Don't grow the capacity of chunk mesh buffers more than is necessary

Author: FiniteReality

src/main/java/org/embeddedt/embeddium/impl/render/chunk/compile/ChunkBuildBuffers.java

@@ -37,7 +37,7 @@ public ChunkBuildBuffers(ChunkVertexType vertexType) {
             var vertexBuffers = new ChunkMeshBufferBuilder[ModelQuadFacing.COUNT];
 
             for (int facing = 0; facing < ModelQuadFacing.COUNT; facing++) {
-                vertexBuffers[facing] = new ChunkMeshBufferBuilder(this.vertexType, 128 * 1024, pass.isSorted() && facing == ModelQuadFacing.UNASSIGNED.ordinal());
+                vertexBuffers[facing] = new ChunkMeshBufferBuilder(this.vertexType, 64 * 1024, pass.isSorted() && facing == ModelQuadFacing.UNASSIGNED.ordinal());
             }
 
             this.builders.put(pass, new BakedChunkModelBuilder(vertexBuffers, !pass.isSorted()));

src/main/java/org/embeddedt/embeddium/impl/render/chunk/vertex/builder/ChunkMeshBufferBuilder.java

@@ -26,21 +26,21 @@ public ChunkMeshBufferBuilder(ChunkVertexType vertexType, int initialCapacity, b
 
         this.buffer = null;
 
-        this.capacity = initialCapacity;
+        this.capacity = 0;
         this.initialCapacity = initialCapacity;
 
         this.analyzer = collectSortState ? new TranslucentQuadAnalyzer() : null;
     }
 
     public void push(ChunkVertexEncoder.Vertex[] vertices, Material material) {
-        var vertexStart = this.count;
-        var vertexCount = vertices.length;
+        var vertexStart = this.count * this.stride;
+        var vertexSize = vertices.length * this.stride;
 
-        if (this.count + vertexCount >= this.capacity) {
-            this.grow(this.stride * vertexCount);
+        if (vertexStart + vertexSize >= this.capacity) {
+            this.grow(vertexSize);
         }
 
-        long ptr = MemoryUtil.memAddress(this.buffer, this.count * this.stride);
+        long ptr = MemoryUtil.memAddress(this.buffer, vertexStart);
 
         if (this.analyzer != null) {
             for (ChunkVertexEncoder.Vertex vertex : vertices) {
@@ -52,20 +52,18 @@ public void push(ChunkVertexEncoder.Vertex[] vertices, Material material) {
             ptr = this.encoder.write(ptr, material, vertex, this.sectionIndex);
         }
 
-        this.count += vertexCount;
+        this.count += vertices.length;
     }
 
-    private void grow(int len) {
-        // The new capacity will at least as large as the write it needs to service
-        int cap = Math.max(this.capacity * 2, this.capacity + len);
+    private void grow(int bytesNeeded) {
+        // Grow by a factor of 2, or by however many bytes more we need, whichever is larger.
+        int newCapacity = Math.max(this.capacity * 2, this.capacity + bytesNeeded);
+        // Ensure we allocate at least initialCapacity bytes
+        newCapacity = Math.max(newCapacity, this.initialCapacity);
 
-        // Update the buffer and capacity now
-        this.setBufferSize(cap * this.stride);
-    }
 
-    private void setBufferSize(int capacity) {
-        this.buffer = MemoryUtil.memRealloc(this.buffer, capacity * this.stride);
-        this.capacity = capacity;
+        this.buffer = MemoryUtil.memRealloc(this.buffer, newCapacity);
+        this.capacity = newCapacity;
     }
 
     public void start(int sectionIndex) {
@@ -74,8 +72,6 @@ public void start(int sectionIndex) {
         if(this.analyzer != null) {
             this.analyzer.clear();
         }
-
-        this.setBufferSize(this.initialCapacity);
     }
 
     @Nullable
@@ -89,6 +85,7 @@ public void destroy() {
         }
 
         this.buffer = null;
+        this.capacity = 0;
     }
 
     public boolean isEmpty() {