WIP

src/pipelines/copy/copy-pipeline.ts

@@ -1,19 +1,28 @@
 import { vec2 } from 'gl-matrix';
 
+import {
+  createCachedFloat32BufferWrite,
+  writeFloat32BufferIfChanged,
+} from '../../utils/graphics/cached-buffer-write';
 import { smartCompile } from '../../utils/graphics/smart-compile';
 import shader from './copy.wgsl?raw';
 
 export class CopyPipeline {
   private static readonly UNIFORM_COUNT = 2;
+  private static readonly DEFAULT_SCALE = vec2.fromValues(1, 1);
 
   private readonly bindGroupLayout: GPUBindGroupLayout;
   private readonly pipeline: GPURenderPipeline;
   private readonly uniforms: GPUBuffer;
+  private readonly uniformValues = new Float32Array(CopyPipeline.UNIFORM_COUNT);
+  private readonly uniformCache = createCachedFloat32BufferWrite(
+    CopyPipeline.UNIFORM_COUNT
+  );
+  private readonly sampler: GPUSampler;
 
   private readonly vertexBuffer: GPUBuffer;
 
-  private bindGroup?: GPUBindGroup;
-  private previousTrailMapIn?: GPUTextureView;
+  private readonly bindGroupsByInput = new WeakMap<GPUTextureView, GPUBindGroup>();
 
   public constructor(private readonly device: GPUDevice) {
     this.bindGroupLayout = device.createBindGroupLayout(CopyPipeline.bindGroupLayout);
@@ -23,6 +32,11 @@ export class CopyPipeline {
       usage: GPUBufferUsage.UNIFORM | GPUBufferUsage.COPY_DST,
     });
 
+    this.sampler = this.device.createSampler({
+      magFilter: 'linear',
+      minFilter: 'linear',
+    });
+
     this.vertexBuffer = device.createBuffer({
       size: 2 * 4 * Float32Array.BYTES_PER_ELEMENT, // 4 x vec2<f32>
       usage: GPUBufferUsage.VERTEX,
@@ -79,9 +93,16 @@ export class CopyPipeline {
     commandEncoder: GPUCommandEncoder,
     trailMapIn: GPUTextureView,
     trailMapOut: GPUTextureView,
-    scale: vec2 = vec2.fromValues(1, 1)
+    scale: vec2 = CopyPipeline.DEFAULT_SCALE
   ) {
-    this.device.queue.writeBuffer(this.uniforms, 0, new Float32Array(scale));
+    this.uniformValues[0] = scale[0];
+    this.uniformValues[1] = scale[1];
+    writeFloat32BufferIfChanged(
+      this.device,
+      this.uniforms,
+      this.uniformValues,
+      this.uniformCache
+    );
 
     const renderPassDescriptor: GPURenderPassDescriptor = {
       colorAttachments: [
@@ -93,10 +114,10 @@ export class CopyPipeline {
       ],
     };
 
-    this.ensureBindGroupExists(trailMapIn);
+    const bindGroup = this.getBindGroup(trailMapIn);
     const passEncoder = commandEncoder.beginRenderPass(renderPassDescriptor);
     passEncoder.setPipeline(this.pipeline);
-    passEncoder.setBindGroup(0, this.bindGroup);
+    passEncoder.setBindGroup(0, bindGroup);
     passEncoder.setVertexBuffer(0, this.vertexBuffer);
     passEncoder.draw(4, 1);
     passEncoder.end();
@@ -104,35 +125,37 @@ export class CopyPipeline {
 
   public destroy() {
     this.vertexBuffer.destroy();
+    this.uniforms.destroy();
   }
 
-  private ensureBindGroupExists(trailMapIn: GPUTextureView) {
-    if (this.previousTrailMapIn !== trailMapIn) {
-      this.bindGroup = this.device.createBindGroup({
-        layout: this.bindGroupLayout,
-        entries: [
-          {
-            binding: 0,
-            resource: {
-              buffer: this.uniforms,
-            },
-          },
-          {
-            binding: 1,
-            resource: this.device.createSampler({
-              magFilter: 'linear',
-              minFilter: 'linear',
-            }),
-          },
-          {
-            binding: 2,
-            resource: trailMapIn,
-          },
-        ],
-      });
-
-      this.previousTrailMapIn = trailMapIn;
+  private getBindGroup(trailMapIn: GPUTextureView): GPUBindGroup {
+    const cached = this.bindGroupsByInput.get(trailMapIn);
+    if (cached) {
+      return cached;
     }
+
+    const bindGroup = this.device.createBindGroup({
+      layout: this.bindGroupLayout,
+      entries: [
+        {
+          binding: 0,
+          resource: {
+            buffer: this.uniforms,
+          },
+        },
+        {
+          binding: 1,
+          resource: this.sampler,
+        },
+        {
+          binding: 2,
+          resource: trailMapIn,
+        },
+      ],
+    });
+
+    this.bindGroupsByInput.set(trailMapIn, bindGroup);
+    return bindGroup;
   }
 
   private static get bindGroupLayout(): GPUBindGroupLayoutDescriptor {