltah[posj] += deltah[posi]; */
|
||
|
||
/* deltah_sediment[posi] += (ht[posi] + uplift_i - (at[posi] - ap[posi].max(0.0))) as Compute - hp[posi];
|
||
deltah_sediment[posj] += deltah_sediment[posi];
|
||
deltah_alluvium[posi] += (at[posi]/* + uplift_i - (hp[posi] - ht[posi]*/) as Compute - ap[posi].max(0.0);
|
||
deltah_alluvium[posj] += deltah_alluvium[posi]; */
|
||
}
|
||
/* if (deltah[posi] - (deltah_sediment[posi] + deltah_alluvium[posi])).abs() > 1.0e-2 {
|
||
println!("deltah_sediment: {:?}, deltah_alluvium: {:?}, deltah: {:?}, hp: {:?}, ap: {:?}, h_p: {:?}, ht: {:?}, at: {:?}",
|
||
deltah_sediment[posi], deltah_alluvium[posi], deltah[posi],
|
||
hp[posi], ap[posi], h_p[posi],
|
||
ht[posi], at[posi]);
|
||
debug_assert_eq!(deltah[posi], deltah_sediment[posi] + deltah_alluvium[posi]);
|
||
} */
|
||
}
|
||
log::debug!("(Done sediment transport computation).");
|
||
// do ij=nn,1,-1
|
||
// ijk=stack(ij)
|
||
// ijr=rec(ijk)
|
||
// if (ijr.ne.ijk) then
|
||
// dh(ijk)=dh(ijk)-(ht(ijk)-hp(ijk))
|
||
// if (lake_sill(ijk).eq.ijk) then
|
||
// if (dh(ijk).le.0.d0) then
|
||
// lake_sediment(ijk)=0.d0
|
||
// else
|
||
// lake_sediment(ijk)=dh(ijk)
|
||
// endif
|
||
// endif
|
||
// dh(ijk)=dh(ijk)+(ht(ijk)-hp(ijk))
|
||
// dh(ijr)=dh(ijr)+dh(ijk)
|
||
// else
|
||
// lake_sediment(ijk)=dh(ijk)
|
||
// endif
|
||
// enddo
|
||
|
||
elev.par_iter_mut().enumerate().for_each(|(posi, mut elev)| {
|
||
let uplift_i = uplift(posi) as Alt;
|
||
// let delta_a = a[posi] - at[posi];
|
||
if dh[posi] < 0 {
|
||
// *elev = (ht[posi] + uplift_i - delta_a) as Compute;
|
||
*elev = (/*ht[posi] + at[posi].max(0.0)*/h_t[posi] + uplift_i) as Compute;
|
||
} else {
|
||
// let old_h_after_uplift_i = (ht[posi] + uplift_i - delta_a) as Compute;
|
||
let old_h_after_uplift_i = (/*ht[posi] + at[posi].max(0.0)*/h_t[posi] + uplift_i) as Compute;
|
||
let area_i = area[posi] as Compute;
|
||
// debug_assert!(area_i > 0.0);
|
||
let uphill_silt_i = deltah[posi] - (old_h_after_uplift_i - h_p[posi]);
|
||
// let uphill_sediment_i = deltah_sediment[posi] - (old_h_after_uplift_i - hp[posi]);
|
||
/* let uphill_sediment_alluvium_i =
|
||
deltah_sediment[posi] - (ht[posi] + uplift_i - (at[posi] - ap[posi].max(0.0)) - hp[posi]) +
|
||
deltah_alluvium[posi] - ((/*at[posi] + uplift_i - (hp[posi] - ht[posi]*/at[posi]) - ap[posi].max(0.0)/*at[posi]*/); */
|
||
/* let uphill_sediment_alluvium_i =
|
||
deltah_sediment[posi] + deltah_alluvium[posi] -
|
||
2.0 * (old_h_after_uplift_i - (hp[posi] + ap[posi])); */
|
||
// let g_i = g(posi) as Compute;
|
||
let old_b_i = b[posi];
|
||
let sed = (h_t[posi] - old_b_i) as f64;
|
||
let g_i = if sed > sediment_thickness {
|
||
g_fs_mult_sed * g(posi) as Compute
|
||
} else {
|
||
g(posi) as Compute
|
||
};
|
||
// Make sure deposition coefficient doesn't result in more deposition than there
|
||
// actually was material to deposit. The current assumption is that as long as we
|
||
// are storing at most as much sediment as there actually was along the river, we
|
||
// are in the clear.
|
||
let g_i_ratio = (g_i / area_i)/*.min(1.0)*/;
|
||
// One side of nonlinear equation (23):
|
||
//
|
||
// h_i(t) + U_i * Δt + G / (p̃ * Ã_i) * Σ{j ∈ upstream_i(t)}(h_j(t, FINAL) + U_j * Δt - h_j(t + Δt, k))
|
||
//
|
||
// where
|
||
//
|
||
// Ã_i = A_i / (∆x∆y) = N_i, number of cells upstream of cell i.
|
||
// *elev = old_h_after_uplift_i + uphill_sediment_i * g_i_ratio;
|
||
*elev = old_h_after_uplift_i + /*uphill_sediment_alluvium_i*/uphill_silt_i * g_i_ratio;
|
||
/* if (*elev - (old_h_after_uplift_i + uphill_silt_i * g_i_ratio)).abs() > 1.0e-6 {
|
||
println!("deltah_sediment: {:?}, deltah_alluvium: {:?}, deltah: {:?}, hp: {:?}, ap: {:?}, h_p: {:?}",
|
||
deltah_sediment[posi], deltah_alluvium[posi], deltah[posi],
|
||
hp[posi], ap[posi], h_p[posi]);
|
||
debug_assert_eq!(*elev, old_h_after_uplift_i + uphill_silt_i * g_i_ratio);
|
||
} */
|
||
}
|
||
});
|
||
log::debug!("(Done elevation estimation).");
|
||
|
||
let start_time = Instant::now();
|
||
// TODO: Consider taking advantage of multi-receiver flow here.
|
||
// Iterate in ascending height order.
|
||
let mut sum_err = 0.0 as Compute;
|
||
/* let mut k_df_weights = Computex8::new(0.0);
|
||
let mut k_fs_weights = Computex8::new(0.0);
|
||
let mut rec_heights = Computex8::new(0.0); */
|
||
/* let mut k_df_weights = [0.0; 8];
|
||
let mut k_fs_weights = [0.0; 8];
|
||
let mut rec_heights = [0.0; 8]; */
|
||
let mut simd_buf = [0.0; 8];
|
||
let mut simd_buf2 = [0.0; 8];
|
||
let mut simd_buf3 = [0.0; 8];
|
||
for &posi in /*&*newh*/mstack.into_iter().rev() {
|
||
let posi = posi as usize;
|
||
let old_elev_i = /*h*/elev[posi] as f64;
|
||
let old_wh_i = wh[posi];
|
||
let old_b_i = b[posi];
|
||
let old_ht_i = /*ht*/h_t[posi];
|
||
let sed = (old_ht_i - old_b_i) as f64;
|
||
|
||
let posj = dh[posi];
|
||
if posj < 0 {
|
||
if posj == -1 {
|
||
panic!("Disconnected lake!");
|
||
}
|
||
if /*ht*/h_t[posi] > 0.0 {
|
||
log::warn!("Ocean above zero?");
|
||
}
|
||
// wh for oceans is always at least min_erosion_height.
|
||
let uplift_i = uplift(posi) as Alt;
|
||
// wh[posi] = min_erosion_height.max(ht[posi] + uplift_i);
|
||
wh[posi] = min_erosion_height.max(/*ht[posi] + at[posi].max(0.0)*/h_t[posi] + uplift_i);
|
||
// debug_assert!(wh[posi].is_normal() || wh[posi] == 0.0);
|
||
lake_sill[posi] = posi as isize;
|
||
lake_water_volume[posi] = 0.0;
|
||
// max_slopes[posi] = kd(posi);
|
||
// Egress with no outgoing flows.
|
||
} else {
|
||
// *is_done.at(posi) = done_val;
|
||
let posj = posj as usize;
|
||
// let dxy = (uniform_idx_as_vec2(posi) - uniform_idx_as_vec2(posj)).map(|e| e as f64);
|
||
|
||
// Has an outgoing flow edge (posi, posj).
|
||
// flux(i) = k * A[i]^m / ((p(i) - p(j)).magnitude()), and δt = 1
|
||
// let neighbor_distance = (neighbor_coef * dxy).magnitude();
|
||
// Since the area is in meters^(2m) and neighbor_distance is in m, so long as m = 0.5,
|
||
// we have meters^(1) / meters^(1), so they should cancel out. Otherwise, we would
|
||
// want to multiply neighbor_distance by height_scale and area[posi] by
|
||
// height_scale^2, to make sure we were working in the correct units for dz
|
||
// (which has height_scale height unit = 1.0 meters).
|
||
/* let uplift_i = uplift(posi) as f64;
|
||
assert!(uplift_i.is_normal() && uplift_i == 0.0 || uplift_i.is_positive()); */
|
||
// h[i](t + dt) = (h[i](t) + δt * (uplift[i] + flux(i) * h[j](t + δt))) / (1 + flux(i) * δt).
|
||
// NOTE: posj has already been computed since it's downhill from us.
|
||
// Therefore, we can rely on wh being set to the water height for that node.
|
||
// let h_j = h[posj] as f64;
|
||
// let a_j = a[posj] as f64;
|
||
let wh_j = wh[posj] as f64;
|
||
// let old_a_i = a[posi] as f64;
|
||
let old_h_i = h[posi] as f64;
|
||
let mut new_h_i = /*old_elev_i*//*old_h_i + old_a_i.max(0.0)*/old_h_i/*h[posi] as f64*//* + uplift_i*/;
|
||
/* let mut df_part;
|
||
|
||
let old_df_part = {
|
||
let uphill_alluvium_i =
|
||
deltah_alluvium[posi] - ((/*at[posi] + uplift_i - (hp[posi] - ht[posi]*/at[posi]) - ap[posi].max(0.0)/*at[posi]*/);
|
||
/* let uphill_sediment_alluvium_i =
|
||
deltah_sediment[posi] + deltah_alluvium[posi] -
|
||
2.0 * (old_h_after_uplift_i - (hp[posi] + ap[posi])); */
|
||
let area_i = area[posi] as Compute;
|
||
let g_i = g(posi) as Compute;
|
||
// Make sure deposition coefficient doesn't result in more deposition than there
|
||
// actually was material to deposit. The current assumption is that as long as we
|
||
// are storing at most as much sediment as there actually was along the river, we
|
||
// are in the clear.
|
||
let g_i_ratio = (g_i / area_i)/*.min(1.0)*/;
|
||
at[posi].max(0.0) + uphill_alluvium_i * g_i_ratio
|
||
}; */
|
||
|
||
// Only perform erosion if we are above the water level of the previous node.
|
||
if old_elev_i > wh_j/*h_j*//*h[posj]*/ {
|
||
let mut dtherm = 0.0f64;
|
||
/* {
|
||
// Thermal erosion (landslide)
|
||
let dxy = (uniform_idx_as_vec2(posi) - uniform_idx_as_vec2(posj)).map(|e| e as f64);
|
||
let neighbor_distance = (neighbor_coef * dxy).magnitude();
|
||
let dz = (new_h_i - /*h_j*//*h_k*//*wh_j*//*h_j*/wh_j.max(hp[posj])).max(0.0) / height_scale/* * CONFIG.mountain_scale as f64*/;
|
||
let mag_slope = dz/*.abs()*/ / neighbor_distance;
|
||
let max_slope = max_slopes[posi] as f64;
|
||
if mag_slope > max_slope {
|
||
let dh = max_slope * neighbor_distance * height_scale/* / CONFIG.mountain_scale as f64*/;
|
||
// new_h_i = (ht[posi] as f64 + l_tot * (mag_slope - max_slope));
|
||
// new_h_i = new_h_i - l_tot * (mag_slope - max_slope);
|
||
let uplift_i = uplift(posi) as f64;
|
||
let g_i = g(posi) as f64;
|
||
dtherm = -((l_tot * (mag_slope - max_slope)).min(/*dh*//*g_i * *//*uplift_i*//*max_uplift as f64*//*dz*//*uplift_i*//*(new_h_i + uplift_i - old_elev_i).abs() * 0.5*//* * 0.5*//*g_i * dz * 0.5*//*dz*/(old_h_i + uplift_i - old_elev_i).abs() * 0.5));
|
||
// new_h_i = hp[posj] + dh;
|
||
// new_h_i = /*old_h_i.max*/(/*wh_j*//*ht[posi] as Compute*//*h_j*/hp[posj]/*ht[posj] as Compute*/ + dh).max(new_h_i - l_tot * (mag_slope - max_slope));
|
||
if compute_stats/* && new_h_i > wh_j*/ {
|
||
ntherm += 1;
|
||
}
|
||
}
|
||
} */
|
||
let h0 = old_elev_i + dtherm;
|
||
|
||
// hi(t + ∂t) = (hi(t) + ∂t(ui + kp^mAi^m(hj(t + ∂t)/||pi - pj||))) / (1 + ∂t * kp^mAi^m / ||pi - pj||)
|
||
/* let k = if sed > sediment_thickness {
|
||
// Sediment
|
||
// k_fs
|
||
k_fs_mult_sed * kf(posi)
|
||
} else {
|
||
// Bedrock
|
||
// k_fb
|
||
kf(posi)
|
||
} * dt;
|
||
// let k = k * uplift_i / max_uplift as f64;
|
||
let n = n_f(posi) as f64;
|
||
let m = m_f(posi) as f64; */
|
||
let n = n_f(posi) as f64;
|
||
|
||
// Fluvial erosion.
|
||
let k_df_fact = &k_df_fact[posi];
|
||
let k_fs_fact = &k_fs_fact[posi];// k * (p * chunk_area * area[posi] as f64).powf(m) / neighbor_distance.powf(n);
|
||
/* // Multiply k_fs_fact by k_fs_mult_water for water.
|
||
let k_fs_fact = if h0 < wh_j {
|
||
k_fs_mult_* k_fs_fact
|
||
} else {
|
||
k_fs_fact
|
||
}; */
|
||
// let elev_j = h_j/* + a_j.max(0.0)*/;
|
||
let new_ht_i = (old_ht_i/* + uplift(posi) as f64*/);
|
||
if /*n == 1.0*/(n - 1.0).abs() <= 1.0e-3/*f64::EPSILON*/ && (q_ - 1.0).abs() <= 1.0e-3 {
|
||
let mut f = h0;
|
||
let mut df = 1.0;
|
||
for (kk, posj) in mrec_downhill(&mrec, posi) {
|
||
// This can happen in cases where receiver kk is neither uphill of
|
||
// nor downhill from posi's direct receiver.
|
||
if /*new_ht_i/*old_ht_i*/ >= (h_t[posj]/* + uplift(posj) as f64*/)*/old_elev_i /*>=*/> wh[posj] as f64/*h[posj]*//*h_j*/ {
|
||
let h_j = h[posj] as f64;
|
||
let elev_j = h_j/* + a_j.max(0.0)*/;
|
||
/* let flux = /*k * (p * chunk_area * area[posi] as f64).powf(m) / neighbor_distance;*/k_fs_fact[kk] + k_df_fact[kk];
|
||
assert!(flux.is_normal() && flux.is_positive() || flux == 0.0);
|
||
new_h_i = (/*new_h_i*//*(old_elev_i + (new_h_i - old_h_i))*/h0 + flux * elev_j) / (1.0 + flux); */
|
||
let fact = k_fs_fact[kk] as f64 + k_df_fact[kk] as f64;
|
||
// let fact = k_fs_fact.extract(kk) as f64 + k_df_fact.extract(kk) as f64;
|
||
f += fact * elev_j;
|
||
df += fact;
|
||
}
|
||
}
|
||
new_h_i = f / df;
|
||
} else {
|
||
// Local Newton-Raphson
|
||
let omega1 = 0.875f64 * n;
|
||
let omega2 = 0.875f64 / q_;/*if q_ < 0.5 { 0.875f64/* * q_*/ } else { 0.875f64 / q_ }*/;
|
||
let omega = omega1.max(omega2);
|
||
let tolp = 1.0e-3/*1.0e-4*/;
|
||
let mut errp = 2.0 * tolp;
|
||
// let h0 = old_elev_i + (new_h_i - old_h_i);
|
||
// let mut count = 0;
|
||
let mut max = 0usize;
|
||
/* let mut k_df_weights = [0.0; 8];//f64s(0.0);//f64x8::splat(0.0);
|
||
let mut k_fs_weights = [0.0; 8];//f64s(0.0);//f64x8::splat(0.0);
|
||
let n_weights = simd_func(n as SimdType - 1.0);
|
||
// let n_weights = f64s(n - 1.0);//f64x8::splat(n - 1.0);
|
||
let q__weights = simd_func(q_ as SimdType - 1.0);
|
||
// let q_weights = f64s(q_ - 1.0);//f64x8::splat(q_ - 1.0);
|
||
let czero = simd_func(0.0);
|
||
// let czero = f64s(0.0);//f64x8::splat(0.0); */
|
||
let mut rec_heights = [0.0; 8];//f64s(0.0);//f64x8::splat(0.0);
|
||
let mut mask = [MaskType::new(false); 8];
|
||
for (kk, posj) in mrec_downhill(&mrec, posi) {
|
||
if old_elev_i > wh[posj] as f64 {
|
||
// k_fs_weights[kk] = k_fs_fact[kk] as SimdType;
|
||
// k_fs_weights[max] = k_fs_fact[kk] as SimdType;
|
||
// /*k_fs_weights = */k_fs_weights.replace(max, k_fs_fact[kk]/*.extract(kk)*/ as f64);
|
||
// k_df_weights[kk] = k_df_fact[kk] as SimdType;
|
||
// k_df_weights[max] = k_df_fact[kk] as SimdType;
|
||
// /*k_df_weights = */k_df_weights.replace(max, k_df_fact[kk]/*.extract(kk)*/ as f64);
|
||
mask[kk] = MaskType::new(true);
|
||
rec_heights[kk] = h[posj] as SimdType;
|
||
// rec_heights[max] = h[posj] as SimdType;
|
||
// /*rec_heights = */rec_heights.replace(max, h[posj] as f64);
|
||
// max += 1;
|
||
}
|
||
}
|
||
/* let (weights_heights, max) = {
|
||
let mut iter = mrec_downhill(&mrec, posi);
|
||
let mut max = 0usize;
|
||
let arr = arr![
|
||
match iter.next() {
|
||
Some((kk, posj)) if old_elev_i >= wh[posj] => {
|
||
max += 1;
|
||
(k_fs_fact[kk], k_df_fact[kk], h[posj])
|
||
},
|
||
_ => (0.0, 0.0, 0.0),
|
||
}; 8];
|
||
(arr, max)
|
||
}; */
|
||
assert!(max <= 8);
|
||
/* let k_fs_weights = &k_fs_weights[..max];
|
||
let k_df_weights = &k_df_weights[..max];
|
||
let rec_heights = &rec_heights[..max];
|
||
let mut simd_buf = &mut simd_buf[..max];
|
||
let mut simd_buf2 = &mut simd_buf2[..max];
|
||
let mut simd_buf3 = &mut simd_buf3[..max]; */
|
||
/* let czero = &czero[..max];
|
||
let n_weights = &n_weights[..max];
|
||
let q__weights = &q__weights[..max]; */
|
||
while errp > tolp {
|
||
// count += 1;
|
||
/* if count > -1 {
|
||
println!("posi={:?} errp={:?} tolp={:?} h0={:?} new_h_i={:?} elev_j={:?} area={:?}", posi, errp, tolp, h0, new_h_i, elev_j, area[posi]);
|
||
} */
|
||
let mut f = new_h_i - h0;
|
||
let mut df = 1.0;
|
||
|
||
/* rec_heights.simd_iter(czero/*simd_func(0.0)*/)
|
||
.simd_map(|elev_j| czero/*simd_func(0.0)*/.max(new_h_i as SimdType - elev_j))
|
||
.scalar_fill(&mut simd_buf);
|
||
|
||
(k_fs_weights/*k_fs_fact*/.simd_iter(czero/*simd_func(0.0)*/), simd_buf.simd_iter(czero/*simd_func(0.0)*/))
|
||
.zip()
|
||
.simd_map(|(k_fs_fact, dh)| k_fs_fact * dh.powf(/*simd_func(n as SimdType - 1.0)*/n_weights))
|
||
.scalar_fill(&mut simd_buf2);
|
||
|
||
(k_df_weights/*k_df_fact*/.simd_iter(czero/*simd_func(0.0)*/), simd_buf.simd_iter(czero/*simd_func(0.0)*/))
|
||
.zip()
|
||
.simd_map(|(k_df_fact, dh)| k_df_fact * dh.powf(/*simd_func(q_ as SimdType - 1.0)*/q__weights))
|
||
.scalar_fill(&mut simd_buf3);
|
||
|
||
f += (simd_buf.simd_iter(czero/*simd_func(0.0)*/), simd_buf2.simd_iter(czero/*simd_func(0.0)*/), simd_buf3.simd_iter(czero/*simd_func(0.0)*/))
|
||
.zip()
|
||
/* .simd_map(|(dh, k_fs_fact, k_df_fact)| (k_fs_fact + k_df_fact) * dh)
|
||
.simd_reduce(czero/*simd_func(0.0)*/, |a, v| a + v) */
|
||
.simd_reduce(czero/*simd_func(0.0)*/, |a, (dh, k_fs_fact, k_df_fact)| a + (k_fs_fact + k_df_fact) * dh)
|
||
.sum() as f64;
|
||
|
||
df += (simd_buf2.simd_iter(czero/*simd_func(0.0)*/), simd_buf3.simd_iter(czero/*simd_func(0.0)*/))
|
||
.zip()
|
||
/* .simd_map(|(k_fs_fact, k_df_fact)| n as SimdType * k_fs_fact + q_ as SimdType * k_df_fact)
|
||
.simd_reduce(czero/*simd_func(0.0)*/, |a, v| a + v) */
|
||
.simd_reduce(czero/*simd_func(0.0)*/, |a, (k_fs_fact, k_df_fact)| n as SimdType * k_fs_fact + q_ as SimdType * k_df_fact)
|
||
.sum() as f64; */
|
||
|
||
/* f += (k_fs_weights.simd_iter(simd_func(0.0)), k_df_weights.simd_iter(simd_func(0.0)), simd_buf.simd_iter(simd_func(0.0)))
|
||
.zip()
|
||
.simd_map(|(k_fs_fact, k_df_fact, dh)| {
|
||
// let dh = simd_func(0.0).max(new_h_i as SimdType - elev_j);
|
||
k_fs_fact * dh.powf(simd_func(n as SimdType)) + k_df_fact * dh.powf(simd_func(q_ as SimdType))
|
||
})
|
||
.simd_reduce(simd_func(0.0), |a, v| a + v)
|
||
.sum() as f64;
|
||
|
||
df += (k_fs_weights.simd_iter(simd_func(0.0)), k_df_weights.simd_iter(simd_func(0.0)), rec_heights.simd_iter(simd_func(0.0)))
|
||
.zip()
|
||
.simd_map(|(k_fs_fact, k_df_fact, dh)| {
|
||
// let dh = simd_func(0.0).max(new_h_i as SimdType - elev_j);
|
||
n as SimdType * k_fs_fact * dh.powf(simd_func(n as SimdType) - 1.0) +
|
||
k_df_fact * q_ as SimdType * dh.powf(simd_func(q_ as SimdType - 1.0))
|
||
})
|
||
.simd_reduce(simd_func(0.0), |a, v| a + v)
|
||
.sum() as f64; */
|
||
|
||
/* let dh = (&rec_heights[..]).simd_iter(f64s(0.0))
|
||
.simd_map(|elev_j| f64s(0.0).max(new_h_i - elev_j));
|
||
let k_fs_fact =
|
||
(dh, (&k_fs_weights[..]).simd_iter(f64s(0.0)))
|
||
.zip()
|
||
.simd_map(|(dh, k_fs_fact)| k_fs_fact * dh.powf(f64s(n - 1.0)));
|
||
let k_df_fact =
|
||
(dh, (&k_df_weights[..]).simd_iter(f64s(0.0)))
|
||
.zip()
|
||
.simd_map(|dh, k_df_fact| k_df_fact * dh.powf(f64s(q_ - 1.0)));
|
||
f += (k_fs_fact, k_df_fact, dh)
|
||
.zip()
|
||
.simd_map(|(k_fs_fact, k_df_fact, dh)| (k_fs_fact + k_df_fact) * dh)
|
||
.simd_reduce(f64s(0.0), |a, v| a + v)
|
||
.sum();
|
||
df += (k_fs_fact, k_df_fact, dh)
|
||
.zip()
|
||
.simd_map(|(k_fs_fact, k_df_fact, dh)| n * k_fs_fact + q_ * k_df_fact)
|
||
.simd_reduce(f64s(0.0), |a, v| a + v)
|
||
.sum(); */
|
||
/* (k_fs_weights.simd_iter(f64s(0.0)), k_df_weights.simd_iter(f64s(0.0)), rec_heights.simd_iter(f64s(0.0)))
|
||
.zip()
|
||
.simd_map(|k_fs_fact, k_df_fact, elev_j| {
|
||
f64s(0.0).max(new_h_i - elev_j)
|
||
}) */
|
||
/* let dh = (-rec_heights + new_h_i).max(czero);
|
||
let dh_fs_sample = k_fs_weights * dh.powf(n_weights);
|
||
let dh_df_sample = k_df_weights * dh.powf(q_weights);
|
||
f += ((dh_fs_sample + dh_df_sample) * dh).sum();
|
||
df += (n * dh_fs_sample + q_ * dh_df_sample).sum(); */
|
||
|
||
/* for kk in (0..max) {
|
||
let dh = 0.0.max((new_h_i - rec_heights[kk])/*.abs()*/);
|
||
let dh_fs_sample = k_fs_weights[kk] * dh.powf(n - 1.0);
|
||
let dh_df_sample = k_df_weights[kk] * dh.powf(q_ - 1.0);
|
||
// Want: h_i(t+Δt) = h0 - fact * (h_i(t+Δt) - h_j(t+Δt))^n
|
||
// Goal: h_i(t+Δt) - h0 + fact * (h_i(t+Δt) - h_j(t+Δt))^n = 0
|
||
f += (dh_fs_sample + dh_df_sample) * dh;
|
||
// ∂h_i(t+Δt)/∂n = 1 + fact * n * (h_i(t+Δt) - h_j(t+Δt))^(n - 1)
|
||
df += n * dh_fs_sample + q_ * dh_df_sample;
|
||
} */
|
||
/* for (k_fs_fact, k_df_fact, elev_j) in weights_heights.iter().take(max) {
|
||
let dh = 0.0.max((new_h_i - elev_j)/*.abs()*/);
|
||
let dh_fs_sample = k_fs_fact * dh.powf(n - 1.0);
|
||
let dh_df_sample = k_df_fact * dh.powf(q_ - 1.0);
|
||
// Want: h_i(t+Δt) = h0 - fact * (h_i(t+Δt) - h_j(t+Δt))^n
|
||
// Goal: h_i(t+Δt) - h0 + fact * (h_i(t+Δt) - h_j(t+Δt))^n = 0
|
||
f += (dh_fs_sample + dh_df_sample) * dh;
|
||
// ∂h_i(t+Δt)/∂n = 1 + fact * n * (h_i(t+Δt) - h_j(t+Δt))^(n - 1)
|
||
df += n * dh_fs_sample + q_ * dh_df_sample;
|
||
} */
|
||
/* for (kk, posj) in mrec_downhill(&mrec, posi) {
|
||
if /*new_ht_i/*old_ht_i*/ > (h_t[posj]/* + uplift(posj) as f64*/)*/old_elev_i /*>=*/> wh[posj] as f64/*h[posj]*//*h_j*/ {
|
||
let h_j = h[posj] as /*f64*/SimdType;
|
||
let elev_j = h_j/* + a_j.max(0.0)*/;
|
||
let dh = 0.0.max((new_h_i as SimdType - elev_j)/*.abs()*/);
|
||
let dh_fs_sample = k_fs_fact[kk] as /*f64*/SimdType * dh.powf(n as SimdType - 1.0);
|
||
let dh_df_sample = k_df_fact[kk] as /*f64*/SimdType * dh.powf(q_ as SimdType - 1.0);
|
||
// Want: h_i(t+Δt) = h0 - fact * (h_i(t+Δt) - h_j(t+Δt))^n
|
||
// Goal: h_i(t+Δt) - h0 + fact * (h_i(t+Δt) - h_j(t+Δt))^n = 0
|
||
f += ((dh_fs_sample + dh_df_sample) * dh) as f64;
|
||
// ∂h_i(t+Δt)/∂n = 1 + fact * n * (h_i(t+Δt) - h_j(t+Δt))^(n - 1)
|
||
df += (n as SimdType * dh_fs_sample + q_ as SimdType * dh_df_sample) as f64;
|
||
}
|
||
} */
|
||
for kk in (0..8) {
|
||
//if /*new_ht_i/*old_ht_i*/ > (h_t[posj]/* + uplift(posj) as f64*/)*/old_elev_i /*>=*/> wh[posj] as f64/*h[posj]*//*h_j*/ {
|
||
if mask[kk].test() {
|
||
let h_j = rec_heights[kk];
|
||
let elev_j = h_j/* + a_j.max(0.0)*/;
|
||
let dh = 0.0.max((new_h_i as SimdType - elev_j)/*.abs()*/);
|
||
let dh_fs_sample = k_fs_fact[kk] as /*f64*/SimdType * dh.powf(n as SimdType - 1.0);
|
||
let dh_df_sample = k_df_fact[kk] as /*f64*/SimdType * dh.powf(q_ as SimdType - 1.0);
|
||
// Want: h_i(t+Δt) = h0 - fact * (h_i(t+Δt) - h_j(t+Δt))^n
|
||
// Goal: h_i(t+Δt) - h0 + fact * (h_i(t+Δt) - h_j(t+Δt))^n = 0
|
||
f += ((dh_fs_sample + dh_df_sample) * dh) as f64;
|
||
// ∂h_i(t+Δt)/∂n = 1 + fact * n * (h_i(t+Δt) - h_j(t+Δt))^(n - 1)
|
||
df += (n as SimdType * dh_fs_sample + q_ as SimdType * dh_df_sample) as f64;
|
||
}
|
||
//}
|
||
}
|
||
/* for (kk, posj) in mrec_downhill(&mrec, posi) {
|
||
if /*new_ht_i/*old_ht_i*/ > (h_t[posj]/* + uplift(posj) as f64*/)*/old_elev_i /*>=*/> wh[posj] as f64/*h[posj]*//*h_j*/ {
|
||
let h_j = h[posj] as f64;
|
||
let elev_j = h_j/* + a_j.max(0.0)*/;
|
||
let dh = 0.0.max((new_h_i - elev_j)/*.abs()*/);
|
||
let dh_fs_sample = k_fs_fact.extract(kk) as f64 * dh.powf(n - 1.0);
|
||
let dh_df_sample = k_df_fact.extract(kk) as f64 * dh.powf(q_ - 1.0);
|
||
// Want: h_i(t+Δt) = h0 - fact * (h_i(t+Δt) - h_j(t+Δt))^n
|
||
// Goal: h_i(t+Δt) - h0 + fact * (h_i(t+Δt) - h_j(t+Δt))^n = 0
|
||
f += (dh_fs_sample + dh_df_sample) * dh;
|
||
// ∂h_i(t+Δt)/∂n = 1 + fact * n * (h_i(t+Δt) - h_j(t+Δt))^(n - 1)
|
||
df += n * dh_fs_sample + q_ * dh_df_sample;
|
||
}
|
||
} */
|
||
// hn = h_i(t+Δt, k) - (h_i(t+Δt, k) - (h0 - fact * (h_i(t+Δt, k) - h_j(t+Δt))^n)) / ∂h_i/∂n(t+Δt, k)
|
||
let hn = new_h_i - f / df;
|
||
// errp = |(h_i(t+Δt, k) - (h0 - fact * (h_i(t+Δt, k) - h_j(t+Δt))^n)) / ∂h_i/∂n(t+Δt, k)|
|
||
errp = (hn - new_h_i).abs();
|
||
// h_i(t+∆t, k+1) = ...
|
||
new_h_i = new_h_i * (1.0 - omega) + hn * omega;
|
||
}
|
||
// Correct new_h_i to keep it at or under h0.
|
||
/* if h0 < new_h_i {
|
||
println!("Huh? h0={:?}, new_h_i={:?},", h0, new_h_i);
|
||
// debug_assert!(new_h_i <= h0);
|
||
} */
|
||
new_h_i = h0.min(new_h_i);
|
||
/* let omega = 0.875f64 / n;
|
||
let tolp = 1.0e-3;
|
||
let mut errp = 2.0 * tolp;
|
||
// let h0 = old_elev_i;
|
||
let fact = k_fs_fact[posi];// k * (p * chunk_area * area[posi] as f64).powf(m) / neighbor_distance.powf(n);
|
||
while errp > tolp {
|
||
let mut f = new_h_i - h0;
|
||
let mut df = 1.0;
|
||
// Want: h_i(t+Δt) = h0 - fact * (h_i(t+Δt) - h_j(t+Δt))^n
|
||
// Goal: h_i(t+Δt) - h0 + fact * (h_i(t+Δt) - h_j(t+Δt))^n = 0
|
||
f += fact * 0.0.max(new_h_i - h_j).powf(n);
|
||
// ∂h_i(t+Δt)/∂n = 1 + fact * n * (h_i(t+Δt) - h_j(t+Δt))^(n - 1)
|
||
df += fact * n * 0.0.max(new_h_i - h_j).powf(n - 1.0);
|
||
// hn = h_i(t+Δt, k) - (h_i(t+Δt, k) - (h0 - fact * (h_i(t+Δt, k) - h_j(t+Δt))^n)) / ∂h_i/∂n(t+Δt, k)
|
||
let hn = new_h_i - f / df;
|
||
// errp = |(h_i(t+Δt, k) - (h0 - fact * (h_i(t+Δt, k) - h_j(t+Δt))^n)) / ∂h_i/∂n(t+Δt, k)|
|
||
errp = (hn - new_h_i).abs();
|
||
// h_i(t+∆t, k+1) = ...
|
||
new_h_i = new_h_i * (1.0 - omega) + hn * omega;
|
||
} */
|
||
/* omega=0.875d0/n
|
||
tolp=1.d-3
|
||
errp=2.d0*tolp
|
||
h0=elev(ijk)
|
||
do while (errp.gt.tolp)
|
||
f=h(ijk)-h0
|
||
df=1.d0
|
||
if (ht(ijk).gt.ht(ijr)) then
|
||
fact = kfint(ijk)*dt*a(ijk)**m/length(ijk)**n
|
||
f=f+fact*max(0.d0,h(ijk)-h(ijr))**n
|
||
df=df+fact*n*max(0.d0,h(ijk)-h(ijr))**(n-1.d0)
|
||
endif
|
||
hn=h(ijk)-f/df
|
||
errp=abs(hn-h(ijk))
|
||
h(ijk)=h(ijk)*(1.d0-omega)+hn*omega
|
||
enddo */
|
||
}
|
||
|
||
// df_part = old_df_part - k_df_fact * 0.0.max((new_h_i - elev_j)/*.abs()*/).powf(q_);
|
||
// df_part = old_df_part;// - k_df_fact * 0.0.max((new_h_i - elev_j)/*.abs()*/).powf(q_);
|
||
|
||
/* // Debris flow erosion.
|
||
{
|
||
let omega = 0.875f64 / q_;
|
||
let tolp = 1.0e-3;
|
||
let mut errp = 2.0 * tolp;
|
||
// let h0 = new_h_i;
|
||
let fact = k_df_fact[posi];// k * (p * chunk_area * area[posi] as f64).powf(m) / neighbor_distance.powf(n);
|
||
while errp > tolp {
|
||
let mut f = new_h_i - h0;
|
||
let mut df = 1.0;
|
||
// Want: h_i(t+Δt) = h0 - fact * (h_i(t+Δt) - h_j(t+Δt))^n
|
||
// Goal: h_i(t+Δt) - h0 + fact * (h_i(t+Δt) - h_j(t+Δt))^n = 0
|
||
f += fact * 0.0.max(new_h_i - h_j).powf(q_);
|
||
// ∂h_i(t+Δt)/∂n = 1 + fact * n * (h_i(t+Δt) - h_j(t+Δt))^(n - 1)
|
||
df += fact * n * 0.0.max(new_h_i - h_j).powf(q_ - 1.0);
|
||
// hn = h_i(t+Δt, k) - (h_i(t+Δt, k) - (h0 - fact * (h_i(t+Δt, k) - h_j(t+Δt))^n)) / ∂h_i/∂n(t+Δt, k)
|
||
let hn = new_h_i - f / df;
|
||
// errp = |(h_i(t+Δt, k) - (h0 - fact * (h_i(t+Δt, k) - h_j(t+Δt))^n)) / ∂h_i/∂n(t+Δt, k)|
|
||
errp = (hn - new_h_i).abs();
|
||
// h_i(t+∆t, k+1) = ...
|
||
new_h_i = new_h_i * (1.0 - omega) + hn * omega;
|
||
}
|
||
} */
|
||
|
||
/* {
|
||
// Thermal erosion (landslide)
|
||
let dxy = (uniform_idx_as_vec2(posi) - uniform_idx_as_vec2(posj)).map(|e| e as f64);
|
||
let neighbor_distance = (neighbor_coef * dxy).magnitude();
|
||
let dz = (new_h_i - /*h_j*//*h_k*//*wh_j*//*h_j*/wh_j/*.max(hp[posj])*/).max(0.0) / height_scale/* * CONFIG.mountain_scale as f64*/;
|
||
let mag_slope = dz/*.abs()*/ / neighbor_distance;
|
||
let max_slope = max_slopes[posi] as f64;
|
||
if mag_slope > max_slope {
|
||
let dh = max_slope * neighbor_distance * height_scale/* / CONFIG.mountain_scale as f64*/;
|
||
// new_h_i = (ht[posi] as f64 + l_tot * (mag_slope - max_slope));
|
||
// new_h_i = new_h_i - l_tot * (mag_slope - max_slope);
|
||
let uplift_i = uplift(posi) as f64;
|
||
let g_i = g(posi) as f64;
|
||
let dtherm =
|
||
//(l_tot * (mag_slope - max_slope)).min(/*dh*//*g_i * *//*uplift_i*//*max_uplift as f64*/dz/*uplift_i*//*(new_h_i/* + uplift_i*/ - /*old_h_i*/old_ht_i)*/./*abs()*/max(0.0) * 0.5/* * 0.5*//*g_i * dz * 0.5*/);
|
||
0.0;
|
||
new_h_i = new_h_i - dtherm;
|
||
// new_h_i = hp[posj] + dh;
|
||
// new_h_i = /*old_h_i.max*/(/*wh_j*//*ht[posi] as Compute*//*h_j*/hp[posj]/*ht[posj] as Compute*/ + dh).max(new_h_i - l_tot * (mag_slope - max_slope));
|
||
if compute_stats/* && new_h_i > wh_j*/ {
|
||
ntherm += 1;
|
||
prodscrit_therm += max_slope.ln();
|
||
prods_therm += mag_slope.ln();
|
||
}
|
||
}
|
||
} */
|
||
lake_sill[posi] = posi as isize;
|
||
lake_water_volume[posi] = 0.0;
|
||
|
||
// If we dipped below the receiver's water level, set our height to the receiver's
|
||
// water level.
|
||
if new_h_i <= wh_j/*elev_j*//*h[posj]*/ {
|
||
if compute_stats {
|
||
ncorr += 1;
|
||
}
|
||
/* lake_sill[posi] = posi as isize;
|
||
lake_water_volume[posi] = 0.0; */
|
||
// h_[posi] = wh_j* (1.0 - uchaos):;
|
||
// new_h_i = elev_j/* + <Alt as Float>::epsilon()*/;
|
||
// NOTE: Why wh_j?
|
||
// Because in the next round, if the old height is still wh_j or under, it
|
||
// will be set precisely equal to the estimated height, meaning it
|
||
// effectively "vanishes" and just deposits sediment to its reciever.
|
||
// (This is probably related to criteria for block Gauss-Seidel, etc.).
|
||
new_h_i = /*h[posj];*/wh_j;// - df_part.max(0.0);
|
||
// df_part = 0.0;
|
||
/* let lposj = lake_sill[posj];
|
||
lake_sill[posi] = lposj;
|
||
// TODO: Delete?
|
||
lake_water_volume[posi] = 0.0;
|
||
if lposj >= 0 {
|
||
let lposj = lposj as usize;
|
||
lake_water_volume[lposj] += wh_j - new_h_i;
|
||
} */
|
||
}/* else if new_h_i <= wh_j {
|
||
// new_h_i = wh_j;
|
||
/* // new_h_i = elev_j;/* + <Alt as Float>::epsilon();*/
|
||
let lposj = lake_sill[posj];
|
||
lake_sill[posi] = lposj;
|
||
// TODO: Delete?
|
||
lake_water_volume[posi] = 0.0;
|
||
if lposj >= 0 {
|
||
let lposj = lposj as usize;
|
||
lake_water_volume[lposj] += wh_j - new_h_i;
|
||
// println!("lake_sill[{:?}] = {:?}", posi, lposj);
|
||
} */
|
||
} *//*else if new_h_i - df_part.max(0.0) <= wh_j {
|
||
if compute_stats {
|
||
ncorr += 1;
|
||
}
|
||
// df_part = 0.0;
|
||
// df_part = (new_h_i - wh_j).max(0.0);
|
||
// df_part = (new_h_i - wh_j).max(0.0);
|
||
h_[posi] = new_h_i;
|
||
df_part = new_h_i - wh_j;
|
||
new_h_i = wh_j;// - df_part.max(0.0);
|
||
// new_h_i = wh_j;
|
||
} */else {
|
||
/* lake_sill[posi] = posi as isize;
|
||
lake_water_volume[posi] = 0.0; */
|
||
// h_[posi] = new_h_i;
|
||
// new_h_i -= df_part.max(0.0);
|
||
|
||
if compute_stats && new_h_i > 0.0 {
|
||
let dxy = (uniform_idx_as_vec2(posi) - uniform_idx_as_vec2(posj)).map(|e| e as f64);
|
||
let neighbor_distance = (neighbor_coef * dxy).magnitude();
|
||
let dz = (new_h_i - /*h_j*//*h_k*/wh_j).max(0.0)/* / height_scale*//* * CONFIG.mountain_scale as f64*/;
|
||
let mag_slope = dz/*.abs()*/ / neighbor_distance;
|
||
|
||
nland += 1;
|
||
sumsed_land += sed;
|
||
// suma_land += df_part;
|
||
sumh += new_h_i;
|
||
sums += mag_slope;
|
||
}
|
||
}
|
||
} else {
|
||
// df_part = old_df_part;
|
||
// df_part = old_a_i;
|
||
// h_[posi] = old_elev_i;
|
||
// new_h_i = old_elev_i - df_part.max(0.0);
|
||
new_h_i = old_elev_i;
|
||
let lposj = lake_sill[posj];
|
||
lake_sill[posi] = lposj;
|
||
if lposj >= 0 {
|
||
let lposj = lposj as usize;
|
||
lake_water_volume[lposj] += (wh_j - old_elev_i) as Compute;
|
||
}
|
||
}
|
||
// Set max_slope to this node's water height (max of receiver's water height and
|
||
// this node's height).
|
||
wh[posi] = wh_j.max(new_h_i/* + df_part.max(0.0)*/) as Alt;
|
||
/* if (wh[posi] - wh_j.max(h_[posi])).abs() > 1.0e-4 {
|
||
println!("deltah_sediment: {:?}, deltah_alluvium: {:?}, deltah: {:?}, hp: {:?}, ap: {:?}, h_p: {:?}, ht: {:?}, at: {:?}, h: {:?}, a: {:?}, h_: {:?}, wh_i: {:?}, wh_j: {:?}",
|
||
deltah_sediment[posi], deltah_alluvium[posi], deltah[posi],
|
||
hp[posi], ap[posi], h_p[posi],
|
||
ht[posi], at[posi],
|
||
h[posi], a[posi], h_[posi],
|
||
wh[posi], wh_j);
|
||
|
||
debug_assert_eq!(wh[posi], wh_j.max(h_[posi]));
|
||
} */
|
||
// Prevent erosion from dropping us below our receiver, unless we were already below it.
|
||
// new_h_i = h_j.min(old_h_i + uplift_i).max(new_h_i);
|
||
// Find out if this is a lake bottom.
|
||
/* let indirection_idx = indirection[posi];
|
||
let is_lake_bottom = indirection_idx < 0;
|
||
let _fake_neighbor = is_lake_bottom && dxy.x.abs() > 1.0 && dxy.y.abs() > 1.0;
|
||
// Test the slope.
|
||
let max_slope = max_slopes[posi] as f64;
|
||
// Hacky version of thermal erosion: only consider lowest neighbor, don't redistribute
|
||
// uplift to other neighbors.
|
||
let (posk, h_k) = /* neighbors(posi)
|
||
.filter(|&posk| *is_done.at(posk) == done_val)
|
||
// .filter(|&posk| *is_done.at(posk) == done_val || is_ocean(posk))
|
||
.map(|posk| (posk, h[posk] as f64))
|
||
// .filter(|&(posk, h_k)| *is_done.at(posk) == done_val || h_k < 0.0)
|
||
.min_by(|&(_, a), &(_, b)| a.partial_cmp(&b).unwrap())
|
||
.unwrap_or((posj, h_j)); */
|
||
(posj, h_j);
|
||
// .max(h_j);
|
||
let (posk, h_k) = if h_k < h_j {
|
||
(posk, h_k)
|
||
} else {
|
||
(posj, h_j)
|
||
};
|
||
let dxy = (uniform_idx_as_vec2(posi) - uniform_idx_as_vec2(posk)).map(|e| e as f64);
|
||
let neighbor_distance = (neighbor_coef * dxy).magnitude();
|
||
let dz = (new_h_i - /*h_j*/h_k).max(0.0) / height_scale/* * CONFIG.mountain_scale as f64*/;
|
||
let mag_slope = dz/*.abs()*/ / neighbor_distance; */
|
||
// If you're on the lake bottom and not right next to your neighbor, don't compute a
|
||
// slope.
|
||
if
|
||
/* !is_lake_bottom */ /* !fake_neighbor */
|
||
true {
|
||
/* if
|
||
/* !is_lake_bottom && */
|
||
mag_slope > max_slope {
|
||
// println!("old slope: {:?}, new slope: {:?}, dz: {:?}, h_j: {:?}, new_h_i: {:?}", mag_slope, max_slope, dz, h_j, new_h_i);
|
||
// Thermal erosion says this can't happen, so we reduce dh_i to make the slope
|
||
// exactly max_slope.
|
||
// max_slope = (old_h_i + dh - h_j) / height_scale/* * CONFIG.mountain_scale */ / NEIGHBOR_DISTANCE
|
||
// dh = max_slope * NEIGHBOR_DISTANCE * height_scale/* / CONFIG.mountain_scale */ + h_j - old_h_i.
|
||
let dh = max_slope * neighbor_distance * height_scale/* / CONFIG.mountain_scale as f64*/;
|
||
new_h_i = /*h_j.max*/(h_k + dh).max(new_h_i - l_tot * (mag_slope - max_slope));
|
||
let dz = (new_h_i - /*h_j*/h_k).max(0.0) / height_scale/* * CONFIG.mountain_scale as f64*/;
|
||
let slope = dz/*.abs()*/ / neighbor_distance;
|
||
sums += slope;
|
||
/* max_slopes[posi] = /*(mag_slope - max_slope) * */kd(posi);
|
||
sums += mag_slope; */
|
||
// let slope = dz.signum() * max_slope;
|
||
// new_h_i = slope * neighbor_distance * height_scale /* / CONFIG.mountain_scale as f64 */ + h_j;
|
||
// sums += max_slope;
|
||
} else {
|
||
// max_slopes[posi] = 0.0;
|
||
sums += mag_slope;
|
||
// Just use the computed rate.
|
||
} */
|
||
h[posi] = new_h_i as Alt;
|
||
// a[posi] = df_part as Alt;
|
||
// Make sure to update the basement as well!
|
||
// b[posi] = (old_b_i + uplift_i).min(new_h_i) as f32;
|
||
}
|
||
}
|
||
// *is_done.at(posi) = done_val;
|
||
if compute_stats {
|
||
sumsed += sed;
|
||
// suma += a[posi];
|
||
let h_i = h[posi];
|
||
if h_i > 0.0 {
|
||
minh = h_i.min(minh);
|
||
}
|
||
maxh = h_i.max(maxh);
|
||
}
|
||
|
||
/* if (h_[posi] - (h[posi] + a[posi].max(0.0))).abs() > 1.0e-6 {
|
||
println!("posi: {:?}, dh: {:?}, deltah_sediment: {:?}, deltah_alluvium: {:?}, deltah: {:?}, hp: {:?}, ap: {:?}, h_p: {:?}, ht: {:?}, at: {:?}, h: {:?}, a: {:?}, h_: {:?}",
|
||
posi, dh[posi],
|
||
deltah_sediment[posi], deltah_alluvium[posi], deltah[posi],
|
||
hp[posi], ap[posi], h_p[posi],
|
||
ht[posi], at[posi],
|
||
h[posi], a[posi], h_[posi],
|
||
);
|
||
debug_assert_eq!(h[posi] + a[posi].max(0.0), h_[posi]);
|
||
} */
|
||
// Add sum of squares of errors.
|
||
sum_err += (h[posi]/*.max(wh[posi])*/ as Compute/* + a[posi].max(0.0) as Compute*/ - /*hp*/h_p[posi] as Compute/* - ap[posi].max(0.0) as Compute*/).powi(2);
|
||
}
|
||
log::debug!(
|
||
"(Done erosion computation, time={:?}ms)",
|
||
start_time.elapsed().as_millis()
|
||
);
|
||
|
||
err = (sum_err / /*newh*/mstack.len() as Compute).sqrt();
|
||
/* if max_g == 0.0 {
|
||
err = 0.0;
|
||
} */
|
||
if n_gs_stream_power_law == max_n_gs_stream_power_law {
|
||
log::warn!(
|
||
"Beware: Gauss-Siedel scheme not convergent: err={:?}, expected={:?}",
|
||
err,
|
||
tol
|
||
);
|
||
}
|
||
}
|
||
|
||
//b=min(h,b)
|
||
|
||
// update the basement
|
||
//
|
||
// NOTE: Despite this not quite applying since basement order and height order differ, we once
|
||
// again borrow the implicit FastScape stack order. If this becomes a problem we can easily
|
||
// compute a separate stack order just for basement.
|
||
/* for &posi in &*newh {
|
||
let posi = posi as usize;
|
||
let old_b_i = b[posi];
|
||
let h_i = h[posi];
|
||
let uplift_i = uplift(posi) as Alt;
|
||
|
||
// First, add uplift...
|
||
let mut new_b_i = (old_b_i + uplift_i).min(h_i);
|
||
|
||
let posj = dh[posi];
|
||
// Sediment height normal to bedrock. NOTE: Currently we can actually have sedment and
|
||
// bedrock slope at different heights, meaning there's no uniform slope. There are
|
||
// probably more correct ways to account for this, such as averaging, integrating, or doing
|
||
// things by mass / volume instead of height, but for now we use the time-honored
|
||
// technique of ignoring the problem.
|
||
let h_normal = if posj < 0 {
|
||
// Egress with no outgoing flows; for now, we assume this means normal and vertical
|
||
// coincide.
|
||
(h_i - new_b_i) as f64
|
||
} else {
|
||
let posj = posj as usize;
|
||
let b_j = b[posj];
|
||
let dxy = (uniform_idx_as_vec2(posi) - uniform_idx_as_vec2(posj)).map(|e| e as f64);
|
||
let neighbor_distance_squared = (neighbor_coef * dxy).magnitude_squared();
|
||
let vertical_sed = (h_i - new_b_i) as f64;
|
||
let db = (new_b_i - b_j) as f64;
|
||
// H_i_fact = (b_i - b_j) / (||p_i - p_j||^2 + (b_i - b_j)^2)
|
||
let h_i_fact = db / (neighbor_distance_squared + db * db);
|
||
let h_i_vertical = 1.0 - h_i_fact * db;
|
||
// ||H_i|| = (h_i - b_i) * √((H_i_fact^2 * ||p_i - p_j||^2 + (1 - H_i_fact * (b_i - b_j))^2))
|
||
vertical_sed * (h_i_fact * h_i_fact * neighbor_distance_squared + h_i_vertical * h_i_vertical).sqrt()
|
||
};
|
||
// Rate of sediment production: -∂z_b / ∂t = ε₀ * e^(-αH)
|
||
let p_i = epsilon_0_tot * f64::exp(-alpha * h_normal);
|
||
// println!("h_normal = {:?}, p_i = {:?}", h_normal, p_i);
|
||
|
||
new_b_i -= p_i as Alt;
|
||
|
||
b[posi] = new_b_i;
|
||
} */
|
||
// TODO: Consider taking advantage of multi-receiver flow here.
|
||
b.par_iter_mut()
|
||
.zip(h.par_iter())
|
||
.enumerate()
|
||
.for_each(|(posi, (mut b, &h_i))| {
|
||
let old_b_i = *b;
|
||
let uplift_i = uplift(posi) as Alt;
|
||
|
||
// First, add uplift...
|
||
/* let mut new_b_i = (old_b_i + uplift_i).min(h_i); */
|
||
let mut new_b_i = old_b_i + uplift_i;
|
||
|
||
let posj = dh[posi];
|
||
// Sediment height normal to bedrock. NOTE: Currently we can actually have sedment and
|
||
// bedrock slope at different heights, meaning there's no uniform slope. There are
|
||
// probably more correct ways to account for this, such as averaging, integrating, or doing
|
||
// things by mass / volume instead of height, but for now we use the time-honored
|
||
// technique of ignoring the problem.
|
||
let vertical_sed = (h_i - new_b_i).max(0.0) as f64;
|
||
let h_normal = if posj < 0 {
|
||
// Egress with no outgoing flows; for now, we assume this means normal and vertical
|
||
// coincide.
|
||
vertical_sed
|
||
} else {
|
||
let posj = posj as usize;
|
||
let h_j = h[posj];
|
||
let dxy = (uniform_idx_as_vec2(posi) - uniform_idx_as_vec2(posj)).map(|e| e as f64);
|
||
let neighbor_distance_squared = (neighbor_coef * dxy).magnitude_squared();
|
||
let dh = (h_i - h_j) as f64;
|
||
// H_i_fact = (h_i - h_j) / (||p_i - p_j||^2 + (h_i - h_j)^2)
|
||
let h_i_fact = dh / (neighbor_distance_squared + dh * dh);
|
||
let h_i_vertical = 1.0 - h_i_fact * dh;
|
||
// ||H_i|| = (h_i - b_i) * √((H_i_fact^2 * ||p_i - p_j||^2 + (1 - H_i_fact * (h_i - h_j))^2))
|
||
vertical_sed
|
||
* (h_i_fact * h_i_fact * neighbor_distance_squared
|
||
+ h_i_vertical * h_i_vertical)
|
||
.sqrt()
|
||
};
|
||
// Rate of sediment production: -∂z_b / ∂t = ε₀ * e^(-αH)
|
||
let p_i = epsilon_0(posi) as f64 * dt * f64::exp(-alpha(posi) as f64 * h_normal);
|
||
// println!("h_normal = {:?}, p_i = {:?}", h_normal, p_i);
|
||
|
||
new_b_i -= p_i as Alt;
|
||
|
||
// Clamp basement so it doesn't exceed height.
|
||
new_b_i = new_b_i.min(h_i);
|
||
*b = new_b_i;
|
||
});
|
||
log::debug!("Done updating basement and applying soil production...");
|
||
|
||
// update the height to reflect sediment flux.
|
||
h.par_iter_mut().enumerate().for_each(|(posi, mut h)| {
|
||
let lposi = lake_sill[posi];
|
||
if lposi >= 0 {
|
||
let lposi = lposi as usize;
|
||
if lake_water_volume[lposi] > 0.0 {
|
||
// +max(0.d0,min(lake_sediment(lake_sill(ij)),lake_water_volume(lake_sill(ij))))/
|
||
// lake_water_volume(lake_sill(ij))*(water(ij)-h(ij))
|
||
*h += (0.0.max(
|
||
/*lake_sediment[lposi]*/ lake_silt[posi].min(lake_water_volume[lposi]),
|
||
) / lake_water_volume[lposi]
|
||
* (wh[posi]/* - a[posi].max(0.0)*/ - *h) as Compute)
|
||
as Alt;
|
||
}
|
||
}
|
||
});
|
||
// do ij=1,nn
|
||
// if (lake_sill(ij).ne.0) then
|
||
// if (lake_water_volume(lake_sill(ij)).gt.0.d0) h(ij)=h(ij) &
|
||
// +max(0.d0,min(lake_sediment(lake_sill(ij)),lake_water_volume(lake_sill(ij))))/ &
|
||
// lake_water_volume(lake_sill(ij))*(water(ij)-h(ij))
|
||
// endif
|
||
// enddo
|
||
|
||
/* a.par_iter_mut().enumerate().for_each(|(posi, mut a)| {
|
||
let lposi = lake_sill[posi];
|
||
if lposi >= 0 {
|
||
let lposi = lposi as usize;
|
||
let sed_flux = (0.0.max(lake_sediment[lposi].min(lake_water_volume[lposi])));
|
||
|
||
let volume = lake_water_volume[lposi] - sed_flux;
|
||
if volume > 0.0 {
|
||
// +max(0.d0,min(lake_sediment(lake_sill(ij)),lake_water_volume(lake_sill(ij))))/
|
||
// lake_water_volume(lake_sill(ij))*(water(ij)-h(ij))
|
||
*a +=
|
||
(0.0.max(lake_alluvium[lposi].min(volume)) /
|
||
lake_water_volume[lposi] *
|
||
(wh[posi] - h[posi] - (*a).max(0.0)) as Compute) as Alt;
|
||
}
|
||
}
|
||
*a = a.max(0.0);
|
||
}); */
|
||
|
||
log::debug!(
|
||
"Done applying stream power (max height: {:?}) (avg height: {:?}) (min height: {:?}) (avg slope: {:?})\n \
|
||
(above talus angle, geom. mean slope [actual/critical/ratio]: {:?} / {:?} / {:?})\n \
|
||
(old avg alluvium thickness [all/land]: {:?} / {:?})\n \
|
||
(old avg sediment thickness [all/land]: {:?} / {:?})\n \
|
||
(num land: {:?}) (num thermal: {:?}) (num corrected: {:?})",
|
||
maxh,
|
||
avgz(sumh, nland),
|
||
minh,
|
||
avgz(sums, nland),
|
||
geomz(prods_therm, ntherm),
|
||
geomz(prodscrit_therm, ntherm),
|
||
geomz(prods_therm - prodscrit_therm, ntherm),
|
||
avgz(suma, newh.len()),
|
||
avgz(suma_land, nland),
|
||
avgz(sumsed, newh.len()),
|
||
avgz(sumsed_land, nland),
|
||
nland,
|
||
ntherm,
|
||
ncorr,
|
||
);
|
||
|
||
// Apply thermal erosion.
|
||
maxh = 0.0;
|
||
minh = <Alt as Float>::infinity();
|
||
sumh = 0.0;
|
||
sums = 0.0;
|
||
sumsed = 0.0;
|
||
suma = 0.0;
|
||
sumsed_land = 0.0;
|
||
suma_land = 0.0;
|
||
nland = 0usize;
|
||
ncorr = 0usize;
|
||
ntherm = 0usize;
|
||
prods_therm = 0.0;
|
||
prodscrit_therm = 0.0;
|
||
for &posi in &*newh {
|
||
let posi = posi as usize;
|
||
let old_h_i = h/*b*/[posi] as f64;
|
||
// let old_a_i = a[posi];
|
||
let old_b_i = b[posi] as f64;
|
||
let sed = (old_h_i - old_b_i) as f64;
|
||
|
||
let max_slope = max_slopes[posi];
|
||
// Remember k_d for this chunk in max_slopes.
|
||
// higher max_slope => much lower kd_factor.
|
||
let kd_factor =
|
||
// 1.0;
|
||
(1.0 / (max_slope / mid_slope/*.sqrt()*//*.powf(0.03125)*/).powf(/*2.0*/2.0))/*.min(kdsed)*/;
|
||
max_slopes[posi] = if sed > sediment_thickness && kdsed > 0.0 {
|
||
// Sediment
|
||
kdsed /* * kd_factor*/
|
||
} else {
|
||
// Bedrock
|
||
kd(posi) /* / kd_factor*/
|
||
};
|
||
|
||
let posj = dh[posi];
|
||
if posj < 0 {
|
||
if posj == -1 {
|
||
panic!("Disconnected lake!");
|
||
}
|
||
// wh for oceans is always at least min_erosion_height.
|
||
// let uplift_i = uplift(posi) as Alt;
|
||
// wh[posi] = min_erosion_height.max(ht[posi] + uplift_i);
|
||
wh[posi] = min_erosion_height.max(
|
||
/*ht[posi] + at[posi].max(0.0)*//*h_t[posi] + uplift_i*/ old_h_i as Alt,
|
||
);
|
||
// Egress with no outgoing flows.
|
||
} else {
|
||
let posj = posj as usize;
|
||
// Find the water height for this chunk's receiver; we only apply thermal erosion
|
||
// for chunks above water.
|
||
let mut wh_j = wh[posj] as f64;
|
||
// If you're on the lake bottom and not right next to your neighbor, don't compute a
|
||
// slope.
|
||
let mut new_h_i = /*old_h_i*//*old_h_i + old_a_i.max(0.0)*/old_h_i; /*old_b_i;*/
|
||
if
|
||
/* !is_lake_bottom */ /* !fake_neighbor */
|
||
wh_j < old_h_i
|
||
/* + old_a_i.max(0.0)*/
|
||
{
|
||
// NOTE: Currently assuming that talus angle is not eroded once the substance is
|
||
// totally submerged in water, and that talus angle if part of the substance is
|
||
// in water is 0 (or the same as the dry part, if this is set to wh_j), but
|
||
// actually that's probably not true.
|
||
let old_h_j = (h[posj]/* + a[posj].max(0.0)*/) as f64;
|
||
let h_j = /*h[posj] as f64*//*wh_j*/old_h_j;
|
||
// let h_j = b[posj] as f64;
|
||
/* let indirection_idx = indirection[posi];
|
||
let is_lake_bottom = indirection_idx < 0;
|
||
let _fake_neighbor = is_lake_bottom && dxy.x.abs() > 1.0 && dxy.y.abs() > 1.0; */
|
||
// Test the slope.
|
||
// Hacky version of thermal erosion: only consider lowest neighbor, don't redistribute
|
||
// uplift to other neighbors.
|
||
let (posk, h_k) = /* neighbors(posi)
|
||
.filter(|&posk| *is_done.at(posk) == done_val)
|
||
// .filter(|&posk| *is_done.at(posk) == done_val || is_ocean(posk))
|
||
.map(|posk| (posk, h[posk] as f64))
|
||
// .filter(|&(posk, h_k)| *is_done.at(posk) == done_val || h_k < 0.0)
|
||
.min_by(|&(_, a), &(_, b)| a.partial_cmp(&b).unwrap())
|
||
.unwrap_or((posj, h_j)); */
|
||
(posj, h_j);
|
||
// .max(h_j);
|
||
let (posk, h_k) = if h_k < h_j { (posk, h_k) } else { (posj, h_j) };
|
||
let dxy = (uniform_idx_as_vec2(posi) - uniform_idx_as_vec2(posk)).map(|e| e as f64);
|
||
let neighbor_distance = (neighbor_coef * dxy).magnitude();
|
||
let dz = (new_h_i - /*h_j*/h_k).max(0.0)/* / height_scale*//* * CONFIG.mountain_scale as f64*/;
|
||
let mag_slope = dz/*.abs()*/ / neighbor_distance;
|
||
if
|
||
/* !is_lake_bottom && */
|
||
mag_slope >= max_slope {
|
||
// println!("old slope: {:?}, new slope: {:?}, dz: {:?}, h_j: {:?}, new_h_i: {:?}", mag_slope, max_slope, dz, h_j, new_h_i);
|
||
// Thermal erosion says this can't happen, so we reduce dh_i to make the slope
|
||
// exactly max_slope.
|
||
// max_slope = (old_h_i + dh - h_j) / height_scale/* * CONFIG.mountain_scale */ / NEIGHBOR_DISTANCE
|
||
// dh = max_slope * NEIGHBOR_DISTANCE * height_scale/* / CONFIG.mountain_scale */ + h_j - old_h_i.
|
||
let dh = max_slope * neighbor_distance/* * height_scale*//* / CONFIG.mountain_scale as f64*/;
|
||
// new_h_i = /*h_j.max*//*(h_k + dh).max*/(/*new_h_i*/ht[posi] as f64 + l_tot * (mag_slope - max_slope));
|
||
// new_h_i = /*h_j.max*//*(h_k + dh).max*/(/*new_h_i*/h_k + dh + l_tot * (mag_slope - max_slope));
|
||
// new_h_i = /*h_j.max*//*(h_k + dh).max*/(new_h_i - l_tot * (mag_slope - max_slope));
|
||
let dtherm = 0.0/*dz - dh*//*(l_tot * (mag_slope - max_slope)).min(/*(dz/* - dh*/) / 2.0*/(1.0 + max_g) * max_uplift as f64)*/;
|
||
new_h_i = /*h_j.max*//*(h_k + dh).max*/(/*new_h_i*//*h_k + dh*/new_h_i - dtherm);
|
||
/* let new_h_j = (old_h_j + dtherm).min(old_h_j.max(new_h_i));
|
||
h[posj] = new_h_j as Alt;
|
||
wh_j = wh_j.max(new_h_j);
|
||
wh[posj] = wh_j as Alt; */
|
||
// No more hillslope processes on newly exposed bedrock.
|
||
// max_slopes[posi] = 0.0;
|
||
// max_slopes[posi] = l;
|
||
// max_slopes[posi] = 0.0;
|
||
if new_h_i <= wh_j {
|
||
if compute_stats {
|
||
ncorr += 1;
|
||
}
|
||
// new_h_i = wh_j;
|
||
// new_h_i = wh_j - old_a_i.max(0.0);
|
||
} else {
|
||
if compute_stats && new_h_i > 0.0 {
|
||
let dz = (new_h_i - /*h_j*//*h_k*//*wh_j*/h_j).max(0.0)/* / height_scale*//* * CONFIG.mountain_scale as f64*/;
|
||
let slope = dz/*.abs()*/ / neighbor_distance;
|
||
sums += slope;
|
||
// max_slopes[posi] = /*(mag_slope - max_slope) * */max_slopes[posi].max(kdsed);
|
||
/* max_slopes[posi] = /*(mag_slope - max_slope) * */kd(posi);
|
||
sums += mag_slope; */
|
||
/* if kd_factor < 1.0 {
|
||
max_slopes[posi] /= kd_factor;
|
||
} else {
|
||
max_slopes[posi] *= kd_factor;
|
||
} */
|
||
// max_slopes[posi] *= kd_factor;
|
||
nland += 1;
|
||
sumh += new_h_i/* - old_a_i*/;
|
||
sumsed_land += sed;
|
||
// suma_land += old_a_i;
|
||
}
|
||
// let slope = dz.signum() * max_slope;
|
||
// new_h_i = slope * neighbor_distance * height_scale /* / CONFIG.mountain_scale as f64 */ + h_j;
|
||
// sums += max_slope;
|
||
}
|
||
if compute_stats {
|
||
ntherm += 1;
|
||
prodscrit_therm += max_slope.ln();
|
||
prods_therm += mag_slope.ln();
|
||
}
|
||
} else {
|
||
// Poorly emulating nonlinear hillslope transport as described by
|
||
// http://eps.berkeley.edu/~bill/papers/112.pdf.
|
||
// sqrt(3)/3*32*32/(128000/2)
|
||
// Also Perron-2011-Journal_of_Geophysical_Research__Earth_Surface.pdf
|
||
let slope_ratio = (mag_slope / max_slope).powi(2);
|
||
let slope_nonlinear_factor =
|
||
slope_ratio * ((3.0 - slope_ratio) / (1.0 - slope_ratio).powi(2));
|
||
max_slopes[posi] += (max_slopes[posi] * slope_nonlinear_factor).min(max_stable);
|
||
// max_slopes[posi] = (max_slopes[posi] * 1.0 / (1.0 - (mag_slope / max_slope).powi(2)));
|
||
/*if kd_factor < 1.0 {
|
||
max_slopes[posi] *= kd_factor;
|
||
}*/
|
||
/* if (old_h_i - old_b_i as f64) <= sediment_thickness {
|
||
max_slopes[posi] *= kd_factor;
|
||
} */
|
||
// max_slopes[posi] *= kd_factor;
|
||
if compute_stats && new_h_i > 0.0 {
|
||
sums += mag_slope;
|
||
// Just use the computed rate.
|
||
nland += 1;
|
||
sumh += new_h_i/* - old_a_i*/;
|
||
sumsed_land += sed;
|
||
// suma_land += old_a_i;
|
||
}
|
||
}
|
||
h/*b*/[posi] = /*old_h_i.min(new_h_i)*/(new_h_i/* - old_a_i.max(0.0)*/) as Alt;
|
||
// Make sure to update the basement as well!
|
||
// b[posi] = old_b_i.min(new_h_i) as Alt;
|
||
b[posi] = old_b_i.min(old_b_i + (/*old_h_i.min(*/new_h_i/*)*/ - old_h_i)) as Alt;
|
||
// sumh += new_h_i;
|
||
}
|
||
// Set wh to this node's water height (max of receiver's water height and
|
||
// this node's height).
|
||
wh[posi] = wh_j.max(new_h_i) as Alt;
|
||
}
|
||
// max_slopes[posi] = max_slopes[posi].min(max_stable);
|
||
|
||
// *is_done.at(posi) = done_val;
|
||
if compute_stats {
|
||
sumsed += sed;
|
||
// suma += old_a_i;
|
||
let h_i = h[posi];
|
||
if h_i > 0.0 {
|
||
minh = h_i.min(minh);
|
||
}
|
||
maxh = h_i.max(maxh);
|
||
}
|
||
}
|
||
log::debug!(
|
||
"Done applying thermal erosion (max height: {:?}) (avg height: {:?}) (min height: {:?}) (avg slope: {:?})\n \
|
||
(above talus angle, geom. mean slope [actual/critical/ratio]: {:?} / {:?} / {:?})\n \
|
||
(avg alluvium thickness [all/land]: {:?} / {:?})\n \
|
||
(avg sediment thickness [all/land]: {:?} / {:?})\n \
|
||
(num land: {:?}) (num thermal: {:?}) (num corrected: {:?})",
|
||
maxh,
|
||
avgz(sumh, nland),
|
||
minh,
|
||
avgz(sums, nland),
|
||
geomz(prods_therm, ntherm),
|
||
geomz(prodscrit_therm, ntherm),
|
||
geomz(prods_therm - prodscrit_therm, ntherm),
|
||
avgz(suma, newh.len()),
|
||
avgz(suma_land, nland),
|
||
avgz(sumsed, newh.len()),
|
||
avgz(sumsed_land, nland),
|
||
nland,
|
||
ntherm,
|
||
ncorr,
|
||
);
|
||
|
||
// Apply hillslope diffusion.
|
||
diffusion(
|
||
nx,
|
||
ny,
|
||
nx as f64 * dx,
|
||
ny as f64 * dy,
|
||
dt,
|
||
(),
|
||
h,
|
||
b,
|
||
|posi| max_slopes[posi], /*kd*/
|
||
/* kdsed */ -1.0,
|
||
);
|
||
log::debug!("Done applying diffusion.");
|
||
log::debug!("Done eroding.");
|
||
}
|
||
|
||
/// The Planchon-Darboux algorithm for extracting drainage networks.
|
||
///
|
||
/// http://horizon.documentation.ird.fr/exl-doc/pleins_textes/pleins_textes_7/sous_copyright/010031925.pdf
|
||
///
|
||
/// See https://github.com/mewo2/terrain/blob/master/terrain.js
|
||
pub fn fill_sinks<F: Float + Send + Sync>(
|
||
h: impl Fn(usize) -> F + Sync,
|
||
is_ocean: impl Fn(usize) -> bool + Sync,
|
||
) -> Box<[F]> {
|
||
// NOTE: We are using the "exact" version of depression-filling, which is slower but doesn't
|
||
// change altitudes.
|
||
let epsilon = /*1.0 / (1 << 7) as f32 * height_scale/* / CONFIG.mountain_scale */*//*0.0*/F::zero();
|
||
let infinity = F::infinity(); //f32::INFINITY;
|
||
let range = 0..WORLD_SIZE.x * WORLD_SIZE.y;
|
||
let oldh = range
|
||
.into_par_iter()
|
||
.map(|posi| {
|
||
/* let h = h(posi);
|
||
let is_near_edge = is_ocean(posi);
|
||
if is_near_edge {
|
||
// debug_assert!(h <= 0.0);
|
||
// h
|
||
h.min(0.0)
|
||
} else {
|
||
h
|
||
} */
|
||
h(posi)
|
||
})
|
||
.collect::<Vec<_>>()
|
||
.into_boxed_slice();
|
||
let mut newh = oldh
|
||
.par_iter()
|
||
.enumerate()
|
||
.map(|(posi, &h)| {
|
||
let is_near_edge = is_ocean(posi);
|
||
if is_near_edge {
|
||
debug_assert!(h <= F::zero());
|
||
h
|
||
} else {
|
||
infinity
|
||
}
|
||
})
|
||
.collect::<Vec<_>>()
|
||
.into_boxed_slice();
|
||
|
||
loop {
|
||
let mut changed = false;
|
||
for posi in 0..newh.len() {
|
||
let nh = newh[posi];
|
||
let oh = oldh[posi];
|
||
if nh == oh {
|
||
continue;
|
||
}
|
||
for nposi in neighbors(posi) {
|
||
let onbh = newh[nposi];
|
||
let nbh = onbh + epsilon;
|
||
// If there is even one path downhill from this node's original height, fix
|
||
// the node's new height to be equal to its original height, and break out of the
|
||
// loop.
|
||
if oh >= nbh {
|
||
newh[posi] = oh;
|
||
changed = true;
|
||
break;
|
||
}
|
||
// Otherwise, we know this node's original height is below the new height of all of
|
||
// its neighbors. Then, we try to choose the minimum new height among all this
|
||
// node's neighbors that is (plus a constant epislon) below this node's new height.
|
||
//
|
||
// (If there is no such node, then the node's new height must be (minus a constant
|
||
// epsilon) lower than the new height of every neighbor, but above its original
|
||
// height. But this can't be true for *all* nodes, because if this is true for any
|
||
// node, it is not true of any of its neighbors. So all neighbors must either be
|
||
// their original heights, or we will have another iteration of the loop (one of
|
||
// its neighbors was changed to its minimum neighbor). In the second case, in the
|
||
// next round, all neighbor heights will be at most nh + epsilon).
|
||
if nh > nbh && nbh > oh {
|
||
newh[posi] = nbh;
|
||
changed = true;
|
||
}
|
||
}
|
||
}
|
||
if !changed {
|
||
return newh;
|
||
}
|
||
}
|
||
}
|
||
|
||
/// Algorithm for finding and connecting lakes. Assumes newh and downhill have already
|
||
/// been computed. When a lake's value is negative, it is its own lake root, and when it is 0, it
|
||
/// is on the boundary of Ω.
|
||
///
|
||
/// Returns a 4-tuple containing:
|
||
/// - The first indirection vector (associating chunk indices with their lake's root node).
|
||
/// - A list of chunks on the boundary (non-lake egress points).
|
||
/// - The second indirection vector (associating chunk indices with their lake's adjacency list).
|
||
/// - The adjacency list (stored in a single vector), indexed by the second indirection vector.
|
||
pub fn get_lakes<F: Float>(
|
||
h: impl Fn(usize) -> F,
|
||
downhill: &mut [isize],
|
||
) -> (usize, Box<[i32]>, Box<[u32]>, F) {
|
||
// Associates each lake index with its root node (the deepest one in the lake), and a list of
|
||
// adjacent lakes. The list of adjacent lakes includes the lake index of the adjacent lake,
|
||
// and a node index in the adjacent lake which has a neighbor in this lake. The particular
|
||
// neighbor should be the one that generates the minimum "pass height" encountered so far,
|
||
// i.e. the chosen pair should minimize the maximum of the heights of the nodes in the pair.
|
||
|
||
// We start by taking steps to allocate an indirection vector to use for storing lake indices.
|
||
// Initially, each entry in this vector will contain 0. We iterate in ascending order through
|
||
// the sorted newh. If the node has downhill == -2, it is a boundary node Ω and we store it in
|
||
// the boundary vector. If the node has downhill == -1, it is a fresh lake, and we store 0 in
|
||
// it. If the node has non-negative downhill, we use the downhill index to find the next node
|
||
// down; if the downhill node has a lake entry < 0, then downhill is a lake and its entry
|
||
// can be negated to find an (over)estimate of the number of entries it needs. If the downhill
|
||
// node has a non-negative entry, then its entry is the lake index for this node, so we should
|
||
// access that entry and increment it, then set our own entry to it.
|
||
let mut boundary = Vec::with_capacity(downhill.len());
|
||
let mut indirection = vec![/*-1i32*/0i32; WORLD_SIZE.x * WORLD_SIZE.y].into_boxed_slice();
|
||
|
||
let mut newh = Vec::with_capacity(downhill.len());
|
||
|
||
// Now, we know that the sum of all the indirection nodes will be the same as the number of
|
||
// nodes. We can allocate a *single* vector with 8 * nodes entries, to be used as storage
|
||
// space, and augment our indirection vector with the starting index, resulting in a vector of
|
||
// slices. As we go, we replace each lake entry with its index in the new indirection buffer,
|
||
// allowing
|
||
let mut lakes = vec![(-1, 0); /*(indirection.len() - boundary.len())*/indirection.len() * 8];
|
||
let mut indirection_ = vec![0u32; indirection.len()];
|
||
// First, find all the lakes.
|
||
let mut lake_roots = Vec::with_capacity(downhill.len()); // Test
|
||
for (chunk_idx, &dh) in (&*downhill)
|
||
.into_iter()
|
||
.enumerate()
|
||
.filter(|(_, &dh_idx)| dh_idx < 0)
|
||
{
|
||
if dh == -2 {
|
||
// On the boundary, add to the boundary vector.
|
||
boundary.push(chunk_idx);
|
||
// Still considered a lake root, though.
|
||
} else if dh == -1 {
|
||
lake_roots.push(chunk_idx);
|
||
} else {
|
||
panic!("Impossible.");
|
||
}
|
||
// Find all the nodes uphill from this lake. Since there is only one outgoing edge
|
||
// in the "downhill" graph, this is guaranteed never to visit a node more than
|
||
// once.
|
||
let start = newh.len();
|
||
let indirection_idx = (start * 8) as u32;
|
||
// New lake root
|
||
newh.push(chunk_idx as u32);
|
||
let mut cur = start;
|
||
while cur < newh.len() {
|
||
let node = newh[cur as usize];
|
||
for child in uphill(downhill, node as usize) {
|
||
// lake_idx is the index of our lake root.
|
||
indirection[child] = chunk_idx as i32;
|
||
indirection_[child] = indirection_idx;
|
||
newh.push(child as u32);
|
||
}
|
||
cur += 1;
|
||
}
|
||
// Find the number of elements pushed.
|
||
let length = (cur - start) * 8;
|
||
// New lake root (lakes have indirection set to -length).
|
||
indirection[chunk_idx] = -(length as i32);
|
||
indirection_[chunk_idx] = indirection_idx;
|
||
}
|
||
assert_eq!(newh.len(), downhill.len());
|
||
|
||
log::debug!("Old lake roots: {:?}", lake_roots.len());
|
||
|
||
let newh = newh.into_boxed_slice();
|
||
let mut maxh = -F::infinity();
|
||
// Now, we know that the sum of all the indirection nodes will be the same as the number of
|
||
// nodes. We can allocate a *single* vector with 8 * nodes entries, to be used as storage
|
||
// space, and augment our indirection vector with the starting index, resulting in a vector of
|
||
// slices. As we go, we replace each lake entry with its index in the new indirection buffer,
|
||
// allowing
|
||
for &chunk_idx_ in newh.into_iter() {
|
||
let chunk_idx = chunk_idx_ as usize;
|
||
let lake_idx_ = indirection_[chunk_idx];
|
||
let lake_idx = lake_idx_ as usize;
|
||
let height = h(chunk_idx_ as usize);
|
||
// While we're here, compute the max elevation difference from zero among all nodes.
|
||
maxh = maxh.max(height.abs());
|
||
// For every neighbor, check to see whether it is already set; if the neighbor is set,
|
||
// its height is ≤ our height. We should search through the edge list for the
|
||
// neighbor's lake to see if there's an entry; if not, we insert, and otherwise we
|
||
// get its height. We do the same thing in our own lake's entry list. If the maximum
|
||
// of the heights we get out from this process is greater than the maximum of this
|
||
// chunk and its neighbor chunk, we switch to this new edge.
|
||
for neighbor_idx in neighbors(chunk_idx) {
|
||
let neighbor_height = h(neighbor_idx);
|
||
let neighbor_lake_idx_ = indirection_[neighbor_idx];
|
||
let neighbor_lake_idx = neighbor_lake_idx_ as usize;
|
||
if neighbor_lake_idx_ < lake_idx_ {
|
||
// We found an adjacent node that is not on the boundary and has already
|
||
// been processed, and also has a non-matching lake. Therefore we can use
|
||
// split_at_mut to get disjoint slices.
|
||
let (lake, neighbor_lake) = {
|
||
// println!("Okay, {:?} < {:?}", neighbor_lake_idx, lake_idx);
|
||
let (neighbor_lake, lake) = lakes.split_at_mut(lake_idx);
|
||
(lake, &mut neighbor_lake[neighbor_lake_idx..])
|
||
};
|
||
|
||
// We don't actually need to know the real length here, because we've reserved
|
||
// enough spaces that we should always either find a -1 (available slot) or an
|
||
// entry for this chunk.
|
||
'outer: for pass in lake.iter_mut() {
|
||
if pass.0 == -1 {
|
||
// println!("One time, in my mind, one time... (neighbor lake={:?} lake={:?})", neighbor_lake_idx, lake_idx_);
|
||
*pass = (chunk_idx_ as i32, neighbor_idx as u32);
|
||
// Should never run out of -1s in the neighbor lake if we didn't find
|
||
// the neighbor lake in our lake.
|
||
*neighbor_lake
|
||
.iter_mut()
|
||
.filter(|neighbor_pass| neighbor_pass.0 == -1)
|
||
.next()
|
||
.unwrap() = (neighbor_idx as i32, chunk_idx_);
|
||
// panic!("Should never happen; maybe didn't reserve enough space in lakes?")
|
||
break;
|
||
} else if indirection_[pass.1 as usize] == neighbor_lake_idx_ {
|
||
for neighbor_pass in neighbor_lake.iter_mut() {
|
||
// Should never run into -1 while looping here, since (i, j)
|
||
// and (j, i) should be added together.
|
||
if indirection_[neighbor_pass.1 as usize] == lake_idx_ {
|
||
let pass_height = h(neighbor_pass.1 as usize);
|
||
let neighbor_pass_height = h(pass.1 as usize);
|
||
if height.max(neighbor_height)
|
||
< pass_height.max(neighbor_pass_height)
|
||
{
|
||
*pass = (chunk_idx_ as i32, neighbor_idx as u32);
|
||
*neighbor_pass = (neighbor_idx as i32, chunk_idx_);
|
||
}
|
||
break 'outer;
|
||
}
|
||
}
|
||
// Should always find a corresponding match in the neighbor lake if
|
||
// we found the neighbor lake in our lake.
|
||
let indirection_idx = indirection[chunk_idx];
|
||
let lake_chunk_idx = if indirection_idx >= 0 {
|
||
indirection_idx as usize
|
||
} else {
|
||
chunk_idx as usize
|
||
};
|
||
let indirection_idx = indirection[neighbor_idx];
|
||
let neighbor_lake_chunk_idx = if indirection_idx >= 0 {
|
||
indirection_idx as usize
|
||
} else {
|
||
neighbor_idx as usize
|
||
};
|
||
panic!(
|
||
"For edge {:?} between lakes {:?}, couldn't find partner \
|
||
for pass {:?}. \
|
||
Should never happen; maybe forgot to set both edges?",
|
||
(
|
||
(chunk_idx, uniform_idx_as_vec2(chunk_idx as usize)),
|
||
(neighbor_idx, uniform_idx_as_vec2(neighbor_idx as usize))
|
||
),
|
||
(
|
||
(
|
||
lake_chunk_idx,
|
||
uniform_idx_as_vec2(lake_chunk_idx as usize),
|
||
lake_idx_
|
||
),
|
||
(
|
||
neighbor_lake_chunk_idx,
|
||
uniform_idx_as_vec2(neighbor_lake_chunk_idx as usize),
|
||
neighbor_lake_idx_
|
||
)
|
||
),
|
||
(
|
||
(pass.0, uniform_idx_as_vec2(pass.0 as usize)),
|
||
(pass.1, uniform_idx_as_vec2(pass.1 as usize))
|
||
),
|
||
);
|
||
}
|
||
}
|
||
}
|
||
}
|
||
}
|
||
|
||
// Now it's time to calculate the lake connections graph T_L covering G_L.
|
||
let mut candidates = BinaryHeap::with_capacity(indirection.len());
|
||
// let mut pass_flows : Vec<i32> = vec![-1; indirection.len()];
|
||
|
||
// We start by going through each pass, deleting the ones that point out of boundary nodes and
|
||
// adding ones that point into boundary nodes from non-boundary nodes.
|
||
for edge in &mut lakes {
|
||
let edge: &mut (i32, u32) = edge;
|
||
// Only consider valid elements.
|
||
if edge.0 == -1 {
|
||
continue;
|
||
}
|
||
// Check to see if this edge points out *from* a boundary node.
|
||
// Delete it if so.
|
||
let from = edge.0 as usize;
|
||
let indirection_idx = indirection[from];
|
||
let lake_idx = if indirection_idx < 0 {
|
||
from
|
||
} else {
|
||
indirection_idx as usize
|
||
};
|
||
if downhill[lake_idx] == -2 {
|
||
edge.0 = -1;
|
||
continue;
|
||
}
|
||
// This edge is not pointing out from a boundary node.
|
||
// Check to see if this edge points *to* a boundary node.
|
||
// Add it to the candidate set if so.
|
||
let to = edge.1 as usize;
|
||
let indirection_idx = indirection[to];
|
||
let lake_idx = if indirection_idx < 0 {
|
||
to
|
||
} else {
|
||
indirection_idx as usize
|
||
};
|
||
if downhill[lake_idx] == -2 {
|
||
// Find the pass height
|
||
let pass = h(from).max(h(to));
|
||
candidates.push(Reverse((
|
||
NotNan::new(pass).unwrap(),
|
||
(edge.0 as u32, edge.1),
|
||
)));
|
||
}
|
||
}
|
||
|
||
let mut pass_flows_sorted: Vec<usize> = Vec::with_capacity(indirection.len());
|
||
|
||
// Now all passes pointing to the boundary are in candidates.
|
||
// As long as there are still candidates, we continue...
|
||
// NOTE: After a lake is added to the stream tree, the lake bottom's indirection entry no
|
||
// longer negates its maximum number of passes, but the lake side of the chosen pass. As such,
|
||
// we should make sure not to rely on using it this way afterwards.
|
||
// provides information about the number of candidate passes in a lake.
|
||
while let Some(Reverse((_, (chunk_idx, neighbor_idx)))) = candidates.pop() {
|
||
// We have the smallest candidate.
|
||
let lake_idx = indirection_[chunk_idx as usize] as usize;
|
||
let indirection_idx = indirection[chunk_idx as usize];
|
||
let lake_chunk_idx = if indirection_idx >= 0 {
|
||
indirection_idx as usize
|
||
} else {
|
||
chunk_idx as usize
|
||
};
|
||
if downhill[lake_chunk_idx] >= 0 {
|
||
// Candidate lake has already been connected.
|
||
continue;
|
||
}
|
||
// println!("Got here...");
|
||
assert_eq!(downhill[lake_chunk_idx], -1);
|
||
// Candidate lake has not yet been connected, and is the lowest candidate.
|
||
// Delete all other outgoing edges.
|
||
let max_len = -if indirection_idx < 0 {
|
||
indirection_idx
|
||
} else {
|
||
indirection[indirection_idx as usize]
|
||
} as usize;
|
||
// Add this chunk to the tree.
|
||
downhill[lake_chunk_idx] = neighbor_idx as isize;
|
||
// Also set the indirection of the lake bottom to the negation of the
|
||
// lake side of the chosen pass (chunk_idx).
|
||
// NOTE: This can't overflow i32 because WORLD_SIZE.x * WORLD_SIZE.y should fit in an i32.
|
||
indirection[lake_chunk_idx] = -(chunk_idx as i32);
|
||
// Add this edge to the sorted list.
|
||
pass_flows_sorted.push(lake_chunk_idx);
|
||
// pass_flows_sorted.push((chunk_idx as u32, neighbor_idx as u32));
|
||
for edge in &mut lakes[lake_idx..lake_idx + max_len] {
|
||
if *edge == (chunk_idx as i32, neighbor_idx as u32) {
|
||
// Skip deleting this edge.
|
||
continue;
|
||
}
|
||
// Delete the old edge, and remember it.
|
||
let edge = mem::replace(edge, (-1, 0));
|
||
if edge.0 == -1 {
|
||
// Don't fall off the end of the list.
|
||
break;
|
||
}
|
||
// Don't add incoming pointers from already-handled lakes or boundary nodes.
|
||
let indirection_idx = indirection[edge.1 as usize];
|
||
let neighbor_lake_idx = if indirection_idx < 0 {
|
||
edge.1 as usize
|
||
} else {
|
||
indirection_idx as usize
|
||
};
|
||
if downhill[neighbor_lake_idx] != -1 {
|
||
continue;
|
||
}
|
||
// Find the pass height
|
||
let pass = h(edge.0 as usize).max(h(edge.1 as usize));
|
||
// Put the reverse edge in candidates, sorted by height, then chunk idx, and finally
|
||
// neighbor idx.
|
||
candidates.push(Reverse((
|
||
NotNan::new(pass).unwrap(),
|
||
(edge.1, edge.0 as u32),
|
||
)));
|
||
}
|
||
// println!("I am a pass: {:?}", (uniform_idx_as_vec2(chunk_idx as usize), uniform_idx_as_vec2(neighbor_idx as usize)));
|
||
}
|
||
log::debug!("Total lakes: {:?}", pass_flows_sorted.len());
|
||
|
||
// Perform the bfs once again.
|
||
#[derive(Clone, Copy, PartialEq)]
|
||
enum Tag {
|
||
UnParsed,
|
||
InQueue,
|
||
WithRcv,
|
||
}
|
||
let mut tag = vec![Tag::UnParsed; WORLD_SIZE.x * WORLD_SIZE.y];
|
||
// TODO: Combine with adding to vector.
|
||
let mut filling_queue = Vec::with_capacity(downhill.len());
|
||
|
||
let mut newh = Vec::with_capacity(downhill.len());
|
||
(&*boundary)
|
||
.iter()
|
||
.chain(pass_flows_sorted.iter())
|
||
.for_each(|&chunk_idx| {
|
||
// Find all the nodes uphill from this lake. Since there is only one outgoing edge
|
||
// in the "downhill" graph, this is guaranteed never to visit a node more than
|
||
// once.
|
||
let mut start = newh.len();
|
||
// First, find the neighbor pass (assuming this is not the ocean).
|
||
let neighbor_pass_idx = downhill[chunk_idx];
|
||
let first_idx = if neighbor_pass_idx < 0 {
|
||
// This is the ocean.
|
||
newh.push(chunk_idx as u32);
|
||
start += 1;
|
||
chunk_idx
|
||
} else {
|
||
// This is a "real" lake.
|
||
let neighbor_pass_idx = neighbor_pass_idx as usize;
|
||
// Let's find our side of the pass.
|
||
let pass_idx = -indirection[chunk_idx];
|
||
// NOTE: Since only lakes are on the boundary, this should be a valid array index.
|
||
assert!(pass_idx >= 0);
|
||
let pass_idx = pass_idx as usize;
|
||
// Now, we should recompute flow paths so downhill nodes are contiguous.
|
||
|
||
/* // Carving strategy: reverse the path from the lake side of the pass to the
|
||
// lake bottom, and also set the lake side of the pass's downhill to its
|
||
// neighbor pass.
|
||
let mut to_idx = neighbor_pass_idx;
|
||
let mut from_idx = pass_idx;
|
||
// NOTE: Since our side of the lake pass must be in the same basin as chunk_idx,
|
||
// and chunk_idx is the basin bottom, we must reach it before we reach an ocean
|
||
// node or other node with an invalid index.
|
||
while from_idx != chunk_idx {
|
||
// Reverse this (from, to) edge by first replacing to_idx with from_idx,
|
||
// then replacing from_idx's downhill with the old to_idx, and finally
|
||
// replacing from_idx with from_idx's old downhill.
|
||
//
|
||
// println!("Reversing (lake={:?}): to={:?}, from={:?}, dh={:?}", chunk_idx, to_idx, from_idx, downhill[from_idx]);
|
||
from_idx = mem::replace(
|
||
&mut downhill[from_idx],
|
||
mem::replace(
|
||
&mut to_idx,
|
||
// NOTE: This cast should be valid since the node is either a path on the way
|
||
// to a lake bottom, or a lake bottom with an actual pass outwards.
|
||
from_idx
|
||
) as isize,
|
||
) as usize;
|
||
}
|
||
// Remember to set the actual lake's from_idx properly!
|
||
downhill[from_idx] = to_idx as isize; */
|
||
|
||
// TODO: Enqueue onto newh simultaneously with filling (this could help prevent
|
||
// needing a special tag just for checking if we are already enqueued).
|
||
// Filling strategy: nodes are assigned paths based on cost.
|
||
{
|
||
assert!(tag[pass_idx] == Tag::UnParsed);
|
||
|
||
filling_queue.push(pass_idx);
|
||
tag[neighbor_pass_idx] = Tag::WithRcv;
|
||
tag[pass_idx] = Tag::InQueue;
|
||
|
||
let outflow_coords = uniform_idx_as_vec2(neighbor_pass_idx);
|
||
let elev = h(neighbor_pass_idx).max(h(pass_idx));;
|
||
|
||
while let Some(node) = filling_queue.pop() {
|
||
let coords = uniform_idx_as_vec2(node);
|
||
|
||
let mut rcv = -1;
|
||
let mut rcv_cost = -f64::INFINITY;/*f64::EPSILON;*/
|
||
let outflow_distance = (outflow_coords - coords).map(|e| e as f64);
|
||
|
||
for ineighbor in neighbors(node) {
|
||
if indirection[ineighbor] != chunk_idx as i32 &&
|
||
ineighbor != chunk_idx && ineighbor != neighbor_pass_idx || h(ineighbor) > elev {
|
||
continue;
|
||
}
|
||
let dxy = (uniform_idx_as_vec2(ineighbor) - coords).map(|e| e as f64);
|
||
let neighbor_distance = (/*neighbor_coef * */dxy);
|
||
let mut tag = &mut tag[ineighbor];
|
||
match *tag {
|
||
Tag::WithRcv => {
|
||
// TODO: Remove outdated comment.
|
||
//
|
||
// // Proportional to
|
||
// // (vec_to_neighbor ⋅ vec_to_outflow) / |vec_to_neighbor|
|
||
// //
|
||
// // (proportional because the numerator of our actual
|
||
// // calculation is in chunk units, while the bottom is in
|
||
// // meters; this is effectively just multiplying the real costs in meters
|
||
// // by a constant [the chunk to meter ratio]).
|
||
//
|
||
// vec_to_outflow ⋅ (vec_to_neighbor / |vec_to_neighbor|) = ||vec_to_outflow||cos Θ
|
||
// where θ is the angle between vec_to_outflow and vec_to_neighbor.
|
||
//
|
||
// Which is also the scalar component of vec_to_outflow in the
|
||
// direction of vec_to_neighbor.
|
||
let cost = (outflow_distance.dot(neighbor_distance / neighbor_distance.magnitude()))/*.abs()*/;
|
||
if cost > rcv_cost {
|
||
rcv = ineighbor as isize;
|
||
rcv_cost = cost;
|
||
}
|
||
},
|
||
Tag::UnParsed => {
|
||
filling_queue.push(ineighbor);
|
||
*tag = Tag::InQueue;
|
||
},
|
||
_ => {}
|
||
}
|
||
}
|
||
assert!(rcv != -1);
|
||
downhill[node] = rcv;
|
||
// dist2receivers(node) = d8_distances[detail::get_d8_distance_id(node, rcv, static_cast<Node_T>(ncols))];
|
||
tag[node] = Tag::WithRcv;
|
||
}
|
||
}
|
||
|
||
// Use our side of the pass as the initial node in the stack order.
|
||
// TODO: Verify that this stack order will not "double reach" any lake chunks.
|
||
// pass_idx
|
||
neighbor_pass_idx
|
||
};
|
||
// newh.push(chunk_idx as u32);
|
||
// New lake root
|
||
/* newh.push(first_idx as u32); */
|
||
let mut cur = start;
|
||
let mut node = first_idx;
|
||
// while cur < newh.len()
|
||
loop {
|
||
// let node = newh[cur as usize];
|
||
// cur += 1;
|
||
|
||
for child in uphill(downhill, node as usize) {
|
||
// lake_idx is the index of our lake root.
|
||
// Check to make sure child (flowing into us) is in the same lake.
|
||
if indirection[child] == chunk_idx as i32 || child == chunk_idx
|
||
// // Check to make sure child (flowing into us) isn't a lake.
|
||
// if indirection[child] >= 0 || child == chunk_idx
|
||
/* Note: equal to chunk_idx should be same */
|
||
{
|
||
// assert!(h[child] >= h[node as usize]);
|
||
newh.push(child as u32);
|
||
}
|
||
}
|
||
|
||
if cur == newh.len() {
|
||
break;
|
||
}
|
||
node = newh[cur] as usize;
|
||
cur += 1;
|
||
}
|
||
});
|
||
assert_eq!(newh.len(), downhill.len());
|
||
(boundary.len(), indirection, newh.into_boxed_slice(), maxh)
|
||
}
|
||
|
||
/// Iterate through set neighbors of multi-receiver flow.
|
||
pub fn mrec_downhill<'a>(
|
||
mrec: &'a [u8],
|
||
posi: usize,
|
||
) -> impl Clone + Iterator<Item = (usize, usize)> + 'a {
|
||
let pos = uniform_idx_as_vec2(posi);
|
||
let mrec_i = mrec[posi];
|
||
NEIGHBOR_DELTA
|
||
.iter()
|
||
.enumerate()
|
||
.filter(move |&(k, _)| (mrec_i >> k as isize) & 1 == 1)
|
||
.map(move |(k, &(x, y))| {
|
||
(
|
||
k,
|
||
vec2_as_uniform_idx(Vec2::new(pos.x + x as i32, pos.y + y as i32)),
|
||
)
|
||
})
|
||
}
|
||
|
||
/// Algorithm for computing multi-receiver flow.
|
||
///
|
||
/// * `h`: altitude
|
||
/// * `downhill`: single receiver
|
||
/// * `newh`: single receiver stack
|
||
/// * `wh`: buffer into which water height will be inserted.
|
||
/// * `nx`, `ny`: resolution in x and y directions.
|
||
/// * `dx`, `dy`: grid spacing in x- and y-directions
|
||
/// * `maxh`: maximum |height| among all nodes.
|
||
///
|
||
///
|
||
/// Updates the water height to a nearly planar surface, and returns a 3-tuple containing:
|
||
/// * A bitmask representing which neighbors are downhill.
|
||
/// * Stack order for multiple receivers (from top to bottom).
|
||
/// * The weight for each receiver, for each node.
|
||
pub fn get_multi_rec<F: fmt::Debug + Float + Sync + Into<Compute>>(
|
||
h: impl Fn(usize) -> F + Sync,
|
||
downhill: &[isize],
|
||
newh: &[u32],
|
||
wh: &mut [F],
|
||
nx: usize,
|
||
ny: usize,
|
||
dx: Compute,
|
||
dy: Compute,
|
||
_maxh: F,
|
||
) -> (Box<[u8]>, Box<[u32]>, Box<[Computex8]>)
|
||
/*where
|
||
Compute: Into<F>,*/
|
||
{
|
||
let nn = nx * ny;
|
||
let dxdy = Vec2::new(dx, dy);
|
||
|
||
// set bc
|
||
let i1 = 0;
|
||
let i2 = nx;
|
||
let j1 = 0;
|
||
let j2 = ny;
|
||
/* let xcyclic = false;
|
||
let ycyclic = false; */
|
||
/*
|
||
write (cbc,'(i4)') ibc
|
||
i1=1
|
||
i2=nx
|
||
j1=1
|
||
j2=ny
|
||
if (cbc(4:4).eq.'1') i1=2
|
||
if (cbc(2:2).eq.'1') i2=nx-1
|
||
if (cbc(1:1).eq.'1') j1=2
|
||
if (cbc(3:3).eq.'1') j2=ny-1
|
||
xcyclic=.FALSE.
|
||
ycyclic=.FALSE.
|
||
if (cbc(4:4).ne.'1'.and.cbc(2:2).ne.'1') xcyclic=.TRUE.
|
||
if (cbc(1:1).ne.'1'.and.cbc(3:3).ne.'1') ycyclic=.TRUE.
|
||
*/
|
||
assert_eq!(nn, wh.len());
|
||
|
||
/* // TODO: Remove this.
|
||
for w in &mut *wh {
|
||
*w = F::nan();
|
||
} */
|
||
|
||
// fill the local minima with a nearly planar surface
|
||
// See https://matthew-brett.github.io/teaching/floating_error.html;
|
||
// our absolute error is bounded by β^(e-(p-1)), where e is the exponent of the largest value we
|
||
// care about. In this case, since we are summing up to nn numbers, we are bounded from above
|
||
// by nn * |maxh|; however, we only need to invoke this when we actually encounter a number, so
|
||
// we compute it dynamically.
|
||
// for nn + |maxh|
|
||
// TODO: Consider that it's probably not possible to have a downhill path the size of the whole grid...
|
||
// either measure explicitly (maybe in get_lakes) or work out a more precise upper bound (since
|
||
// using nn * 2 * (maxh + epsilon) makes f32 not work very well).
|
||
let deltah = F::epsilon() + F::epsilon();
|
||
// let deltah = F::epsilon() * 2 * maxh;
|
||
// NumCast::from(nn); /* 1.0e-8 */
|
||
// let deltah : F = (1.0e-7 as Compute).into();
|
||
for &ijk in newh {
|
||
let ijk = ijk as usize;
|
||
let h_i = h(ijk);
|
||
let ijr = downhill[ijk];
|
||
wh[ijk] = if ijr >= 0 {
|
||
let ijr = ijr as usize;
|
||
let wh_j = wh[ijr];
|
||
// debug_assert!(wh_j.is_normal() || wh_j == F::zero());
|
||
if wh_j /*>*/>= h_i {
|
||
/* if wh_j == h_i {
|
||
log::debug!("Interesting... ijk={:?}, ijr={:?}, wh_j{:?} h_i={:?}", uniform_idx_as_vec2(ijk), uniform_idx_as_vec2(ijr), wh_j, h_i);
|
||
} */
|
||
let deltah = deltah * wh_j.abs();
|
||
wh_j + deltah
|
||
} else {
|
||
h_i
|
||
}
|
||
// wh[ijk] = h_i.max(wh_j + deltah);
|
||
} else {
|
||
h_i
|
||
};
|
||
}
|
||
|
||
let mut wrec = Vec::<Computex8>::with_capacity(nn);
|
||
let mut mrec = Vec::with_capacity(nn);
|
||
let mut don_vis = Vec::with_capacity(nn);
|
||
|
||
// loop on all nodes
|
||
(0..nn)
|
||
.into_par_iter()
|
||
.map(|ij| {
|
||
// TODO: SIMDify? Seems extremely amenable to that.
|
||
// let h_ij = h(ij);
|
||
let wh_ij = wh[ij];
|
||
let mut mrec_ij = 0u8;
|
||
let mut ndon_ij = 0u8;
|
||
let neighbor_iter = |posi| {
|
||
let pos = uniform_idx_as_vec2(posi);
|
||
NEIGHBOR_DELTA
|
||
.iter()
|
||
.map(move |&(x, y)| Vec2::new(pos.x + x, pos.y + y))
|
||
.enumerate()
|
||
.filter(move |&(_, pos)| {
|
||
pos.x >= 0
|
||
&& pos.y >= 0
|
||
&& pos.x < WORLD_SIZE.x as i32
|
||
&& pos.y < WORLD_SIZE.y as i32
|
||
})
|
||
.map(move |(k, pos)| (k, vec2_as_uniform_idx(pos)))
|
||
};
|
||
|
||
for (k, ijk) in neighbor_iter(ij) {
|
||
let wh_ijk = wh[ijk];
|
||
// let h_ijk = h(ijk);
|
||
if
|
||
/*h_ij*/
|
||
wh_ij > wh_ijk {
|
||
// Set neighboring edge lower than this one as being downhill.
|
||
// NOTE: relying on at most 8 neighbors.
|
||
mrec_ij |= (1 << k);
|
||
} else if
|
||
/*h_ijk*/
|
||
wh_ijk > wh_ij {
|
||
// Avoiding ambiguous cases.
|
||
ndon_ij += 1;
|
||
}
|
||
}
|
||
// let vis_ij = mrec_ij.count_ones();
|
||
(mrec_ij, (ndon_ij, ndon_ij))
|
||
})
|
||
.unzip_into_vecs(&mut mrec, &mut don_vis);
|
||
|
||
let czero = <Compute as Zero>::zero();
|
||
let (wrec, stack) = rayon::join(
|
||
|| {
|
||
(0..nn)
|
||
.into_par_iter()
|
||
.map(|ij| {
|
||
let mut sumweight = czero;
|
||
let mut wrec = /*Computex8::splat(czero)*/[czero; 8];
|
||
let mut nrec = 0;
|
||
// let mut wrec: [Compute; 8] = [czero, czero, czero, czero, czero, czero, czero, czero];
|
||
for (k, ijk) in mrec_downhill(&mrec, ij) {
|
||
let lrec_ijk = ((uniform_idx_as_vec2(ijk) - uniform_idx_as_vec2(ij))
|
||
.map(|e| e as Compute)
|
||
* dxdy)
|
||
.magnitude();
|
||
let wrec_ijk = (wh[ij] - wh[ijk]).into() / lrec_ijk;
|
||
// let wrec_ijk = if ijk as isize == downhill[ij] { <Compute as One>::one() } else { <Compute as Zero>::zero() };
|
||
wrec[k] = wrec_ijk;
|
||
// wrec = wrec.replace(k, wrec_ijk);
|
||
sumweight += wrec_ijk;
|
||
nrec += 1;
|
||
}
|
||
// let (_, ndon_ij) = ndon[ij];
|
||
let slope = sumweight / (nrec as Compute).max(1.0);
|
||
let p_mfd_exp = 0.5 + 0.6 * slope;
|
||
// let p_mfd_exp = 10.0;
|
||
/* let ijr = downhill[ij];
|
||
if ijr < 0 {
|
||
if sumweight != <Compute as Zero>::zero() {
|
||
log::error!("Huh? ij={:?} [h={:?}, wh={:?}], downhill={:?}, sum={:?}, mrec={:?}, mwrec={:?}",
|
||
uniform_idx_as_vec2(ij), h(ij), wh[ij],
|
||
ijr,
|
||
sumweight, mrec[ij], wrec);
|
||
}
|
||
debug_assert_eq!(sumweight, <Compute as Zero>::zero());
|
||
} else {
|
||
if sumweight != <Compute as One>::one() {
|
||
let ijr = ijr as usize;
|
||
log::error!("Huh? ij={:?} [h={:?}, wh={:?}], downhill={:?} [h={:?}, wh={:?}], sum={:?}, mrec={:?}, mwrec={:?}",
|
||
uniform_idx_as_vec2(ij), h(ij), wh[ij],
|
||
uniform_idx_as_vec2(ijr), h(ijr), wh[ijr],
|
||
sumweight, mrec[ij], wrec);
|
||
}
|
||
debug_assert_eq!(sumweight, <Compute as One>::one());
|
||
} */
|
||
sumweight = czero;
|
||
for wrec_k in &mut wrec {
|
||
let wrec_ijk = wrec_k.powf(p_mfd_exp);
|
||
sumweight += wrec_ijk;
|
||
*wrec_k = wrec_ijk;
|
||
}
|
||
if sumweight > czero {
|
||
// wrec /= sumweight;
|
||
for wrec_k in &mut wrec {
|
||
*wrec_k /= sumweight;
|
||
}
|
||
}
|
||
wrec
|
||
})
|
||
.collect_into_vec(&mut wrec);
|
||
wrec
|
||
},
|
||
|| {
|
||
let mut stack = Vec::with_capacity(nn);
|
||
let mut parse = Vec::with_capacity(nn);
|
||
|
||
// we go through the nodes
|
||
for ij in 0..nn {
|
||
let (ndon_ij, _) = don_vis[ij];
|
||
// when we find a "summit" (ie a node that has no donors)
|
||
// we parse it (put it in a stack called parse)
|
||
if ndon_ij == 0 {
|
||
parse.push(ij);
|
||
}
|
||
// we go through the parsing stack
|
||
while let Some(ijn) = parse.pop() {
|
||
// we add the node to the stack
|
||
stack.push(ijn as u32);
|
||
for (_, ijr) in mrec_downhill(&mrec, ijn) {
|
||
let (_, ref mut vis_ijr) = don_vis[ijr];
|
||
if *vis_ijr >= 1 {
|
||
*vis_ijr -= 1;
|
||
if *vis_ijr == 0 {
|
||
parse.push(ijr);
|
||
}
|
||
}
|
||
}
|
||
}
|
||
}
|
||
|
||
assert_eq!(stack.len(), nn);
|
||
stack
|
||
},
|
||
);
|
||
|
||
(
|
||
mrec.into_boxed_slice(),
|
||
stack.into_boxed_slice(),
|
||
wrec.into_boxed_slice(),
|
||
)
|
||
}
|
||
|
||
/// Perform erosion n times.
|
||
pub fn do_erosion(
|
||
erosion_base: f32,
|
||
_max_uplift: f32,
|
||
n_steps: usize,
|
||
seed: &RandomField,
|
||
rock_strength_nz: &(impl NoiseFn<Point3<f64>> + Sync),
|
||
oldh: impl Fn(usize) -> f32 + Sync,
|
||
oldb: impl Fn(usize) -> f32 + Sync,
|
||
// olda: impl Fn(usize) -> f32 + Sync,
|
||
is_ocean: impl Fn(usize) -> bool + Sync,
|
||
uplift: impl Fn(usize) -> f64 + Sync,
|
||
n: impl Fn(usize) -> f32 + Sync,
|
||
theta: impl Fn(usize) -> f32 + Sync,
|
||
kf: impl Fn(usize) -> f64 + Sync,
|
||
kd: impl Fn(usize) -> f64 + Sync,
|
||
g: impl Fn(usize) -> f32 + Sync,
|
||
epsilon_0: impl Fn(usize) -> f32 + Sync,
|
||
alpha: impl Fn(usize) -> f32 + Sync,
|
||
) -> (Box<[Alt]>, Box<[Alt]> /*, Box<[Alt]>*/) {
|
||
log::debug!("Initializing erosion arrays...");
|
||
let oldh_ = (0..WORLD_SIZE.x * WORLD_SIZE.y)
|
||
.into_par_iter()
|
||
.map(|posi| oldh(posi) as Alt)
|
||
.collect::<Vec<_>>()
|
||
.into_boxed_slice();
|
||
// Topographic basement (The height of bedrock, not including sediment).
|
||
let mut b = (0..WORLD_SIZE.x * WORLD_SIZE.y)
|
||
.into_par_iter()
|
||
.map(|posi| oldb(posi) as Alt)
|
||
.collect::<Vec<_>>()
|
||
.into_boxed_slice();
|
||
/* // Alluvium (the total depth of alluvium above the topsoil).
|
||
let mut a = (0..WORLD_SIZE.x * WORLD_SIZE.y)
|
||
.into_par_iter()
|
||
.map(|posi| olda(posi) as Alt)
|
||
.collect::<Vec<_>>()
|
||
.into_boxed_slice(); */
|
||
// Stream power law slope exponent--link between channel slope and erosion rate.
|
||
let n = (0..WORLD_SIZE.x * WORLD_SIZE.y)
|
||
.into_par_iter()
|
||
.map(|posi| n(posi))
|
||
.collect::<Vec<_>>()
|
||
.into_boxed_slice();
|
||
// Stream power law concavity index (θ = m/n), turned into an exponent on drainage
|
||
// (which is a proxy for discharge according to Hack's Law).
|
||
let m = (0..WORLD_SIZE.x * WORLD_SIZE.y)
|
||
.into_par_iter()
|
||
.map(|posi| theta(posi) * n[posi])
|
||
.collect::<Vec<_>>()
|
||
.into_boxed_slice();
|
||
// Stream power law erodability constant for fluvial erosion (bedrock)
|
||
let kf = (0..WORLD_SIZE.x * WORLD_SIZE.y)
|
||
.into_par_iter()
|
||
.map(|posi| kf(posi))
|
||
.collect::<Vec<_>>()
|
||
.into_boxed_slice();
|
||
// Stream power law erodability constant for hillslope diffusion (bedrock)
|
||
let kd = (0..WORLD_SIZE.x * WORLD_SIZE.y)
|
||
.into_par_iter()
|
||
.map(|posi| kd(posi))
|
||
.collect::<Vec<_>>()
|
||
.into_boxed_slice();
|
||
// Deposition coefficient
|
||
let g = (0..WORLD_SIZE.x * WORLD_SIZE.y)
|
||
.into_par_iter()
|
||
.map(|posi| g(posi))
|
||
.collect::<Vec<_>>()
|
||
.into_boxed_slice();
|
||
let epsilon_0 = (0..WORLD_SIZE.x * WORLD_SIZE.y)
|
||
.into_par_iter()
|
||
.map(|posi| epsilon_0(posi))
|
||
.collect::<Vec<_>>()
|
||
.into_boxed_slice();
|
||
let alpha = (0..WORLD_SIZE.x * WORLD_SIZE.y)
|
||
.into_par_iter()
|
||
.map(|posi| alpha(posi))
|
||
.collect::<Vec<_>>()
|
||
.into_boxed_slice();
|
||
let mut wh = vec![0.0; WORLD_SIZE.x * WORLD_SIZE.y].into_boxed_slice();
|
||
// TODO: Don't do this, maybe?
|
||
// (To elaborate, maybe we should have varying uplift or compute it some other way).
|
||
let uplift = (0..oldh_.len())
|
||
.into_par_iter()
|
||
.map(|posi| uplift(posi) as f32)
|
||
.collect::<Vec<_>>()
|
||
.into_boxed_slice();
|
||
let sum_uplift = uplift
|
||
.into_par_iter()
|
||
.cloned()
|
||
.map(|e| e as f64)
|
||
.sum::<f64>();
|
||
log::debug!("Sum uplifts: {:?}", sum_uplift);
|
||
|
||
let max_uplift = uplift
|
||
.into_par_iter()
|
||
.cloned()
|
||
.max_by(|a, b| a.partial_cmp(&b).unwrap())
|
||
.unwrap();
|
||
let max_g = g
|
||
.into_par_iter()
|
||
.cloned()
|
||
.max_by(|a, b| a.partial_cmp(&b).unwrap())
|
||
.unwrap();
|
||
log::debug!("Max uplift: {:?}", max_uplift);
|
||
log::debug!("Max g: {:?}", max_g);
|
||
// Height of terrain, including sediment.
|
||
let mut h = oldh_;
|
||
// 0.01 / 2e-5 = 500
|
||
// Bedrock transport coefficients (diffusivity) in m^2 / year. For now, we set them all to be equal
|
||
// on land, but in theory we probably want to at least differentiate between soil, bedrock, and
|
||
// sediment.
|
||
let height_scale = 1.0; // 1.0 / CONFIG.mountain_scale as f64;
|
||
let mmaxh = CONFIG.mountain_scale as f64 * height_scale;
|
||
let dt = max_uplift as f64 / height_scale /* * CONFIG.mountain_scale as f64*/ / 5.010e-4;
|
||
let k_fb = /*(erosion_base as f64 + 2.244 / mmaxh as f64 * /*10.0*//*5.0*//*9.0*//*7.5*//*5.0*//*2.5*//*1.5*/4.0/*1.0*//*3.75*/ * max_uplift as f64) / dt;*/
|
||
2.0e-5 * dt;
|
||
let kd_bedrock =
|
||
/*1e-2*//*0.25e-2*/1e-2 / 1.0 * height_scale * height_scale/* / (CONFIG.mountain_scale as f64 * CONFIG.mountain_scale as f64) */
|
||
/* * k_fb / 2e-5 */;
|
||
let kdsed =
|
||
/*1.5e-2*//*1e-4*//*1.25e-2*//*1.5e-2 */1.5e-2/ 1.0 * height_scale * height_scale/* / (CONFIG.mountain_scale as f64 * CONFIG.mountain_scale as f64) */
|
||
/* * k_fb / 2e-5 */;
|
||
// let kd = |posi: usize| kd_bedrock; // if is_ocean(posi) { /*0.0*/kd_bedrock } else { kd_bedrock };
|
||
let n = |posi: usize| n[posi];
|
||
let m = |posi: usize| m[posi];
|
||
let kd = |posi: usize| kd[posi]; // if is_ocean(posi) { /*0.0*/kd_bedrock } else { kd_bedrock };
|
||
let kf = |posi: usize| kf[posi];
|
||
let g = |posi: usize| g[posi];
|
||
let epsilon_0 = |posi: usize| epsilon_0[posi];
|
||
let alpha = |posi: usize| alpha[posi];
|
||
// Hillslope diffusion coefficient for sediment.
|
||
let mut is_done = bitbox![0; WORLD_SIZE.x * WORLD_SIZE.y];
|
||
for i in 0..n_steps {
|
||
log::debug!("Erosion iteration #{:?}", i);
|
||
erode(
|
||
&mut h,
|
||
&mut b,
|
||
// &mut a,
|
||
&mut wh,
|
||
&mut is_done,
|
||
// The value to use to indicate that erosion is complete on a chunk. Should toggle
|
||
// once per iteration, to avoid having to reset the bits, and start at true, since
|
||
// we initialize to 0 (false).
|
||
i & 1 == 0,
|
||
erosion_base,
|
||
max_uplift,
|
||
max_g,
|
||
// -1.0,
|
||
kdsed,
|
||
seed,
|
||
rock_strength_nz,
|
||
|posi| uplift[posi],
|
||
n,
|
||
m,
|
||
kf,
|
||
kd,
|
||
g,
|
||
epsilon_0,
|
||
alpha,
|
||
|posi| is_ocean(posi),
|
||
);
|
||
}
|
||
(h, b /*, a*/)
|
||
}
|