web-html5-scripts/landing-page-canvas-color/function.js

1240 lines
39 KiB
JavaScript
Raw Normal View History

'use strict';
const canvas = document.getElementsByTagName('canvas')[0];
resizeCanvas();
let config = {
SIM_RESOLUTION: 128,
DYE_RESOLUTION: 1024,
CAPTURE_RESOLUTION: 512,
DENSITY_DISSIPATION: 2,
VELOCITY_DISSIPATION: 2,
PRESSURE: 0.8,
PRESSURE_ITERATIONS: 20,
CURL: 30,
SPLAT_RADIUS: 0.25,
SPLAT_FORCE: 6000,
SHADING: true,
COLORFUL: true,
COLOR_UPDATE_SPEED: 10,
PAUSED: false,
BACK_COLOR: { r: 0, g: 0, b: 0 },
TRANSPARENT: false,
BLOOM: true,
BLOOM_ITERATIONS: 8,
BLOOM_RESOLUTION: 256,
BLOOM_INTENSITY: 0.8,
BLOOM_THRESHOLD: 0.6,
BLOOM_SOFT_KNEE: 0.7
}
function pointerPrototype() {
this.id = -1;
this.texcoordX = 0;
this.texcoordY = 0;
this.prevTexcoordX = 0;
this.prevTexcoordY = 0;
this.deltaX = 0;
this.deltaY = 0;
this.down = false;
this.moved = false;
this.color = [30, 0, 300];
}
let pointers = [];
let splatStack = [];
let bloomFramebuffers = [];
pointers.push(new pointerPrototype());
const { gl, ext } = getWebGLContext(canvas);
if (isMobile()) {
config.DYE_RESOLUTION = 512;
}
if (!ext.supportLinearFiltering) {
config.DYE_RESOLUTION = 512;
config.SHADING = false;
config.BLOOM = false;
}
// startGUI();
function getWebGLContext(canvas) {
const params = { alpha: true, depth: false, stencil: false, antialias: false, preserveDrawingBuffer: false };
let gl = canvas.getContext('webgl2', params);
const isWebGL2 = !!gl;
if (!isWebGL2)
gl = canvas.getContext('webgl', params) || canvas.getContext('experimental-webgl', params);
let halfFloat;
let supportLinearFiltering;
if (isWebGL2) {
gl.getExtension('EXT_color_buffer_float');
supportLinearFiltering = gl.getExtension('OES_texture_float_linear');
} else {
halfFloat = gl.getExtension('OES_texture_half_float');
supportLinearFiltering = gl.getExtension('OES_texture_half_float_linear');
}
gl.clearColor(0.0, 0.0, 0.0, 1.0);
const halfFloatTexType = isWebGL2 ? gl.HALF_FLOAT : halfFloat.HALF_FLOAT_OES;
let formatRGBA;
let formatRG;
let formatR;
if (isWebGL2) {
formatRGBA = getSupportedFormat(gl, gl.RGBA16F, gl.RGBA, halfFloatTexType);
formatRG = getSupportedFormat(gl, gl.RG16F, gl.RG, halfFloatTexType);
formatR = getSupportedFormat(gl, gl.R16F, gl.RED, halfFloatTexType);
}
else {
formatRGBA = getSupportedFormat(gl, gl.RGBA, gl.RGBA, halfFloatTexType);
formatRG = getSupportedFormat(gl, gl.RGBA, gl.RGBA, halfFloatTexType);
formatR = getSupportedFormat(gl, gl.RGBA, gl.RGBA, halfFloatTexType);
}
//ga('send', 'event', isWebGL2 ? 'webgl2' : 'webgl', formatRGBA == null ? 'not supported' : 'supported');
return {
gl,
ext: {
formatRGBA,
formatRG,
formatR,
halfFloatTexType,
supportLinearFiltering
}
};
}
function getSupportedFormat(gl, internalFormat, format, type) {
if (!supportRenderTextureFormat(gl, internalFormat, format, type)) {
switch (internalFormat) {
case gl.R16F:
return getSupportedFormat(gl, gl.RG16F, gl.RG, type);
case gl.RG16F:
return getSupportedFormat(gl, gl.RGBA16F, gl.RGBA, type);
default:
return null;
}
}
return {
internalFormat,
format
}
}
function supportRenderTextureFormat(gl, internalFormat, format, type) {
let texture = gl.createTexture();
gl.bindTexture(gl.TEXTURE_2D, texture);
gl.texParameteri(gl.TEXTURE_2D, gl.TEXTURE_MIN_FILTER, gl.NEAREST);
gl.texParameteri(gl.TEXTURE_2D, gl.TEXTURE_MAG_FILTER, gl.NEAREST);
gl.texParameteri(gl.TEXTURE_2D, gl.TEXTURE_WRAP_S, gl.CLAMP_TO_EDGE);
gl.texParameteri(gl.TEXTURE_2D, gl.TEXTURE_WRAP_T, gl.CLAMP_TO_EDGE);
gl.texImage2D(gl.TEXTURE_2D, 0, internalFormat, 4, 4, 0, format, type, null);
let fbo = gl.createFramebuffer();
gl.bindFramebuffer(gl.FRAMEBUFFER, fbo);
gl.framebufferTexture2D(gl.FRAMEBUFFER, gl.COLOR_ATTACHMENT0, gl.TEXTURE_2D, texture, 0);
const status = gl.checkFramebufferStatus(gl.FRAMEBUFFER);
return status == gl.FRAMEBUFFER_COMPLETE;
}
function isMobile() {
return /Mobi|Android/i.test(navigator.userAgent);
}
function captureScreenshot() {
let res = getResolution(config.CAPTURE_RESOLUTION);
let target = createFBO(res.width, res.height, ext.formatRGBA.internalFormat, ext.formatRGBA.format, ext.halfFloatTexType, gl.NEAREST);
render(target);
let texture = framebufferToTexture(target);
texture = normalizeTexture(texture, target.width, target.height);
let captureCanvas = textureToCanvas(texture, target.width, target.height);
let datauri = captureCanvas.toDataURL();
downloadURI('fluid.png', datauri);
URL.revokeObjectURL(datauri);
}
function framebufferToTexture(target) {
gl.bindFramebuffer(gl.FRAMEBUFFER, target.fbo);
let length = target.width * target.height * 4;
let texture = new Float32Array(length);
gl.readPixels(0, 0, target.width, target.height, gl.RGBA, gl.FLOAT, texture);
return texture;
}
function normalizeTexture(texture, width, height) {
let result = new Uint8Array(texture.length);
let id = 0;
for (let i = height - 1; i >= 0; i--) {
for (let j = 0; j < width; j++) {
let nid = i * width * 4 + j * 4;
result[nid + 0] = clamp01(texture[id + 0]) * 255;
result[nid + 1] = clamp01(texture[id + 1]) * 255;
result[nid + 2] = clamp01(texture[id + 2]) * 255;
result[nid + 3] = clamp01(texture[id + 3]) * 255;
id += 4;
}
}
return result;
}
function clamp01(input) {
return Math.min(Math.max(input, 0), 1);
}
function textureToCanvas(texture, width, height) {
let captureCanvas = document.createElement('canvas');
let ctx = captureCanvas.getContext('2d');
captureCanvas.width = width;
captureCanvas.height = height;
let imageData = ctx.createImageData(width, height);
imageData.data.set(texture);
ctx.putImageData(imageData, 0, 0);
return captureCanvas;
}
function downloadURI(filename, uri) {
let link = document.createElement('a');
link.download = filename;
link.href = uri;
document.body.appendChild(link);
link.click();
document.body.removeChild(link);
}
class GLProgram {
constructor(vertexShader, fragmentShader) {
this.uniforms = {};
this.program = gl.createProgram();
gl.attachShader(this.program, vertexShader);
gl.attachShader(this.program, fragmentShader);
gl.linkProgram(this.program);
if (!gl.getProgramParameter(this.program, gl.LINK_STATUS))
throw gl.getProgramInfoLog(this.program);
const uniformCount = gl.getProgramParameter(this.program, gl.ACTIVE_UNIFORMS);
for (let i = 0; i < uniformCount; i++) {
const uniformName = gl.getActiveUniform(this.program, i).name;
this.uniforms[uniformName] = gl.getUniformLocation(this.program, uniformName);
}
}
bind() {
gl.useProgram(this.program);
}
}
function compileShader(type, source, keywords) {
if (keywords != null) {
let keywordsString = '';
keywords.forEach(keyword => {
keywordsString += '#define ' + keyword + '\n';
});
source = keywordsString + source;
}
const shader = gl.createShader(type);
gl.shaderSource(shader, source);
gl.compileShader(shader);
if (!gl.getShaderParameter(shader, gl.COMPILE_STATUS))
throw gl.getShaderInfoLog(shader);
return shader;
};
const baseVertexShader = compileShader(gl.VERTEX_SHADER, `
precision highp float;
attribute vec2 aPosition;
varying vec2 vUv;
varying vec2 vL;
varying vec2 vR;
varying vec2 vT;
varying vec2 vB;
uniform vec2 texelSize;
void main () {
vUv = aPosition * 0.5 + 0.5;
vL = vUv - vec2(texelSize.x, 0.0);
vR = vUv + vec2(texelSize.x, 0.0);
vT = vUv + vec2(0.0, texelSize.y);
vB = vUv - vec2(0.0, texelSize.y);
gl_Position = vec4(aPosition, 0.0, 1.0);
}
`);
const copyShader = compileShader(gl.FRAGMENT_SHADER, `
precision mediump float;
precision mediump sampler2D;
varying highp vec2 vUv;
uniform sampler2D uTexture;
void main () {
gl_FragColor = texture2D(uTexture, vUv);
}
`);
const clearShader = compileShader(gl.FRAGMENT_SHADER, `
precision mediump float;
precision mediump sampler2D;
varying highp vec2 vUv;
uniform sampler2D uTexture;
uniform float value;
void main () {
gl_FragColor = value * texture2D(uTexture, vUv);
}
`);
const colorShader = compileShader(gl.FRAGMENT_SHADER, `
precision mediump float;
uniform vec4 color;
void main () {
gl_FragColor = color;
}
`);
const checkerboardShader = compileShader(gl.FRAGMENT_SHADER, `
precision highp float;
precision highp sampler2D;
varying vec2 vUv;
uniform sampler2D uTexture;
uniform float aspectRatio;
#define SCALE 25.0
void main () {
vec2 uv = floor(vUv * SCALE * vec2(aspectRatio, 1.0));
float v = mod(uv.x + uv.y, 2.0);
v = v * 0.1 + 0.8;
gl_FragColor = vec4(vec3(v), 1.0);
}
`);
const displayShaderSource = `
precision highp float;
precision highp sampler2D;
varying vec2 vUv;
varying vec2 vL;
varying vec2 vR;
varying vec2 vT;
varying vec2 vB;
uniform sampler2D uTexture;
uniform sampler2D uBloom;
uniform sampler2D uDithering;
uniform vec2 ditherScale;
uniform vec2 texelSize;
vec3 linearToGamma (vec3 color) {
color = max(color, vec3(0));
return max(1.055 * pow(color, vec3(0.416666667)) - 0.055, vec3(0));
}
void main () {
vec3 c = texture2D(uTexture, vUv).rgb;
#ifdef SHADING
vec3 lc = texture2D(uTexture, vL).rgb;
vec3 rc = texture2D(uTexture, vR).rgb;
vec3 tc = texture2D(uTexture, vT).rgb;
vec3 bc = texture2D(uTexture, vB).rgb;
float dx = length(rc) - length(lc);
float dy = length(tc) - length(bc);
vec3 n = normalize(vec3(dx, dy, length(texelSize)));
vec3 l = vec3(0.0, 0.0, 1.0);
float diffuse = clamp(dot(n, l) + 0.7, 0.7, 1.0);
c *= diffuse;
#endif
#ifdef BLOOM
vec3 bloom = texture2D(uBloom, vUv).rgb;
float noise = texture2D(uDithering, vUv * ditherScale).r;
noise = noise * 2.0 - 1.0;
bloom += noise / 255.0;
bloom = linearToGamma(bloom);
c += bloom;
#endif
float a = max(c.r, max(c.g, c.b));
gl_FragColor = vec4(c, a);
}
`;
const displayShader = compileShader(gl.FRAGMENT_SHADER, displayShaderSource);
const displayBloomShader = compileShader(gl.FRAGMENT_SHADER, displayShaderSource, ['BLOOM']);
const displayShadingShader = compileShader(gl.FRAGMENT_SHADER, displayShaderSource, ['SHADING']);
const displayBloomShadingShader = compileShader(gl.FRAGMENT_SHADER, displayShaderSource, ['BLOOM', 'SHADING']);
const bloomPrefilterShader = compileShader(gl.FRAGMENT_SHADER, `
precision mediump float;
precision mediump sampler2D;
varying vec2 vUv;
uniform sampler2D uTexture;
uniform vec3 curve;
uniform float threshold;
void main () {
vec3 c = texture2D(uTexture, vUv).rgb;
float br = max(c.r, max(c.g, c.b));
float rq = clamp(br - curve.x, 0.0, curve.y);
rq = curve.z * rq * rq;
c *= max(rq, br - threshold) / max(br, 0.0001);
gl_FragColor = vec4(c, 0.0);
}
`);
const bloomBlurShader = compileShader(gl.FRAGMENT_SHADER, `
precision mediump float;
precision mediump sampler2D;
varying vec2 vL;
varying vec2 vR;
varying vec2 vT;
varying vec2 vB;
uniform sampler2D uTexture;
void main () {
vec4 sum = vec4(0.0);
sum += texture2D(uTexture, vL);
sum += texture2D(uTexture, vR);
sum += texture2D(uTexture, vT);
sum += texture2D(uTexture, vB);
sum *= 0.25;
gl_FragColor = sum;
}
`);
const bloomFinalShader = compileShader(gl.FRAGMENT_SHADER, `
precision mediump float;
precision mediump sampler2D;
varying vec2 vL;
varying vec2 vR;
varying vec2 vT;
varying vec2 vB;
uniform sampler2D uTexture;
uniform float intensity;
void main () {
vec4 sum = vec4(0.0);
sum += texture2D(uTexture, vL);
sum += texture2D(uTexture, vR);
sum += texture2D(uTexture, vT);
sum += texture2D(uTexture, vB);
sum *= 0.25;
gl_FragColor = sum * intensity;
}
`);
const splatShader = compileShader(gl.FRAGMENT_SHADER, `
precision highp float;
precision highp sampler2D;
varying vec2 vUv;
uniform sampler2D uTarget;
uniform float aspectRatio;
uniform vec3 color;
uniform vec2 point;
uniform float radius;
void main () {
vec2 p = vUv - point.xy;
p.x *= aspectRatio;
vec3 splat = exp(-dot(p, p) / radius) * color;
vec3 base = texture2D(uTarget, vUv).xyz;
gl_FragColor = vec4(base + splat, 1.0);
}
`);
const advectionShader = compileShader(gl.FRAGMENT_SHADER, `
precision highp float;
precision highp sampler2D;
varying vec2 vUv;
uniform sampler2D uVelocity;
uniform sampler2D uSource;
uniform vec2 texelSize;
uniform vec2 dyeTexelSize;
uniform float dt;
uniform float dissipation;
vec4 bilerp (sampler2D sam, vec2 uv, vec2 tsize) {
vec2 st = uv / tsize - 0.5;
vec2 iuv = floor(st);
vec2 fuv = fract(st);
vec4 a = texture2D(sam, (iuv + vec2(0.5, 0.5)) * tsize);
vec4 b = texture2D(sam, (iuv + vec2(1.5, 0.5)) * tsize);
vec4 c = texture2D(sam, (iuv + vec2(0.5, 1.5)) * tsize);
vec4 d = texture2D(sam, (iuv + vec2(1.5, 1.5)) * tsize);
return mix(mix(a, b, fuv.x), mix(c, d, fuv.x), fuv.y);
}
void main () {
#ifdef MANUAL_FILTERING
vec2 coord = vUv - dt * bilerp(uVelocity, vUv, texelSize).xy * texelSize;
vec4 result = bilerp(uSource, coord, dyeTexelSize);
#else
vec2 coord = vUv - dt * texture2D(uVelocity, vUv).xy * texelSize;
vec4 result = texture2D(uSource, coord);
#endif
float decay = 1.0 + dissipation * dt;
gl_FragColor = result / decay;
}`,
ext.supportLinearFiltering ? null : ['MANUAL_FILTERING']
);
const divergenceShader = compileShader(gl.FRAGMENT_SHADER, `
precision mediump float;
precision mediump sampler2D;
varying highp vec2 vUv;
varying highp vec2 vL;
varying highp vec2 vR;
varying highp vec2 vT;
varying highp vec2 vB;
uniform sampler2D uVelocity;
void main () {
float L = texture2D(uVelocity, vL).x;
float R = texture2D(uVelocity, vR).x;
float T = texture2D(uVelocity, vT).y;
float B = texture2D(uVelocity, vB).y;
vec2 C = texture2D(uVelocity, vUv).xy;
if (vL.x < 0.0) { L = -C.x; }
if (vR.x > 1.0) { R = -C.x; }
if (vT.y > 1.0) { T = -C.y; }
if (vB.y < 0.0) { B = -C.y; }
float div = 0.5 * (R - L + T - B);
gl_FragColor = vec4(div, 0.0, 0.0, 1.0);
}
`);
const curlShader = compileShader(gl.FRAGMENT_SHADER, `
precision mediump float;
precision mediump sampler2D;
varying highp vec2 vUv;
varying highp vec2 vL;
varying highp vec2 vR;
varying highp vec2 vT;
varying highp vec2 vB;
uniform sampler2D uVelocity;
void main () {
float L = texture2D(uVelocity, vL).y;
float R = texture2D(uVelocity, vR).y;
float T = texture2D(uVelocity, vT).x;
float B = texture2D(uVelocity, vB).x;
float vorticity = R - L - T + B;
gl_FragColor = vec4(0.5 * vorticity, 0.0, 0.0, 1.0);
}
`);
const vorticityShader = compileShader(gl.FRAGMENT_SHADER, `
precision highp float;
precision highp sampler2D;
varying vec2 vUv;
varying vec2 vL;
varying vec2 vR;
varying vec2 vT;
varying vec2 vB;
uniform sampler2D uVelocity;
uniform sampler2D uCurl;
uniform float curl;
uniform float dt;
void main () {
float L = texture2D(uCurl, vL).x;
float R = texture2D(uCurl, vR).x;
float T = texture2D(uCurl, vT).x;
float B = texture2D(uCurl, vB).x;
float C = texture2D(uCurl, vUv).x;
vec2 force = 0.5 * vec2(abs(T) - abs(B), abs(R) - abs(L));
force /= length(force) + 0.0001;
force *= curl * C;
force.y *= -1.0;
vec2 vel = texture2D(uVelocity, vUv).xy;
gl_FragColor = vec4(vel + force * dt, 0.0, 1.0);
}
`);
const pressureShader = compileShader(gl.FRAGMENT_SHADER, `
precision mediump float;
precision mediump sampler2D;
varying highp vec2 vUv;
varying highp vec2 vL;
varying highp vec2 vR;
varying highp vec2 vT;
varying highp vec2 vB;
uniform sampler2D uPressure;
uniform sampler2D uDivergence;
void main () {
float L = texture2D(uPressure, vL).x;
float R = texture2D(uPressure, vR).x;
float T = texture2D(uPressure, vT).x;
float B = texture2D(uPressure, vB).x;
float C = texture2D(uPressure, vUv).x;
float divergence = texture2D(uDivergence, vUv).x;
float pressure = (L + R + B + T - divergence) * 0.25;
gl_FragColor = vec4(pressure, 0.0, 0.0, 1.0);
}
`);
const gradientSubtractShader = compileShader(gl.FRAGMENT_SHADER, `
precision mediump float;
precision mediump sampler2D;
varying highp vec2 vUv;
varying highp vec2 vL;
varying highp vec2 vR;
varying highp vec2 vT;
varying highp vec2 vB;
uniform sampler2D uPressure;
uniform sampler2D uVelocity;
void main () {
float L = texture2D(uPressure, vL).x;
float R = texture2D(uPressure, vR).x;
float T = texture2D(uPressure, vT).x;
float B = texture2D(uPressure, vB).x;
vec2 velocity = texture2D(uVelocity, vUv).xy;
velocity.xy -= vec2(R - L, T - B);
gl_FragColor = vec4(velocity, 0.0, 1.0);
}
`);
const blit = (() => {
gl.bindBuffer(gl.ARRAY_BUFFER, gl.createBuffer());
gl.bufferData(gl.ARRAY_BUFFER, new Float32Array([-1, -1, -1, 1, 1, 1, 1, -1]), gl.STATIC_DRAW);
gl.bindBuffer(gl.ELEMENT_ARRAY_BUFFER, gl.createBuffer());
gl.bufferData(gl.ELEMENT_ARRAY_BUFFER, new Uint16Array([0, 1, 2, 0, 2, 3]), gl.STATIC_DRAW);
gl.vertexAttribPointer(0, 2, gl.FLOAT, false, 0, 0);
gl.enableVertexAttribArray(0);
return (destination) => {
gl.bindFramebuffer(gl.FRAMEBUFFER, destination);
gl.drawElements(gl.TRIANGLES, 6, gl.UNSIGNED_SHORT, 0);
}
})();
let dye;
let velocity;
let divergence;
let curl;
let pressure;
let bloom;
let ditheringTexture = createTextureAsync('');
const copyProgram = new GLProgram(baseVertexShader, copyShader);
const clearProgram = new GLProgram(baseVertexShader, clearShader);
const colorProgram = new GLProgram(baseVertexShader, colorShader);
const checkerboardProgram = new GLProgram(baseVertexShader, checkerboardShader);
const displayProgram = new GLProgram(baseVertexShader, displayShader);
const displayBloomProgram = new GLProgram(baseVertexShader, displayBloomShader);
const displayShadingProgram = new GLProgram(baseVertexShader, displayShadingShader);
const displayBloomShadingProgram = new GLProgram(baseVertexShader, displayBloomShadingShader);
const bloomPrefilterProgram = new GLProgram(baseVertexShader, bloomPrefilterShader);
const bloomBlurProgram = new GLProgram(baseVertexShader, bloomBlurShader);
const bloomFinalProgram = new GLProgram(baseVertexShader, bloomFinalShader);
const splatProgram = new GLProgram(baseVertexShader, splatShader);
const advectionProgram = new GLProgram(baseVertexShader, advectionShader);
const divergenceProgram = new GLProgram(baseVertexShader, divergenceShader);
const curlProgram = new GLProgram(baseVertexShader, curlShader);
const vorticityProgram = new GLProgram(baseVertexShader, vorticityShader);
const pressureProgram = new GLProgram(baseVertexShader, pressureShader);
const gradienSubtractProgram = new GLProgram(baseVertexShader, gradientSubtractShader);
function initFramebuffers() {
let simRes = getResolution(config.SIM_RESOLUTION);
let dyeRes = getResolution(config.DYE_RESOLUTION);
const texType = ext.halfFloatTexType;
const rgba = ext.formatRGBA;
const rg = ext.formatRG;
const r = ext.formatR;
const filtering = ext.supportLinearFiltering ? gl.LINEAR : gl.NEAREST;
if (dye == null)
dye = createDoubleFBO(dyeRes.width, dyeRes.height, rgba.internalFormat, rgba.format, texType, filtering);
else
dye = resizeDoubleFBO(dye, dyeRes.width, dyeRes.height, rgba.internalFormat, rgba.format, texType, filtering);
if (velocity == null)
velocity = createDoubleFBO(simRes.width, simRes.height, rg.internalFormat, rg.format, texType, filtering);
else
velocity = resizeDoubleFBO(velocity, simRes.width, simRes.height, rg.internalFormat, rg.format, texType, filtering);
divergence = createFBO(simRes.width, simRes.height, r.internalFormat, r.format, texType, gl.NEAREST);
curl = createFBO(simRes.width, simRes.height, r.internalFormat, r.format, texType, gl.NEAREST);
pressure = createDoubleFBO(simRes.width, simRes.height, r.internalFormat, r.format, texType, gl.NEAREST);
initBloomFramebuffers();
}
function initBloomFramebuffers() {
let res = getResolution(config.BLOOM_RESOLUTION);
const texType = ext.halfFloatTexType;
const rgba = ext.formatRGBA;
const filtering = ext.supportLinearFiltering ? gl.LINEAR : gl.NEAREST;
bloom = createFBO(res.width, res.height, rgba.internalFormat, rgba.format, texType, filtering);
bloomFramebuffers.length = 0;
for (let i = 0; i < config.BLOOM_ITERATIONS; i++) {
let width = res.width >> (i + 1);
let height = res.height >> (i + 1);
if (width < 2 || height < 2) break;
let fbo = createFBO(width, height, rgba.internalFormat, rgba.format, texType, filtering);
bloomFramebuffers.push(fbo);
}
}
function createFBO(w, h, internalFormat, format, type, param) {
gl.activeTexture(gl.TEXTURE0);
let texture = gl.createTexture();
gl.bindTexture(gl.TEXTURE_2D, texture);
gl.texParameteri(gl.TEXTURE_2D, gl.TEXTURE_MIN_FILTER, param);
gl.texParameteri(gl.TEXTURE_2D, gl.TEXTURE_MAG_FILTER, param);
gl.texParameteri(gl.TEXTURE_2D, gl.TEXTURE_WRAP_S, gl.CLAMP_TO_EDGE);
gl.texParameteri(gl.TEXTURE_2D, gl.TEXTURE_WRAP_T, gl.CLAMP_TO_EDGE);
gl.texImage2D(gl.TEXTURE_2D, 0, internalFormat, w, h, 0, format, type, null);
let fbo = gl.createFramebuffer();
gl.bindFramebuffer(gl.FRAMEBUFFER, fbo);
gl.framebufferTexture2D(gl.FRAMEBUFFER, gl.COLOR_ATTACHMENT0, gl.TEXTURE_2D, texture, 0);
gl.viewport(0, 0, w, h);
gl.clear(gl.COLOR_BUFFER_BIT);
return {
texture,
fbo,
width: w,
height: h,
attach(id) {
gl.activeTexture(gl.TEXTURE0 + id);
gl.bindTexture(gl.TEXTURE_2D, texture);
return id;
}
};
}
function createDoubleFBO(w, h, internalFormat, format, type, param) {
let fbo1 = createFBO(w, h, internalFormat, format, type, param);
let fbo2 = createFBO(w, h, internalFormat, format, type, param);
let texelSizeX = 1.0 / w;
let texelSizeY = 1.0 / h;
return {
width: w,
height: h,
texelSizeX,
texelSizeY,
get read() {
return fbo1;
},
set read(value) {
fbo1 = value;
},
get write() {
return fbo2;
},
set write(value) {
fbo2 = value;
},
swap() {
let temp = fbo1;
fbo1 = fbo2;
fbo2 = temp;
}
}
}
function resizeFBO(target, w, h, internalFormat, format, type, param) {
let newFBO = createFBO(w, h, internalFormat, format, type, param);
copyProgram.bind();
gl.uniform1i(copyProgram.uniforms.uTexture, target.attach(0));
blit(newFBO.fbo);
return newFBO;
}
function resizeDoubleFBO(target, w, h, internalFormat, format, type, param) {
if (target.width == w && target.height == h)
return target;
target.read = resizeFBO(target.read, w, h, internalFormat, format, type, param);
target.write = createFBO(w, h, internalFormat, format, type, param);
target.width = w;
target.height = h;
target.texelSizeX = 1.0 / w;
target.texelSizeY = 1.0 / h;
return target;
}
function createTextureAsync(url) {
let texture = gl.createTexture();
gl.bindTexture(gl.TEXTURE_2D, texture);
gl.texParameteri(gl.TEXTURE_2D, gl.TEXTURE_MIN_FILTER, gl.LINEAR);
gl.texParameteri(gl.TEXTURE_2D, gl.TEXTURE_MAG_FILTER, gl.LINEAR);
gl.texParameteri(gl.TEXTURE_2D, gl.TEXTURE_WRAP_S, gl.REPEAT);
gl.texParameteri(gl.TEXTURE_2D, gl.TEXTURE_WRAP_T, gl.REPEAT);
gl.texImage2D(gl.TEXTURE_2D, 0, gl.RGB, 1, 1, 0, gl.RGB, gl.UNSIGNED_BYTE, new Uint8Array([255, 255, 255]));
let obj = {
texture,
width: 1,
height: 1,
attach(id) {
gl.activeTexture(gl.TEXTURE0 + id);
gl.bindTexture(gl.TEXTURE_2D, texture);
return id;
}
};
let image = new Image();
image.onload = () => {
obj.width = image.width;
obj.height = image.height;
gl.bindTexture(gl.TEXTURE_2D, texture);
gl.texImage2D(gl.TEXTURE_2D, 0, gl.RGB, gl.RGB, gl.UNSIGNED_BYTE, image);
};
image.src = url;
return obj;
}
initFramebuffers();
multipleSplats(parseInt(Math.random() * 20) + 5);
let lastUpdateTime = Date.now();
let colorUpdateTimer = 0.0;
update();
function update() {
const dt = calcDeltaTime();
if (resizeCanvas())
initFramebuffers();
updateColors(dt);
applyInputs();
if (!config.PAUSED)
step(dt);
render(null);
requestAnimationFrame(update);
}
function calcDeltaTime() {
let now = Date.now();
let dt = (now - lastUpdateTime) / 1000;
dt = Math.min(dt, 0.016666);
lastUpdateTime = now;
return dt;
}
function resizeCanvas() {
let width = scaleByPixelRatio(canvas.clientWidth);
let height = scaleByPixelRatio(canvas.clientHeight);
if (canvas.width != width || canvas.height != height) {
canvas.width = width;
canvas.height = height;
return true;
}
return false;
}
function updateColors(dt) {
if (!config.COLORFUL) return;
colorUpdateTimer += dt * config.COLOR_UPDATE_SPEED;
if (colorUpdateTimer >= 1) {
colorUpdateTimer = wrap(colorUpdateTimer, 0, 1);
pointers.forEach(p => {
p.color = generateColor();
});
}
}
function applyInputs() {
if (splatStack.length > 0)
multipleSplats(splatStack.pop());
pointers.forEach(p => {
if (p.moved) {
p.moved = false;
splatPointer(p);
}
});
}
function step(dt) {
gl.disable(gl.BLEND);
gl.viewport(0, 0, velocity.width, velocity.height);
curlProgram.bind();
gl.uniform2f(curlProgram.uniforms.texelSize, velocity.texelSizeX, velocity.texelSizeY);
gl.uniform1i(curlProgram.uniforms.uVelocity, velocity.read.attach(0));
blit(curl.fbo);
vorticityProgram.bind();
gl.uniform2f(vorticityProgram.uniforms.texelSize, velocity.texelSizeX, velocity.texelSizeY);
gl.uniform1i(vorticityProgram.uniforms.uVelocity, velocity.read.attach(0));
gl.uniform1i(vorticityProgram.uniforms.uCurl, curl.attach(1));
gl.uniform1f(vorticityProgram.uniforms.curl, config.CURL);
gl.uniform1f(vorticityProgram.uniforms.dt, dt);
blit(velocity.write.fbo);
velocity.swap();
divergenceProgram.bind();
gl.uniform2f(divergenceProgram.uniforms.texelSize, velocity.texelSizeX, velocity.texelSizeY);
gl.uniform1i(divergenceProgram.uniforms.uVelocity, velocity.read.attach(0));
blit(divergence.fbo);
clearProgram.bind();
gl.uniform1i(clearProgram.uniforms.uTexture, pressure.read.attach(0));
gl.uniform1f(clearProgram.uniforms.value, config.PRESSURE);
blit(pressure.write.fbo);
pressure.swap();
pressureProgram.bind();
gl.uniform2f(pressureProgram.uniforms.texelSize, velocity.texelSizeX, velocity.texelSizeY);
gl.uniform1i(pressureProgram.uniforms.uDivergence, divergence.attach(0));
for (let i = 0; i < config.PRESSURE_ITERATIONS; i++) {
gl.uniform1i(pressureProgram.uniforms.uPressure, pressure.read.attach(1));
blit(pressure.write.fbo);
pressure.swap();
}
gradienSubtractProgram.bind();
gl.uniform2f(gradienSubtractProgram.uniforms.texelSize, velocity.texelSizeX, velocity.texelSizeY);
gl.uniform1i(gradienSubtractProgram.uniforms.uPressure, pressure.read.attach(0));
gl.uniform1i(gradienSubtractProgram.uniforms.uVelocity, velocity.read.attach(1));
blit(velocity.write.fbo);
velocity.swap();
advectionProgram.bind();
gl.uniform2f(advectionProgram.uniforms.texelSize, velocity.texelSizeX, velocity.texelSizeY);
if (!ext.supportLinearFiltering)
gl.uniform2f(advectionProgram.uniforms.dyeTexelSize, velocity.texelSizeX, velocity.texelSizeY);
let velocityId = velocity.read.attach(0);
gl.uniform1i(advectionProgram.uniforms.uVelocity, velocityId);
gl.uniform1i(advectionProgram.uniforms.uSource, velocityId);
gl.uniform1f(advectionProgram.uniforms.dt, dt);
gl.uniform1f(advectionProgram.uniforms.dissipation, config.VELOCITY_DISSIPATION);
blit(velocity.write.fbo);
velocity.swap();
gl.viewport(0, 0, dye.width, dye.height);
if (!ext.supportLinearFiltering)
gl.uniform2f(advectionProgram.uniforms.dyeTexelSize, dye.texelSizeX, dye.texelSizeY);
gl.uniform1i(advectionProgram.uniforms.uVelocity, velocity.read.attach(0));
gl.uniform1i(advectionProgram.uniforms.uSource, dye.read.attach(1));
gl.uniform1f(advectionProgram.uniforms.dissipation, config.DENSITY_DISSIPATION);
blit(dye.write.fbo);
dye.swap();
}
function render(target) {
if (config.BLOOM)
applyBloom(dye.read, bloom);
if (target == null || !config.TRANSPARENT) {
gl.blendFunc(gl.ONE, gl.ONE_MINUS_SRC_ALPHA);
gl.enable(gl.BLEND);
}
else {
gl.disable(gl.BLEND);
}
let width = target == null ? gl.drawingBufferWidth : target.width;
let height = target == null ? gl.drawingBufferHeight : target.height;
gl.viewport(0, 0, width, height);
let fbo = target == null ? null : target.fbo;
if (!config.TRANSPARENT)
drawColor(fbo, normalizeColor(config.BACK_COLOR));
if (target == null && config.TRANSPARENT)
drawCheckerboard(fbo);
drawDisplay(fbo, width, height);
}
function drawColor(fbo, color) {
colorProgram.bind();
gl.uniform4f(colorProgram.uniforms.color, color.r, color.g, color.b, 1);
blit(fbo);
}
function drawCheckerboard(fbo) {
checkerboardProgram.bind();
gl.uniform1f(checkerboardProgram.uniforms.aspectRatio, canvas.width / canvas.height);
blit(fbo);
}
function drawDisplay(fbo, width, height) {
let program = pickDisplayProgram();
program.bind();
if (config.SHADING)
gl.uniform2f(program.uniforms.texelSize, 1.0 / width, 1.0 / height);
gl.uniform1i(program.uniforms.uTexture, dye.read.attach(0));
if (config.BLOOM) {
gl.uniform1i(program.uniforms.uBloom, bloom.attach(1));
gl.uniform1i(program.uniforms.uDithering, ditheringTexture.attach(2));
let scale = getTextureScale(ditheringTexture, width, height);
gl.uniform2f(program.uniforms.ditherScale, scale.x, scale.y);
}
blit(fbo);
}
function pickDisplayProgram() {
if (config.SHADING) return config.BLOOM ? displayBloomShadingProgram : displayShadingProgram;
return config.BLOOM ? displayBloomProgram : displayProgram;
}
function applyBloom(source, destination) {
if (bloomFramebuffers.length < 2)
return;
let last = destination;
gl.disable(gl.BLEND);
bloomPrefilterProgram.bind();
let knee = config.BLOOM_THRESHOLD * config.BLOOM_SOFT_KNEE + 0.0001;
let curve0 = config.BLOOM_THRESHOLD - knee;
let curve1 = knee * 2;
let curve2 = 0.25 / knee;
gl.uniform3f(bloomPrefilterProgram.uniforms.curve, curve0, curve1, curve2);
gl.uniform1f(bloomPrefilterProgram.uniforms.threshold, config.BLOOM_THRESHOLD);
gl.uniform1i(bloomPrefilterProgram.uniforms.uTexture, source.attach(0));
gl.viewport(0, 0, last.width, last.height);
blit(last.fbo);
bloomBlurProgram.bind();
for (let i = 0; i < bloomFramebuffers.length; i++) {
let dest = bloomFramebuffers[i];
gl.uniform2f(bloomBlurProgram.uniforms.texelSize, 1.0 / last.width, 1.0 / last.height);
gl.uniform1i(bloomBlurProgram.uniforms.uTexture, last.attach(0));
gl.viewport(0, 0, dest.width, dest.height);
blit(dest.fbo);
last = dest;
}
gl.blendFunc(gl.ONE, gl.ONE);
gl.enable(gl.BLEND);
for (let i = bloomFramebuffers.length - 2; i >= 0; i--) {
let baseTex = bloomFramebuffers[i];
gl.uniform2f(bloomBlurProgram.uniforms.texelSize, 1.0 / last.width, 1.0 / last.height);
gl.uniform1i(bloomBlurProgram.uniforms.uTexture, last.attach(0));
gl.viewport(0, 0, baseTex.width, baseTex.height);
blit(baseTex.fbo);
last = baseTex;
}
gl.disable(gl.BLEND);
bloomFinalProgram.bind();
gl.uniform2f(bloomFinalProgram.uniforms.texelSize, 1.0 / last.width, 1.0 / last.height);
gl.uniform1i(bloomFinalProgram.uniforms.uTexture, last.attach(0));
gl.uniform1f(bloomFinalProgram.uniforms.intensity, config.BLOOM_INTENSITY);
gl.viewport(0, 0, destination.width, destination.height);
blit(destination.fbo);
}
function splatPointer(pointer) {
let dx = pointer.deltaX * config.SPLAT_FORCE;
let dy = pointer.deltaY * config.SPLAT_FORCE;
splat(pointer.texcoordX, pointer.texcoordY, dx, dy, pointer.color);
}
function multipleSplats(amount) {
for (let i = 0; i < amount; i++) {
const color = generateColor();
color.r *= 10.0;
color.g *= 10.0;
color.b *= 10.0;
const x = Math.random();
const y = Math.random();
const dx = 1000 * (Math.random() - 0.5);
const dy = 1000 * (Math.random() - 0.5);
splat(x, y, dx, dy, color);
}
}
function splat(x, y, dx, dy, color) {
gl.viewport(0, 0, velocity.width, velocity.height);
splatProgram.bind();
gl.uniform1i(splatProgram.uniforms.uTarget, velocity.read.attach(0));
gl.uniform1f(splatProgram.uniforms.aspectRatio, canvas.width / canvas.height);
gl.uniform2f(splatProgram.uniforms.point, x, y);
gl.uniform3f(splatProgram.uniforms.color, dx, dy, 0.0);
gl.uniform1f(splatProgram.uniforms.radius, correctRadius(config.SPLAT_RADIUS / 100.0));
blit(velocity.write.fbo);
velocity.swap();
gl.viewport(0, 0, dye.width, dye.height);
gl.uniform1i(splatProgram.uniforms.uTarget, dye.read.attach(0));
gl.uniform3f(splatProgram.uniforms.color, color.r, color.g, color.b);
blit(dye.write.fbo);
dye.swap();
}
function correctRadius(radius) {
let aspectRatio = canvas.width / canvas.height;
if (aspectRatio > 1)
radius *= aspectRatio;
return radius;
}
canvas.addEventListener('mousedown', e => {
let posX = scaleByPixelRatio(e.offsetX);
let posY = scaleByPixelRatio(e.offsetY);
updatePointerDownData(pointers[0], -1, posX, posY);
});
canvas.addEventListener('mousemove', e => {
let posX = scaleByPixelRatio(e.offsetX);
let posY = scaleByPixelRatio(e.offsetY);
updatePointerMoveData(pointers[0], posX, posY);
});
window.addEventListener('mouseup', () => {
updatePoinerUpData(pointers[0]);
});
canvas.addEventListener('touchstart', e => {
e.preventDefault();
const touches = e.targetTouches;
for (let i = 0; i < touches.length; i++) {
if (i >= pointers.length)
pointers.push(new pointerPrototype());
let posX = scaleByPixelRatio(touches[i].pageX);
let posY = scaleByPixelRatio(touches[i].pageY);
updatePointerDownData(pointers[i], touches[i].identifier, posX, posY);
}
});
canvas.addEventListener('touchmove', e => {
e.preventDefault();
const touches = e.targetTouches;
for (let i = 0; i < touches.length; i++) {
let posX = scaleByPixelRatio(touches[i].pageX);
let posY = scaleByPixelRatio(touches[i].pageY);
updatePointerMoveData(pointers[i], posX, posY);
}
}, false);
window.addEventListener('touchend', e => {
const touches = e.changedTouches;
for (let i = 0; i < touches.length; i++)
for (let j = 0; j < pointers.length; j++)
if (touches[i].identifier == pointers[j].id)
updatePoinerUpData(pointers[j]);
});
window.addEventListener('keydown', e => {
if (e.code === 'KeyP')
config.PAUSED = !config.PAUSED;
if (e.key === ' ')
splatStack.push(parseInt(Math.random() * 20) + 5);
});
function updatePointerDownData(pointer, id, posX, posY) {
pointer.id = id;
pointer.down = true;
pointer.moved = false;
pointer.texcoordX = posX / canvas.width;
pointer.texcoordY = 1.0 - posY / canvas.height;
pointer.prevTexcoordX = pointer.texcoordX;
pointer.prevTexcoordY = pointer.texcoordY;
pointer.deltaX = 0;
pointer.deltaY = 0;
pointer.color = generateColor();
}
function updatePointerMoveData(pointer, posX, posY) {
pointer.moved = pointer.down;
pointer.down = true;
pointer.prevTexcoordX = pointer.texcoordX;
pointer.prevTexcoordY = pointer.texcoordY;
pointer.texcoordX = posX / canvas.width;
pointer.texcoordY = 1.0 - posY / canvas.height;
pointer.deltaX = correctDeltaX(pointer.texcoordX - pointer.prevTexcoordX);
pointer.deltaY = correctDeltaY(pointer.texcoordY - pointer.prevTexcoordY);
}
function updatePoinerUpData(pointer) {
pointer.down = false;
}
function correctDeltaX(delta) {
let aspectRatio = canvas.width / canvas.height;
if (aspectRatio < 1) delta *= aspectRatio;
return delta;
}
function correctDeltaY(delta) {
let aspectRatio = canvas.width / canvas.height;
if (aspectRatio > 1) delta /= aspectRatio;
return delta;
}
function generateColor() {
let c = HSVtoRGB(Math.random(), 1.0, 1.0);
c.r *= 0.15;
c.g *= 0.15;
c.b *= 0.15;
return c;
}
function HSVtoRGB(h, s, v) {
let r, g, b, i, f, p, q, t;
i = Math.floor(h * 6);
f = h * 6 - i;
p = v * (1 - s);
q = v * (1 - f * s);
t = v * (1 - (1 - f) * s);
switch (i % 6) {
case 0: r = v, g = t, b = p; break;
case 1: r = q, g = v, b = p; break;
case 2: r = p, g = v, b = t; break;
case 3: r = p, g = q, b = v; break;
case 4: r = t, g = p, b = v; break;
case 5: r = v, g = p, b = q; break;
}
return {
r,
g,
b
};
}
function normalizeColor(input) {
let output = {
r: input.r / 255,
g: input.g / 255,
b: input.b / 255
};
return output;
}
function wrap(value, min, max) {
let range = max - min;
if (range == 0) return min;
return (value - min) % range + min;
}
function getResolution(resolution) {
let aspectRatio = gl.drawingBufferWidth / gl.drawingBufferHeight;
if (aspectRatio < 1)
aspectRatio = 1.0 / aspectRatio;
let min = Math.round(resolution);
let max = Math.round(resolution * aspectRatio);
if (gl.drawingBufferWidth > gl.drawingBufferHeight)
return { width: max, height: min };
else
return { width: min, height: max };
}
function getTextureScale(texture, width, height) {
return {
x: width / texture.width,
y: height / texture.height
};
}
function scaleByPixelRatio(input) {
let pixelRatio = window.devicePixelRatio || 1;
return Math.floor(input * pixelRatio);
}