Remove unnecessary cast

src/math.rs

@@ -78,6 +78,7 @@ pub fn tri_lerp_block(p: &[f32], dims: &[u32], vals: &mut [f32]) {
 }
 
 /// Maps a 3d index to a 1d index
+// TODO: Handle out of range!!
 pub fn to_1d_index(p: glam::UVec3, dim: glam::UVec3) -> usize {
     (p.x + p.y * dim.x + p.z * dim.x * dim.y) as usize
 }

src/voxel/brickworld/brickgrid.rs

@@ -0,0 +1,139 @@
+use std::collections::HashSet;
+
+use crate::{
+    gfx::{BulkBufferBuilder, Context},
+    math,
+};
+
+#[derive(Debug, Clone, Copy, PartialEq)]
+pub enum BrickgridFlag {
+    Empty = 0,
+    Unloaded = 1,
+    Loading = 2,
+    Loaded = 4,
+}
+
+impl From<u32> for BrickgridFlag {
+    fn from(value: u32) -> Self {
+        match value {
+            x if x == Self::Unloaded as u32 => Self::Unloaded,
+            x if x == Self::Loading as u32 => Self::Loading,
+            x if x == Self::Loaded as u32 => Self::Loaded,
+            _ => Self::Empty,
+        }
+    }
+}
+
+#[repr(C)]
+#[derive(Debug, Default, Clone, Copy, PartialEq, bytemuck::Pod, bytemuck::Zeroable)]
+pub struct BrickgridElement(pub u32);
+
+impl BrickgridElement {
+    pub fn new(brickmap_cache_idx: usize, flag: BrickgridFlag) -> Self {
+        Self(((brickmap_cache_idx as u32) << 8) + flag as u32)
+    }
+
+    pub fn get_pointer(&self) -> usize {
+        (self.0 >> 8) as usize
+    }
+
+    pub fn get_flag(&self) -> BrickgridFlag {
+        BrickgridFlag::from(self.0 & 0xF)
+    }
+}
+
+#[derive(Debug)]
+pub struct Brickgrid {
+    dimensions: glam::UVec3,
+    data: Vec<BrickgridElement>,
+    staged: HashSet<usize>,
+    max_upload_count: usize,
+    buffer: wgpu::Buffer,
+    upload_buffer: wgpu::Buffer,
+}
+
+impl Brickgrid {
+    pub fn new(context: &Context, dimensions: glam::UVec3, max_upload_count: usize) -> Self {
+        let element_count = (dimensions.x * dimensions.y * dimensions.z) as usize;
+        let data = vec![BrickgridElement::new(0, BrickgridFlag::Unloaded); element_count];
+
+        // TODO: change type of upload data. Will need some messyness with bytemucking probably
+        // but should lead to clearer data definitions
+        let mut upload_data = vec![0u32; 4 + 4 * max_upload_count];
+        upload_data[0] = max_upload_count as u32;
+
+        let mut buffers = BulkBufferBuilder::new()
+            .set_usage(wgpu::BufferUsages::STORAGE | wgpu::BufferUsages::COPY_DST)
+            .with_init_buffer_bm("Brickgrid", &data)
+            .with_init_buffer_bm("Brickgrid Upload", &upload_data)
+            .build(context);
+
+        Self {
+            dimensions,
+            data,
+            staged: HashSet::new(),
+            max_upload_count,
+            buffer: buffers.remove(0),
+            upload_buffer: buffers.remove(0),
+        }
+    }
+
+    /// Panics if position maps to out of range index
+    // pub fn set(&mut self, pos: glam::UVec3, value: BrickgridElement) -> BrickgridElement {
+    //      let index = math::to_1d_index(pos, self.dimensions);
+    pub fn set(&mut self, index: usize, value: BrickgridElement) -> BrickgridElement {
+        let current = self.data[index];
+        self.data[index] = value;
+        self.staged.insert(index);
+        current
+    }
+
+    /// Panics if position maps to out of range index
+    // pub fn get(&mut self, pos: glam::UVec3) -> BrickgridElement {
+    //     let index = math::to_1d_index(pos, self.dimensions);
+    pub fn get(&mut self, index: usize) -> BrickgridElement {
+        self.data[index]
+    }
+
+    pub fn upload(&mut self, context: &Context) {
+        let mut upload_data = Vec::new();
+        let mut idx = 0;
+        self.staged.retain(|e| {
+            // We have a limit of how many elements to upload each frame. So we need
+            // to keep any excess
+            if idx >= self.max_upload_count {
+                return true;
+            }
+
+            // Index of the brickgrid element, and the value of it
+            upload_data.push(*e as u32);
+            upload_data.push(self.data[*e].0);
+
+            idx += 1;
+            false
+        });
+
+        // Upload buffer is {max_count, count, pad, pad, bricks[]}. So we need to add
+        // the count and pads, and upload at an offset to skip max_count
+        let data = [&[upload_data.len() as u32, 0, 0], &upload_data[..]].concat();
+        context
+            .queue
+            .write_buffer(&self.upload_buffer, 4, bytemuck::cast_slice(&data));
+
+        if idx != 0 {
+            log::info!(
+                "Uploading {} brickgrid entries. ({} remaining)",
+                idx,
+                self.staged.len()
+            );
+        }
+    }
+
+    pub fn get_buffer(&self) -> &wgpu::Buffer {
+        &self.buffer
+    }
+
+    pub fn get_upload_buffer(&self) -> &wgpu::Buffer {
+        &self.upload_buffer
+    }
+}

src/voxel/brickworld/brickmap.rs

@@ -1,20 +1,14 @@
-use std::collections::HashSet;
-
 use crate::{
     gfx::{self, BufferExt},
     math,
-    voxel::world::{Voxel, WorldManager},
+    voxel::world::WorldManager,
 };
 
-use super::shading_table::ShadingTableAllocator;
-
-#[repr(C)]
-#[derive(Debug, Default, Copy, Clone, bytemuck::Pod, bytemuck::Zeroable)]
-struct Brickmap {
-    pub bitmask: [u32; 16],
-    pub shading_table_offset: u32,
-    pub lod_color: u32,
-}
+use super::{
+    brickgrid::{Brickgrid, BrickgridElement, BrickgridFlag},
+    brickmap_cache::{BrickmapCache, BrickmapCacheEntry},
+    shading_table::ShadingTableAllocator,
+};
 
 #[repr(C)]
 #[derive(Debug, Default, Copy, Clone, bytemuck::Pod, bytemuck::Zeroable)]
@@ -23,46 +17,17 @@ struct WorldState {
     _pad: u32,
 }
 
-#[derive(Debug, Default, Copy, Clone)]
-struct BrickmapCacheEntry {
-    grid_idx: usize,
-    shading_table_offset: u32,
-}
-
-#[repr(C)]
-#[derive(Debug, Copy, Clone, bytemuck::Pod, bytemuck::Zeroable)]
-struct BrickmapUnpackElement {
-    cache_idx: u32,
-    brickmap: Brickmap,
-    shading_element_count: u32,
-    shading_elements: [u32; 512],
-}
-
-enum BrickgridFlag {
-    _Empty = 0,
-    _Unloaded = 1,
-    _Loading = 2,
-    Loaded = 4,
-}
-
 #[derive(Debug)]
 pub struct BrickmapManager {
     state_uniform: WorldState,
     state_buffer: wgpu::Buffer,
-    brickgrid: Vec<u32>,
-    brickgrid_buffer: wgpu::Buffer,
-    brickmap_cache_map: Vec<Option<BrickmapCacheEntry>>,
-    brickmap_cache_idx: usize,
-    brickmap_buffer: wgpu::Buffer,
+    brickgrid: Brickgrid,
+    brickmap_cache: BrickmapCache,
     shading_table_buffer: wgpu::Buffer,
     shading_table_allocator: ShadingTableAllocator,
     feedback_buffer: wgpu::Buffer,
     feedback_result_buffer: wgpu::Buffer,
     unpack_max_count: usize,
-    brickgrid_staged: HashSet<usize>,
-    brickgrid_unpack_buffer: wgpu::Buffer,
-    brickmap_staged: Vec<BrickmapUnpackElement>,
-    brickmap_unpack_buffer: wgpu::Buffer,
 }
 
 // TODO:
@@ -81,11 +46,12 @@ impl BrickmapManager {
             ..Default::default()
         };
 
-        let brickgrid =
-            vec![1u32; (brickgrid_dims.x * brickgrid_dims.y * brickgrid_dims.z) as usize];
-
-        let brickmap_cache = vec![Brickmap::default(); brickmap_cache_size];
-        let brickmap_cache_map = vec![None; brickmap_cache.capacity()];
+        let brickgrid = Brickgrid::new(context, brickgrid_dims, max_uploaded_brickmaps as usize);
+        let brickmap_cache = BrickmapCache::new(
+            context,
+            brickmap_cache_size,
+            max_uploaded_brickmaps as usize,
+        );
 
         let shading_table_allocator = ShadingTableAllocator::new(4, shading_table_bucket_size);
         let shading_table = vec![0u32; shading_table_allocator.total_elements as usize];
@@ -94,22 +60,13 @@ impl BrickmapManager {
         feedback_data[0] = max_requested_brickmaps;
         let feedback_data_u8 = bytemuck::cast_slice(&feedback_data);
 
-        let mut brickgrid_upload_data = vec![0u32; 4 + 4 * max_uploaded_brickmaps as usize];
-        brickgrid_upload_data[0] = max_uploaded_brickmaps;
-        let brickgrid_staged = HashSet::new();
-
         let mut brickmap_upload_data = vec![0u32; 4 + 532 * max_uploaded_brickmaps as usize];
         brickmap_upload_data[0] = max_uploaded_brickmaps;
-        let brickmap_staged = Vec::new();
 
         let mut buffers = gfx::BulkBufferBuilder::new()
             .with_init_buffer_bm("Brick World State", &[state_uniform])
             .set_usage(wgpu::BufferUsages::STORAGE | wgpu::BufferUsages::COPY_DST)
-            .with_init_buffer_bm("Brickgrid", &brickgrid)
-            .with_init_buffer_bm("Brickmap Cache", &brickmap_cache)
             .with_init_buffer_bm("Shading Table", &shading_table)
-            .with_init_buffer_bm("Brickgrid Unpack", &brickgrid_upload_data)
-            .with_init_buffer_bm("Brickmap Unpack", &brickmap_upload_data)
             .set_usage(
                 wgpu::BufferUsages::STORAGE
                     | wgpu::BufferUsages::COPY_DST
@@ -123,26 +80,19 @@ impl BrickmapManager {
         Self {
             state_uniform,
             brickgrid,
-            brickmap_cache_map,
-            brickmap_cache_idx: 0,
+            brickmap_cache,
             shading_table_allocator,
             unpack_max_count: max_uploaded_brickmaps as usize,
-            brickgrid_staged,
-            brickmap_staged,
 
             state_buffer: buffers.remove(0),
-            brickgrid_buffer: buffers.remove(0),
-            brickmap_buffer: buffers.remove(0),
             shading_table_buffer: buffers.remove(0),
-            brickgrid_unpack_buffer: buffers.remove(0),
-            brickmap_unpack_buffer: buffers.remove(0),
             feedback_buffer: buffers.remove(0),
             feedback_result_buffer: buffers.remove(0),
         }
     }
 
     pub fn get_brickgrid_buffer(&self) -> &wgpu::Buffer {
-        &self.brickgrid_buffer
+        self.brickgrid.get_buffer()
     }
 
     pub fn get_worldstate_buffer(&self) -> &wgpu::Buffer {
@@ -150,7 +100,7 @@ impl BrickmapManager {
     }
 
     pub fn get_brickmap_buffer(&self) -> &wgpu::Buffer {
-        &self.brickmap_buffer
+        self.brickmap_cache.get_buffer()
     }
 
     pub fn get_shading_buffer(&self) -> &wgpu::Buffer {
@@ -166,11 +116,11 @@ impl BrickmapManager {
     }
 
     pub fn get_brickmap_unpack_buffer(&self) -> &wgpu::Buffer {
-        &self.brickmap_unpack_buffer
+        self.brickmap_cache.get_upload_buffer()
     }
 
     pub fn get_brickgrid_unpack_buffer(&self) -> &wgpu::Buffer {
-        &self.brickgrid_unpack_buffer
+        self.brickgrid.get_upload_buffer()
     }
 
     pub fn get_unpack_max_count(&self) -> usize {
@@ -198,8 +148,7 @@ impl BrickmapManager {
         // TODO: Why do we call this here rather than doing it outside of here?
         self.upload_unpack_buffers(context);
 
-        // TODO: This is inaccurate if we've looped
-        log::info!("Num loaded brickmaps: {}", self.brickmap_cache_idx);
+        log::info!("Num loaded brickmaps: {}", self.brickmap_cache.num_loaded);
     }
 
     fn handle_request(&mut self, world: &mut WorldManager, data: &[u32]) {
@@ -215,264 +164,73 @@ impl BrickmapManager {
         // We only want to upload voxels that are on the surface, so we cull anything
         // that is surrounded by solid voxels
         let grid_pos = grid_pos.as_ivec3();
-        let (bitmask_data, albedo_data) = Self::cull_interior_voxels(world, grid_pos);
+        let (bitmask_data, albedo_data) = super::util::cull_interior_voxels(world, grid_pos);
 
         // If there's no voxel colour data post-culling it means the brickmap is
         // empty. We don't need to upload it, just mark the relevant brickgrid entry.
         if albedo_data.is_empty() {
-            self.update_brickgrid_element(grid_idx, 0);
+            if let Some(entry) = self.update_brickgrid_element(grid_idx, 0) {
+                // TODO: We need to actually remove the cache entry lmao
+                // The brickgrid element had a brickmap entry so we need to unload it's
+                // shading data
+                if let Err(e) = self
+                    .shading_table_allocator
+                    .try_dealloc(entry.shading_table_offset)
+                {
+                    log::warn!("{}", e)
+                }
+            }
             return;
         }
 
-        // Update the brickgrid index
-        self.update_brickgrid_element(
-            grid_idx,
-            Self::to_brickgrid_element(self.brickmap_cache_idx as u32, BrickgridFlag::Loaded),
-        );
-
-        // If there's already something in the cache spot we want to write to, we
-        // need to unload it.
-        if self.brickmap_cache_map[self.brickmap_cache_idx].is_some() {
-            let entry = self.brickmap_cache_map[self.brickmap_cache_idx].unwrap();
-            self.update_brickgrid_element(entry.grid_idx, 1);
-        }
-
         // Update the shading table
         let shading_idx = self
             .shading_table_allocator
             .try_alloc(albedo_data.len() as u32)
             .unwrap() as usize;
 
-        // We're all good to overwrite the cache map entry now :)
-        self.brickmap_cache_map[self.brickmap_cache_idx] = Some(BrickmapCacheEntry {
+        if let Some(entry) =
+            self.brickmap_cache
+                .add_entry(grid_idx, shading_idx as u32, bitmask_data, albedo_data)
+        {
+            self.update_brickgrid_element(entry.grid_idx, 1);
+        }
+
+        // Update the brickgrid index
+        if let Some(old_entry) = self.update_brickgrid_element(
             grid_idx,
-            shading_table_offset: shading_idx as u32,
-        });
-
-        // Update the brickmap
-        let brickmap = Brickmap {
-            bitmask: bitmask_data,
-            shading_table_offset: shading_idx as u32,
-            lod_color: 0,
-        };
-
-        let shading_element_count = albedo_data.len();
-        let mut shading_elements = [0u32; 512];
-        shading_elements[..shading_element_count].copy_from_slice(&albedo_data);
-
-        let staged_brickmap = BrickmapUnpackElement {
-            cache_idx: self.brickmap_cache_idx as u32,
-            brickmap,
-            shading_element_count: shading_element_count as u32,
-            shading_elements,
-        };
-        self.brickmap_staged.push(staged_brickmap);
-        self.brickmap_cache_idx = (self.brickmap_cache_idx + 1) % self.brickmap_cache_map.len();
+            super::util::to_brickgrid_element(
+                self.brickmap_cache.index as u32,
+                BrickgridFlag::Loaded,
+            ),
+        ) {
+            // TODO: We need to actually remove the cache entry lmao
+            // The brickgrid element had a brickmap entry so we need to unload it's
+            // shading data
+            if let Err(e) = self
+                .shading_table_allocator
+                .try_dealloc(old_entry.shading_table_offset)
+            {
+                log::warn!("{}", e)
+            }
+        }
     }
 
-    fn update_brickgrid_element(&mut self, index: usize, data: u32) {
-        // If we're updating a brickgrid element, we need to make sure to deallocate anything
-        // that's already there. The shading table gets deallocated, and the brickmap cache entry
-        // is marked as None.
-        if (self.brickgrid[index] & 0xF) == 4 {
-            let brickmap_idx = (self.brickgrid[index] >> 8) as usize;
-            let cache_map_entry = self.brickmap_cache_map[brickmap_idx];
-            match cache_map_entry {
-                Some(entry) => {
-                    match self
-                        .shading_table_allocator
-                        .try_dealloc(entry.shading_table_offset)
-                    {
-                        Ok(_) => (),
-                        Err(e) => log::warn!("{}", e),
-                    }
-                    self.brickmap_cache_map[brickmap_idx] = None;
-                }
-                None => log::warn!("Expected brickmap cache entry, found None!"),
-            }
+    fn update_brickgrid_element(&mut self, index: usize, data: u32) -> Option<BrickmapCacheEntry> {
+        let mut brickmap_cache_entry = None;
+        let current = self.brickgrid.get(index);
+        if current.get_flag() == BrickgridFlag::Loaded {
+            let cache_index = current.get_pointer();
+            brickmap_cache_entry = self.brickmap_cache.get_entry(cache_index);
         }
 
         // We're safe to overwrite the CPU brickgrid and mark for GPU upload now
-        self.brickgrid[index] = data;
-        self.brickgrid_staged.insert(index);
+        self.brickgrid.set(index, BrickgridElement(data));
+        brickmap_cache_entry
     }
 
     fn upload_unpack_buffers(&mut self, context: &gfx::Context) {
-        // Brickgrid
-        let mut data = Vec::new();
-        let mut iter = self.brickgrid_staged.iter();
-        let mut to_remove = Vec::new();
-        for _ in 0..self.unpack_max_count {
-            let el = iter.next();
-            if el.is_none() {
-                break;
-            }
-
-            let val = el.unwrap();
-            to_remove.push(*val as u32);
-            data.push(*val as u32);
-            data.push(self.brickgrid[*val]);
-        }
-        for val in &to_remove {
-            self.brickgrid_staged.remove(&(*val as usize));
-        }
-
-        if !data.is_empty() {
-            log::info!(
-                "Uploading {} brickgrid entries. ({} remaining)",
-                to_remove.len(),
-                self.brickgrid_staged.len()
-            );
-        }
-
-        context.queue.write_buffer(
-            &self.brickgrid_unpack_buffer,
-            4,
-            bytemuck::cast_slice(&[data.len()]),
-        );
-        context.queue.write_buffer(
-            &self.brickgrid_unpack_buffer,
-            16,
-            bytemuck::cast_slice(&data),
-        );
-
-        // Brickmap
-        let end = self.unpack_max_count.min(self.brickmap_staged.len());
-        let iter = self.brickmap_staged.drain(0..end);
-        let data = iter.as_slice();
-        context.queue.write_buffer(
-            &self.brickmap_unpack_buffer,
-            4,
-            bytemuck::cast_slice(&[end]),
-        );
-        context
-            .queue
-            .write_buffer(&self.brickmap_unpack_buffer, 16, bytemuck::cast_slice(data));
-        drop(iter);
-
-        if end > 0 {
-            log::info!(
-                "Uploading {} brickmap entries. ({} remaining)",
-                end,
-                self.brickmap_staged.len()
-            );
-        }
-    }
-
-    fn cull_interior_voxels(
-        world: &mut WorldManager,
-        grid_pos: glam::IVec3,
-    ) -> ([u32; 16], Vec<u32>) {
-        // This is the data we want to return
-        let mut bitmask_data = [0xFFFFFFFF_u32; 16];
-        let mut albedo_data = Vec::<u32>::new();
-
-        // Calculate world chunk and block positions for each that may be accessed
-        let center_pos = Self::grid_pos_to_world_pos(world, grid_pos);
-        let forward_pos = Self::grid_pos_to_world_pos(world, grid_pos + glam::ivec3(1, 0, 0));
-        let backward_pos = Self::grid_pos_to_world_pos(world, grid_pos + glam::ivec3(-1, 0, 0));
-        let left_pos = Self::grid_pos_to_world_pos(world, grid_pos + glam::ivec3(0, 0, -1));
-        let right_pos = Self::grid_pos_to_world_pos(world, grid_pos + glam::ivec3(0, 0, 1));
-        let up_pos = Self::grid_pos_to_world_pos(world, grid_pos + glam::ivec3(0, 1, 0));
-        let down_pos = Self::grid_pos_to_world_pos(world, grid_pos + glam::ivec3(0, -1, 0));
-
-        // Fetch those blocks
-        let center_block = world.get_block(center_pos.0, center_pos.1);
-        let forward_block = world.get_block(forward_pos.0, forward_pos.1);
-        let backward_block = world.get_block(backward_pos.0, backward_pos.1);
-        let left_block = world.get_block(left_pos.0, left_pos.1);
-        let right_block = world.get_block(right_pos.0, right_pos.1);
-        let up_block = world.get_block(up_pos.0, up_pos.1);
-        let down_block = world.get_block(down_pos.0, down_pos.1);
-
-        //  Reusable array of whether cardinal neighbours are empty
-        let mut neighbours = [false; 6];
-        for z in 0..8 {
-            // Each z level contains two bitmask segments of voxels
-            let mut entry = 0u64;
-            for y in 0..8 {
-                for x in 0..8 {
-                    // Ignore non-solids
-                    let idx = x + y * 8 + z * 8 * 8;
-                    let empty_voxel = Voxel::Empty;
-
-                    match center_block[idx] {
-                        Voxel::Empty => continue,
-                        Voxel::Color(r, g, b) => {
-                            // A voxel is on the surface if at least one of it's
-                            // cardinal neighbours is non-solid.
-                            neighbours[0] = if x == 7 {
-                                forward_block[idx - 7] == empty_voxel
-                            } else {
-                                center_block[idx + 1] == empty_voxel
-                            };
-
-                            neighbours[1] = if x == 0 {
-                                backward_block[idx + 7] == empty_voxel
-                            } else {
-                                center_block[idx - 1] == empty_voxel
-                            };
-
-                            neighbours[2] = if z == 7 {
-                                right_block[idx - 448] == empty_voxel
-                            } else {
-                                center_block[idx + 64] == empty_voxel
-                            };
-
-                            neighbours[3] = if z == 0 {
-                                left_block[idx + 448] == empty_voxel
-                            } else {
-                                center_block[idx - 64] == empty_voxel
-                            };
-
-                            neighbours[4] = if y == 7 {
-                                up_block[idx - 56] == empty_voxel
-                            } else {
-                                center_block[idx + 8] == empty_voxel
-                            };
-
-                            neighbours[5] = if y == 0 {
-                                down_block[idx + 56] == empty_voxel
-                            } else {
-                                center_block[idx - 8] == empty_voxel
-                            };
-
-                            // Set the appropriate bit in the z entry and add the
-                            // shading data
-                            let surface_voxel = neighbours.iter().any(|v| *v);
-                            if surface_voxel {
-                                entry += 1 << (x + y * 8);
-                                let albedo = ((r as u32) << 24)
-                                    + ((g as u32) << 16)
-                                    + ((b as u32) << 8)
-                                    + 255u32;
-                                albedo_data.push(albedo);
-                            }
-                        }
-                    }
-                }
-            }
-            let offset = 2 * z;
-            bitmask_data[offset] = (entry & 0xFFFFFFFF).try_into().unwrap();
-            bitmask_data[offset + 1] = ((entry >> 32) & 0xFFFFFFFF).try_into().unwrap();
-        }
-
-        (bitmask_data, albedo_data)
-    }
-
-    fn to_brickgrid_element(brickmap_cache_idx: u32, flags: BrickgridFlag) -> u32 {
-        (brickmap_cache_idx << 8) + flags as u32
-    }
-
-    fn grid_pos_to_world_pos(
-        world: &mut WorldManager,
-        grid_pos: glam::IVec3,
-    ) -> (glam::IVec3, glam::UVec3) {
-        // We deal with dvecs here because we want a negative grid_pos to have floored
-        // chunk_pos
-        let chunk_dims = world.get_chunk_dims().as_dvec3();
-        let chunk_pos = (grid_pos.as_dvec3() / chunk_dims).floor();
-        let block_pos = grid_pos - (chunk_pos * chunk_dims).as_ivec3();
-        (chunk_pos.as_ivec3(), block_pos.as_uvec3())
+        self.brickgrid.upload(context);
+        self.brickmap_cache.upload(context);
     }
 }

src/voxel/brickworld/brickmap_cache.rs

@@ -0,0 +1,156 @@
+use crate::gfx::{BulkBufferBuilder, Context};
+
+#[repr(C)]
+#[derive(Debug, Default, Copy, Clone, bytemuck::Pod, bytemuck::Zeroable)]
+pub struct Brickmap {
+    pub bitmask: [u32; 16],
+    pub shading_table_offset: u32,
+    pub lod_color: u32,
+}
+
+#[derive(Debug, Default, Copy, Clone)]
+pub struct BrickmapCacheEntry {
+    pub grid_idx: usize,
+    pub shading_table_offset: u32,
+}
+
+#[repr(C)]
+#[derive(Debug, Copy, Clone, bytemuck::Pod, bytemuck::Zeroable)]
+// TODO: Rename struct
+struct BrickmapUnpackElement {
+    cache_idx: u32, // TODO: Change to usize?
+    brickmap: Brickmap,
+    shading_element_count: u32,
+    shading_elements: [u32; 512], // TODO: Replace u32 with custom type?
+}
+
+#[derive(Debug)]
+pub struct BrickmapCache {
+    cache: Vec<Option<BrickmapCacheEntry>>,
+    pub index: usize,
+    pub num_loaded: u32,
+    staged: Vec<BrickmapUnpackElement>,
+    max_upload_count: usize,
+    buffer: wgpu::Buffer,
+    upload_buffer: wgpu::Buffer,
+}
+
+impl BrickmapCache {
+    pub fn new(context: &Context, size: usize, max_upload_count: usize) -> Self {
+        let data = vec![Brickmap::default(); size];
+
+        // TODO: change type of upload data. Will need some messyness with bytemucking probably
+        // but should lead to clearer data definitions
+        let mut upload_data = vec![0u32; 4 + 532 * max_upload_count];
+        upload_data[0] = max_upload_count as u32;
+
+        let mut buffers = BulkBufferBuilder::new()
+            .set_usage(wgpu::BufferUsages::STORAGE | wgpu::BufferUsages::COPY_DST)
+            .with_init_buffer_bm("Brickmap Cache", &data)
+            .with_init_buffer_bm("Brickmap Unpack", &upload_data)
+            .build(context);
+
+        Self {
+            cache: vec![None; size],
+            index: 0,
+            num_loaded: 0,
+            staged: vec![],
+            max_upload_count,
+            buffer: buffers.remove(0),
+            upload_buffer: buffers.remove(0),
+        }
+    }
+
+    pub fn get_buffer(&self) -> &wgpu::Buffer {
+        &self.buffer
+    }
+
+    pub fn get_upload_buffer(&self) -> &wgpu::Buffer {
+        &self.upload_buffer
+    }
+
+    /// Adds a brickmap entry and returns the entry that was overwritten.
+    pub fn add_entry(
+        &mut self,
+        grid_idx: usize,
+        shading_table_offset: u32,
+        bitmask: [u32; 16],
+        albedo_data: Vec<u32>,
+    ) -> Option<BrickmapCacheEntry> {
+        // We do this first because we want this to be the index of the most recently added entry
+        // This has the side effect of meaning that on the first loop through the cache the first
+        // entry is empty, but it's fine.
+        self.index = (self.index + 1) % self.cache.len();
+
+        let existing_entry = self.cache[self.index];
+        if existing_entry.is_none() {
+            self.num_loaded += 1;
+        }
+
+        self.cache[self.index] = Some(BrickmapCacheEntry {
+            grid_idx,
+            shading_table_offset,
+        });
+
+        // Need to stage this entry
+        let brickmap = Brickmap {
+            bitmask,
+            shading_table_offset,
+            lod_color: 0,
+        };
+
+        let shading_element_count = albedo_data.len();
+        let mut shading_elements = [0u32; 512];
+        shading_elements[..shading_element_count].copy_from_slice(&albedo_data);
+
+        let staged_brickmap = BrickmapUnpackElement {
+            cache_idx: self.index as u32,
+            brickmap,
+            shading_element_count: shading_element_count as u32,
+            shading_elements,
+        };
+        self.staged.push(staged_brickmap);
+
+        existing_entry
+    }
+
+    /// Remove an entry from the cache and return it
+    pub fn remove_entry(&mut self, index: usize) -> Option<BrickmapCacheEntry> {
+        let entry = self.cache[index];
+        if entry.is_some() {
+            self.cache[index] = None;
+            self.num_loaded -= 1;
+        }
+
+        entry
+    }
+
+    pub fn get_entry(&self, index: usize) -> Option<BrickmapCacheEntry> {
+        self.cache[index]
+    }
+
+    pub fn upload(&mut self, context: &Context) {
+        // Takes up to max_upload_count upload elements
+        let count = usize::min(self.max_upload_count, self.staged.len());
+        let iter = self.staged.drain(0..count);
+        let upload_data = iter.as_slice();
+
+        // Upload buffer is {max_count, count, pad, pad, maps[]}. So we need to add
+        // the count and pads, and upload at an offset to skip max_count
+        let data: Vec<u8> = [
+            bytemuck::cast_slice(&[count as u32, 0, 0]),
+            bytemuck::cast_slice(upload_data),
+        ]
+        .concat();
+        context.queue.write_buffer(&self.upload_buffer, 4, &data);
+        drop(iter);
+
+        if count > 0 {
+            log::info!(
+                "Uploading {} brickmap entries. ({} remaining)",
+                count,
+                self.staged.len()
+            );
+        }
+    }
+}

src/voxel/brickworld/mod.rs

@@ -1,4 +1,7 @@
+mod brickgrid;
 mod brickmap;
+mod brickmap_cache;
 mod shading_table;
+mod util;
 
 pub use brickmap::BrickmapManager;

src/voxel/brickworld/util.rs

@@ -0,0 +1,120 @@
+use crate::voxel::world::{Voxel, WorldManager};
+
+use super::brickgrid::BrickgridFlag;
+
+pub fn cull_interior_voxels(
+    world: &mut WorldManager,
+    grid_pos: glam::IVec3,
+) -> ([u32; 16], Vec<u32>) {
+    // This is the data we want to return
+    let mut bitmask_data = [0xFFFFFFFF_u32; 16];
+    let mut albedo_data = Vec::<u32>::new();
+
+    // Calculate world chunk and block positions for each that may be accessed
+    let center_pos = grid_pos_to_world_pos(world, grid_pos);
+    let forward_pos = grid_pos_to_world_pos(world, grid_pos + glam::ivec3(1, 0, 0));
+    let backward_pos = grid_pos_to_world_pos(world, grid_pos + glam::ivec3(-1, 0, 0));
+    let left_pos = grid_pos_to_world_pos(world, grid_pos + glam::ivec3(0, 0, -1));
+    let right_pos = grid_pos_to_world_pos(world, grid_pos + glam::ivec3(0, 0, 1));
+    let up_pos = grid_pos_to_world_pos(world, grid_pos + glam::ivec3(0, 1, 0));
+    let down_pos = grid_pos_to_world_pos(world, grid_pos + glam::ivec3(0, -1, 0));
+
+    // Fetch those blocks
+    let center_block = world.get_block(center_pos.0, center_pos.1);
+    let forward_block = world.get_block(forward_pos.0, forward_pos.1);
+    let backward_block = world.get_block(backward_pos.0, backward_pos.1);
+    let left_block = world.get_block(left_pos.0, left_pos.1);
+    let right_block = world.get_block(right_pos.0, right_pos.1);
+    let up_block = world.get_block(up_pos.0, up_pos.1);
+    let down_block = world.get_block(down_pos.0, down_pos.1);
+
+    //  Reusable array of whether cardinal neighbours are empty
+    let mut neighbours = [false; 6];
+    for z in 0..8 {
+        // Each z level contains two bitmask segments of voxels
+        let mut entry = 0u64;
+        for y in 0..8 {
+            for x in 0..8 {
+                // Ignore non-solids
+                let idx = x + y * 8 + z * 8 * 8;
+                let empty_voxel = Voxel::Empty;
+
+                match center_block[idx] {
+                    Voxel::Empty => continue,
+                    Voxel::Color(r, g, b) => {
+                        // A voxel is on the surface if at least one of it's
+                        // cardinal neighbours is non-solid.
+                        neighbours[0] = if x == 7 {
+                            forward_block[idx - 7] == empty_voxel
+                        } else {
+                            center_block[idx + 1] == empty_voxel
+                        };
+
+                        neighbours[1] = if x == 0 {
+                            backward_block[idx + 7] == empty_voxel
+                        } else {
+                            center_block[idx - 1] == empty_voxel
+                        };
+
+                        neighbours[2] = if z == 7 {
+                            right_block[idx - 448] == empty_voxel
+                        } else {
+                            center_block[idx + 64] == empty_voxel
+                        };
+
+                        neighbours[3] = if z == 0 {
+                            left_block[idx + 448] == empty_voxel
+                        } else {
+                            center_block[idx - 64] == empty_voxel
+                        };
+
+                        neighbours[4] = if y == 7 {
+                            up_block[idx - 56] == empty_voxel
+                        } else {
+                            center_block[idx + 8] == empty_voxel
+                        };
+
+                        neighbours[5] = if y == 0 {
+                            down_block[idx + 56] == empty_voxel
+                        } else {
+                            center_block[idx - 8] == empty_voxel
+                        };
+
+                        // Set the appropriate bit in the z entry and add the
+                        // shading data
+                        let surface_voxel = neighbours.iter().any(|v| *v);
+                        if surface_voxel {
+                            entry += 1 << (x + y * 8);
+                            let albedo = ((r as u32) << 24)
+                                + ((g as u32) << 16)
+                                + ((b as u32) << 8)
+                                + 255u32;
+                            albedo_data.push(albedo);
+                        }
+                    }
+                }
+            }
+        }
+        let offset = 2 * z;
+        bitmask_data[offset] = (entry & 0xFFFFFFFF).try_into().unwrap();
+        bitmask_data[offset + 1] = ((entry >> 32) & 0xFFFFFFFF).try_into().unwrap();
+    }
+
+    (bitmask_data, albedo_data)
+}
+
+pub fn to_brickgrid_element(brickmap_cache_idx: u32, flags: BrickgridFlag) -> u32 {
+    (brickmap_cache_idx << 8) + flags as u32
+}
+
+pub fn grid_pos_to_world_pos(
+    world: &mut WorldManager,
+    grid_pos: glam::IVec3,
+) -> (glam::IVec3, glam::UVec3) {
+    // We deal with dvecs here because we want a negative grid_pos to have floored
+    // chunk_pos
+    let chunk_dims = world.get_chunk_dims().as_dvec3();
+    let chunk_pos = (grid_pos.as_dvec3() / chunk_dims).floor();
+    let block_pos = grid_pos - (chunk_pos * chunk_dims).as_ivec3();
+    (chunk_pos.as_ivec3(), block_pos.as_uvec3())
+}

src/voxel/voxel_renderer.rs

@@ -177,6 +177,15 @@ impl VoxelRenderer {
             unpack_bind_group,
         })
     }
+
+    pub fn update_brickmap(
+        &mut self,
+        context: &gfx::Context,
+        world: &mut super::world::WorldManager,
+    ) {
+        self.brickmap_manager
+            .process_feedback_buffer(context, world);
+    }
 }
 
 impl gfx::Renderer for VoxelRenderer {
@@ -240,14 +249,3 @@ impl gfx::Renderer for VoxelRenderer {
         Ok(())
     }
 }
-
-impl VoxelRenderer {
-    pub fn update_brickmap(
-        &mut self,
-        context: &gfx::Context,
-        world: &mut super::world::WorldManager,
-    ) {
-        self.brickmap_manager
-            .process_feedback_buffer(context, world);
-    }
-}