veloren/world/src/layer/tree.rs
2021-03-07 14:25:00 +00:00

432 lines
17 KiB
Rust

use crate::{
all::ForestKind,
block::block_from_structure,
column::ColumnGen,
util::{RandomPerm, Sampler, UnitChooser},
Canvas, CONFIG,
};
use common::{
assets::AssetHandle,
terrain::{Block, BlockKind, structure::{Structure, StructureBlock, StructuresGroup}},
vol::ReadVol,
};
use hashbrown::HashMap;
use lazy_static::lazy_static;
use std::{f32, ops::Range};
use vek::*;
use rand::prelude::*;
lazy_static! {
static ref OAKS: AssetHandle<StructuresGroup> = Structure::load_group("oaks");
static ref OAK_STUMPS: AssetHandle<StructuresGroup> = Structure::load_group("oak_stumps");
static ref PINES: AssetHandle<StructuresGroup> = Structure::load_group("pines");
static ref PALMS: AssetHandle<StructuresGroup> = Structure::load_group("palms");
static ref ACACIAS: AssetHandle<StructuresGroup> = Structure::load_group("acacias");
static ref BAOBABS: AssetHandle<StructuresGroup> = Structure::load_group("baobabs");
static ref FRUIT_TREES: AssetHandle<StructuresGroup> = Structure::load_group("fruit_trees");
static ref BIRCHES: AssetHandle<StructuresGroup> = Structure::load_group("birch");
static ref MANGROVE_TREES: AssetHandle<StructuresGroup> =
Structure::load_group("mangrove_trees");
static ref QUIRKY: AssetHandle<StructuresGroup> = Structure::load_group("quirky");
static ref QUIRKY_DRY: AssetHandle<StructuresGroup> = Structure::load_group("quirky_dry");
static ref SWAMP_TREES: AssetHandle<StructuresGroup> = Structure::load_group("swamp_trees");
}
static MODEL_RAND: RandomPerm = RandomPerm::new(0xDB21C052);
static UNIT_CHOOSER: UnitChooser = UnitChooser::new(0x700F4EC7);
static QUIRKY_RAND: RandomPerm = RandomPerm::new(0xA634460F);
#[allow(clippy::if_same_then_else)]
pub fn apply_trees_to(canvas: &mut Canvas) {
// TODO: Get rid of this
enum TreeModel {
Structure(Structure),
Procedural(ProceduralTree, StructureBlock),
}
struct Tree {
pos: Vec3<i32>,
model: TreeModel,
seed: u32,
units: (Vec2<i32>, Vec2<i32>),
}
let mut tree_cache = HashMap::new();
let info = canvas.info();
canvas.foreach_col(|canvas, wpos2d, col| {
let trees = info.land().get_near_trees(wpos2d);
for (tree_wpos, seed) in trees {
let tree = if let Some(tree) = tree_cache.entry(tree_wpos).or_insert_with(|| {
let col = ColumnGen::new(info.land()).get((tree_wpos, info.index()))?;
let is_quirky = QUIRKY_RAND.chance(seed, 1.0 / 500.0);
// Ensure that it's valid to place a *thing* here
if col.alt < col.water_level
|| col.spawn_rate < 0.9
|| col.water_dist.map(|d| d < 8.0).unwrap_or(false)
|| col.path.map(|(d, _, _, _)| d < 12.0).unwrap_or(false)
{
return None;
}
// Ensure that it's valid to place a tree here
if !is_quirky && ((seed.wrapping_mul(13)) & 0xFF) as f32 / 256.0 > col.tree_density
{
return None;
}
Some(Tree {
pos: Vec3::new(tree_wpos.x, tree_wpos.y, col.alt as i32),
model: 'model: {
let models: AssetHandle<_> = if is_quirky {
if col.temp > CONFIG.desert_temp {
*QUIRKY_DRY
} else {
*QUIRKY
}
} else {
match col.forest_kind {
ForestKind::Oak if QUIRKY_RAND.chance(seed + 1, 1.0 / 16.0) => {
*OAK_STUMPS
},
ForestKind::Oak if QUIRKY_RAND.chance(seed + 2, 1.0 / 20.0) => {
*FRUIT_TREES
},
ForestKind::Palm => *PALMS,
ForestKind::Acacia => *ACACIAS,
ForestKind::Baobab => *BAOBABS,
// ForestKind::Oak => *OAKS,
ForestKind::Oak => break 'model TreeModel::Procedural(
ProceduralTree::generate(TreeConfig::OAK, seed),
StructureBlock::TemperateLeaves,
),
//ForestKind::Pine => *PINES,
ForestKind::Pine => break 'model TreeModel::Procedural(
ProceduralTree::generate(TreeConfig::PINE, seed),
StructureBlock::PineLeaves,
),
ForestKind::Birch => *BIRCHES,
ForestKind::Mangrove => *MANGROVE_TREES,
ForestKind::Swamp => *SWAMP_TREES,
}
};
let models = models.read();
TreeModel::Structure(models[(MODEL_RAND.get(seed.wrapping_mul(17)) / 13) as usize % models.len()]
.clone())
},
seed,
units: UNIT_CHOOSER.get(seed),
})
}) {
tree
} else {
continue;
};
let bounds = match &tree.model {
TreeModel::Structure(s) => s.get_bounds(),
TreeModel::Procedural(t, _) => t.get_bounds().map(|e| e as i32),
};
let rpos2d = (wpos2d - tree.pos.xy())
.map2(Vec2::new(tree.units.0, tree.units.1), |p, unit| {
unit * p
})
.sum();
if !Aabr::from(bounds).contains_point(rpos2d) {
// Skip this column
continue;
}
let mut is_top = true;
let mut is_leaf_top = true;
for z in (bounds.min.z..bounds.max.z).rev() {
let wpos = Vec3::new(wpos2d.x, wpos2d.y, tree.pos.z + z);
let model_pos = Vec3::from(
(wpos - tree.pos)
.xy()
.map2(Vec2::new(tree.units.0, tree.units.1), |rpos, unit| {
unit * rpos
})
.sum(),
) + Vec3::unit_z() * (wpos.z - tree.pos.z);
block_from_structure(
info.index(),
if let Some(block) = match &tree.model {
TreeModel::Structure(s) => s.get(model_pos).ok().copied(),
TreeModel::Procedural(t, leaf_block) => Some(match t.is_branch_or_leaves_at(model_pos.map(|e| e as f32 + 0.5)) {
(true, _) => StructureBlock::Normal(Rgb::new(60, 30, 0)),
(_, true) => *leaf_block,
(_, _) => StructureBlock::None,
}),
} {
block
} else {
break
},
wpos,
tree.pos.xy(),
tree.seed,
col,
Block::air,
)
.map(|block| {
// Add a snow covering to the block above under certain circumstances
if col.snow_cover
&& ((block.kind() == BlockKind::Leaves && is_leaf_top)
|| (is_top && block.is_filled()))
{
canvas.set(
wpos + Vec3::unit_z(),
Block::new(BlockKind::Snow, Rgb::new(210, 210, 255)),
);
}
canvas.set(wpos, block);
is_leaf_top = false;
is_top = false;
})
.unwrap_or_else(|| {
is_leaf_top = true;
});
}
}
});
}
/// A type that specifies the generation properties of a tree.
pub struct TreeConfig {
/// Length of trunk, also scales other branches.
pub trunk_len: f32,
/// Radius of trunk, also scales other branches.
pub trunk_radius: f32,
// The scale that child branch lengths should be compared to their parents.
pub branch_child_len: f32,
// The scale that child branch radii should be compared to their parents.
pub branch_child_radius: f32,
/// The range of radii that leaf-emitting branches might have.
pub leaf_radius: Range<f32>,
/// 0 - 1 (0 = chaotic, 1 = straight).
pub straightness: f32,
/// Maximum number of branch layers (not including trunk).
pub max_depth: usize,
/// The number of branches that form from each branch.
pub splits: usize,
/// The range of proportions along a branch at which a split into another branch might occur.
/// This value is clamped between 0 and 1, but a wider range may bias the results towards branch ends.
pub split_range: Range<f32>,
/// The bias applied to the length of branches based on the proportion along their parent that they eminate from.
/// -1.0 = negative bias (branches at ends are longer, branches at the start are shorter)
/// 0.0 = no bias (branches do not change their length with regard to parent branch proportion)
/// 1.0 = positive bias (branches at ends are shorter, branches at the start are longer)
pub branch_len_bias: f32,
}
impl TreeConfig {
pub const OAK: Self = Self {
trunk_len: 12.0,
trunk_radius: 3.0,
branch_child_len: 0.8,
branch_child_radius: 0.6,
leaf_radius: 3.0..5.0,
straightness: 0.5,
max_depth: 4,
splits: 3,
split_range: 0.5..1.5,
branch_len_bias: 0.0,
};
pub const PINE: Self = Self {
trunk_len: 32.0,
trunk_radius: 1.5,
branch_child_len: 0.3,
branch_child_radius: 0.0,
leaf_radius: 1.0..1.25,
straightness: 0.0,
max_depth: 1,
splits: 128,
split_range: 0.2..1.1,
branch_len_bias: 0.8,
};
}
// TODO: Rename this to `Tree` when the name conflict is gone
pub struct ProceduralTree {
branches: Vec<Branch>,
trunk_idx: usize,
}
impl ProceduralTree {
/// Generate a new tree using the given configuration and seed.
pub fn generate(config: TreeConfig, seed: u32) -> Self {
let mut rng = RandomPerm::new(seed);
let mut this = Self {
branches: Vec::new(),
trunk_idx: 0, // Gets replaced later
};
// Add the tree trunk (and sub-branches) recursively
let (trunk_idx, _) = this.add_branch(
&config,
// Our trunk starts at the origin...
Vec3::zero(),
// ...and has a roughly upward direction
Vec3::new(rng.gen_range(-1.0, 1.0), rng.gen_range(-1.0, 1.0), 5.0).normalized(),
config.trunk_len,
config.trunk_radius,
0,
None,
&mut rng,
);
this.trunk_idx = trunk_idx;
this
}
// Recursively add a branch (with sub-branches) to the tree's branch graph, returning the index and AABB of the
// branch. This AABB gets propagated down to the parent and is used later during sampling to cull the branches to
// be sampled.
fn add_branch(
&mut self,
config: &TreeConfig,
start: Vec3<f32>,
dir: Vec3<f32>,
branch_len: f32,
branch_radius: f32,
depth: usize,
sibling_idx: Option<usize>,
rng: &mut impl Rng,
) -> (usize, Aabb<f32>) {
let end = start + dir * branch_len;
let line = LineSegment3 { start, end };
let wood_radius = branch_radius;
let leaf_radius = if depth == config.max_depth {
rng.gen_range(config.leaf_radius.start, config.leaf_radius.end)
} else {
0.0
};
// The AABB that covers this branch, along with wood and leaves that eminate from it
let mut aabb = Aabb {
min: Vec3::partial_min(start, end) - wood_radius.max(leaf_radius),
max: Vec3::partial_max(start, end) + wood_radius.max(leaf_radius),
};
let mut child_idx = None;
// Don't add child branches if we're already enough layers into the tree
if depth < config.max_depth {
for _ in 0..config.splits {
// Choose a point close to the branch to act as the target direction for the branch to grow in
let split_factor = rng.gen_range(config.split_range.start, config.split_range.end).clamped(0.0, 1.0);
let tgt = Lerp::lerp(
start,
end,
split_factor,
) + Vec3::<f32>::zero().map(|_| rng.gen_range(-1.0, 1.0));
// Start the branch at the closest point to the target
let branch_start = line.projected_point(tgt);
// Now, interpolate between the target direction and the parent branch's direction to find a direction
let branch_dir = Lerp::lerp(tgt - branch_start, dir, config.straightness).normalized();
let (branch_idx, branch_aabb) = self.add_branch(
config,
branch_start,
branch_dir,
branch_len
* config.branch_child_len
* (1.0 - (split_factor - 0.5) * 2.0 * config.branch_len_bias.clamped(-1.0, 1.0)),
branch_radius * config.branch_child_radius,
depth + 1,
child_idx,
rng,
);
child_idx = Some(branch_idx);
// Parent branches AABBs include the AABBs of child branches to allow for culling during sampling
aabb.expand_to_contain(branch_aabb);
}
}
let idx = self.branches.len(); // Compute the index that this branch is going to have
self.branches.push(Branch {
line,
wood_radius,
leaf_radius,
aabb,
sibling_idx,
child_idx,
});
(idx, aabb)
}
/// Get the bounding box that covers the tree (all branches and leaves)
pub fn get_bounds(&self) -> Aabb<f32> {
self.branches[self.trunk_idx].aabb
}
// Recursively search for branches or leaves by walking the tree's branch graph.
fn is_branch_or_leaves_at_inner(&self, pos: Vec3<f32>, branch_idx: usize) -> (bool, bool) {
let branch = &self.branches[branch_idx];
// Always probe the sibling branch, since our AABB doesn't include its bounds (it's not one of our children)
let branch_or_leaves = branch.sibling_idx
.map(|idx| Vec2::from(self.is_branch_or_leaves_at_inner(pos, idx)))
.unwrap_or_default();
// Only continue probing this sub-graph of the tree if the sample position falls within its AABB
if branch.aabb.contains_point(pos) {
(branch_or_leaves
// Probe this branch
| Vec2::from(branch.is_branch_or_leaves_at(pos))
// Probe the children of this branch
| branch.child_idx
.map(|idx| Vec2::from(self.is_branch_or_leaves_at_inner(pos, idx)))
.unwrap_or_default())
.into_tuple()
} else {
branch_or_leaves.into_tuple()
}
}
/// Determine whether there are either branches or leaves at the given position in the tree.
#[inline(always)]
pub fn is_branch_or_leaves_at(&self, pos: Vec3<f32>) -> (bool, bool) {
self.is_branch_or_leaves_at_inner(pos, self.trunk_idx)
}
}
// Branches are arranged in a graph shape. Each branch points to both its first child (if any) and also to the next
// branch in the list of child branches associated with the parent. This means that the entire tree is laid out in a
// walkable graph where each branch refers only to two other branches. As a result, walking the tree is simply a case
// of performing double recursion.
struct Branch {
line: LineSegment3<f32>,
wood_radius: f32,
leaf_radius: f32,
aabb: Aabb<f32>,
sibling_idx: Option<usize>,
child_idx: Option<usize>,
}
impl Branch {
/// Determine whether there are either branches or leaves at the given position in the branch.
pub fn is_branch_or_leaves_at(&self, pos: Vec3<f32>) -> (bool, bool) {
// fn finvsqrt(x: f32) -> f32 {
// let y = f32::from_bits(0x5f375a86 - (x.to_bits() >> 1));
// y * (1.5 - ( x * 0.5 * y * y ))
// }
let p_d2 = self.line.projected_point(pos).distance_squared(pos);
if p_d2 < self.wood_radius.powi(2) {
(true, false)
} else {
(false, p_d2 < self.leaf_radius.powi(2))
}
}
}