Start work on brickgrids

assets/shaders/voxel_volume.wgsl

@@ -1,8 +1,9 @@
 @group(0) @binding(0) var output: texture_storage_2d<rgba8unorm, write>;
 @group(0) @binding(1) var<uniform> world_state: WorldState;
-@group(0) @binding(2) var<storage, read> brickmap_cache: array<Brickmap>;
+@group(0) @binding(2) var<storage, read> brickgrid: array<u32>;
-@group(0) @binding(3) var<storage, read> shading_table: array<ShadingElement>;
+@group(0) @binding(3) var<storage, read> brickmap_cache: array<Brickmap>;
-@group(0) @binding(4) var<uniform> camera: Camera;
+@group(0) @binding(4) var<storage, read> shading_table: array<ShadingElement>;
+@group(0) @binding(5) var<uniform> camera: Camera;
 
 struct ShadingElement {
     albedo: u32,
@@ -75,9 +76,14 @@ fn point_inside_aabb(p: vec3<i32>) -> bool {
 }
 
 fn voxel_hit(p: vec3<i32>) -> bool {
-    let brickmap_index = to_1d_index(p / 8, vec3<i32>(world_state.brickmap_cache_dims));
+    let brickgrid_index = to_1d_index(p / 8, vec3<i32>(world_state.brickmap_cache_dims));
+    let brick_ptr = brickgrid[brickgrid_index];
+    if ((brick_ptr & 1u) == 0u){
+        return false;
+    }
+
     let local_index = to_1d_index(p % 8, vec3<i32>(8));
-    let bitmask_segment = brickmap_cache[brickmap_index].bitmask[local_index / 32u];
+    let bitmask_segment = brickmap_cache[brick_ptr >> 8u].bitmask[local_index / 32u];
     return (bitmask_segment >> (local_index % 32u) & 1u) != 0u;
 }
 

src/voxel/brickmap.rs

@@ -31,6 +31,8 @@ struct WorldState {
 pub struct BrickmapManager {
     state_uniform: WorldState,
     state_buffer: wgpu::Buffer,
+    brickgrid: Vec<u32>,
+    brickgrid_buffer: wgpu::Buffer,
     brickmap_cache: Vec<Brickmap>,
     brickmap_buffer: wgpu::Buffer,
     shading_table: Vec<u32>,
@@ -45,6 +47,9 @@ impl BrickmapManager {
         let mut brickmap_cache = Vec::<Brickmap>::with_capacity(32768);
         brickmap_cache.resize(32768, Brickmap::default());
 
+        let mut brickgrid = Vec::<u32>::with_capacity(32768);
+        brickgrid.resize(brickgrid.capacity(), 0);
+
         let device = &context.device;
         let state_buffer = device.create_buffer_init(&wgpu::util::BufferInitDescriptor {
             label: None,
@@ -52,6 +57,12 @@ impl BrickmapManager {
             usage: wgpu::BufferUsages::UNIFORM,
         });
 
+        let brickgrid_buffer = device.create_buffer_init(&wgpu::util::BufferInitDescriptor {
+            label: None,
+            contents: bytemuck::cast_slice(&brickgrid),
+            usage: wgpu::BufferUsages::STORAGE | wgpu::BufferUsages::COPY_DST,
+        });
+
         let brickmap_buffer = device.create_buffer_init(&wgpu::util::BufferInitDescriptor {
             label: None,
             contents: bytemuck::cast_slice(&brickmap_cache),
@@ -70,6 +81,8 @@ impl BrickmapManager {
         Self {
             state_uniform,
             state_buffer,
+            brickgrid,
+            brickgrid_buffer,
             brickmap_cache,
             brickmap_buffer,
             shading_table,
@@ -83,6 +96,8 @@ impl BrickmapManager {
             .try_into()
             .unwrap();
         let shading_idx = idx * 512;
+        self.brickgrid
+            .splice(idx..idx + 1, [((idx as u32) << 8) + 1]);
         self.brickmap_cache[idx].bitmask = *data;
         self.brickmap_cache[idx].shading_table_offset = shading_idx as u32;
         self.shading_table.splice(
@@ -103,6 +118,15 @@ impl BrickmapManager {
             0,
             bytemuck::cast_slice(&self.shading_table),
         );
+        queue.write_buffer(
+            &self.brickgrid_buffer,
+            0,
+            bytemuck::cast_slice(&self.brickgrid),
+        )
+    }
+
+    pub fn get_brickgrid_buffer(&self) -> &wgpu::Buffer {
+        &self.brickgrid_buffer
     }
 
     pub fn get_worldstate_buffer(&self) -> &wgpu::Buffer {

src/voxel/voxel_renderer.rs

@@ -64,6 +64,10 @@ impl VoxelRenderer {
         let sphere_center = glam::vec3(3.5, 3.5, 3.5);
         let sphere_r2 = u32::pow(4, 2) as f32;
         for chunk_idx in 0..32768 {
+            if chunk_idx % 3 == 0 || chunk_idx % 5 == 0 || chunk_idx % 7 == 0 {
+                continue;
+            }
+
             let chunk_pos = glam::uvec3(chunk_idx % 32, (chunk_idx / 32) % 32, chunk_idx / 1024);
             let mut bitmask_data = [0xFFFFFFFF as u32; 16];
             let mut albedo_data = Vec::<u32>::new();
@@ -131,6 +135,15 @@ impl VoxelRenderer {
                 },
                 None,
             )
+            .with_entry(
+                wgpu::ShaderStages::COMPUTE,
+                wgpu::BindingType::Buffer {
+                    ty: wgpu::BufferBindingType::Storage { read_only: true },
+                    has_dynamic_offset: false,
+                    min_binding_size: None,
+                },
+                None,
+            )
             .with_entry(
                 wgpu::ShaderStages::COMPUTE,
                 wgpu::BindingType::Buffer {
@@ -145,6 +158,7 @@ impl VoxelRenderer {
             .with_layout(&compute_layout)
             .with_entry(wgpu::BindingResource::TextureView(&render_texture.view))
             .with_entry(brickmap_manager.get_worldstate_buffer().as_entire_binding())
+            .with_entry(brickmap_manager.get_brickgrid_buffer().as_entire_binding())
             .with_entry(brickmap_manager.get_brickmap_buffer().as_entire_binding())
             .with_entry(brickmap_manager.get_shading_buffer().as_entire_binding())
             .with_entry(camera_controller.get_buffer().as_entire_binding())