veloren/common/systems/src/phys.rs

1587 lines
66 KiB
Rust

use common::{
comp::{
body::ship::figuredata::{VoxelCollider, VOXEL_COLLIDER_MANIFEST},
BeamSegment, Body, CharacterState, Collider, Density, Fluid, Mass, Mounting, Ori,
PhysicsState, Pos, PosVelDefer, PreviousPhysCache, Projectile, Scale, Shockwave, Sticky,
Vel,
},
consts::{AIR_DENSITY, FRIC_GROUND, GRAVITY},
event::{EventBus, ServerEvent},
outcome::Outcome,
resources::DeltaTime,
terrain::{Block, TerrainGrid},
uid::Uid,
util::{Projection, SpatialGrid},
vol::{BaseVol, ReadVol},
};
use common_base::{prof_span, span};
use common_ecs::{Job, Origin, ParMode, Phase, PhysicsMetrics, System};
use rayon::iter::ParallelIterator;
use specs::{
shred::{ResourceId, World},
Entities, Entity, Join, ParJoin, Read, ReadExpect, ReadStorage, SystemData, Write, WriteExpect,
WriteStorage,
};
use std::ops::Range;
use vek::*;
/// The density of the fluid as a function of submersion ratio in given fluid
/// where it is assumed that any unsubmersed part is is air.
// TODO: Better suited partial submersion curve?
fn fluid_density(height: f32, fluid: &Fluid) -> Density {
// If depth is less than our height (partial submersion), remove
// fluid density based on the ratio of displacement to full volume.
let immersion = fluid
.depth()
.map_or(1.0, |depth| (depth / height).clamp(0.0, 1.0));
Density(fluid.density().0 * immersion + AIR_DENSITY * (1.0 - immersion))
}
#[allow(clippy::too_many_arguments)]
fn integrate_forces(
dt: &DeltaTime,
mut vel: Vel,
body: &Body,
density: &Density,
mass: &Mass,
character_state: Option<&CharacterState>,
fluid: &Fluid,
gravity: f32,
) -> Vel {
let dim = body.dimensions();
let height = dim.z;
let rel_flow = fluid.relative_flow(&vel);
let fluid_density = fluid_density(height, fluid);
debug_assert!(mass.0 > 0.0);
debug_assert!(density.0 > 0.0);
// Aerodynamic/hydrodynamic forces
if !rel_flow.0.is_approx_zero() {
debug_assert!(!rel_flow.0.map(|a| a.is_nan()).reduce_or());
let impulse = dt.0 * body.aerodynamic_forces(&rel_flow, fluid_density.0, character_state);
debug_assert!(!impulse.map(|a| a.is_nan()).reduce_or());
if !impulse.is_approx_zero() {
let new_v = vel.0 + impulse / mass.0;
// If the new velocity is in the opposite direction, it's because the forces
// involved are too high for the current tick to handle. We deal with this by
// removing the component of our velocity vector along the direction of force.
// This way we can only ever lose velocity and will never experience a reverse
// in direction from events such as falling into water at high velocities.
if new_v.dot(vel.0) < 0.0 {
// Multiply by a factor to prevent full stop, as this can cause things to get
// stuck in high-density medium
vel.0 -= vel.0.projected(&impulse) * 0.7;
} else {
vel.0 = new_v;
}
};
debug_assert!(!vel.0.map(|a| a.is_nan()).reduce_or());
};
// Hydrostatic/aerostatic forces
// modify gravity to account for the effective density as a result of buoyancy
let down_force = dt.0 * gravity * (density.0 - fluid_density.0) / density.0;
vel.0.z -= down_force;
vel
}
fn calc_z_limit(
char_state_maybe: Option<&CharacterState>,
collider: Option<&Collider>,
) -> (f32, f32) {
let modifier = if char_state_maybe.map_or(false, |c_s| c_s.is_dodge()) {
0.5
} else {
1.0
};
collider
.map(|c| c.get_z_limits(modifier))
.unwrap_or((-0.5 * modifier, 0.5 * modifier))
}
/// This system applies forces and calculates new positions and velocities.
#[derive(Default)]
pub struct Sys;
#[derive(SystemData)]
pub struct PhysicsRead<'a> {
entities: Entities<'a>,
uids: ReadStorage<'a, Uid>,
terrain: ReadExpect<'a, TerrainGrid>,
dt: Read<'a, DeltaTime>,
event_bus: Read<'a, EventBus<ServerEvent>>,
scales: ReadStorage<'a, Scale>,
stickies: ReadStorage<'a, Sticky>,
masses: ReadStorage<'a, Mass>,
colliders: ReadStorage<'a, Collider>,
mountings: ReadStorage<'a, Mounting>,
projectiles: ReadStorage<'a, Projectile>,
beams: ReadStorage<'a, BeamSegment>,
shockwaves: ReadStorage<'a, Shockwave>,
char_states: ReadStorage<'a, CharacterState>,
bodies: ReadStorage<'a, Body>,
character_states: ReadStorage<'a, CharacterState>,
densities: ReadStorage<'a, Density>,
}
#[derive(SystemData)]
pub struct PhysicsWrite<'a> {
physics_metrics: WriteExpect<'a, PhysicsMetrics>,
cached_spatial_grid: Write<'a, common::CachedSpatialGrid>,
physics_states: WriteStorage<'a, PhysicsState>,
positions: WriteStorage<'a, Pos>,
velocities: WriteStorage<'a, Vel>,
pos_vel_defers: WriteStorage<'a, PosVelDefer>,
orientations: WriteStorage<'a, Ori>,
previous_phys_cache: WriteStorage<'a, PreviousPhysCache>,
outcomes: Write<'a, Vec<Outcome>>,
}
#[derive(SystemData)]
pub struct PhysicsData<'a> {
read: PhysicsRead<'a>,
write: PhysicsWrite<'a>,
}
impl<'a> PhysicsData<'a> {
/// Add/reset physics state components
fn reset(&mut self) {
span!(_guard, "Add/reset physics state components");
for (entity, _, _, _, _) in (
&self.read.entities,
&self.read.colliders,
&self.write.positions,
&self.write.velocities,
&self.write.orientations,
)
.join()
{
let _ = self
.write
.physics_states
.entry(entity)
.map(|e| e.or_insert_with(Default::default));
}
}
fn maintain_pushback_cache(&mut self) {
span!(_guard, "Maintain pushback cache");
// Add PreviousPhysCache for all relevant entities
for entity in (
&self.read.entities,
&self.write.velocities,
&self.write.positions,
!&self.write.previous_phys_cache,
!&self.read.mountings,
!&self.read.beams,
!&self.read.shockwaves,
)
.join()
.map(|(e, _, _, _, _, _, _)| e)
.collect::<Vec<_>>()
{
let _ = self
.write
.previous_phys_cache
.insert(entity, PreviousPhysCache {
velocity_dt: Vec3::zero(),
center: Vec3::zero(),
collision_boundary: 0.0,
scale: 0.0,
scaled_radius: 0.0,
ori: Quaternion::identity(),
});
}
// Update PreviousPhysCache
for (_, vel, position, mut phys_cache, collider, scale, cs, _, _, _) in (
&self.read.entities,
&self.write.velocities,
&self.write.positions,
&mut self.write.previous_phys_cache,
self.read.colliders.maybe(),
self.read.scales.maybe(),
self.read.char_states.maybe(),
!&self.read.mountings,
!&self.read.beams,
!&self.read.shockwaves,
)
.join()
{
let scale = scale.map(|s| s.0).unwrap_or(1.0);
let z_limits = calc_z_limit(cs, collider);
let z_limits = (z_limits.0 * scale, z_limits.1 * scale);
let half_height = (z_limits.1 - z_limits.0) / 2.0;
phys_cache.velocity_dt = vel.0 * self.read.dt.0;
let entity_center = position.0 + Vec3::new(0.0, z_limits.0 + half_height, 0.0);
let flat_radius = collider.map(|c| c.get_radius()).unwrap_or(0.5) * scale;
let radius = (flat_radius.powi(2) + half_height.powi(2)).sqrt();
// Move center to the middle between OLD and OLD+VEL_DT so that we can reduce
// the collision_boundary
phys_cache.center = entity_center + phys_cache.velocity_dt / 2.0;
phys_cache.collision_boundary = radius + (phys_cache.velocity_dt / 2.0).magnitude();
phys_cache.scale = scale;
phys_cache.scaled_radius = flat_radius;
}
}
fn construct_spatial_grid(&mut self) -> SpatialGrid {
span!(_guard, "Construct spatial grid");
let PhysicsData {
ref read,
ref write,
} = self;
// NOTE: i32 places certain constraints on how far out collision works
// NOTE: uses the radius of the entity and their current position rather than
// the radius of their bounding sphere for the current frame of movement
// because the nonmoving entity is what is collided against in the inner
// loop of the pushback collision code
// TODO: maintain frame to frame? (requires handling deletion)
// TODO: if not maintaining frame to frame consider counting entities to
// preallocate?
// TODO: assess parallelizing (overhead might dominate here? would need to merge
// the vecs in each hashmap)
let lg2_cell_size = 5;
let lg2_large_cell_size = 6;
let radius_cutoff = 8;
let mut spatial_grid = SpatialGrid::new(lg2_cell_size, lg2_large_cell_size, radius_cutoff);
for (entity, pos, phys_cache, _, _, _, _, _) in (
&read.entities,
&write.positions,
&write.previous_phys_cache,
write.velocities.mask(),
!&read.projectiles, // Not needed because they are skipped in the inner loop below
!&read.mountings,
!&read.beams,
!&read.shockwaves,
)
.join()
{
// Note: to not get too fine grained we use a 2D grid for now
let radius_2d = phys_cache.scaled_radius.ceil() as u32;
let pos_2d = pos.0.xy().map(|e| e as i32);
const POS_TRUNCATION_ERROR: u32 = 1;
spatial_grid.insert(pos_2d, radius_2d + POS_TRUNCATION_ERROR, entity);
}
spatial_grid
}
#[allow(clippy::nonminimal_bool)]
fn apply_pushback(&mut self, job: &mut Job<Sys>, spatial_grid: &SpatialGrid) {
span!(_guard, "Apply pushback");
job.cpu_stats.measure(ParMode::Rayon);
let PhysicsData {
ref read,
ref mut write,
} = self;
let (positions, previous_phys_cache) = (&write.positions, &write.previous_phys_cache);
let metrics = (
&read.entities,
positions,
&mut write.velocities,
previous_phys_cache,
&read.masses,
read.colliders.maybe(),
!&read.mountings,
read.stickies.maybe(),
&mut write.physics_states,
// TODO: if we need to avoid collisions for other things consider moving whether it
// should interact into the collider component or into a separate component
read.projectiles.maybe(),
read.char_states.maybe(),
)
.par_join()
.map(|(e, p, v, vd, m, c, _, sticky, ph, pr, c_s)| {
(e, p, v, vd, m, c, sticky, ph, pr, c_s)
})
.map_init(
|| {
prof_span!(guard, "physics e<>e rayon job");
guard
},
|_guard,
(
entity,
pos,
vel,
previous_cache,
mass,
collider,
sticky,
physics,
projectile,
char_state_maybe,
)| {
let is_sticky = sticky.is_some();
let is_mid_air = physics.on_wall.is_none() && physics.on_ground;
let mut entity_entity_collision_checks = 0;
let mut entity_entity_collisions = 0;
// TODO: quick fix for bad performance at extrememly high velocities
// use oriented rectangles at some threshold of displacement/radius
// to query the spatial grid and limit max displacement per tick somehow
if previous_cache.collision_boundary > 128.0 {
return PhysicsMetrics {
entity_entity_collision_checks,
entity_entity_collisions,
};
}
let z_limits = calc_z_limit(char_state_maybe, collider);
// Resets touch_entities in physics
physics.touch_entities.clear();
let is_projectile = projectile.is_some();
let mut vel_delta = Vec3::zero();
let query_center = previous_cache.center.xy();
let query_radius = previous_cache.collision_boundary;
spatial_grid
.in_circle_aabr(query_center, query_radius)
.filter_map(|entity| {
read.uids
.get(entity)
.and_then(|l| positions.get(entity).map(|r| (l, r)))
.and_then(|l| previous_phys_cache.get(entity).map(|r| (l, r)))
.and_then(|l| read.masses.get(entity).map(|r| (l, r)))
.map(|(((uid, pos), previous_cache), mass)| {
(
entity,
uid,
pos,
previous_cache,
mass,
read.colliders.get(entity),
read.char_states.get(entity),
)
})
})
.for_each(
|(
entity_other,
other,
pos_other,
previous_cache_other,
mass_other,
collider_other,
char_state_other_maybe,
)| {
let collision_boundary = previous_cache.collision_boundary
+ previous_cache_other.collision_boundary;
if previous_cache
.center
.distance_squared(previous_cache_other.center)
> collision_boundary.powi(2)
|| entity == entity_other
{
return;
}
let collision_dist = previous_cache.scaled_radius
+ previous_cache_other.scaled_radius;
let z_limits_other =
calc_z_limit(char_state_other_maybe, collider_other);
entity_entity_collision_checks += 1;
const MIN_COLLISION_DIST: f32 = 0.3;
let increments = ((previous_cache.velocity_dt
- previous_cache_other.velocity_dt)
.magnitude()
/ MIN_COLLISION_DIST)
.max(1.0)
.ceil()
as usize;
let step_delta = 1.0 / increments as f32;
let mut collided = false;
for i in 0..increments {
let factor = i as f32 * step_delta;
let pos = pos.0 + previous_cache.velocity_dt * factor;
let pos_other =
pos_other.0 + previous_cache_other.velocity_dt * factor;
let diff = pos.xy() - pos_other.xy();
if diff.magnitude_squared() <= collision_dist.powi(2)
&& pos.z + z_limits.1 * previous_cache.scale
>= pos_other.z
+ z_limits_other.0 * previous_cache_other.scale
&& pos.z + z_limits.0 * previous_cache.scale
<= pos_other.z
+ z_limits_other.1 * previous_cache_other.scale
{
if !collided {
physics.touch_entities.insert(*other);
entity_entity_collisions += 1;
}
// Don't apply repulsive force to projectiles or if
// we're
// colliding
// with a terrain-like entity, or if we are a
// terrain-like
// entity
//
// Don't apply force when entity is a sticky which is on the
// ground (or on the wall)
if !(is_sticky && !is_mid_air)
&& diff.magnitude_squared() > 0.0
&& !is_projectile
&& !matches!(
collider_other,
Some(Collider::Voxel { .. })
)
&& !matches!(collider, Some(Collider::Voxel { .. }))
{
let force = 400.0
* (collision_dist - diff.magnitude())
* mass_other.0
/ (mass.0 + mass_other.0);
vel_delta +=
Vec3::from(diff.normalized()) * force * step_delta;
}
collided = true;
}
}
},
);
// Change velocity
vel.0 += vel_delta * read.dt.0;
// Metrics
PhysicsMetrics {
entity_entity_collision_checks,
entity_entity_collisions,
}
},
)
.reduce(PhysicsMetrics::default, |old, new| PhysicsMetrics {
entity_entity_collision_checks: old.entity_entity_collision_checks
+ new.entity_entity_collision_checks,
entity_entity_collisions: old.entity_entity_collisions
+ new.entity_entity_collisions,
});
write.physics_metrics.entity_entity_collision_checks =
metrics.entity_entity_collision_checks;
write.physics_metrics.entity_entity_collisions = metrics.entity_entity_collisions;
}
fn construct_voxel_collider_spatial_grid(&mut self) -> SpatialGrid {
span!(_guard, "Construct voxel collider spatial grid");
let PhysicsData {
ref read,
ref write,
} = self;
// NOTE: i32 places certain constraints on how far out collision works
// NOTE: uses the radius of the entity and their current position rather than
// the radius of their bounding sphere for the current frame of movement
// because the nonmoving entity is what is collided against in the inner
// loop of the pushback collision code
// TODO: optimize these parameters (especially radius cutoff)
let lg2_cell_size = 7; // 128
let lg2_large_cell_size = 8; // 256
let radius_cutoff = 64;
let mut spatial_grid = SpatialGrid::new(lg2_cell_size, lg2_large_cell_size, radius_cutoff);
// TODO: give voxel colliders their own component type
for (entity, pos, collider, ori) in (
&read.entities,
&write.positions,
&read.colliders,
&write.orientations,
)
.join()
{
let voxel_id = match collider {
Collider::Voxel { id } => id,
_ => continue,
};
if let Some(voxel_collider) = VOXEL_COLLIDER_MANIFEST.read().colliders.get(&*voxel_id) {
let sphere = voxel_collider_bounding_sphere(voxel_collider, pos, ori);
let radius = sphere.radius.ceil() as u32;
let pos_2d = sphere.center.xy().map(|e| e as i32);
const POS_TRUNCATION_ERROR: u32 = 1;
spatial_grid.insert(pos_2d, radius + POS_TRUNCATION_ERROR, entity);
}
}
spatial_grid
}
fn handle_movement_and_terrain(
&mut self,
job: &mut Job<Sys>,
voxel_collider_spatial_grid: &SpatialGrid,
) {
let PhysicsData {
ref read,
ref mut write,
} = self;
prof_span!(guard, "insert PosVelDefer");
// NOTE: keep in sync with join below
(
&read.entities,
read.colliders.mask(),
&write.positions,
&write.velocities,
write.orientations.mask(),
write.physics_states.mask(),
!&write.pos_vel_defers, // This is the one we are adding
write.previous_phys_cache.mask(),
!&read.mountings,
)
.join()
.map(|t| (t.0, *t.2, *t.3))
.collect::<Vec<_>>()
.into_iter()
.for_each(|(entity, pos, vel)| {
let _ = write.pos_vel_defers.insert(entity, PosVelDefer {
pos: Some(pos),
vel: Some(vel),
});
});
drop(guard);
// Apply movement inputs
span!(guard, "Apply movement and terrain collision");
let (positions, velocities, previous_phys_cache, orientations) = (
&write.positions,
&mut write.velocities,
&write.previous_phys_cache,
&write.orientations,
);
// First pass: update velocity using air resistance and gravity for each entity.
// We do this in a first pass because it helps keep things more stable for
// entities that are anchored to other entities (such as airships).
(
positions,
velocities,
read.stickies.maybe(),
&read.bodies,
read.character_states.maybe(),
&write.physics_states,
&read.masses,
&read.densities,
!&read.mountings,
)
.par_join()
.for_each_init(
|| {
prof_span!(guard, "velocity update rayon job");
guard
},
|_guard,
(
pos,
vel,
sticky,
body,
character_state,
physics_state,
mass,
density,
_,
)| {
let in_loaded_chunk = read
.terrain
.get_key(read.terrain.pos_key(pos.0.map(|e| e.floor() as i32)))
.is_some();
// Apply physics only if in a loaded chunk
if in_loaded_chunk
// And not already stuck on a block (e.g., for arrows)
&& !(physics_state.on_surface().is_some() && sticky.is_some())
{
// Clamp dt to an effective 10 TPS, to prevent gravity from slamming the
// players into the floor when stationary if other systems cause the server
// to lag (as observed in the 0.9 release party).
let dt = DeltaTime(read.dt.0.min(0.1));
match physics_state.in_fluid {
None => {
vel.0.z -= dt.0 * GRAVITY;
},
Some(fluid) => {
vel.0 = integrate_forces(
&dt,
*vel,
body,
density,
mass,
character_state,
&fluid,
GRAVITY,
)
.0
},
}
}
},
);
let velocities = &write.velocities;
// Second pass: resolve collisions
let (land_on_grounds, mut outcomes) = (
&read.entities,
read.scales.maybe(),
read.stickies.maybe(),
&read.colliders,
positions,
velocities,
orientations,
read.bodies.maybe(),
read.character_states.maybe(),
&mut write.physics_states,
&mut write.pos_vel_defers,
previous_phys_cache,
!&read.mountings,
)
.par_join()
.map_init(
|| {
prof_span!(guard, "physics e<>t rayon job");
guard
},
|_guard,
(
entity,
scale,
sticky,
collider,
pos,
vel,
_ori,
body,
character_state,
mut physics_state,
pos_vel_defer,
_previous_cache,
_,
)| {
let mut land_on_ground = None;
let mut outcomes = Vec::new();
// Defer the writes of positions and velocities to allow an inner loop over
// terrain-like entities
let old_vel = *vel;
let mut vel = *vel;
let scale = if let Collider::Voxel { .. } = collider {
scale.map(|s| s.0).unwrap_or(1.0)
} else {
// TODO: Use scale & actual proportions when pathfinding is good
// enough to manage irregular entity sizes
1.0
};
let in_loaded_chunk = read
.terrain
.get_key(read.terrain.pos_key(pos.0.map(|e| e.floor() as i32)))
.is_some();
// Don't move if we're not in a loaded chunk
let pos_delta = if in_loaded_chunk {
vel.0 * read.dt.0
} else {
Vec3::zero()
};
// What's going on here? Because collisions need to be resolved against multiple
// colliders, this code takes the current position and
// propagates it forward according to velocity to find a
// 'target' position. This is where we'd ideally end up at the end of the tick,
// assuming no collisions. Then, we refine this target by
// stepping from the original position to the target for
// every obstacle, refining the target position as we go. It's not perfect, but
// it works pretty well in practice. Oddities can occur on
// the intersection between multiple colliders, but it's not
// like any game physics system resolves these sort of things well anyway. At
// the very least, we don't do things that result in glitchy
// velocities or entirely broken position snapping.
let mut tgt_pos = pos.0 + pos_delta;
let was_on_ground = physics_state.on_ground;
let block_snap =
body.map_or(false, |b| !matches!(b, Body::Object(_) | Body::Ship(_)));
let climbing =
character_state.map_or(false, |cs| matches!(cs, CharacterState::Climb(_)));
match &collider {
Collider::Voxel { .. } => {
// for now, treat entities with voxel colliders as their bounding
// cylinders for the purposes of colliding them with terrain
// Additionally, multiply radius by 0.1 to make the cylinder smaller to
// avoid lag
let radius = collider.get_radius() * scale * 0.1;
let (z_min, z_max) = collider.get_z_limits(scale);
let mut cpos = *pos;
let cylinder = (radius, z_min, z_max);
box_voxel_collision(
cylinder,
&*read.terrain,
entity,
&mut cpos,
tgt_pos,
&mut vel,
&mut physics_state,
Vec3::zero(),
&read.dt,
was_on_ground,
block_snap,
climbing,
|entity, vel| land_on_ground = Some((entity, vel)),
);
tgt_pos = cpos.0;
},
Collider::Box {
radius,
z_min,
z_max,
} => {
// Scale collider
let radius = radius.min(0.45) * scale;
let z_min = *z_min * scale;
let z_max = z_max.clamped(1.2, 1.95) * scale;
let cylinder = (radius, z_min, z_max);
let mut cpos = *pos;
box_voxel_collision(
cylinder,
&*read.terrain,
entity,
&mut cpos,
tgt_pos,
&mut vel,
&mut physics_state,
Vec3::zero(),
&read.dt,
was_on_ground,
block_snap,
climbing,
|entity, vel| land_on_ground = Some((entity, vel)),
);
// Sticky things shouldn't move when on a surface
if physics_state.on_surface().is_some() && sticky.is_some() {
vel.0 = physics_state.ground_vel;
}
tgt_pos = cpos.0;
},
Collider::Point => {
let mut pos = *pos;
// If the velocity is exactly 0, a raycast may not pick up the current
// block. Handle this.
let (dist, block) = if let Some(block) = read
.terrain
.get(pos.0.map(|e| e.floor() as i32))
.ok()
.filter(|b| b.is_filled())
// TODO: `is_solid`, when arrows are special-cased
{
(0.0, Some(block))
} else {
let (dist, block) = read
.terrain
.ray(pos.0, pos.0 + pos_delta)
.until(|block: &Block| block.is_filled())
.ignore_error()
.cast();
(dist, block.unwrap()) // Can't fail since we do ignore_error above
};
pos.0 += pos_delta.try_normalized().unwrap_or_else(Vec3::zero) * dist;
// TODO: Not all projectiles should count as sticky!
if sticky.is_some() {
if let Some((projectile, body)) = read
.projectiles
.get(entity)
.filter(|_| vel.0.magnitude_squared() > 1.0 && block.is_some())
.zip(read.bodies.get(entity).copied())
{
outcomes.push(Outcome::ProjectileHit {
pos: pos.0,
body,
vel: vel.0,
source: projectile.owner,
target: None,
});
}
}
if block.is_some() {
let block_center = pos.0.map(|e| e.floor()) + 0.5;
let block_rpos = (pos.0 - block_center)
.try_normalized()
.unwrap_or_else(Vec3::zero);
// See whether we're on the top/bottom of a block, or the side
if block_rpos.z.abs()
> block_rpos.xy().map(|e| e.abs()).reduce_partial_max()
{
if block_rpos.z > 0.0 {
physics_state.on_ground = true;
} else {
physics_state.on_ceiling = true;
}
vel.0.z = 0.0;
} else {
physics_state.on_wall =
Some(if block_rpos.x.abs() > block_rpos.y.abs() {
vel.0.x = 0.0;
Vec3::unit_x() * -block_rpos.x.signum()
} else {
vel.0.y = 0.0;
Vec3::unit_y() * -block_rpos.y.signum()
});
}
// Sticky things shouldn't move
if sticky.is_some() {
vel.0 = physics_state.ground_vel;
}
}
physics_state.in_fluid = read
.terrain
.get(pos.0.map(|e| e.floor() as i32))
.ok()
.and_then(|vox| vox.is_liquid().then_some(1.0))
.map(|depth| Fluid::Water {
depth,
vel: Vel::zero(),
})
.or_else(|| match physics_state.in_fluid {
Some(Fluid::Water { .. }) | None => Some(Fluid::Air {
elevation: pos.0.z,
vel: Vel::default(),
}),
fluid => fluid,
});
tgt_pos = pos.0;
},
}
// Compute center and radius of tick path bounding sphere for the entity
// for broad checks of whether it will collide with a voxel collider
let path_sphere = {
// TODO: duplicated with maintain_pushback_cache, make a common function
// to call to compute all this info?
let z_limits = calc_z_limit(character_state, Some(collider));
let z_limits = (z_limits.0 * scale, z_limits.1 * scale);
let half_height = (z_limits.1 - z_limits.0) / 2.0;
let entity_center = pos.0 + (z_limits.0 + half_height) * Vec3::unit_z();
let path_center = entity_center + pos_delta / 2.0;
let flat_radius = collider.get_radius() * scale;
let radius = (flat_radius.powi(2) + half_height.powi(2)).sqrt();
let path_bounding_radius = radius + (pos_delta / 2.0).magnitude();
Sphere {
center: path_center,
radius: path_bounding_radius,
}
};
// Collide with terrain-like entities
let query_center = path_sphere.center.xy();
let query_radius = path_sphere.radius;
voxel_collider_spatial_grid
.in_circle_aabr(query_center, query_radius)
.filter_map(|entity| {
positions
.get(entity)
.and_then(|l| velocities.get(entity).map(|r| (l, r)))
.and_then(|l| previous_phys_cache.get(entity).map(|r| (l, r)))
.and_then(|l| read.colliders.get(entity).map(|r| (l, r)))
.and_then(|l| orientations.get(entity).map(|r| (l, r)))
.map(|((((pos, vel), previous_cache), collider), ori)| {
(entity, pos, vel, previous_cache, collider, ori)
})
})
.for_each(
|(
entity_other,
pos_other,
vel_other,
previous_cache_other,
collider_other,
ori_other,
)| {
if entity == entity_other {
return;
}
let voxel_id = if let Collider::Voxel { id } = collider_other {
id
} else {
return;
};
// use bounding cylinder regardless of our collider
// TODO: extract point-terrain collision above to its own
// function
let radius = collider.get_radius();
let (z_min, z_max) = collider.get_z_limits(1.0);
let radius = radius.min(0.45) * scale;
let z_min = z_min * scale;
let z_max = z_max.clamped(1.2, 1.95) * scale;
if let Some(voxel_collider) =
VOXEL_COLLIDER_MANIFEST.read().colliders.get(voxel_id)
{
// TODO: cache/precompute sphere?
let voxel_sphere = voxel_collider_bounding_sphere(
voxel_collider,
pos_other,
ori_other,
);
// Early check
if voxel_sphere.center.distance_squared(path_sphere.center)
> (voxel_sphere.radius + path_sphere.radius).powi(2)
{
return;
}
let mut physics_state_delta = physics_state.clone();
// deliberately don't use scale yet here, because the
// 11.0/0.8 thing is
// in the comp::Scale for visual reasons
let mut cpos = *pos;
let wpos = cpos.0;
// TODO: Cache the matrices here to avoid recomputing
let transform_from =
Mat4::<f32>::translation_3d(pos_other.0 - wpos)
* Mat4::from(ori_other.to_quat())
* Mat4::<f32>::translation_3d(
voxel_collider.translation,
);
let transform_to = transform_from.inverted();
let ori_from = Mat4::from(ori_other.to_quat());
let ori_to = ori_from.inverted();
// The velocity of the collider, taking into account
// orientation.
let wpos_rel = (Mat4::<f32>::translation_3d(pos_other.0)
* Mat4::from(ori_other.to_quat())
* Mat4::<f32>::translation_3d(voxel_collider.translation))
.inverted()
.mul_point(wpos);
let wpos_last = (Mat4::<f32>::translation_3d(pos_other.0)
* Mat4::from(previous_cache_other.ori)
* Mat4::<f32>::translation_3d(voxel_collider.translation))
.mul_point(wpos_rel);
let vel_other = vel_other.0 + (wpos - wpos_last) / read.dt.0;
cpos.0 = transform_to.mul_point(Vec3::zero());
vel.0 = ori_to.mul_direction(vel.0 - vel_other);
let cylinder = (radius, z_min, z_max);
box_voxel_collision(
cylinder,
&voxel_collider.dyna,
entity,
&mut cpos,
transform_to.mul_point(tgt_pos - wpos),
&mut vel,
&mut physics_state_delta,
ori_to.mul_direction(vel_other),
&read.dt,
was_on_ground,
block_snap,
climbing,
|entity, vel| {
land_on_ground =
Some((entity, Vel(ori_from.mul_direction(vel.0))));
},
);
cpos.0 = transform_from.mul_point(cpos.0) + wpos;
vel.0 = ori_from.mul_direction(vel.0) + vel_other;
tgt_pos = cpos.0;
// union in the state updates, so that the state isn't just
// based on the most
// recent terrain that collision was attempted with
if physics_state_delta.on_ground {
physics_state.ground_vel = vel_other;
}
physics_state.on_ground |= physics_state_delta.on_ground;
physics_state.on_ceiling |= physics_state_delta.on_ceiling;
physics_state.on_wall = physics_state.on_wall.or_else(|| {
physics_state_delta
.on_wall
.map(|dir| ori_from.mul_direction(dir))
});
physics_state.in_fluid = match (
physics_state.in_fluid,
physics_state_delta.in_fluid,
) {
(Some(x), Some(y)) => x
.depth()
.and_then(|xh| {
y.depth()
.map(|yh| xh > yh)
.unwrap_or(true)
.then_some(x)
})
.or(Some(y)),
(x @ Some(_), _) => x,
(_, y @ Some(_)) => y,
_ => None,
};
}
},
);
if tgt_pos != pos.0 {
pos_vel_defer.pos = Some(Pos(tgt_pos));
} else {
pos_vel_defer.pos = None;
}
if vel != old_vel {
pos_vel_defer.vel = Some(vel);
} else {
pos_vel_defer.vel = None;
}
(land_on_ground, outcomes)
},
)
.fold(
|| (Vec::new(), Vec::new()),
|(mut land_on_grounds, mut all_outcomes), (land_on_ground, mut outcomes)| {
land_on_ground.map(|log| land_on_grounds.push(log));
all_outcomes.append(&mut outcomes);
(land_on_grounds, all_outcomes)
},
)
.reduce(
|| (Vec::new(), Vec::new()),
|(mut land_on_grounds_a, mut outcomes_a),
(mut land_on_grounds_b, mut outcomes_b)| {
land_on_grounds_a.append(&mut land_on_grounds_b);
outcomes_a.append(&mut outcomes_b);
(land_on_grounds_a, outcomes_a)
},
);
drop(guard);
job.cpu_stats.measure(ParMode::Single);
write.outcomes.append(&mut outcomes);
prof_span!(guard, "write deferred pos and vel");
for (_, pos, vel, pos_vel_defer) in (
&read.entities,
&mut write.positions,
&mut write.velocities,
&mut write.pos_vel_defers,
)
.join()
{
if let Some(new_pos) = pos_vel_defer.pos.take() {
*pos = new_pos;
}
if let Some(new_vel) = pos_vel_defer.vel.take() {
*vel = new_vel;
}
}
drop(guard);
prof_span!(guard, "record ori into phys_cache");
for (ori, previous_phys_cache) in
(&write.orientations, &mut write.previous_phys_cache).join()
{
previous_phys_cache.ori = ori.to_quat();
}
drop(guard);
let mut event_emitter = read.event_bus.emitter();
land_on_grounds.into_iter().for_each(|(entity, vel)| {
event_emitter.emit(ServerEvent::LandOnGround { entity, vel: vel.0 });
});
}
fn update_cached_spatial_grid(&mut self) {
span!(_guard, "Update cached spatial grid");
let PhysicsData {
ref read,
ref mut write,
} = self;
let spatial_grid = &mut write.cached_spatial_grid.0;
spatial_grid.clear();
(
&read.entities,
&write.positions,
read.scales.maybe(),
read.colliders.maybe(),
)
.join()
.for_each(|(entity, pos, scale, collider)| {
let scale = scale.map(|s| s.0).unwrap_or(1.0);
let radius_2d =
(collider.map(|c| c.get_radius()).unwrap_or(0.5) * scale).ceil() as u32;
let pos_2d = pos.0.xy().map(|e| e as i32);
const POS_TRUNCATION_ERROR: u32 = 1;
spatial_grid.insert(pos_2d, radius_2d + POS_TRUNCATION_ERROR, entity);
});
}
}
impl<'a> System<'a> for Sys {
type SystemData = PhysicsData<'a>;
const NAME: &'static str = "phys";
const ORIGIN: Origin = Origin::Common;
const PHASE: Phase = Phase::Create;
fn run(job: &mut Job<Self>, mut physics_data: Self::SystemData) {
physics_data.reset();
// Apply pushback
//
// Note: We now do this first because we project velocity ahead. This is slighty
// imperfect and implies that we might get edge-cases where entities
// standing right next to the edge of a wall may get hit by projectiles
// fired into the wall very close to them. However, this sort of thing is
// already possible with poorly-defined hitboxes anyway so it's not too
// much of a concern.
//
// If this situation becomes a problem, this code should be integrated with the
// terrain collision code below, although that's not trivial to do since
// it means the step needs to take into account the speeds of both
// entities.
physics_data.maintain_pushback_cache();
let spatial_grid = physics_data.construct_spatial_grid();
physics_data.apply_pushback(job, &spatial_grid);
let voxel_collider_spatial_grid = physics_data.construct_voxel_collider_spatial_grid();
physics_data.handle_movement_and_terrain(job, &voxel_collider_spatial_grid);
// Spatial grid used by other systems
physics_data.update_cached_spatial_grid();
}
}
#[allow(clippy::too_many_arguments)]
fn box_voxel_collision<'a, T: BaseVol<Vox = Block> + ReadVol>(
cylinder: (f32, f32, f32), // effective collision cylinder
terrain: &'a T,
entity: Entity,
pos: &mut Pos,
tgt_pos: Vec3<f32>,
vel: &mut Vel,
physics_state: &mut PhysicsState,
ground_vel: Vec3<f32>,
dt: &DeltaTime,
was_on_ground: bool,
block_snap: bool,
climbing: bool,
mut land_on_ground: impl FnMut(Entity, Vel),
) {
let (radius, z_min, z_max) = cylinder;
// Probe distances
let hdist = radius.ceil() as i32;
// Neighbouring blocks iterator
let near_iter = (-hdist..hdist + 1)
.map(move |i| {
(-hdist..hdist + 1).map(move |j| {
(1 - Block::MAX_HEIGHT.ceil() as i32 + z_min.floor() as i32
..z_max.ceil() as i32 + 1)
.map(move |k| (i, j, k))
})
})
.flatten()
.flatten();
// Function for iterating over the blocks the player at a specific position
// collides with
fn collision_iter<'a, T: BaseVol<Vox = Block> + ReadVol>(
pos: Vec3<f32>,
terrain: &'a T,
hit: &'a impl Fn(&Block) -> bool,
height: &'a impl Fn(&Block) -> f32,
near_iter: impl Iterator<Item = (i32, i32, i32)> + 'a,
radius: f32,
z_range: Range<f32>,
) -> impl Iterator<Item = Aabb<f32>> + 'a {
near_iter.filter_map(move |(i, j, k)| {
let block_pos = pos.map(|e| e.floor() as i32) + Vec3::new(i, j, k);
if let Some(block) = terrain.get(block_pos).ok().copied().filter(hit) {
let player_aabb = Aabb {
min: pos + Vec3::new(-radius, -radius, z_range.start),
max: pos + Vec3::new(radius, radius, z_range.end),
};
let block_aabb = Aabb {
min: block_pos.map(|e| e as f32),
max: block_pos.map(|e| e as f32) + Vec3::new(1.0, 1.0, height(&block)),
};
if player_aabb.collides_with_aabb(block_aabb) {
return Some(block_aabb);
}
}
None
})
}
let z_range = z_min..z_max;
// Function for determining whether the player at a specific position collides
// with blocks with the given criteria
fn collision_with<'a, T: BaseVol<Vox = Block> + ReadVol>(
pos: Vec3<f32>,
terrain: &'a T,
hit: impl Fn(&Block) -> bool,
near_iter: impl Iterator<Item = (i32, i32, i32)> + 'a,
radius: f32,
z_range: Range<f32>,
) -> bool {
collision_iter(
pos,
terrain,
&|block| block.is_solid() && hit(block),
&Block::solid_height,
near_iter,
radius,
z_range,
)
.next()
.is_some()
}
physics_state.on_ground = false;
let mut on_ground = false;
let mut on_ceiling = false;
let mut attempts = 0; // Don't loop infinitely here
let mut pos_delta = tgt_pos - pos.0;
// Don't jump too far at once
let increments = (pos_delta.map(|e| e.abs()).reduce_partial_max() / 0.3)
.ceil()
.max(1.0);
let old_pos = pos.0;
fn block_true(_: &Block) -> bool { true }
for _ in 0..increments as usize {
pos.0 += pos_delta / increments;
const MAX_ATTEMPTS: usize = 16;
// While the player is colliding with the terrain...
while let Some((_block_pos, block_aabb, block_height)) =
(attempts < MAX_ATTEMPTS).then(|| {
// Calculate the player's AABB
let player_aabb = Aabb {
min: pos.0 + Vec3::new(-radius, -radius, z_min),
max: pos.0 + Vec3::new(radius, radius, z_max),
};
// Determine the block that we are colliding with most (based on minimum
// collision axis) (if we are colliding with one)
near_iter
.clone()
// Calculate the block's position in world space
.map(|(i, j, k)| pos.0.map(|e| e.floor() as i32) + Vec3::new(i, j, k))
// Make sure the block is actually solid
.filter_map(|block_pos| {
terrain
.get(block_pos)
.ok()
.filter(|block| block.is_solid())
.map(|block| (block_pos, block))
})
// Calculate block AABB
.map(|(block_pos, block)| {
(
block_pos,
Aabb {
min: block_pos.map(|e| e as f32),
max: block_pos.map(|e| e as f32) + Vec3::new(1.0, 1.0, block.solid_height()),
},
block.solid_height(),
)
})
// Determine whether the block's AABB collides with the player's AABB
.filter(|(_, block_aabb, _)| block_aabb.collides_with_aabb(player_aabb))
// Find the maximum of the minimum collision axes (this bit is weird, trust me that it works)
.min_by_key(|(_, block_aabb, _)| {
ordered_float::OrderedFloat((block_aabb.center() - player_aabb.center() - Vec3::unit_z() * 0.5)
.map(f32::abs)
.sum())
})
}).flatten()
{
// Calculate the player's AABB
let player_aabb = Aabb {
min: pos.0 + Vec3::new(-radius, -radius, z_min),
max: pos.0 + Vec3::new(radius, radius, z_max),
};
// Find the intrusion vector of the collision
let dir = player_aabb.collision_vector_with_aabb(block_aabb);
// Determine an appropriate resolution vector (i.e: the minimum distance
// needed to push out of the block)
let max_axis = dir.map(|e| e.abs()).reduce_partial_min();
let resolve_dir = -dir.map(|e| {
if e.abs().to_bits() == max_axis.to_bits() {
e
} else {
0.0
}
});
// When the resolution direction is pointing upwards, we must be on the
// ground
if resolve_dir.z > 0.0
/* && vel.0.z <= 0.0 */
{
on_ground = true;
if !was_on_ground {
land_on_ground(entity, *vel);
}
} else if resolve_dir.z < 0.0 && vel.0.z >= 0.0 {
on_ceiling = true;
}
// When the resolution direction is non-vertical, we must be colliding
// with a wall If we're being pushed out horizontally...
if resolve_dir.z == 0.0
// ...and the vertical resolution direction is sufficiently great...
&& dir.z < -0.1
// ...and the space above is free...
&& !collision_with(Vec3::new(pos.0.x, pos.0.y, (pos.0.z + 0.1).ceil()), &terrain, block_true, near_iter.clone(), radius, z_range.clone())
// ...and we're falling/standing OR there is a block *directly* beneath our current origin (note: not hitbox)...
// && terrain
// .get((pos.0 - Vec3::unit_z() * 0.1).map(|e| e.floor() as i32))
// .map(|block| block.is_solid())
// .unwrap_or(false)
// ...and there is a collision with a block beneath our current hitbox...
&& collision_with(
pos.0 + resolve_dir - Vec3::unit_z() * 1.25,
&terrain,
block_true,
near_iter.clone(),
radius,
z_range.clone(),
)
{
// ...block-hop!
pos.0.z = (pos.0.z + 0.1).floor() + block_height;
vel.0.z = vel.0.z.max(0.0);
// Push the character on to the block very slightly to avoid jitter due to imprecision
if (vel.0 * resolve_dir).xy().magnitude_squared() < 1.0f32.powi(2) {
pos.0 -= resolve_dir.normalized() * 0.05;
}
on_ground = true;
break;
} else {
// Correct the velocity
vel.0 = vel.0.map2(
resolve_dir,
|e, d| {
if d * e.signum() < 0.0 { 0.0 } else { e }
},
);
pos_delta *= resolve_dir.map(|e| if e != 0.0 { 0.0 } else { 1.0 });
}
// Resolve the collision normally
pos.0 += resolve_dir;
attempts += 1;
}
if attempts == MAX_ATTEMPTS {
vel.0 = Vec3::zero();
pos.0 = old_pos;
break;
}
}
if on_ceiling {
physics_state.on_ceiling = true;
}
if on_ground {
physics_state.on_ground = true;
// If the space below us is free, then "snap" to the ground
} else if collision_with(
pos.0 - Vec3::unit_z() * 1.1,
&terrain,
block_true,
near_iter.clone(),
radius,
z_range.clone(),
) && vel.0.z <= 0.0
&& was_on_ground
&& block_snap
{
let snap_height = terrain
.get(Vec3::new(pos.0.x, pos.0.y, pos.0.z - 0.1).map(|e| e.floor() as i32))
.ok()
.filter(|block| block.is_solid())
.map(|block| block.solid_height())
.unwrap_or(0.0);
vel.0.z = 0.0;
pos.0.z = (pos.0.z - 0.1).floor() + snap_height;
physics_state.on_ground = true;
}
let player_aabb = Aabb {
min: pos.0 + Vec3::new(-radius, -radius, z_range.start),
max: pos.0 + Vec3::new(radius, radius, z_range.end),
};
let player_voxel_pos = pos.0.map(|e| e.floor() as i32);
let dirs = [
Vec3::unit_x(),
Vec3::unit_y(),
-Vec3::unit_x(),
-Vec3::unit_y(),
];
let player_wall_aabbs = dirs.map(|dir| {
let pos = pos.0 + dir * 0.01;
Aabb {
min: pos + Vec3::new(-radius, -radius, z_range.start),
max: pos + Vec3::new(radius, radius, z_range.end),
}
});
// Find liquid immersion and wall collision all in one round of iteration
let mut max_liquid_z = None::<f32>;
let mut wall_dir_collisions = [false; 4];
near_iter.for_each(|(i, j, k)| {
let block_pos = player_voxel_pos + Vec3::new(i, j, k);
if let Some(block) = terrain.get(block_pos).ok().copied() {
// Check for liquid blocks
if block.is_liquid() {
let liquid_aabb = Aabb {
min: block_pos.map(|e| e as f32),
// The liquid part of a liquid block always extends 1 block high.
max: block_pos.map(|e| e as f32) + Vec3::one(),
};
if player_aabb.collides_with_aabb(liquid_aabb) {
max_liquid_z = Some(match max_liquid_z {
Some(z) => z.max(liquid_aabb.max.z),
None => liquid_aabb.max.z,
});
}
}
// Check for walls
if block.is_solid() {
let block_aabb = Aabb {
min: block_pos.map(|e| e as f32),
max: block_pos.map(|e| e as f32) + Vec3::new(1.0, 1.0, block.solid_height()),
};
for dir in 0..4 {
if player_wall_aabbs[dir].collides_with_aabb(block_aabb) {
wall_dir_collisions[dir] = true;
}
}
}
}
});
// Use wall collision results to determine if we are against a wall
let mut on_wall = None;
for dir in 0..4 {
if wall_dir_collisions[dir] {
on_wall = Some(match on_wall {
Some(acc) => acc + dirs[dir],
None => dirs[dir],
});
}
}
physics_state.on_wall = on_wall;
if physics_state.on_ground || (physics_state.on_wall.is_some() && climbing) {
vel.0 *= (1.0 - FRIC_GROUND.min(1.0)).powf(dt.0 * 60.0);
physics_state.ground_vel = ground_vel;
}
physics_state.in_fluid = max_liquid_z
.map(|max_z| max_z - pos.0.z) // NOTE: assumes min_z == 0.0
.map(|depth| {
physics_state
.in_liquid()
// This is suboptimal because it doesn't check for true depth,
// so it can cause problems for situations like swimming down
// a river and spawning or teleporting in(/to) water
.map(|old_depth| (old_depth + old_pos.z - pos.0.z).max(depth))
.unwrap_or(depth)
})
.map(|depth| Fluid::Water {
depth,
vel: Vel::zero(),
})
.or_else(|| match physics_state.in_fluid {
Some(Fluid::Water { .. }) | None => Some(Fluid::Air {
elevation: pos.0.z,
vel: Vel::default(),
}),
fluid => fluid,
});
}
fn voxel_collider_bounding_sphere(
voxel_collider: &VoxelCollider,
pos: &Pos,
ori: &Ori,
) -> Sphere<f32, f32> {
let origin_offset = voxel_collider.translation;
use common::vol::SizedVol;
let lower_bound = voxel_collider.dyna.lower_bound().map(|e| e as f32);
let upper_bound = voxel_collider.dyna.upper_bound().map(|e| e as f32);
let center = (lower_bound + upper_bound) / 2.0;
// Compute vector from the origin (where pos value corresponds to) and the model
// center
let center_offset = center + origin_offset;
// Rotate
let oriented_center_offset = ori.local_to_global(center_offset);
// Add to pos to get world coordinates of the center
let wpos_center = oriented_center_offset + pos.0;
// Note: to not get too fine grained we use a 2D grid for now
const SPRITE_AND_MAYBE_OTHER_THINGS: f32 = 4.0;
let radius = ((upper_bound - lower_bound) / 2.0
+ Vec3::broadcast(SPRITE_AND_MAYBE_OTHER_THINGS))
.magnitude();
Sphere {
center: wpos_center,
radius,
}
}