src/voxel/brickworld/brickgrid.rs

@@ -1,6 +1,9 @@
 use std::collections::HashSet;
 
-use crate::gfx::{BulkBufferBuilder, Context};
+use crate::{
+    gfx::{BulkBufferBuilder, Context},
+    math,
+};
 
 #[derive(Debug, Clone, Copy, PartialEq)]
 pub enum BrickgridFlag {
@@ -75,15 +78,9 @@ impl Brickgrid {
         }
     }
 
-    pub fn get_buffer(&self) -> &wgpu::Buffer {
-        &self.buffer
-    }
-
-    pub fn get_upload_buffer(&self) -> &wgpu::Buffer {
-        &self.upload_buffer
-    }
-
-    /// Panics if index out of range
+    /// 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;
@@ -91,7 +88,9 @@ impl Brickgrid {
         current
     }
 
-    /// Panics if index out of range
+    /// 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]
     }
@@ -129,4 +128,12 @@ impl Brickgrid {
             );
         }
     }
+
+    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

@@ -6,7 +6,7 @@ use crate::{
 
 use super::{
     brickgrid::{Brickgrid, BrickgridElement, BrickgridFlag},
-    brickmap_cache::BrickmapCache,
+    brickmap_cache::{BrickmapCache, BrickmapCacheEntry},
     shading_table::ShadingTableAllocator,
 };
 
@@ -166,63 +166,69 @@ impl BrickmapManager {
         let grid_pos = grid_pos.as_ivec3();
         let (bitmask_data, albedo_data) = super::util::cull_interior_voxels(world, grid_pos);
 
-        let mut brickgrid_element = BrickgridElement::default();
+        // 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() {
+            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;
+        }
 
-        // We have voxel data so we have a brickmap to upload
-        if !albedo_data.is_empty() {
-            let shading_idx = self
+        // Update the shading table
+        let shading_idx = self
+            .shading_table_allocator
+            .try_alloc(albedo_data.len() as u32)
+            .unwrap() as usize;
+
+        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,
+            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_alloc(albedo_data.len() as u32)
-                .unwrap() as usize;
-
-            if let Some(entry) = self.brickmap_cache.add_entry(
-                grid_idx,
-                shading_idx as u32,
-                bitmask_data,
-                albedo_data,
-            ) {
-                // An entry got removed so we need to deallocate it's shading table elements
-                // and mark the relevant brickgrid as unloaded
-                if let Err(e) = self
-                    .shading_table_allocator
-                    .try_dealloc(entry.shading_table_offset)
-                {
-                    log::warn!("{}", e)
-                }
-                self.brickgrid.set(
-                    entry.grid_idx,
-                    BrickgridElement::new(0, BrickgridFlag::Unloaded),
-                );
-            }
-
-            brickgrid_element =
-                BrickgridElement::new(self.brickmap_cache.index, BrickgridFlag::Loaded);
-        }
-
-        let old = self.brickgrid.set(grid_idx, brickgrid_element);
-        if old.get_flag() == BrickgridFlag::Loaded {
-            // The brickgrid element was previously loaded so we need to unload any of
-            // the data that was associated with it
-            if let Some(entry) = self.brickmap_cache.remove_entry(old.get_pointer()) {
-                if entry.grid_idx != grid_idx {
-                    log::error!(
-                        "Mismatch between brickgrid index and brickmap grid index: {} vs {}",
-                        grid_idx,
-                        entry.grid_idx
-                    );
-                }
-
-                // We need to deallocate the removed entries shading table elements
-                if let Err(e) = self
-                    .shading_table_allocator
-                    .try_dealloc(entry.shading_table_offset)
-                {
-                    log::warn!("{}", e)
-                }
+                .try_dealloc(old_entry.shading_table_offset)
+            {
+                log::warn!("{}", e)
             }
         }
     }
 
+    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.set(index, BrickgridElement(data));
+        brickmap_cache_entry
+    }
+
     fn upload_unpack_buffers(&mut self, context: &gfx::Context) {
         self.brickgrid.upload(context);
         self.brickmap_cache.upload(context);

src/voxel/brickworld/util.rs

@@ -1,5 +1,7 @@
 use crate::voxel::world::{Voxel, WorldManager};
 
+use super::brickgrid::BrickgridFlag;
+
 pub fn cull_interior_voxels(
     world: &mut WorldManager,
     grid_pos: glam::IVec3,
@@ -101,6 +103,10 @@ pub fn cull_interior_voxels(
     (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,