kamyukamiWebsite/boidsSimGPU.html at main · kamyukami/kamyukamiWebsite · GitHub

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<!DOCTYPE html>
<html lang="en">
<head>
  <meta charset="UTF-8">
  <title>GPU Boids WebGL2 (Fixed)</title>
  <style>
    html, body { margin: 0; padding: 0; overflow: hidden; background: black; }
    canvas { display: block; width: 100vw; height: 100vh; }
  </style>
</head>
<body>
<canvas id="glCanvas"></canvas>
<script src="https://cdn.jsdelivr.net/npm/dat.gui@0.7.9/build/dat.gui.min.js"></script>
<script type="module">
// Simplified working GPU boids example with fixed framebuffer formats
const canvas = document.getElementById('glCanvas');
const gl = canvas.getContext('webgl2');
canvas.width = window.innerWidth;
canvas.height = window.innerHeight;
if (!gl) alert("WebGL2 is required.");

const settings = {
  numBoids: 256,
  align: 1.0,
  cohesion: 0.5,
  separation: 1.5,
  speed: 1.0,
  perception: 0.05
};
const gui = new dat.GUI();
gui.add(settings, 'numBoids', 64, 1024).step(1).onChange(() => location.reload());
gui.add(settings, 'align', 0, 2);
gui.add(settings, 'cohesion', 0, 2);
gui.add(settings, 'separation', 0, 2);
gui.add(settings, 'speed', 0.1, 5);
gui.add(settings, 'perception', 0.01, 0.2);

const simSize = Math.ceil(Math.sqrt(settings.numBoids));
const texSize = simSize;

function createFBO(w, h) {
  const tex = gl.createTexture();
  gl.bindTexture(gl.TEXTURE_2D, tex);
  gl.texImage2D(gl.TEXTURE_2D, 0, gl.RGBA32F, w, h, 0, gl.RGBA, gl.FLOAT, null);
  gl.texParameteri(gl.TEXTURE_2D, gl.TEXTURE_MIN_FILTER, gl.NEAREST);
  gl.texParameteri(gl.TEXTURE_2D, gl.TEXTURE_MAG_FILTER, gl.NEAREST);
  const fbo = gl.createFramebuffer();
  gl.bindFramebuffer(gl.FRAMEBUFFER, fbo);
  gl.framebufferTexture2D(gl.FRAMEBUFFER, gl.COLOR_ATTACHMENT0, gl.TEXTURE_2D, tex, 0);
  return { fbo, tex };
}

const posA = createFBO(texSize, texSize);
const posB = createFBO(texSize, texSize);
const velA = createFBO(texSize, texSize);
const velB = createFBO(texSize, texSize);

function fillTex(fbo, fill) {
  const data = new Float32Array(texSize * texSize * 4);
  for (let i = 0; i < texSize * texSize; i++) fill(data, i);
  gl.bindTexture(gl.TEXTURE_2D, fbo.tex);
  gl.texSubImage2D(gl.TEXTURE_2D, 0, 0, 0, texSize, texSize, gl.RGBA, gl.FLOAT, data);
}
fillTex(posA, (d, i) => { d[i*4] = Math.random(); d[i*4+1] = Math.random(); });
fillTex(velA, (d, i) => {
  const a = Math.random() * 6.28;
  d[i*4] = Math.cos(a) * settings.speed;
  d[i*4+1] = Math.sin(a) * settings.speed;
});

const quadVAO = gl.createVertexArray();
const quadVBO = gl.createBuffer();
gl.bindVertexArray(quadVAO);
gl.bindBuffer(gl.ARRAY_BUFFER, quadVBO);
gl.bufferData(gl.ARRAY_BUFFER, new Float32Array([-1,-1,1,-1,-1,1,1,1]), gl.STATIC_DRAW);
gl.enableVertexAttribArray(0);
gl.vertexAttribPointer(0, 2, gl.FLOAT, false, 0, 0);

function compile(type, src) {
  const s = gl.createShader(type);
  gl.shaderSource(s, src);
  gl.compileShader(s);
  if (!gl.getShaderParameter(s, gl.COMPILE_STATUS)) throw gl.getShaderInfoLog(s);
  return s;
}
function link(vs, fs) {
  const p = gl.createProgram();
  gl.attachShader(p, compile(gl.VERTEX_SHADER, vs));
  gl.attachShader(p, compile(gl.FRAGMENT_SHADER, fs));
  gl.linkProgram(p);
  if (!gl.getProgramParameter(p, gl.LINK_STATUS)) throw gl.getProgramInfoLog(p);
  return p;
}

const simProg = link(`#version 300 es
in vec2 a_position;
out vec2 v_uv;
void main() {
  v_uv = a_position * 0.5 + 0.5;
  gl_Position = vec4(a_position, 0, 1);
}`, `#version 300 es
precision highp float;
uniform sampler2D u_pos, u_vel;
uniform float u_speed, u_align, u_cohesion, u_separation, u_perception, u_size;
in vec2 v_uv;
out vec4 outColor;
void main() {
  vec2 pos = texture(u_pos, v_uv).xy;
  vec2 vel = texture(u_vel, v_uv).xy;
  vec2 align = vec2(0), cohesion = vec2(0), separation = vec2(0);
  int count = 0;
  for (int y = 0; y < int(u_size); y++) {
    for (int x = 0; x < int(u_size); x++) {
      vec2 uv = (vec2(x,y)+0.5)/u_size;
      vec2 p = texture(u_pos, uv).xy;
      vec2 v = texture(u_vel, uv).xy;
      float d = distance(p, pos);
      if (d < u_perception && d > 0.0) {
        align += v;
        cohesion += p;
        separation += (pos - p)/d;
        count++;
      }
    }
  }
  if (count > 0) {
    align = normalize(align/float(count)) * u_speed - vel;
    cohesion = (cohesion/float(count) - pos) * 0.1;
    separation = separation / float(count);
  }
  vec2 acc = align * u_align + cohesion * u_cohesion + separation * u_separation;
  vel += acc;
  vel = normalize(vel) * u_speed;
  outColor = vec4(vel, 0, 1);
}`);

const posProg = link(`#version 300 es
in vec2 a_position;
out vec2 v_uv;
void main() {
  v_uv = a_position * 0.5 + 0.5;
  gl_Position = vec4(a_position, 0, 1);
}`, `#version 300 es
precision highp float;
uniform sampler2D u_pos, u_vel;
in vec2 v_uv;
out vec4 outColor;
void main() {
  vec2 p = texture(u_pos, v_uv).xy;
  vec2 v = texture(u_vel, v_uv).xy;
  p += v * 0.01;
  p = mod(p, 1.0);
  outColor = vec4(p, 0, 1);
}`);

const drawProg = link(`#version 300 es
layout(location=0) in float id;
uniform sampler2D u_pos;
uniform float u_size;
void main() {
  float i = mod(id, u_size);
  float j = floor(id / u_size);
  vec2 uv = (vec2(i, j) + 0.5) / u_size;
  vec2 p = texture(u_pos, uv).xy;
  gl_Position = vec4(p*2.0 - 1.0, 0, 1);
  gl_PointSize = 2.0;
}`, `#version 300 es
precision mediump float;
out vec4 outColor;
void main() {
  outColor = vec4(0.1, 1.0, 1.0, 1.0);
}`);

const ids = new Float32Array(texSize*texSize).map((_, i) => i);
const idBuf = gl.createBuffer();
gl.bindBuffer(gl.ARRAY_BUFFER, idBuf);
gl.bufferData(gl.ARRAY_BUFFER, ids, gl.STATIC_DRAW);

let posIn = posA, posOut = posB;
let velIn = velA, velOut = velB;

function swap() {
  [posIn, posOut] = [posOut, posIn];
  [velIn, velOut] = [velOut, velIn];
}

function step() {
  gl.useProgram(simProg);
  gl.bindFramebuffer(gl.FRAMEBUFFER, velOut.fbo);
  gl.viewport(0, 0, texSize, texSize);
  gl.bindVertexArray(quadVAO);
  gl.activeTexture(gl.TEXTURE0);
  gl.bindTexture(gl.TEXTURE_2D, posIn.tex);
  gl.uniform1i(gl.getUniformLocation(simProg, 'u_pos'), 0);
  gl.activeTexture(gl.TEXTURE1);
  gl.bindTexture(gl.TEXTURE_2D, velIn.tex);
  gl.uniform1i(gl.getUniformLocation(simProg, 'u_vel'), 1);
  gl.uniform1f(gl.getUniformLocation(simProg, 'u_speed'), settings.speed);
  gl.uniform1f(gl.getUniformLocation(simProg, 'u_align'), settings.align);
  gl.uniform1f(gl.getUniformLocation(simProg, 'u_cohesion'), settings.cohesion);
  gl.uniform1f(gl.getUniformLocation(simProg, 'u_separation'), settings.separation);
  gl.uniform1f(gl.getUniformLocation(simProg, 'u_perception'), settings.perception);
  gl.uniform1f(gl.getUniformLocation(simProg, 'u_size'), texSize);
  gl.drawArrays(gl.TRIANGLE_STRIP, 0, 4);

  gl.useProgram(posProg);
  gl.bindFramebuffer(gl.FRAMEBUFFER, posOut.fbo);
  gl.activeTexture(gl.TEXTURE0);
  gl.bindTexture(gl.TEXTURE_2D, posIn.tex);
  gl.uniform1i(gl.getUniformLocation(posProg, 'u_pos'), 0);
  gl.activeTexture(gl.TEXTURE1);
  gl.bindTexture(gl.TEXTURE_2D, velOut.tex);
  gl.uniform1i(gl.getUniformLocation(posProg, 'u_vel'), 1);
  gl.drawArrays(gl.TRIANGLE_STRIP, 0, 4);

  gl.useProgram(drawProg);
  gl.bindFramebuffer(gl.FRAMEBUFFER, null);
  gl.viewport(0, 0, canvas.width, canvas.height);
  gl.clear(gl.COLOR_BUFFER_BIT);
  gl.bindBuffer(gl.ARRAY_BUFFER, idBuf);
  gl.enableVertexAttribArray(0);
  gl.vertexAttribPointer(0, 1, gl.FLOAT, false, 0, 0);
  gl.uniform1f(gl.getUniformLocation(drawProg, 'u_size'), texSize);
  gl.activeTexture(gl.TEXTURE0);
  gl.bindTexture(gl.TEXTURE_2D, posOut.tex);
  gl.uniform1i(gl.getUniformLocation(drawProg, 'u_pos'), 0);
  gl.drawArrays(gl.POINTS, 0, texSize * texSize);

  swap();
  requestAnimationFrame(step);
}
step();
</script>
</body>
</html>