mirror_js/WebGL-Fluid-Simulation
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Pavel Dobryakov
2017-08-14 09:13:31 +03:00
parent badc1b5d06
commit f385c2bec1
1 changed files with 267 additions and 243 deletions
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script.js
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@@ -8,15 +8,21 @@ if (!gl.getExtension("OES_texture_float")) {
console.log("does not support OES_texture_float"); console.log("does not support OES_texture_float");
} }
if (!gl.getExtension("OES_texture_float_linear")) { const support_linear_float = gl.getExtension("OES_texture_float_linear");
console.log("does not support OES_texture_float_linear"); if (!support_linear_float) {
console.log("does not support OES_texture_float_linear");
} }
resizeCanvas(); resizeCanvas();
const TEXTURE_WIDTH = 200;//gl.drawingBufferWidth; const TEXTURE_DOWNSAMPLE = 2;
const TEXTURE_HEIGHT = 200;//gl.drawingBufferHeight; const TEXTURE_WIDTH = 200//gl.drawingBufferWidth >> TEXTURE_DOWNSAMPLE;
const TEXTURE_HEIGHT = 200//gl.drawingBufferHeight >> TEXTURE_DOWNSAMPLE;
const CELL_SIZE = 1.0; const CELL_SIZE = 1.0;
const DENSITY_DISSIPATION = 0.99;
const VELOCITY_DISSIPATION = 0.999;
const SPLAT_RADIUS = 0.001;
const PRESSURE_ITERATIONS = 20;
class GLProgram { class GLProgram {
constructor (vertexShader, fragmentShader) { constructor (vertexShader, fragmentShader) {
@@ -55,46 +61,193 @@ function compileShader (type, source) {
return shader; return shader;
}; };
let texId = -1; const baseVertexShader = compileShader(gl.VERTEX_SHADER, `
function createFBO (width, height, type) { attribute vec2 aPosition;
texId++; varying vec2 vUv;
gl.activeTexture(gl.TEXTURE0 + texId); varying vec2 vL;
var texture = gl.createTexture(); varying vec2 vR;
gl.bindTexture(gl.TEXTURE_2D, texture); varying vec2 vT;
gl.texParameteri(gl.TEXTURE_2D, gl.TEXTURE_MIN_FILTER, type); varying vec2 vB;
gl.texParameteri(gl.TEXTURE_2D, gl.TEXTURE_MAG_FILTER, type); uniform vec2 texelSize;
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, gl.RGBA, width, height, 0, gl.RGBA, gl.FLOAT, null);
var fbo = gl.createFramebuffer(); void main () {
gl.bindFramebuffer(gl.FRAMEBUFFER, fbo); vUv = aPosition * 0.5 + 0.5;
gl.framebufferTexture2D(gl.FRAMEBUFFER, gl.COLOR_ATTACHMENT0, gl.TEXTURE_2D, texture, 0); vL = vUv - vec2(texelSize.x, 0.0);
gl.viewport(0, 0, width, height); vR = vUv + vec2(texelSize.x, 0.0);
gl.clearColor(0.0, 0.0, 0.0, 1.0); vT = vUv + vec2(0.0, texelSize.y);
gl.clear(gl.COLOR_BUFFER_BIT); vB = vUv - vec2(0.0, texelSize.y);
return [texture, fbo, texId]; gl_Position = vec4(aPosition, 0.0, 1.0);
}
function createDoubleFBO (width, height, type) {
let fbo1 = createFBO(width, height, type);
let fbo2 = createFBO(width, height, type);
return {
get first () {
return fbo1;
},
get second () {
return fbo2;
},
swap: () => {
let temp = fbo1;
fbo1 = fbo2;
fbo2 = temp;
}
} }
} `);
const displayShader = compileShader(gl.FRAGMENT_SHADER, `
precision highp float;
varying vec2 vUv;
uniform sampler2D uTexture;
void main () {
gl_FragColor = texture2D(uTexture, vUv);
}
`);
const initDensityShader = compileShader(gl.FRAGMENT_SHADER, `
precision highp float;
varying vec2 vUv;
void main () {
float d = mod(floor(vUv.x * 10.0) + floor(vUv.y * 10.0), 2.0);
gl_FragColor = vec4(vec3(d), 1.0);
}
`);
const initVelocityShader = compileShader(gl.FRAGMENT_SHADER, `
precision highp float;
varying vec2 vUv;
void main () {
gl_FragColor = vec4(sin(6.28 * vUv.y), sin(6.28 * vUv.x), 0.0, 1.0);
}
`);
const splatShader = compileShader(gl.FRAGMENT_SHADER, `
precision highp float;
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 advectionManualFilteringShader = compileShader(gl.FRAGMENT_SHADER, `
precision highp float;
varying vec2 vUv;
uniform sampler2D uVelocity;
uniform sampler2D uSource;
uniform vec2 texelSize;
uniform float rdx;
uniform float dt;
uniform float dissipation;
vec4 bilerp (sampler2D sam, vec2 p) {
vec4 st;
st.xy = floor(p - 0.5) + 0.5;
st.zw = st.xy + 1.0;
vec4 uv = st * texelSize.xyxy;
vec4 a = texture2D(sam, uv.xy);
vec4 b = texture2D(sam, uv.zy);
vec4 c = texture2D(sam, uv.xw);
vec4 d = texture2D(sam, uv.zw);
vec2 f = p - st.xy;
return mix(mix(a, b, f.x), mix(c, d, f.x), f.y);
}
void main () {
vec2 coord = gl_FragCoord.xy - rdx * dt * texture2D(uVelocity, vUv).xy;
gl_FragColor = dissipation * bilerp(uSource, coord);
gl_FragColor.a = 1.0;
}
`);
const advectionShader = compileShader(gl.FRAGMENT_SHADER, `
precision highp float;
varying vec2 vUv;
uniform sampler2D uVelocity;
uniform sampler2D uSource;
uniform vec2 texelSize;
uniform float rdx;
uniform float dt;
uniform float dissipation;
void main () {
vec2 coord = vUv - rdx * dt * texture2D(uVelocity, vUv).xy * texelSize;
gl_FragColor = dissipation * texture2D(uSource, coord);
gl_FragColor.a = 1.0;
}
`);
const divergenceShader = compileShader(gl.FRAGMENT_SHADER, `
precision highp float;
varying vec2 vUv;
varying vec2 vL;
varying vec2 vR;
varying vec2 vT;
varying vec2 vB;
uniform sampler2D uVelocity;
uniform float halfrdx;
void main () {
vec2 L = texture2D(uVelocity, vL).xy;
vec2 R = texture2D(uVelocity, vR).xy;
vec2 T = texture2D(uVelocity, vT).xy;
vec2 B = texture2D(uVelocity, vB).xy;
float div = halfrdx * (R.x - L.x + T.y - B.y);
gl_FragColor = vec4(div, 0.0, 0.0, 1.0);
}
`);
const pressureShader = compileShader(gl.FRAGMENT_SHADER, `
precision highp float;
varying vec2 vUv;
varying vec2 vL;
varying vec2 vR;
varying vec2 vT;
varying vec2 vB;
uniform sampler2D uPressure;
uniform sampler2D uDivergence;
uniform float alpha;
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 divergence = texture2D(uDivergence, vUv).x;
float pressure = (L + R + B + T + alpha * divergence) * .25;
gl_FragColor = vec4(pressure, 0.0, 0.0, 1.0);
}
`);
const gradientSubtractShader = compileShader(gl.FRAGMENT_SHADER, `
precision highp float;
varying vec2 vUv;
varying vec2 vL;
varying vec2 vR;
varying vec2 vT;
varying vec2 vB;
uniform sampler2D uPressure;
uniform sampler2D uVelocity;
uniform float halfrdx;
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 -= halfrdx * vec2(R - L, T - B);
gl_FragColor = vec4(velocity, 0.0, 1.0);
}
`);
const blit = (() => { const blit = (() => {
gl.bindBuffer(gl.ARRAY_BUFFER, gl.createBuffer()); gl.bindBuffer(gl.ARRAY_BUFFER, gl.createBuffer());
@@ -116,191 +269,58 @@ function clear (target) {
gl.clear(gl.COLOR_BUFFER_BIT); gl.clear(gl.COLOR_BUFFER_BIT);
} }
let density = createDoubleFBO(TEXTURE_WIDTH, TEXTURE_HEIGHT, gl.LINEAR); let texId = -1;
let velocity = createDoubleFBO(TEXTURE_WIDTH, TEXTURE_HEIGHT, gl.LINEAR); function createFBO (width, height, format, type) {
let divergence = createFBO(TEXTURE_WIDTH, TEXTURE_HEIGHT, gl.NEAREST); texId++;
let pressure = createDoubleFBO(TEXTURE_WIDTH, TEXTURE_HEIGHT, gl.NEAREST); gl.activeTexture(gl.TEXTURE0 + texId);
var texture = gl.createTexture();
gl.bindTexture(gl.TEXTURE_2D, texture);
gl.texParameteri(gl.TEXTURE_2D, gl.TEXTURE_MIN_FILTER, type);
gl.texParameteri(gl.TEXTURE_2D, gl.TEXTURE_MAG_FILTER, type);
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, gl.RGBA, width, height, 0, gl.RGBA, format, null);
const baseVertexShader = compileShader(gl.VERTEX_SHADER, ` var fbo = gl.createFramebuffer();
attribute vec2 aPosition; gl.bindFramebuffer(gl.FRAMEBUFFER, fbo);
varying vec2 vUv; gl.framebufferTexture2D(gl.FRAMEBUFFER, gl.COLOR_ATTACHMENT0, gl.TEXTURE_2D, texture, 0);
gl.viewport(0, 0, width, height);
gl.clearColor(0.0, 0.0, 0.0, 1.0);
gl.clear(gl.COLOR_BUFFER_BIT);
void main () { return [texture, fbo, texId];
vUv = aPosition * 0.5 + 0.5; }
gl_Position = vec4(aPosition, 0.0, 1.0);
function createDoubleFBO (width, height, format, type) {
let fbo1 = createFBO(width, height, format, type);
let fbo2 = createFBO(width, height, format, type);
return {
get first () {
return fbo1;
},
get second () {
return fbo2;
},
swap: () => {
let temp = fbo1;
fbo1 = fbo2;
fbo2 = temp;
}
} }
`); }
const displayShader = compileShader(gl.FRAGMENT_SHADER, ` let density = createDoubleFBO(TEXTURE_WIDTH, TEXTURE_HEIGHT, gl.FLOAT, support_linear_float ? gl.LINEAR : gl.NEAREST);
precision highp float; let velocity = createDoubleFBO(TEXTURE_WIDTH, TEXTURE_HEIGHT, gl.FLOAT, support_linear_float ? gl.LINEAR : gl.NEAREST);
let divergence = createFBO(TEXTURE_WIDTH, TEXTURE_HEIGHT, gl.FLOAT, gl.NEAREST);
varying vec2 vUv; let pressure = createDoubleFBO(TEXTURE_WIDTH, TEXTURE_HEIGHT, gl.FLOAT, gl.NEAREST);
uniform sampler2D uTexture;
void main () {
gl_FragColor = texture2D(uTexture, vUv);
}
`);
const testShader = compileShader(gl.FRAGMENT_SHADER, `
precision highp float;
varying vec2 vUv;
uniform sampler2D uTexture;
uniform vec2 uMouse;
void main () {
vec4 color = texture2D(uTexture, vUv);
// gl_FragColor = vec4(vUv.xy, uMouse.x, 1.0);// + color;
gl_FragColor = color + vec4(0.0, 0.005, 0.0, 0.0);
}
`);
const initDensityShader = compileShader(gl.FRAGMENT_SHADER, `
precision highp float;
varying vec2 vUv;
void main () {
float d = mod(floor(vUv.x * 10.0) + floor(vUv.y * 10.0), 2.0);
// vec2 p = vec2(0.5, 0.2);
// float d = length(vUv - p);
// float radius = 0.1;
// float c = smoothstep(radius - .01, radius + .01, d);
gl_FragColor = vec4(vec3(d), 1.0);
}
`);
const initVelocityShader = compileShader(gl.FRAGMENT_SHADER, `
precision highp float;
varying vec2 vUv;
void main () {
gl_FragColor = vec4(sin(6.28 * vUv.y), sin(6.28 * vUv.x), 0.0, 1.0);
}
`);
const splatShader = compileShader(gl.FRAGMENT_SHADER, `
precision highp float;
varying vec2 vUv;
uniform sampler2D uTarget;
uniform vec3 color;
uniform vec2 point;
uniform float radius;
void main () {
vec2 p = vUv - point.xy;
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;
varying vec2 vUv;
uniform sampler2D uVelocity;
uniform sampler2D uSource;
uniform vec2 texelSize;
uniform float rdx;
uniform float dt;
uniform float dissipation;
vec4 bilerp (sampler2D sam, vec2 p) {
vec4 st;
st.xy = floor(p - 0.5) + 0.5;
st.zw = st.xy + 1.0;
vec4 uv = st * texelSize.xyxy;
vec4 a = texture2D(sam, uv.xy);
vec4 b = texture2D(sam, uv.zy);
vec4 c = texture2D(sam, uv.xw);
vec4 d = texture2D(sam, uv.zw);
vec2 f = p - st.xy;
return mix(mix(a, b, f.x), mix(c, d, f.x), f.y);
}
void main () {
vec2 coord = vUv - rdx * dt * texture2D(uVelocity, vUv).xy * texelSize;
gl_FragColor = dissipation * texture2D(uSource, coord);
gl_FragColor.a = 1.0;
}
`);
const divergenceShader = compileShader(gl.FRAGMENT_SHADER, `
precision highp float;
varying vec2 vUv;
uniform sampler2D uVelocity;
uniform vec2 texelSize;
uniform float halfrdx;
void main () {
vec2 T = texture2D(uVelocity, vUv + vec2(0.0, texelSize.y)).xy;
vec2 B = texture2D(uVelocity, vUv - vec2(0.0, texelSize.y)).xy;
vec2 R = texture2D(uVelocity, vUv + vec2(texelSize.x, 0.0)).xy;
vec2 L = texture2D(uVelocity, vUv - vec2(texelSize.x, 0.0)).xy;
//vec2 C = texture2D(uVelocity, vUv).xy;
float div = halfrdx * (R.x - L.x + T.y - B.y);
gl_FragColor = vec4(div, 0.0, 0.0, 1.0);
}
`);
const pressureShader = compileShader(gl.FRAGMENT_SHADER, `
precision highp float;
varying vec2 vUv;
uniform sampler2D uPressure;
uniform sampler2D uDivergence;
uniform vec2 texelSize;
uniform float alpha;
void main () {
float T = texture2D(uPressure, vUv + vec2(0.0, texelSize.y)).x;
float B = texture2D(uPressure, vUv - vec2(0.0, texelSize.y)).x;
float R = texture2D(uPressure, vUv + vec2(texelSize.x, 0.0)).x;
float L = texture2D(uPressure, vUv - vec2(texelSize.x, 0.0)).x;
float divergence = texture2D(uDivergence, vUv).x;
float pressure = (L + R + B + T + alpha * divergence) * .25;
gl_FragColor = vec4(pressure, 0.0, 0.0, 1.0);
}
`);
const gradientSubtractShader = compileShader(gl.FRAGMENT_SHADER, `
precision highp float;
varying vec2 vUv;
uniform sampler2D uPressure;
uniform sampler2D uVelocity;
uniform vec2 texelSize;
uniform float halfrdx;
void main () {
float T = texture2D(uPressure, vUv + vec2(0.0, texelSize.y)).x;
float B = texture2D(uPressure, vUv - vec2(0.0, texelSize.y)).x;
float R = texture2D(uPressure, vUv + vec2(texelSize.x, 0.0)).x;
float L = texture2D(uPressure, vUv - vec2(texelSize.x, 0.0)).x;
vec2 velocity = texture2D(uVelocity, vUv).xy;
velocity.xy -= halfrdx * vec2(R - L, T - B);
gl_FragColor = vec4(velocity, 0.0, 1.0);
}
`);
const splatProgram = new GLProgram(baseVertexShader, splatShader);
const displayProgram = new GLProgram(baseVertexShader, displayShader); const displayProgram = new GLProgram(baseVertexShader, displayShader);
const testProgram = new GLProgram(baseVertexShader, testShader); const splatProgram = new GLProgram(baseVertexShader, splatShader);
const initDensityProgram = new GLProgram(baseVertexShader, initDensityShader); const initDensityProgram = new GLProgram(baseVertexShader, initDensityShader);
const initVelocityProgram = new GLProgram(baseVertexShader, initVelocityShader); const initVelocityProgram = new GLProgram(baseVertexShader, initVelocityShader);
const advectionProgram = new GLProgram(baseVertexShader, advectionShader); const advectionProgram = new GLProgram(baseVertexShader, support_linear_float ? advectionShader : advectionManualFilteringShader);
const divergenceProgram = new GLProgram(baseVertexShader, divergenceShader); const divergenceProgram = new GLProgram(baseVertexShader, divergenceShader);
const pressureProgram = new GLProgram(baseVertexShader, pressureShader); const pressureProgram = new GLProgram(baseVertexShader, pressureShader);
const gradienSubtractProgram = new GLProgram(baseVertexShader, gradientSubtractShader); const gradienSubtractProgram = new GLProgram(baseVertexShader, gradientSubtractShader);
@@ -317,8 +337,8 @@ let pointer = {
initDensityProgram.bind(); initDensityProgram.bind();
blit(density.first[1]); blit(density.first[1]);
// initVelocityProgram.bind(); initVelocityProgram.bind();
// blit(velocity.first[1]); blit(velocity.first[1]);
Update(); Update();
@@ -327,21 +347,19 @@ function Update () {
gl.viewport(0, 0, TEXTURE_WIDTH, TEXTURE_HEIGHT); gl.viewport(0, 0, TEXTURE_WIDTH, TEXTURE_HEIGHT);
// advect velocity
advectionProgram.bind(); advectionProgram.bind();
gl.uniform2f(advectionProgram.uniforms.texelSize, 1.0 / TEXTURE_WIDTH, 1.0 / TEXTURE_HEIGHT);
gl.uniform1i(advectionProgram.uniforms.uVelocity, velocity.first[2]); gl.uniform1i(advectionProgram.uniforms.uVelocity, velocity.first[2]);
gl.uniform1i(advectionProgram.uniforms.uSource, velocity.first[2]); gl.uniform1i(advectionProgram.uniforms.uSource, velocity.first[2]);
gl.uniform2f(advectionProgram.uniforms.texelSize, 1.0 / TEXTURE_WIDTH, 1.0 / TEXTURE_HEIGHT);
gl.uniform1f(advectionProgram.uniforms.rdx, 1.0 / CELL_SIZE); gl.uniform1f(advectionProgram.uniforms.rdx, 1.0 / CELL_SIZE);
gl.uniform1f(advectionProgram.uniforms.dt, 0.16); gl.uniform1f(advectionProgram.uniforms.dt, 0.16);
gl.uniform1f(advectionProgram.uniforms.dissipation, .99); gl.uniform1f(advectionProgram.uniforms.dissipation, VELOCITY_DISSIPATION);
blit(velocity.second[1]); blit(velocity.second[1]);
velocity.swap(); velocity.swap();
// advect density
gl.uniform1i(advectionProgram.uniforms.uVelocity, velocity.first[2]); gl.uniform1i(advectionProgram.uniforms.uVelocity, velocity.first[2]);
gl.uniform1i(advectionProgram.uniforms.uSource, density.first[2]); gl.uniform1i(advectionProgram.uniforms.uSource, density.first[2]);
gl.uniform1f(advectionProgram.uniforms.dissipation, .999); gl.uniform1f(advectionProgram.uniforms.dissipation, DENSITY_DISSIPATION);
blit(density.second[1]); blit(density.second[1]);
density.swap(); density.swap();
@@ -349,9 +367,10 @@ function Update () {
{ {
splatProgram.bind(); splatProgram.bind();
gl.uniform1i(splatProgram.uniforms.uTarget, velocity.first[2]); gl.uniform1i(splatProgram.uniforms.uTarget, velocity.first[2]);
gl.uniform1f(splatProgram.uniforms.aspectRatio, TEXTURE_WIDTH / TEXTURE_HEIGHT);
gl.uniform2f(splatProgram.uniforms.point, pointer.x / canvas.width, 1.0 - pointer.y / canvas.height); gl.uniform2f(splatProgram.uniforms.point, pointer.x / canvas.width, 1.0 - pointer.y / canvas.height);
gl.uniform3f(splatProgram.uniforms.color, pointer.deltax, -pointer.deltay, 1.0); gl.uniform3f(splatProgram.uniforms.color, pointer.deltax, -pointer.deltay, 1.0);
gl.uniform1f(splatProgram.uniforms.radius, .001); gl.uniform1f(splatProgram.uniforms.radius, SPLAT_RADIUS);
blit(velocity.second[1]); blit(velocity.second[1]);
velocity.swap(); velocity.swap();
@@ -361,41 +380,31 @@ function Update () {
density.swap(); density.swap();
} }
// calculate divergence
divergenceProgram.bind(); divergenceProgram.bind();
gl.uniform1i(divergenceProgram.uniforms.uVelocity, velocity.first[2]);
gl.uniform2f(divergenceProgram.uniforms.texelSize, 1.0 / TEXTURE_WIDTH, 1.0 / TEXTURE_HEIGHT); gl.uniform2f(divergenceProgram.uniforms.texelSize, 1.0 / TEXTURE_WIDTH, 1.0 / TEXTURE_HEIGHT);
gl.uniform1i(divergenceProgram.uniforms.uVelocity, velocity.first[2]);
gl.uniform1f(divergenceProgram.uniforms.halfrdx, 0.5 / CELL_SIZE); gl.uniform1f(divergenceProgram.uniforms.halfrdx, 0.5 / CELL_SIZE);
blit(divergence[1]); blit(divergence[1]);
// pressure
clear(pressure.first[1]); clear(pressure.first[1]);
// clear(pressure.second[1]);
pressureProgram.bind(); pressureProgram.bind();
gl.uniform2f(pressureProgram.uniforms.texelSize, 1.0 / TEXTURE_WIDTH, 1.0 / TEXTURE_HEIGHT); gl.uniform2f(pressureProgram.uniforms.texelSize, 1.0 / TEXTURE_WIDTH, 1.0 / TEXTURE_HEIGHT);
// gl.uniform1i(pressureProgram.uniforms.uDivergence, density.first[2]);
// gl.uniform1i(pressureProgram.uniforms.uPressure, pressure.second[2]);
// gl.uniform1f(pressureProgram.uniforms.alpha, 0.1);
// blit(pressure.first[1]);
gl.uniform1i(pressureProgram.uniforms.uDivergence, divergence[2]); gl.uniform1i(pressureProgram.uniforms.uDivergence, divergence[2]);
gl.uniform1f(pressureProgram.uniforms.alpha, -CELL_SIZE * CELL_SIZE); gl.uniform1f(pressureProgram.uniforms.alpha, -CELL_SIZE * CELL_SIZE);
for (let i = 0; i < PRESSURE_ITERATIONS; i++) {
for (let i = 0; i < 20; i++) {
gl.uniform1i(pressureProgram.uniforms.uPressure, pressure.first[2]); gl.uniform1i(pressureProgram.uniforms.uPressure, pressure.first[2]);
blit(pressure.second[1]); blit(pressure.second[1]);
pressure.swap(); pressure.swap();
} }
// subtract gradient
gradienSubtractProgram.bind(); gradienSubtractProgram.bind();
gl.uniform2f(gradienSubtractProgram.uniforms.texelSize, 1.0 / TEXTURE_WIDTH, 1.0 / TEXTURE_HEIGHT);
gl.uniform1i(gradienSubtractProgram.uniforms.uPressure, pressure.first[2]); gl.uniform1i(gradienSubtractProgram.uniforms.uPressure, pressure.first[2]);
gl.uniform1i(gradienSubtractProgram.uniforms.uVelocity, velocity.first[2]); gl.uniform1i(gradienSubtractProgram.uniforms.uVelocity, velocity.first[2]);
gl.uniform2f(gradienSubtractProgram.uniforms.texelSize, 1.0 / TEXTURE_WIDTH, 1.0 / TEXTURE_HEIGHT);
gl.uniform1f(gradienSubtractProgram.uniforms.halfrdx, 0.5 / CELL_SIZE); gl.uniform1f(gradienSubtractProgram.uniforms.halfrdx, 0.5 / CELL_SIZE);
blit(velocity.second[1]); blit(velocity.second[1]);
velocity.swap(); velocity.swap();
// display result
gl.viewport(0, 0, gl.drawingBufferWidth, gl.drawingBufferHeight); gl.viewport(0, 0, gl.drawingBufferWidth, gl.drawingBufferHeight);
displayProgram.bind(); displayProgram.bind();
gl.uniform1i(displayProgram.uniforms.uTexture, density.first[2]); gl.uniform1i(displayProgram.uniforms.uTexture, density.first[2]);
@@ -422,11 +431,26 @@ canvas.addEventListener('mousemove', (e) => {
pointer.y = e.offsetY; pointer.y = e.offsetY;
}); });
canvas.addEventListener('mousedown', (e) => { canvas.addEventListener('touchmove', (e) => {
pointer.down = true; e.preventDefault();
pointer.color = [Math.random() + 0.5, Math.random() + 0.5, Math.random()]; const touch = e.touches[0];
pointer.moved = pointer.down;
pointer.deltax = touch.offsetX - pointer.x;
pointer.deltay = touch.offsetY - pointer.y;
pointer.x = touch.offsetX;
pointer.y = touch.offsetY;
}); });
window.addEventListener('mouseup', (e) => { canvas.addEventListener('mousedown', onPointerDown);
canvas.addEventListener('touchstart', onPointerDown);
window.addEventListener('mouseup', onPointerUp);
window.addEventListener('touchend', onPointerUp);
function onPointerDown () {
pointer.down = true;
pointer.color = [Math.random() + 0.5, Math.random() + 0.5, Math.random()];
}
function onPointerUp () {
pointer.down = false; pointer.down = false;
}); }