reduce allocations for collision detection

7 files changed, 90 insertions, 92 deletions

diff --git a/Cargo.lock b/Cargo.lock
index 168ac60b..6f228d2d 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -460,6 +460,7 @@ dependencies = [
  "nohash-hasher",
  "once_cell",
  "parking_lot",
+ "smallvec",
  "tracing",
  "uuid",
 ]
diff --git a/azalea-block/src/lib.rs b/azalea-block/src/lib.rs
index dc41b405..2a46fd01 100755
--- a/azalea-block/src/lib.rs
+++ b/azalea-block/src/lib.rs
@@ -59,6 +59,8 @@ impl BlockState {
         state_id <= Self::max_state()
     }
 
+    /// Returns true if the block is air. This only checks for normal air, not
+    /// other types like cave air.
     #[inline]
     pub fn is_air(&self) -> bool {
         self == &Self::AIR
diff --git a/azalea-physics/Cargo.toml b/azalea-physics/Cargo.toml
index 043c0548..7b762896 100644
--- a/azalea-physics/Cargo.toml
+++ b/azalea-physics/Cargo.toml
@@ -21,6 +21,7 @@ tracing = "0.1.40"
 once_cell = "1.19.0"
 parking_lot = "^0.12.1"
 nohash-hasher = "0.2.0"
+smallvec = "1.13.1"
 
 [dev-dependencies]
 bevy_time = "0.13.0"
diff --git a/azalea-physics/src/collision/discrete_voxel_shape.rs b/azalea-physics/src/collision/discrete_voxel_shape.rs
index f63b7c2a..211e6303 100755
--- a/azalea-physics/src/collision/discrete_voxel_shape.rs
+++ b/azalea-physics/src/collision/discrete_voxel_shape.rs
@@ -13,6 +13,7 @@ pub enum DiscreteVoxelShape {
 }
 
 impl DiscreteVoxelShape {
+    #[inline]
     pub fn size(&self, axis: Axis) -> u32 {
         match self {
             DiscreteVoxelShape::BitSet(shape) => shape.size(axis),
@@ -305,6 +306,7 @@ impl BitSetDiscreteVoxelShape {
 }
 
 impl BitSetDiscreteVoxelShape {
+    #[inline]
     fn size(&self, axis: Axis) -> u32 {
         axis.choose(self.x_size, self.y_size, self.z_size)
     }
diff --git a/azalea-physics/src/collision/shape.rs b/azalea-physics/src/collision/shape.rs
index 41ade73c..56befa39 100755
--- a/azalea-physics/src/collision/shape.rs
+++ b/azalea-physics/src/collision/shape.rs
@@ -169,22 +169,22 @@ impl Shapes {
         // var5.getList(), var6.getList(), var7.getList()));
         let var5 = Self::create_index_merger(
             1,
-            a.get_coords(Axis::X),
-            b.get_coords(Axis::X),
+            a.get_coords(Axis::X).to_vec(),
+            b.get_coords(Axis::X).to_vec(),
             op_true_false,
             op_false_true,
         );
         let var6 = Self::create_index_merger(
             (var5.size() - 1).try_into().unwrap(),
-            a.get_coords(Axis::Y),
-            b.get_coords(Axis::Y),
+            a.get_coords(Axis::Y).to_vec(),
+            b.get_coords(Axis::Y).to_vec(),
             op_true_false,
             op_false_true,
         );
         let var7 = Self::create_index_merger(
             ((var5.size() - 1) * (var6.size() - 1)).try_into().unwrap(),
-            a.get_coords(Axis::Z),
-            b.get_coords(Axis::Z),
+            a.get_coords(Axis::Z).to_vec(),
+            b.get_coords(Axis::Z).to_vec(),
             op_true_false,
             op_false_true,
         );
@@ -233,22 +233,22 @@ impl Shapes {
 
         let x_merger = Self::create_index_merger(
             1,
-            a.get_coords(Axis::X),
-            b.get_coords(Axis::X),
+            a.get_coords(Axis::X).to_vec(),
+            b.get_coords(Axis::X).to_vec(),
             op_true_false,
             op_false_true,
         );
         let y_merger = Self::create_index_merger(
             (x_merger.size() - 1) as i32,
-            a.get_coords(Axis::Y),
-            b.get_coords(Axis::Y),
+            a.get_coords(Axis::Y).to_vec(),
+            b.get_coords(Axis::Y).to_vec(),
             op_true_false,
             op_false_true,
         );
         let z_merger = Self::create_index_merger(
             ((x_merger.size() - 1) * (y_merger.size() - 1)) as i32,
-            a.get_coords(Axis::Z),
-            b.get_coords(Axis::Z),
+            a.get_coords(Axis::Z).to_vec(),
+            b.get_coords(Axis::Z).to_vec(),
             op_true_false,
             op_false_true,
         );
@@ -361,7 +361,7 @@ impl VoxelShape {
         }
     }
 
-    pub fn get_coords(&self, axis: Axis) -> Vec<f64> {
+    pub fn get_coords(&self, axis: Axis) -> &[f64] {
         match self {
             VoxelShape::Array(s) => s.get_coords(axis),
             VoxelShape::Cube(s) => s.get_coords(axis),
@@ -625,6 +625,10 @@ pub struct CubeVoxelShape {
     // TODO: check where faces is used in minecraft
     #[allow(dead_code)]
     faces: Option<Vec<VoxelShape>>,
+
+    x_coords: Vec<f64>,
+    y_coords: Vec<f64>,
+    z_coords: Vec<f64>,
 }
 
 impl ArrayVoxelShape {
@@ -634,9 +638,9 @@ impl ArrayVoxelShape {
         let z_size = shape.size(Axis::Z) + 1;
 
         // Lengths of point arrays must be consistent with the size of the VoxelShape.
-        assert_eq!(x_size, xs.len() as u32);
-        assert_eq!(y_size, ys.len() as u32);
-        assert_eq!(z_size, zs.len() as u32);
+        debug_assert_eq!(x_size, xs.len() as u32);
+        debug_assert_eq!(y_size, ys.len() as u32);
+        debug_assert_eq!(z_size, zs.len() as u32);
 
         Self {
             faces: None,
@@ -648,19 +652,30 @@ impl ArrayVoxelShape {
     }
 }
 
-impl CubeVoxelShape {
-    pub fn new(shape: DiscreteVoxelShape) -> Self {
-        Self { shape, faces: None }
-    }
-}
-
 impl ArrayVoxelShape {
     fn shape(&self) -> &DiscreteVoxelShape {
         &self.shape
     }
 
-    fn get_coords(&self, axis: Axis) -> Vec<f64> {
-        axis.choose(self.xs.clone(), self.ys.clone(), self.zs.clone())
+    fn get_coords(&self, axis: Axis) -> &[f64] {
+        axis.choose(&self.xs, &self.ys, &self.zs)
+    }
+}
+
+impl CubeVoxelShape {
+    pub fn new(shape: DiscreteVoxelShape) -> Self {
+        // pre-calculate the coor
+        let x_coords = Self::calculate_coords(&shape, Axis::X);
+        let y_coords = Self::calculate_coords(&shape, Axis::Y);
+        let z_coords = Self::calculate_coords(&shape, Axis::Z);
+
+        Self {
+            shape,
+            faces: None,
+            x_coords,
+            y_coords,
+            z_coords,
+        }
     }
 }
 
@@ -669,8 +684,8 @@ impl CubeVoxelShape {
         &self.shape
     }
 
-    fn get_coords(&self, axis: Axis) -> Vec<f64> {
-        let size = self.shape.size(axis);
+    fn calculate_coords(shape: &DiscreteVoxelShape, axis: Axis) -> Vec<f64> {
+        let size = shape.size(axis);
         let mut parts = Vec::with_capacity(size as usize);
         for i in 0..=size {
             parts.push(i as f64 / size as f64);
@@ -678,6 +693,10 @@ impl CubeVoxelShape {
         parts
     }
 
+    fn get_coords(&self, axis: Axis) -> &[f64] {
+        axis.choose(&self.x_coords, &self.y_coords, &self.z_coords)
+    }
+
     fn find_index(&self, axis: Axis, coord: f64) -> i32 {
         let n = self.shape().size(axis);
         (f64::clamp(coord * (n as f64), -1f64, n as f64)) as i32
diff --git a/azalea-physics/src/collision/world_collisions.rs b/azalea-physics/src/collision/world_collisions.rs
index cb721f00..8493b847 100644
--- a/azalea-physics/src/collision/world_collisions.rs
+++ b/azalea-physics/src/collision/world_collisions.rs
@@ -22,6 +22,7 @@ pub struct BlockCollisions<'a> {
     pub only_suffocating_blocks: bool,
 
     cached_sections: Vec<(ChunkSectionPos, azalea_world::Section)>,
+    cached_block_shapes: Vec<(BlockState, &'static VoxelShape)>,
 }
 
 impl<'a> BlockCollisions<'a> {
@@ -44,6 +45,7 @@ impl<'a> BlockCollisions<'a> {
             only_suffocating_blocks: false,
 
             cached_sections: Vec::new(),
+            cached_block_shapes: Vec::new(),
         }
     }
 
@@ -95,8 +97,27 @@ impl<'a> BlockCollisions<'a> {
 
         self.cached_sections.push((section_pos, section.clone()));
 
+        // println!(
+        //     "chunk section length: {}",
+        //     section.states.storage.data.len()
+        // );
+        // println!("biome length: {}", section.biomes.storage.data.len());
+
         section.get(section_block_pos)
     }
+
+    fn get_block_shape(&mut self, block_state: BlockState) -> &'static VoxelShape {
+        for (cached_block_state, cached_shape) in &self.cached_block_shapes {
+            if block_state == *cached_block_state {
+                return cached_shape;
+            }
+        }
+
+        let shape = block_state.shape();
+        self.cached_block_shapes.push((block_state, shape));
+
+        shape
+    }
 }
 
 impl<'a> Iterator for BlockCollisions<'a> {
@@ -138,7 +159,7 @@ impl<'a> Iterator for BlockCollisions<'a> {
                 ));
             }
 
-            let block_shape = block_state.shape();
+            let block_shape = self.get_block_shape(block_state);
 
             let block_shape =
                 block_shape.move_relative(item.pos.x as f64, item.pos.y as f64, item.pos.z as f64);
diff --git a/azalea/benches/physics.rs b/azalea/benches/physics.rs
index 6f8dc7bc..0d4a3f2f 100644
--- a/azalea/benches/physics.rs
+++ b/azalea/benches/physics.rs
@@ -28,29 +28,22 @@ fn generate_world(partial_chunks: &mut PartialChunkStorage, size: u32) -> ChunkS
         }
     }
 
-    // for chunk_x in -size..size {
-    //     for chunk_z in -size..size {
-    //         let chunk_pos = ChunkPos::new(chunk_x, chunk_z);
-    //         let chunk = chunks.get(&chunk_pos).unwrap();
-    //         let mut chunk = chunk.write();
-    //         for x in 0..16_u8 {
-    //             for z in 0..16_u8 {
-    //                 chunk.set(
-    //                     &ChunkBlockPos::new(x, 1, z),
-    //                     azalea_registry::Block::Bedrock.into(),
-    //                     chunks.min_y,
-    //                 );
-    //                 if rng.gen_bool(0.5) {
-    //                     chunk.set(
-    //                         &ChunkBlockPos::new(x, 2, z),
-    //                         azalea_registry::Block::Bedrock.into(),
-    //                         chunks.min_y,
-    //                     );
-    //                 }
-    //             }
-    //         }
-    //     }
-    // }
+    for chunk_x in -size..size {
+        for chunk_z in -size..size {
+            let chunk_pos = ChunkPos::new(chunk_x, chunk_z);
+            let chunk = chunks.get(&chunk_pos).unwrap();
+            let mut chunk = chunk.write();
+            for x in 0..16_u8 {
+                for z in 0..16_u8 {
+                    chunk.set(
+                        &ChunkBlockPos::new(x, 1, z),
+                        azalea_registry::Block::OakFence.into(),
+                        chunks.min_y,
+                    );
+                }
+            }
+        }
+    }
 
     // let mut start = BlockPos::new(-64, 4, -64);
     // // move start down until it's on a solid block
@@ -69,47 +62,6 @@ fn generate_world(partial_chunks: &mut PartialChunkStorage, size: u32) -> ChunkS
     chunks
 }
 
-fn generate_mining_world(
-    partial_chunks: &mut PartialChunkStorage,
-    size: u32,
-) -> (ChunkStorage, BlockPos, BlockPos) {
-    let size = size as i32;
-
-    let mut chunks = ChunkStorage::default();
-    for chunk_x in -size..size {
-        for chunk_z in -size..size {
-            let chunk_pos = ChunkPos::new(chunk_x, chunk_z);
-            partial_chunks.set(&chunk_pos, Some(Chunk::default()), &mut chunks);
-        }
-    }
-
-    // let mut rng = StdRng::seed_from_u64(0);
-
-    for chunk_x in -size..size {
-        for chunk_z in -size..size {
-            let chunk_pos = ChunkPos::new(chunk_x, chunk_z);
-            let chunk = chunks.get(&chunk_pos).unwrap();
-            let mut chunk = chunk.write();
-            for y in chunks.min_y..(chunks.min_y + chunks.height as i32) {
-                for x in 0..16_u8 {
-                    for z in 0..16_u8 {
-                        chunk.set(
-                            &ChunkBlockPos::new(x, y, z),
-                            azalea_registry::Block::Stone.into(),
-                            chunks.min_y,
-                        );
-                    }
-                }
-            }
-        }
-    }
-
-    let start = BlockPos::new(-64, 4, -64);
-    let end = BlockPos::new(0, 4, 0);
-
-    (chunks, start, end)
-}
-
 fn run_physics_benchmark(b: &mut Bencher<'_>) {
     let mut partial_chunks = PartialChunkStorage::new(32);
 
@@ -126,7 +78,7 @@ fn run_physics_benchmark(b: &mut Bencher<'_>) {
     // std::process::exit(0);
 
     b.iter(|| {
-        let entity = simulation_set.spawn(SimulatedPlayerBundle::new(Vec3::new(0.0, 4.0, 0.0)));
+        let entity = simulation_set.spawn(SimulatedPlayerBundle::new(Vec3::new(0.5, 2.0, 0.5)));
         for _ in 0..20 {
             simulation_set.tick();
         }