'use client';
import { useEffect, useRef } from 'react';
function SplashCursor({
// You can customize these props if you want
SIM_RESOLUTION = 128,
DYE_RESOLUTION = 1440,
CAPTURE_RESOLUTION = 512,
DENSITY_DISSIPATION = 3.5,
VELOCITY_DISSIPATION = 2,
PRESSURE = 0.1,
PRESSURE_ITERATIONS = 20,
CURL = 3,
SPLAT_RADIUS = 0.2,
SPLAT_FORCE = 6000,
SHADING = true,
COLOR_UPDATE_SPEED = 10,
BACK_COLOR = { r: 0.5, g: 0, b: 0 },
TRANSPARENT = true
}) {
const canvasRef = useRef(null);
useEffect(() => {
const canvas = canvasRef.current;
if (!canvas) return;
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 = [0, 0, 0];
}
let config = {
SIM_RESOLUTION,
DYE_RESOLUTION,
CAPTURE_RESOLUTION,
DENSITY_DISSIPATION,
VELOCITY_DISSIPATION,
PRESSURE,
PRESSURE_ITERATIONS,
CURL,
SPLAT_RADIUS,
SPLAT_FORCE,
SHADING,
COLOR_UPDATE_SPEED,
PAUSED: false,
BACK_COLOR,
TRANSPARENT,
};
let pointers = [new pointerPrototype()];
const { gl, ext } = getWebGLContext(canvas);
if (!ext.supportLinearFiltering) {
config.DYE_RESOLUTION = 256;
config.SHADING = false;
}
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 && 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);
}
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) {
const 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);
const 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;
}
class Material {
constructor(vertexShader, fragmentShaderSource) {
this.vertexShader = vertexShader;
this.fragmentShaderSource = fragmentShaderSource;
this.programs = [];
this.activeProgram = null;
this.uniforms = [];
}
setKeywords(keywords) {
let hash = 0;
for (let i = 0; i < keywords.length; i++) hash += hashCode(keywords[i]);
let program = this.programs[hash];
if (program == null) {
let fragmentShader = compileShader(
gl.FRAGMENT_SHADER,
this.fragmentShaderSource,
keywords
);
program = createProgram(this.vertexShader, fragmentShader);
this.programs[hash] = program;
}
if (program === this.activeProgram) return;
this.uniforms = getUniforms(program);
this.activeProgram = program;
}
bind() {
gl.useProgram(this.activeProgram);
}
}
class Program {
constructor(vertexShader, fragmentShader) {
this.uniforms = {};
this.program = createProgram(vertexShader, fragmentShader);
this.uniforms = getUniforms(this.program);
}
bind() {
gl.useProgram(this.program);
}
}
function createProgram(vertexShader, fragmentShader) {
let program = gl.createProgram();
gl.attachShader(program, vertexShader);
gl.attachShader(program, fragmentShader);
gl.linkProgram(program);
if (!gl.getProgramParameter(program, gl.LINK_STATUS))
console.trace(gl.getProgramInfoLog(program));
return program;
}
function getUniforms(program) {
let uniforms = [];
let uniformCount = gl.getProgramParameter(program, gl.ACTIVE_UNIFORMS);
for (let i = 0; i < uniformCount; i++) {
let uniformName = gl.getActiveUniform(program, i).name;
uniforms[uniformName] = gl.getUniformLocation(program, uniformName);
}
return uniforms;
}
function compileShader(type, source, keywords) {
source = addKeywords(source, keywords);
const shader = gl.createShader(type);
gl.shaderSource(shader, source);
gl.compileShader(shader);
if (!gl.getShaderParameter(shader, gl.COMPILE_STATUS))
console.trace(gl.getShaderInfoLog(shader));
return shader;
}
function addKeywords(source, keywords) {
if (!keywords) return source;
let keywordsString = '';
keywords.forEach((keyword) => {
keywordsString += '#define ' + keyword + '\n';
});
return keywordsString + source;
}
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 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 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
float a = max(c.r, max(c.g, c.b));
gl_FragColor = vec4(c, a);
}
`;
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 velocity = texture2D(uVelocity, vUv).xy;
velocity += force * dt;
velocity = min(max(velocity, -1000.0), 1000.0);
gl_FragColor = vec4(velocity, 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 (target, clear = false) => {
if (target == null) {
gl.viewport(0, 0, gl.drawingBufferWidth, gl.drawingBufferHeight);
gl.bindFramebuffer(gl.FRAMEBUFFER, null);
} else {
gl.viewport(0, 0, target.width, target.height);
gl.bindFramebuffer(gl.FRAMEBUFFER, target.fbo);
}
if (clear) {
gl.clearColor(0.0, 0.0, 0.0, 1.0);
gl.clear(gl.COLOR_BUFFER_BIT);
}
gl.drawElements(gl.TRIANGLES, 6, gl.UNSIGNED_SHORT, 0);
};
})();
let dye, velocity, divergence, curl, pressure;
const copyProgram = new Program(baseVertexShader, copyShader);
const clearProgram = new Program(baseVertexShader, clearShader);
const splatProgram = new Program(baseVertexShader, splatShader);
const advectionProgram = new Program(baseVertexShader, advectionShader);
const divergenceProgram = new Program(baseVertexShader, divergenceShader);
const curlProgram = new Program(baseVertexShader, curlShader);
const vorticityProgram = new Program(baseVertexShader, vorticityShader);
const pressureProgram = new Program(baseVertexShader, pressureShader);
const gradienSubtractProgram = new Program(baseVertexShader, gradientSubtractShader);
const displayMaterial = new Material(baseVertexShader, displayShaderSource);
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;
gl.disable(gl.BLEND);
if (!dye)
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)
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
);
}
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);
let texelSizeX = 1.0 / w;
let texelSizeY = 1.0 / h;
return {
texture,
fbo,
width: w,
height: h,
texelSizeX,
texelSizeY,
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);
return {
width: w,
height: h,
texelSizeX: fbo1.texelSizeX,
texelSizeY: fbo1.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);
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 updateKeywords() {
let displayKeywords = [];
if (config.SHADING) displayKeywords.push('SHADING');
displayMaterial.setKeywords(displayKeywords);
}
updateKeywords();
initFramebuffers();
let lastUpdateTime = Date.now();
let colorUpdateTimer = 0.0;
function updateFrame() {
const dt = calcDeltaTime();
if (resizeCanvas()) initFramebuffers();
updateColors(dt);
applyInputs();
step(dt);
render(null);
requestAnimationFrame(updateFrame);
}
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) {
colorUpdateTimer += dt * config.COLOR_UPDATE_SPEED;
if (colorUpdateTimer >= 1) {
colorUpdateTimer = wrap(colorUpdateTimer, 0, 1);
pointers.forEach((p) => {
p.color = generateColor();
});
}
}
function applyInputs() {
pointers.forEach((p) => {
if (p.moved) {
p.moved = false;
splatPointer(p);
}
});
}
function step(dt) {
gl.disable(gl.BLEND);
// Curl
curlProgram.bind();
gl.uniform2f(
curlProgram.uniforms.texelSize,
velocity.texelSizeX,
velocity.texelSizeY
);
gl.uniform1i(curlProgram.uniforms.uVelocity, velocity.read.attach(0));
blit(curl);
// Vorticity
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);
velocity.swap();
// Divergence
divergenceProgram.bind();
gl.uniform2f(
divergenceProgram.uniforms.texelSize,
velocity.texelSizeX,
velocity.texelSizeY
);
gl.uniform1i(divergenceProgram.uniforms.uVelocity, velocity.read.attach(0));
blit(divergence);
// Clear pressure
clearProgram.bind();
gl.uniform1i(clearProgram.uniforms.uTexture, pressure.read.attach(0));
gl.uniform1f(clearProgram.uniforms.value, config.PRESSURE);
blit(pressure.write);
pressure.swap();
// Pressure
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);
pressure.swap();
}
// Gradient Subtract
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);
velocity.swap();
// Advection
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);
velocity.swap();
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);
dye.swap();
}
function render(target) {
gl.blendFunc(gl.ONE, gl.ONE_MINUS_SRC_ALPHA);
gl.enable(gl.BLEND);
drawDisplay(target);
}
function drawDisplay(target) {
let width = target == null ? gl.drawingBufferWidth : target.width;
let height = target == null ? gl.drawingBufferHeight : target.height;
displayMaterial.bind();
if (config.SHADING)
gl.uniform2f(displayMaterial.uniforms.texelSize, 1.0 / width, 1.0 / height);
gl.uniform1i(displayMaterial.uniforms.uTexture, dye.read.attach(0));
blit(target);
}
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 clickSplat(pointer) {
const color = generateColor();
color.r *= 10.0;
color.g *= 10.0;
color.b *= 10.0;
let dx = 10 * (Math.random() - 0.5);
let dy = 30 * (Math.random() - 0.5);
splat(pointer.texcoordX, pointer.texcoordY, dx, dy, color);
}
function splat(x, y, dx, dy, color) {
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);
velocity.swap();
gl.uniform1i(splatProgram.uniforms.uTarget, dye.read.attach(0));
gl.uniform3f(splatProgram.uniforms.color, color.r, color.g, color.b);
blit(dye.write);
dye.swap();
}
function correctRadius(radius) {
let aspectRatio = canvas.width / canvas.height;
if (aspectRatio > 1) radius *= aspectRatio;
return radius;
}
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, color) {
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);
pointer.moved = Math.abs(pointer.deltaX) > 0 || Math.abs(pointer.deltaY) > 0;
pointer.color = color;
}
function updatePointerUpData(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;
default:
break;
}
return { r, g, b };
}
function wrap(value, min, max) {
const 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;
const min = Math.round(resolution);
const max = Math.round(resolution * aspectRatio);
if (gl.drawingBufferWidth > gl.drawingBufferHeight)
return { width: max, height: min };
else return { width: min, height: max };
}
function scaleByPixelRatio(input) {
const pixelRatio = window.devicePixelRatio || 1;
return Math.floor(input * pixelRatio);
}
function hashCode(s) {
if (s.length === 0) return 0;
let hash = 0;
for (let i = 0; i < s.length; i++) {
hash = (hash << 5) - hash + s.charCodeAt(i);
hash |= 0;
}
return hash;
}
window.addEventListener('mousedown', (e) => {
let pointer = pointers[0];
let posX = scaleByPixelRatio(e.clientX);
let posY = scaleByPixelRatio(e.clientY);
updatePointerDownData(pointer, -1, posX, posY);
clickSplat(pointer);
});
document.body.addEventListener('mousemove', function handleFirstMouseMove(e) {
let pointer = pointers[0];
let posX = scaleByPixelRatio(e.clientX);
let posY = scaleByPixelRatio(e.clientY);
let color = generateColor();
updateFrame(); // start animation loop
updatePointerMoveData(pointer, posX, posY, color);
document.body.removeEventListener('mousemove', handleFirstMouseMove);
});
window.addEventListener('mousemove', (e) => {
let pointer = pointers[0];
let posX = scaleByPixelRatio(e.clientX);
let posY = scaleByPixelRatio(e.clientY);
let color = pointer.color;
updatePointerMoveData(pointer, posX, posY, color);
});
document.body.addEventListener('touchstart', function handleFirstTouchStart(e) {
const touches = e.targetTouches;
let pointer = pointers[0];
for (let i = 0; i < touches.length; i++) {
let posX = scaleByPixelRatio(touches[i].clientX);
let posY = scaleByPixelRatio(touches[i].clientY);
updateFrame(); // start animation loop
updatePointerDownData(pointer, touches[i].identifier, posX, posY);
}
document.body.removeEventListener('touchstart', handleFirstTouchStart);
});
window.addEventListener('touchstart', (e) => {
const touches = e.targetTouches;
let pointer = pointers[0];
for (let i = 0; i < touches.length; i++) {
let posX = scaleByPixelRatio(touches[i].clientX);
let posY = scaleByPixelRatio(touches[i].clientY);
updatePointerDownData(pointer, touches[i].identifier, posX, posY);
}
});
window.addEventListener(
'touchmove',
(e) => {
const touches = e.targetTouches;
let pointer = pointers[0];
for (let i = 0; i < touches.length; i++) {
let posX = scaleByPixelRatio(touches[i].clientX);
let posY = scaleByPixelRatio(touches[i].clientY);
updatePointerMoveData(pointer, posX, posY, pointer.color);
}
},
false
);
window.addEventListener('touchend', (e) => {
const touches = e.changedTouches;
let pointer = pointers[0];
for (let i = 0; i < touches.length; i++) {
updatePointerUpData(pointer);
}
});
updateFrame();
// eslint-disable-next-line react-hooks/exhaustive-deps
}, [
SIM_RESOLUTION,
DYE_RESOLUTION,
CAPTURE_RESOLUTION,
DENSITY_DISSIPATION,
VELOCITY_DISSIPATION,
PRESSURE,
PRESSURE_ITERATIONS,
CURL,
SPLAT_RADIUS,
SPLAT_FORCE,
SHADING,
COLOR_UPDATE_SPEED,
BACK_COLOR,
TRANSPARENT,
]);
return (
);
}
export default SplashCursor;
