Copy from https://playground.babylonjs.com/#GXJ3FZ#51

src/index.html

@@ -15,7 +15,6 @@
     <link rel="icon" href="favicon.ico" type="image/x-icon" />
     <link rel="icon" type="image/png" sizes="32x32" href="/favicon-32x32.png" />
     <link rel="icon" type="image/png" sizes="16x16" href="/favicon-16x16.png" />
-    <link rel="manifest" href="/site.webmanifest" />
     <meta
       name="description"
       content="I'm Andras Schmelczer, and this is my portfolio. Discover some of my projects. I'm passionate about solving challenging problems and designing large-scale systems, especially in the context of machine learning."

src/index.scss

@@ -1,15 +1,29 @@
-html,
+*,
-body {
+*::before,
+*::after {
   margin: 0;
   padding: 0;
-  border: 0;
+  box-sizing: border-box;
-  font-size: 100%;
+
-  font: inherit;
+  @media (prefers-reduced-motion) {
-  vertical-align: baseline;
+    transition: none !important;
-  background: #000;
+    animation: none !important;
-  width: 100%;
+  }
-  height: 100%;
+}
-  display: flex;
+
-  align-items: center;
+html {
-  justify-content: center;
+  height: 100%;
+  -webkit-font-smooth: antialiased;
+}
+
+body {
+  height: 100%;
+  background-color: hotpink;
+  display: flex;
+}
+
+canvas {
+  background: hotpink;
+  height: 100%;
+  width: 100%;
 }

src/index.ts

@@ -1,5 +1,6 @@
 import './index.scss';
 import Renderer from './renderer';
+import './utils/mulberry32';
 
 const canvas = document.querySelector('canvas') as HTMLCanvasElement;
 canvas.width = canvas.height = 640;

src/pipelines/agents/agent-pipeline.ts

@@ -0,0 +1,140 @@
+import { AGENT_SIZE, Agent } from './agent';
+import shader from './agent.wgsl';
+
+export class AgentPipeline {
+  private static readonly WORKGROUP_SIZE = 64;
+  private static readonly UNIFORM_COUNT = 10;
+
+  private readonly pipeline: GPUComputePipeline;
+  private readonly uniforms: GPUBuffer;
+  private readonly agentsBuffer: GPUBuffer;
+  private bindGroup?: GPUBindGroup;
+  private previousTrailMapIn?: GPUTexture;
+  private previousTrailMapOut?: GPUTexture;
+
+  public constructor(private readonly device: GPUDevice, agents: Array<Agent>) {
+    this.pipeline = device.createComputePipeline({
+      layout: 'auto',
+      compute: {
+        module: device.createShaderModule({
+          code: shader,
+        }),
+        entryPoint: 'main',
+      },
+    });
+
+    this.uniforms = this.device.createBuffer({
+      size: AgentPipeline.UNIFORM_COUNT * Float32Array.BYTES_PER_ELEMENT,
+      usage: GPUBufferUsage.UNIFORM | GPUBufferUsage.COPY_DST,
+    });
+
+    const serializedAgents = new Float32Array(
+      new ArrayBuffer(agents.length * AGENT_SIZE)
+    );
+    agents.forEach((agent, index) => {
+      serializedAgents[index * 4 + 0] = agent.position[0];
+      serializedAgents[index * 4 + 1] = agent.position[1];
+      serializedAgents[index * 4 + 2] = agent.angle;
+    });
+
+    this.agentsBuffer = device.createBuffer({
+      size: agents.length * AGENT_SIZE,
+      usage: GPUBufferUsage.STORAGE | GPUBufferUsage.COPY_SRC | GPUBufferUsage.COPY_DST,
+    });
+
+    device.queue.writeBuffer(this.agentsBuffer, 0, serializedAgents.buffer);
+  }
+
+  public setParameters({
+    width,
+    height,
+    trailWeight,
+    deltaTime,
+    time,
+    moveSpeed,
+    turnSpeed,
+    sensorAngleDegrees,
+    sensorOffsetDst,
+    sensorSize,
+  }: {
+    width: number;
+    height: number;
+    trailWeight: number;
+    deltaTime: number;
+    time: number;
+    moveSpeed: number;
+    turnSpeed: number;
+    sensorAngleDegrees: number;
+    sensorOffsetDst: number;
+    sensorSize: number;
+  }) {
+    this.device.queue.writeBuffer(
+      this.uniforms,
+      0,
+      new Float32Array([
+        width,
+        height,
+        trailWeight,
+        deltaTime,
+        time,
+        moveSpeed,
+        turnSpeed,
+        sensorAngleDegrees,
+        sensorOffsetDst,
+        sensorSize,
+      ])
+    );
+  }
+
+  public execute(
+    commandEncoder: GPUCommandEncoder,
+    trailMapIn: GPUTexture,
+    trailMapOut: GPUTexture
+  ) {
+    this.ensureBindGroupExists(trailMapIn, trailMapOut);
+
+    const passEncoder = commandEncoder.beginComputePass();
+    passEncoder.setPipeline(this.pipeline);
+    passEncoder.setBindGroup(0, this.bindGroup);
+    passEncoder.dispatchWorkgroups(
+      Math.ceil(this.agentsBuffer.size / AGENT_SIZE / AgentPipeline.WORKGROUP_SIZE)
+    );
+    passEncoder.end();
+  }
+
+  private ensureBindGroupExists(trailMapIn: GPUTexture, trailMapOut: GPUTexture) {
+    if (
+      this.previousTrailMapIn !== trailMapIn ||
+      this.previousTrailMapOut !== trailMapOut
+    ) {
+      this.bindGroup = this.device.createBindGroup({
+        layout: this.pipeline.getBindGroupLayout(0),
+        entries: [
+          {
+            binding: 0,
+            resource: {
+              buffer: this.uniforms,
+            },
+          },
+          {
+            binding: 1,
+            resource: {
+              buffer: this.agentsBuffer,
+            },
+          },
+          {
+            binding: 2,
+            resource: trailMapIn.createView(),
+          },
+          {
+            binding: 3,
+            resource: trailMapOut.createView(),
+          },
+        ],
+      });
+
+      this.previousTrailMapIn = trailMapIn;
+      this.previousTrailMapOut = trailMapOut;
+    }
+  }
+}

src/pipelines/agents/agent.ts

@@ -0,0 +1,8 @@
+import { vec2 } from 'gl-matrix';
+
+export interface Agent {
+  position: vec2;
+  angle: number;
+}
+
+export const AGENT_SIZE = 4;

src/pipelines/agents/agent.wgsl

@@ -0,0 +1,125 @@
+struct Agent {
+  position: vec2<f32>,
+  angle: f32,
+}
+
+struct Settings {
+  width : i32,
+  height : i32,
+  trailWeight : f32,
+  deltaTime : f32,
+  time : f32,
+
+  moveSpeed : f32,
+  turnSpeed : f32,
+  sensorAngleDegrees : f32,
+  sensorOffsetDst : f32,
+  sensorSize : f32,
+};
+
+@group(0) @binding(0) var<uniform> settings : Settings;
+@group(0) @binding(1) var<storage, read_write> agents: array<Agent>;
+@group(0) @binding(2) var TrailMapIn : texture_2d<f32>;
+@group(0) @binding(3) var TrailMapOut : texture_storage_2d<rgba16float, write>;
+
+
+// Hash function www.cs.ubc.ca/~rbridson/docs/schechter-sca08-turbulence.pdf
+fn hash(state0 : u32) -> u32
+{
+  var state : u32 = state0;
+  state = state ^ 2747636419u;
+  state = state * 2654435769u;
+  state = state ^ (state >> 16u);
+  state = state * 2654435769u;
+  state = state ^ (state >> 16u);
+  state = state * 2654435769u;
+  return state;
+}
+
+@compute @workgroup_size(64)
+fn main(@builtin(global_invocation_id) global_id : vec3<u32>) {
+  let id = global_id.x;
+
+  if (id >= arrayLength(&agents)) {
+    return;
+  }
+
+  var agent = agents[id];
+
+
+
+  var random = f32(hash(
+    u32(
+      agent.position.y * f32(settings.width) + agent.position.x
+    )
+    + hash(
+      id + u32(settings.time * 100000.)
+    )
+  )) / 4294967295.0;
+
+  // Steer based on sensory data
+  let sensorAngleRad : f32 = settings.sensorAngleDegrees * (3.1415 / 180.);
+  let weightForward : f32 = sense(agent, 0.);
+  let weightLeft : f32 = sense(agent, sensorAngleRad);
+  let weightRight : f32 = sense(agent, -sensorAngleRad);
+
+  let randomSteerStrength : f32 = random;
+  let turnSpeed : f32 = settings.turnSpeed * 2. * 3.1415;
+
+  // choose random direction
+  if (weightForward < weightLeft && weightForward < weightRight) {
+   agent.angle = agent.angle + (randomSteerStrength - 0.5) * 2. * turnSpeed * settings.deltaTime;
+  }
+  // Turn right
+  else if (weightRight > weightLeft) {
+    agent.angle = agent.angle - randomSteerStrength * turnSpeed * settings.deltaTime;
+  }
+  // Turn left
+  else if (weightLeft > weightRight) {
+    agent.angle = agent.angle + randomSteerStrength * turnSpeed * settings.deltaTime;
+  }
+
+  // Update position
+  let direction : vec2<f32> = vec2<f32>(cos(agent.angle), sin(agent.angle));
+  var newPos : vec2<f32> = agent.position + direction * settings.deltaTime * settings.moveSpeed;
+
+  // Clamp position to map boundaries, and pick new random move dir if hit boundary
+  if (newPos.x < 0. || newPos.x >= f32(settings.width) || newPos.y < 0. || newPos.y >= f32(settings.height)) {
+    // random = hash(random);
+    let randomAngle : f32 = random * 2. * 3.1415;
+
+    newPos.x = min(f32(settings.width - 1), max(0., newPos.x));
+    newPos.y = min(f32(settings.height - 1), max(0., newPos.y));
+    agent.angle = randomAngle;
+  } else {
+    let offset : i32 = i32() * settings.width * 4 + i32() * 4;
+    textureStore(TrailMapOut, vec2<i32>(i32(newPos.x), i32(newPos.y)), vec4(vec3<f32>(1.) * settings.trailWeight * settings.deltaTime, 1.));
+  }
+
+ agent.position = newPos;
+  agents[id] = agent;
+}
+
+fn sense(agent : Agent, sensorAngleOffset : f32) -> f32 {
+  let sensorAngle : f32 = agent.angle + sensorAngleOffset;
+  let sensorDir : vec2<f32> = vec2<f32>(cos(sensorAngle), sin(sensorAngle));
+
+  let sensorPos : vec2<f32> = agent.position + sensorDir * settings.sensorOffsetDst;
+  let sensorCentreX : i32 = i32(sensorPos.x);
+  let sensorCentreY : i32 = i32(sensorPos.y);
+
+  var sum : f32 = 0.;
+
+  let senseWeight : vec4<i32> = vec4<i32>(2, 2, 2, 2) - vec4<i32>(1, 1, 1, 1);
+
+  let sensorSize : i32 = i32(settings.sensorSize);
+  for (var offsetX : i32 = -sensorSize; offsetX <= sensorSize; offsetX = offsetX + 1) {
+    for (var offsetY : i32 = -sensorSize; offsetY <= sensorSize; offsetY = offsetY + 1) {
+      let sampleX : i32 = min(settings.width - 1, max(0, sensorCentreX + offsetX));
+      let sampleY : i32 = min(settings.height - 1, max(0, sensorCentreY + offsetY));
+      sum = sum + dot(vec4<f32>(senseWeight), textureLoad(TrailMapIn,  vec2<i32>(sampleX, sampleY), 1));
+    }
+  }
+
+  return sum;
+}

src/pipelines/diffusion/diffuse.wgsl

@@ -0,0 +1,34 @@
+struct VertexOutput {
+  @builtin(position) Position : vec4<f32>,
+  @location(0) fragUV : vec2<f32>,
+}
+
+@vertex
+fn vertex(@builtin(vertex_index) i : u32) -> VertexOutput {
+  var pos = array<vec2<f32>, 4>(
+    vec2(-1.0, 1.0),
+    vec2(-1.0, -1.0),
+    vec2(1.0, 1.0),
+    vec2(1.0, -1.0),
+  );
+
+  var output : VertexOutput;
+  output.Position = vec4<f32>(pos[i], 0.0, 1.0);
+  output.fragUV = output.Position.xy * 0.5 + 0.5;
+  return output;
+}
+
+
+@group(0) @binding(0) var mySampler: sampler;
+@group(0) @binding(1) var TargetTexture : texture_2d<f32>;
+
+
+@fragment
+fn fragment(@location(0) fragUV: vec2<f32>) -> @location(0) vec4<f32> {
+  // return vec4(1.0, 0.0, 0.0, 1.0);
+  return mix(
+    vec4(textureSample(TargetTexture, mySampler, fragUV).rgb, 0.1),
+    vec4(1.0, 1.0, 1.0, 1.0), 
+    0.01
+  );
+}

src/pipelines/diffusion/diffusion-pipeline.ts

@@ -0,0 +1,81 @@
+import shader from './diffuse.wgsl';
+
+export class DiffusionPipeline {
+  private readonly pipeline: GPURenderPipeline;
+  private bindGroup?: GPUBindGroup;
+  private previousTrailMapIn?: GPUTexture;
+
+  public constructor(private readonly device: GPUDevice) {
+    this.pipeline = device.createRenderPipeline({
+      layout: 'auto',
+      vertex: {
+        module: device.createShaderModule({
+          code: shader,
+        }),
+        entryPoint: 'vertex',
+      },
+      fragment: {
+        module: device.createShaderModule({
+          code: shader,
+        }),
+        entryPoint: 'fragment',
+        targets: [
+          {
+            format: 'rgba16float',
+          },
+        ],
+      },
+      primitive: {
+        topology: 'triangle-strip',
+      },
+    });
+  }
+
+  public execute(
+    commandEncoder: GPUCommandEncoder,
+    trailMapIn: GPUTexture,
+    trailMapOut: GPUTexture
+  ) {
+    this.ensureBindGroupExists(trailMapIn);
+
+    const renderPassDescriptor: GPURenderPassDescriptor = {
+      colorAttachments: [
+        {
+          view: trailMapOut.createView(),
+          clearValue: { r: 1.0, g: 1.0, b: 1.0, a: 1.0 },
+          loadOp: 'clear',
+          storeOp: 'store',
+        },
+      ],
+    };
+
+    const renderPassEncoder = commandEncoder.beginRenderPass(renderPassDescriptor);
+    renderPassEncoder.setBindGroup(0, this.bindGroup!);
+    renderPassEncoder.setPipeline(this.pipeline);
+    renderPassEncoder.draw(4, 1);
+    renderPassEncoder.end();
+  }
+
+  private ensureBindGroupExists(trailMapIn: GPUTexture) {
+    if (this.previousTrailMapIn !== trailMapIn) {
+      this.bindGroup = this.device.createBindGroup({
+        layout: this.pipeline.getBindGroupLayout(0),
+        entries: [
+          {
+            binding: 0,
+            resource: this.device.createSampler({
+              magFilter: 'linear',
+              minFilter: 'linear',
+            }),
+          },
+          {
+            binding: 1,
+            resource: trailMapIn.createView(),
+          },
+        ],
+      });
+
+      this.previousTrailMapIn = trailMapIn;
+    }
+  }
+}

src/pipelines/render/render-pipeline.ts

@@ -0,0 +1,80 @@
+import shader from './render.wgsl';
+
+export class RenderPipeline {
+  private readonly pipeline: GPURenderPipeline;
+  private bindGroup?: GPUBindGroup;
+  private previousColorTexture?: GPUTexture;
+
+  public constructor(
+    private readonly context: GPUCanvasContext,
+    private readonly device: GPUDevice,
+    preferredCanvasFormat: GPUTextureFormat
+  ) {
+    this.pipeline = device.createRenderPipeline({
+      layout: 'auto',
+      vertex: {
+        module: device.createShaderModule({
+          code: shader,
+        }),
+        entryPoint: 'vertex',
+      },
+      fragment: {
+        module: device.createShaderModule({
+          code: shader,
+        }),
+        entryPoint: 'fragment',
+        targets: [
+          {
+            format: preferredCanvasFormat,
+          },
+        ],
+      },
+      primitive: {
+        topology: 'triangle-strip',
+      },
+    });
+  }
+
+  public execute(commandEncoder: GPUCommandEncoder, colorTexture: GPUTexture) {
+    this.ensureBindGroupExists(colorTexture);
+
+    const renderPassDescriptor: GPURenderPassDescriptor = {
+      colorAttachments: [
+        {
+          view: this.context.getCurrentTexture().createView(),
+          clearValue: { r: 0.0, g: 0.0, b: 0.0, a: 1.0 },
+          loadOp: 'clear',
+          storeOp: 'store',
+        },
+      ],
+    };
+    const renderPassEncoder = commandEncoder.beginRenderPass(renderPassDescriptor);
+    renderPassEncoder.setBindGroup(0, this.bindGroup);
+    renderPassEncoder.setPipeline(this.pipeline);
+    renderPassEncoder.draw(4, 1);
+    renderPassEncoder.end();
+  }
+
+  private ensureBindGroupExists(colorTexture: GPUTexture) {
+    if (this.previousColorTexture !== colorTexture) {
+      this.bindGroup = this.device.createBindGroup({
+        layout: this.pipeline.getBindGroupLayout(0),
+        entries: [
+          {
+            binding: 0,
+            resource: this.device.createSampler({
+              magFilter: 'linear',
+              minFilter: 'linear',
+            }),
+          },
+          {
+            binding: 1,
+            resource: colorTexture.createView(),
+          },
+        ],
+      });
+
+      this.previousColorTexture = colorTexture;
+    }
+  }
+}

src/pipelines/render/render.wgsl

@@ -0,0 +1,30 @@
+struct VertexOutput {
+  @builtin(position) Position : vec4<f32>,
+  @location(0) fragUV : vec2<f32>,
+}
+
+@vertex
+fn vertex(@builtin(vertex_index) i : u32) -> VertexOutput {
+  var pos = array<vec2<f32>, 4>(
+    vec2(-1.0, 1.0),
+    vec2(-1.0, -1.0),
+    vec2(1.0, 1.0),
+    vec2(1.0, -1.0),
+  );
+
+  var output : VertexOutput;
+  output.Position = vec4<f32>(pos[i], 0.0, 1.0);
+  output.fragUV = output.Position.xy * 0.5 + 0.5;
+  return output;
+}
+
+
+@group(0) @binding(0) var mySampler: sampler;
+@group(0) @binding(1) var TargetTexture : texture_2d<f32>;
+
+
+@fragment
+fn fragment(@location(0) fragUV: vec2<f32>) -> @location(0) vec4<f32> {
+//   return vec4(1.0, 0.0, 0.0, 1.0);
+  return textureSample(TargetTexture, mySampler, fragUV);
+}

src/renderer.ts

@@ -1,227 +1,124 @@
-import fragShaderCode from './shaders/triangle.frag.wgsl';
+import { Agent } from './pipelines/agents/agent';
-import vertShaderCode from './shaders/triangle.vert.wgsl';
+import { AgentPipeline } from './pipelines/agents/agent-pipeline';
+import { DiffusionPipeline } from './pipelines/diffusion/diffusion-pipeline';
+import { RenderPipeline } from './pipelines/render/render-pipeline';
+import { settings } from './settings';
+import { randomBetween } from './utils/random-between';
 
-const positions = new Float32Array([1.0, -1.0, 0.0, -1.0, -1.0, 0.0, 0.0, 1.0, 0.0]);
+import { vec2 } from 'gl-matrix';
-const colors = new Float32Array([1.0, 0.0, 0.0, 0.0, 1.0, 1.0, 1.0, 0.0, 1.0]);
-
-const indices = new Uint16Array([0, 1, 2]);
 
 export default class Renderer {
-  canvas: HTMLCanvasElement;
+  private context: GPUCanvasContext;
+  private adapter: GPUAdapter;
+  private device: GPUDevice;
+  private queue: GPUQueue;
 
-  adapter: GPUAdapter;
+  private agentPipeline: AgentPipeline;
-  device: GPUDevice;
+  private renderPipeline: RenderPipeline;
-  queue: GPUQueue;
+  private diffusionPipeline: any;
 
-  context: GPUCanvasContext;
+  private preferredCanvasFormat: GPUTextureFormat;
-  colorTexture: GPUTexture;
+  private trailMapA?: GPUTexture;
-  colorTextureView: GPUTextureView;
+  private trailMapB?: GPUTexture;
-  depthTexture: GPUTexture;
-  depthTextureView: GPUTextureView;
 
-  positionBuffer: GPUBuffer;
+  public constructor(private canvas: HTMLCanvasElement) {}
-  colorBuffer: GPUBuffer;
-  indexBuffer: GPUBuffer;
-  vertModule: GPUShaderModule;
-  fragModule: GPUShaderModule;
-  pipeline: GPURenderPipeline;
-
-  commandEncoder: GPUCommandEncoder;
-  passEncoder: GPURenderPassEncoder;
-
-  constructor(canvas: HTMLCanvasElement) {
-    this.canvas = canvas;
-  }
 
   async start() {
-    if (await this.initializeAPI()) {
+    await this.initialize();
-      this.resizeBackings();
+    requestAnimationFrame(this.render.bind(this));
-      await this.initializeResources();
-      this.render();
-    }
   }
 
-  async initializeAPI(): Promise<boolean> {
+  private async initialize(): Promise<void> {
-    try {
+    await this.initializeDevice();
-      const entry: GPU = navigator.gpu;
-      if (!entry) {
-        return false;
-      }
 
-      this.adapter = await entry.requestAdapter();
+    this.resize();
-      this.device = await this.adapter.requestDevice();
+    window.addEventListener('resize', this.resize.bind(this));
-      this.queue = this.device.queue;
+
-    } catch (e) {
+    const agents: Array<Agent> = new Array(settings.numAgents).fill(0).map(() => ({
-      console.error(e);
+      position: vec2.fromValues(randomBetween(0, 500), randomBetween(0, 500)),
-      return false;
+      angle: randomBetween(0, Math.PI * 2),
+    }));
+
+    this.agentPipeline = new AgentPipeline(this.device, agents);
+    this.renderPipeline = new RenderPipeline(
+      this.context,
+      this.device,
+      this.preferredCanvasFormat
+    );
+    this.diffusionPipeline = new DiffusionPipeline(this.device);
+  }
+
+  private resize() {
+    const devicePixelRatio = window.devicePixelRatio || 1;
+    this.canvas.width = this.canvas.clientWidth * devicePixelRatio;
+    this.canvas.height = this.canvas.clientHeight * devicePixelRatio;
+
+    this.trailMapA?.destroy();
+    this.trailMapA = this.device.createTexture({
+      size: {
+        width: this.canvas.width,
+        height: this.canvas.height,
+        depthOrArrayLayers: 1,
+      },
+      format: 'rgba16float',
+      usage:
+        GPUTextureUsage.STORAGE_BINDING |
+        GPUTextureUsage.TEXTURE_BINDING |
+        GPUTextureUsage.RENDER_ATTACHMENT,
+    });
+
+    this.trailMapB?.destroy();
+    this.trailMapB = this.device.createTexture({
+      size: {
+        width: this.canvas.width,
+        height: this.canvas.height,
+        depthOrArrayLayers: 1,
+      },
+      format: 'rgba16float',
+      usage:
+        GPUTextureUsage.STORAGE_BINDING |
+        GPUTextureUsage.TEXTURE_BINDING |
+        GPUTextureUsage.RENDER_ATTACHMENT,
+    });
+  }
+
+  private async initializeDevice(): Promise<void> {
+    const gpu = navigator.gpu;
+    if (!gpu) {
+      throw new Error('WebGPU is not supported');
     }
 
-    return true;
+    this.adapter = await gpu.requestAdapter();
+    this.device = await this.adapter.requestDevice(); // could request more resources
+    this.queue = this.device.queue;
+
+    this.context = this.canvas.getContext('webgpu') as any;
+    this.preferredCanvasFormat = navigator.gpu.getPreferredCanvasFormat();
+    this.context.configure({
+      device: this.device,
+      format: this.preferredCanvasFormat,
+      alphaMode: 'premultiplied',
+    });
   }
 
-  async initializeResources() {
+  private render(time: DOMHighResTimeStamp) {
-    const createBuffer = (arr: Float32Array | Uint16Array, usage: number) => {
+    this.agentPipeline.setParameters({
-      // 📏 Align to 4 bytes (thanks @chrimsonite)
+      width: this.canvas.width,
-      const desc = {
+      height: this.canvas.height,
-        size: (arr.byteLength + 3) & ~3,
+      time,
-        usage,
+      deltaTime: 0.016,
-        mappedAtCreation: true,
+      sensorAngleDegrees: 45,
-      };
+      ...settings,
-      const buffer = this.device.createBuffer(desc);
+    });
-      const writeArray =
+    const commandEncoder = this.device.createCommandEncoder();
-        arr instanceof Uint16Array
-          ? new Uint16Array(buffer.getMappedRange())
-          : new Float32Array(buffer.getMappedRange());
-      writeArray.set(arr);
-      buffer.unmap();
-      return buffer;
-    };
 
-    this.positionBuffer = createBuffer(positions, GPUBufferUsage.VERTEX);
+    this.agentPipeline.execute(commandEncoder, this.trailMapA, this.trailMapB);
-    this.colorBuffer = createBuffer(colors, GPUBufferUsage.VERTEX);
+    this.diffusionPipeline.execute(commandEncoder, this.trailMapB, this.trailMapA);
-    this.indexBuffer = createBuffer(indices, GPUBufferUsage.INDEX);
+    this.renderPipeline.execute(commandEncoder, this.trailMapB);
+    [this.trailMapA, this.trailMapB] = [this.trailMapB, this.trailMapA];
 
-    const vsmDesc = {
+    this.queue.submit([commandEncoder.finish()]);
-      code: vertShaderCode,
-    };
-    this.vertModule = this.device.createShaderModule(vsmDesc);
 
-    const fsmDesc = {
+    requestAnimationFrame(this.render.bind(this));
-      code: fragShaderCode,
-    };
-    this.fragModule = this.device.createShaderModule(fsmDesc);
-
-    const positionAttribDesc: GPUVertexAttribute = {
-      shaderLocation: 0, // [[location(0)]]
-      offset: 0,
-      format: 'float32x3',
-    };
-    const colorAttribDesc: GPUVertexAttribute = {
-      shaderLocation: 1, // [[location(1)]]
-      offset: 0,
-      format: 'float32x3',
-    };
-    const positionBufferDesc: GPUVertexBufferLayout = {
-      attributes: [positionAttribDesc],
-      arrayStride: 4 * 3, // sizeof(float) * 3
-      stepMode: 'vertex',
-    };
-    const colorBufferDesc: GPUVertexBufferLayout = {
-      attributes: [colorAttribDesc],
-      arrayStride: 4 * 3, // sizeof(float) * 3
-      stepMode: 'vertex',
-    };
-
-    const depthStencil: GPUDepthStencilState = {
-      depthWriteEnabled: true,
-      depthCompare: 'less',
-      format: 'depth24plus-stencil8',
-    };
-
-    const pipelineLayoutDesc = { bindGroupLayouts: [] };
-    const layout = this.device.createPipelineLayout(pipelineLayoutDesc);
-
-    const vertex: GPUVertexState = {
-      module: this.vertModule,
-      entryPoint: 'main',
-      buffers: [positionBufferDesc, colorBufferDesc],
-    };
-
-    const colorState: GPUColorTargetState = {
-      format: 'bgra8unorm',
-    };
-
-    const fragment: GPUFragmentState = {
-      module: this.fragModule,
-      entryPoint: 'main',
-      targets: [colorState],
-    };
-
-    const primitive: GPUPrimitiveState = {
-      frontFace: 'cw',
-      cullMode: 'none',
-      topology: 'triangle-list',
-    };
-
-    const pipelineDesc: GPURenderPipelineDescriptor = {
-      layout,
-
-      vertex,
-      fragment,
-
-      primitive,
-      depthStencil,
-    };
-    this.pipeline = this.device.createRenderPipeline(pipelineDesc);
   }
-
-  resizeBackings() {
-    if (!this.context) {
-      this.context = this.canvas.getContext('webgpu') as any;
-      const canvasConfig: GPUCanvasConfiguration = {
-        device: this.device,
-        format: 'bgra8unorm',
-        usage: GPUTextureUsage.RENDER_ATTACHMENT | GPUTextureUsage.COPY_SRC,
-        alphaMode: 'opaque',
-      };
-      this.context.configure(canvasConfig);
-    }
-
-    const depthTextureDesc: GPUTextureDescriptor = {
-      size: [this.canvas.width, this.canvas.height, 1],
-      dimension: '2d',
-      format: 'depth24plus-stencil8',
-      usage: GPUTextureUsage.RENDER_ATTACHMENT | GPUTextureUsage.COPY_SRC,
-    };
-
-    this.depthTexture = this.device.createTexture(depthTextureDesc);
-    this.depthTextureView = this.depthTexture.createView();
-  }
-
-  encodeCommands() {
-    const colorAttachment: GPURenderPassColorAttachment = {
-      view: this.colorTextureView,
-      clearValue: { r: 0, g: 0, b: 0, a: 1 },
-      loadOp: 'clear',
-      storeOp: 'store',
-    };
-
-    const depthAttachment: GPURenderPassDepthStencilAttachment = {
-      view: this.depthTextureView,
-      depthClearValue: 1,
-      depthLoadOp: 'clear',
-      depthStoreOp: 'store',
-      stencilClearValue: 0,
-      stencilLoadOp: 'clear',
-      stencilStoreOp: 'store',
-    };
-
-    const renderPassDesc: GPURenderPassDescriptor = {
-      colorAttachments: [colorAttachment],
-      depthStencilAttachment: depthAttachment,
-    };
-
-    this.commandEncoder = this.device.createCommandEncoder();
-
-    this.passEncoder = this.commandEncoder.beginRenderPass(renderPassDesc);
-    this.passEncoder.setPipeline(this.pipeline);
-    this.passEncoder.setViewport(0, 0, this.canvas.width, this.canvas.height, 0, 1);
-    this.passEncoder.setScissorRect(0, 0, this.canvas.width, this.canvas.height);
-    this.passEncoder.setVertexBuffer(0, this.positionBuffer);
-    this.passEncoder.setVertexBuffer(1, this.colorBuffer);
-    this.passEncoder.setIndexBuffer(this.indexBuffer, 'uint16');
-    this.passEncoder.drawIndexed(3, 1);
-    this.passEncoder.end();
-
-    this.queue.submit([this.commandEncoder.finish()]);
-  }
-
-  render = () => {
-    this.colorTexture = this.context.getCurrentTexture();
-    this.colorTextureView = this.colorTexture.createView();
-
-    this.encodeCommands();
-
-    requestAnimationFrame(this.render);
-  };
 }

src/settings.ts

@@ -0,0 +1,30 @@
+const SpawnMode = { Random: 0, Point: 1, InwardCircle: 2, RandomCircle: 3 };
+
+interface Settings {
+  stepsPerFrame: number;
+  numAgents: number;
+  spawnMode: number;
+  trailWeight: number;
+  decayRate: number;
+  diffuseRate: number;
+  moveSpeed: number;
+  turnSpeed: number;
+  sensorAngleSpacing: number;
+  sensorOffsetDst: number;
+  sensorSize: number;
+}
+
+export const settings: Settings = {
+  stepsPerFrame: 2,
+  numAgents: 250000,
+  spawnMode: SpawnMode.InwardCircle,
+  trailWeight: 5,
+  decayRate: 0.2,
+  diffuseRate: 3,
+
+  moveSpeed: 20,
+  turnSpeed: 2,
+  sensorAngleSpacing: 30,
+  sensorOffsetDst: 35,
+  sensorSize: 1,
+};

src/shaders/triangle.frag.wgsl

@@ -1,4 +0,0 @@
-@fragment
-fn main(@location(0) inColor: vec3<f32>) -> @location(0) vec4<f32> {
-    return vec4<f32>(inColor, 1.0);
-}

src/shaders/triangle.vert.wgsl

@@ -1,13 +0,0 @@
-struct VSOut {
-    @builtin(position) Position: vec4<f32>,
-    @location(0) color: vec3<f32>,
- };
-
-@vertex
-fn main(@location(0) inPos: vec3<f32>,
-        @location(1) inColor: vec3<f32>) -> VSOut {
-    var vsOut: VSOut;
-    vsOut.Position = vec4<f32>(inPos, 1.0);
-    vsOut.color = inColor;
-    return vsOut;
-}

src/utils/mulberry32.ts

@@ -0,0 +1,8 @@
+export const mulberry32 = (seed) => () => {
+  let t = (seed += 0x6d2b79f5);
+  t = Math.imul(t ^ (t >>> 15), t | 1);
+  t ^= t + Math.imul(t ^ (t >>> 7), t | 61);
+  return ((t ^ (t >>> 14)) >>> 0) / 4294967296;
+};
+
+Math.random = mulberry32(123);

src/utils/random-between.ts

@@ -0,0 +1,3 @@
+export const randomBetween = (min: number, max: number) => {
+  return Math.random() * (max - min) + min;
+};

webpack.config.js

@@ -42,7 +42,7 @@ module.exports = (env, argv) => ({
         use: 'svg-inline-loader',
       },
       {
-        test: /\.wgsl/,
+        test: /\.wgsl$/i,
         type: 'asset/source',
         generator: {
           filename: '[name][ext]',