diff --git a/script.js b/script.js index 8b7a31d..a844070 100644 --- a/script.js +++ b/script.js @@ -13,23 +13,41 @@ let config = { PRESSURE_ITERATIONS: 20, CURL: 30, SPLAT_RADIUS: 0.5, - SHADING: true + SHADING: true, + COLORFUL: true, + PAUSED: false, + BACK_COLOR: { r: 0, g: 0, b: 0 }, + TRANSPARENT: false +} + +function pointerPrototype () { + this.id = -1; + this.x = 0; + this.y = 0; + this.dx = 0; + this.dy = 0; + this.down = false; + this.moved = false; + this.color = [30, 0, 300]; } let pointers = []; let splatStack = []; +pointers.push(new pointerPrototype()); const { gl, ext } = getWebGLContext(canvas); -if (isMobile()) +if (isMobile()) { config.DYE_RESOLUTION = 256; + config.SHADING = false; +} if (!ext.supportLinearFiltering) config.SHADING = false; startGUI(); function getWebGLContext (canvas) { - const params = { alpha: false, depth: false, stencil: false, antialias: false }; + const params = { alpha: true, depth: false, stencil: false, antialias: false, preserveDrawingBuffer: false }; let gl = canvas.getContext('webgl2', params); const isWebGL2 = !!gl; @@ -134,11 +152,18 @@ function startGUI () { gui.add(config, 'CURL', 0, 50).name('vorticity').step(1); gui.add(config, 'SPLAT_RADIUS', 0.01, 1.0).name('splat radius'); gui.add(config, 'SHADING').name('shading'); + gui.add(config, 'COLORFUL').name('colorful'); + gui.add(config, 'PAUSED').name('paused').listen(); gui.add({ fun: () => { splatStack.push(parseInt(Math.random() * 20) + 5); } }, 'fun').name('Random splats'); + let captureFolder = gui.addFolder('Capture'); + captureFolder.addColor(config, 'BACK_COLOR').name('background color'); + captureFolder.add(config, 'TRANSPARENT').name('transparent'); + captureFolder.add({ fun: CaptureScreenshot }, 'fun').name('take screenshot'); + let github = gui.add({ fun : () => { window.open('https://github.com/PavelDoGreat/WebGL-Fluid-Simulation'); ga('send', 'event', 'link button', 'github'); @@ -173,23 +198,64 @@ function startGUI () { gui.close(); } +function CaptureScreenshot () { + colorProgram.bind(); + gl.uniform4f(colorProgram.uniforms.color, 0, 0, 0, 1); + blit(density.write.fbo); + + render(density.write.fbo); + gl.bindFramebuffer(gl.FRAMEBUFFER, density.write.fbo); + + let length = dyeWidth * dyeHeight * 4; + let pixels = new Float32Array(length); + gl.readPixels(0, 0, dyeWidth, dyeHeight, gl.RGBA, gl.FLOAT, pixels); + + let newPixels = new Uint8Array(length); + + let id = 0; + for (let i = dyeHeight - 1; i >= 0; i--) { + for (let j = 0; j < dyeWidth; j++) { + let nid = i * dyeWidth * 4 + j * 4; + newPixels[nid + 0] = clamp01(pixels[id + 0]) * 255; + newPixels[nid + 1] = clamp01(pixels[id + 1]) * 255; + newPixels[nid + 2] = clamp01(pixels[id + 2]) * 255; + newPixels[nid + 3] = clamp01(pixels[id + 3]) * 255; + id += 4; + } + } + + let captureCanvas = document.createElement('canvas'); + let ctx = captureCanvas.getContext('2d'); + captureCanvas.width = dyeWidth; + captureCanvas.height = dyeHeight; + + let imageData = ctx.createImageData(dyeWidth, dyeHeight); + imageData.data.set(newPixels); + ctx.putImageData(imageData, 0, 0); + let datauri = captureCanvas.toDataURL(); + + downloadURI("fluid.png", datauri); + + URL.revokeObjectURL(datauri); +} + +function clamp01 (input) { + return Math.min(Math.max(input, 0), 1); +} + +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); +} + function isMobile () { return /Mobi|Android/i.test(navigator.userAgent); } -function pointerPrototype () { - this.id = -1; - this.x = 0; - this.y = 0; - this.dx = 0; - this.dy = 0; - this.down = false; - this.moved = false; - this.color = [30, 0, 300]; -} - -pointers.push(new pointerPrototype()); - class GLProgram { constructor (vertexShader, fragmentShader) { this.uniforms = {}; @@ -227,7 +293,6 @@ function compileShader (type, source) { const baseVertexShader = compileShader(gl.VERTEX_SHADER, ` precision highp float; - precision mediump sampler2D; attribute vec2 aPosition; varying vec2 vUv; @@ -248,10 +313,10 @@ const baseVertexShader = compileShader(gl.VERTEX_SHADER, ` `); const clearShader = compileShader(gl.FRAGMENT_SHADER, ` - precision highp float; + precision mediump float; precision mediump sampler2D; - varying vec2 vUv; + varying highp vec2 vUv; uniform sampler2D uTexture; uniform float value; @@ -260,21 +325,51 @@ const clearShader = compileShader(gl.FRAGMENT_SHADER, ` } `); +const colorShader = compileShader(gl.FRAGMENT_SHADER, ` + precision mediump float; + + uniform vec4 color; + + void main () { + gl_FragColor = color; + } +`); + +const backgroundShader = 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 displayShader = compileShader(gl.FRAGMENT_SHADER, ` precision highp float; - precision mediump sampler2D; + precision highp sampler2D; varying vec2 vUv; uniform sampler2D uTexture; void main () { - gl_FragColor = texture2D(uTexture, vUv); + vec3 C = texture2D(uTexture, vUv).rgb; + float a = max(C.r, max(C.g, C.b)); + gl_FragColor = vec4(C, a); } `); const displayShadingShader = compileShader(gl.FRAGMENT_SHADER, ` precision highp float; - precision mediump sampler2D; + precision highp sampler2D; varying vec2 vUv; varying vec2 vL; @@ -300,13 +395,14 @@ const displayShadingShader = compileShader(gl.FRAGMENT_SHADER, ` float diffuse = clamp(dot(n, l) + 0.7, 0.7, 1.0); C.rgb *= diffuse; - gl_FragColor = vec4(C, 1.0); + 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 mediump sampler2D; + precision highp sampler2D; varying vec2 vUv; uniform sampler2D uTarget; @@ -326,7 +422,7 @@ const splatShader = compileShader(gl.FRAGMENT_SHADER, ` const advectionManualFilteringShader = compileShader(gl.FRAGMENT_SHADER, ` precision highp float; - precision mediump sampler2D; + precision highp sampler2D; varying vec2 vUv; uniform sampler2D uVelocity; @@ -336,7 +432,7 @@ const advectionManualFilteringShader = compileShader(gl.FRAGMENT_SHADER, ` uniform float dt; uniform float dissipation; - vec4 bilerp (in sampler2D sam, in vec2 uv, in vec2 tsize) { + vec4 bilerp (sampler2D sam, vec2 uv, vec2 tsize) { vec2 st = uv / tsize - 0.5; vec2 iuv = floor(st); @@ -359,7 +455,7 @@ const advectionManualFilteringShader = compileShader(gl.FRAGMENT_SHADER, ` const advectionShader = compileShader(gl.FRAGMENT_SHADER, ` precision highp float; - precision mediump sampler2D; + precision highp sampler2D; varying vec2 vUv; uniform sampler2D uVelocity; @@ -376,44 +472,42 @@ const advectionShader = compileShader(gl.FRAGMENT_SHADER, ` `); const divergenceShader = compileShader(gl.FRAGMENT_SHADER, ` - precision highp float; + precision mediump float; precision mediump sampler2D; - varying vec2 vUv; - varying vec2 vL; - varying vec2 vR; - varying vec2 vT; - varying vec2 vB; + varying highp vec2 vUv; + varying highp vec2 vL; + varying highp vec2 vR; + varying highp vec2 vT; + varying highp vec2 vB; uniform sampler2D uVelocity; - vec2 sampleVelocity (in vec2 uv) { - vec2 multiplier = vec2(1.0, 1.0); - if (uv.x < 0.0) { uv.x = 0.0; multiplier.x = -1.0; } - if (uv.x > 1.0) { uv.x = 1.0; multiplier.x = -1.0; } - if (uv.y < 0.0) { uv.y = 0.0; multiplier.y = -1.0; } - if (uv.y > 1.0) { uv.y = 1.0; multiplier.y = -1.0; } - return multiplier * texture2D(uVelocity, uv).xy; - } - void main () { - float L = sampleVelocity(vL).x; - float R = sampleVelocity(vR).x; - float T = sampleVelocity(vT).y; - float B = sampleVelocity(vB).y; + 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 highp float; + precision mediump float; precision mediump sampler2D; - varying vec2 vUv; - varying vec2 vL; - varying vec2 vR; - varying vec2 vT; - varying vec2 vB; + 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 () { @@ -428,7 +522,7 @@ const curlShader = compileShader(gl.FRAGMENT_SHADER, ` const vorticityShader = compileShader(gl.FRAGMENT_SHADER, ` precision highp float; - precision mediump sampler2D; + precision highp sampler2D; varying vec2 vUv; varying vec2 vL; @@ -458,20 +552,22 @@ const vorticityShader = compileShader(gl.FRAGMENT_SHADER, ` `); const pressureShader = compileShader(gl.FRAGMENT_SHADER, ` - precision highp float; + precision mediump float; precision mediump sampler2D; - varying vec2 vUv; - varying vec2 vL; - varying vec2 vR; - varying vec2 vT; - varying vec2 vB; + 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; - vec2 boundary (in vec2 uv) { - uv = min(max(uv, 0.0), 1.0); + vec2 boundary (vec2 uv) { return uv; + // uncomment if you use wrap or repeat texture mode + // uv = min(max(uv, 0.0), 1.0); + // return uv; } void main () { @@ -487,20 +583,21 @@ const pressureShader = compileShader(gl.FRAGMENT_SHADER, ` `); const gradientSubtractShader = compileShader(gl.FRAGMENT_SHADER, ` - precision highp float; + precision mediump float; precision mediump sampler2D; - varying vec2 vUv; - varying vec2 vL; - varying vec2 vR; - varying vec2 vT; - varying vec2 vB; + 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; - vec2 boundary (in vec2 uv) { - uv = min(max(uv, 0.0), 1.0); + vec2 boundary (vec2 uv) { return uv; + // uv = min(max(uv, 0.0), 1.0); + // return uv; } void main () { @@ -539,6 +636,8 @@ let curl; let pressure; const clearProgram = new GLProgram(baseVertexShader, clearShader); +const colorProgram = new GLProgram(baseVertexShader, colorShader); +const backgroundProgram = new GLProgram(baseVertexShader, backgroundShader); const displayProgram = new GLProgram(baseVertexShader, displayShader); const displayShadingProgram = new GLProgram(baseVertexShader, displayShadingShader); const splatProgram = new GLProgram(baseVertexShader, splatShader); @@ -575,8 +674,8 @@ function getResolution (resolution) { if (aspectRatio < 1) aspectRatio = 1.0 / aspectRatio; - let max = resolution * aspectRatio; - let min = resolution; + let max = Math.round(resolution * aspectRatio); + let min = Math.round(resolution); if (gl.drawingBufferWidth > gl.drawingBufferHeight) return { width: max, height: min }; @@ -629,13 +728,16 @@ function createDoubleFBO (texId, w, h, internalFormat, format, type, param) { initFramebuffers(); multipleSplats(parseInt(Math.random() * 20) + 5); +let lastColorChangeTime = Date.now(); + update(); function update () { resizeCanvas(); input(); - step(0.016); - render(); + if (!config.PAUSED) + step(0.016); + render(null); requestAnimationFrame(update); } @@ -644,15 +746,28 @@ function input () { multipleSplats(splatStack.pop()); for (let i = 0; i < pointers.length; i++) { - const pointer = pointers[i]; - if (pointer.moved) { - splat(pointer.x, pointer.y, pointer.dx, pointer.dy, pointer.color); - pointer.moved = false; + const p = pointers[i]; + if (p.moved) { + splat(p.x, p.y, p.dx, p.dy, p.color); + p.moved = false; + } + } + + if (!config.COLORFUL) + return; + + if (lastColorChangeTime + 100 < Date.now()) + { + lastColorChangeTime = Date.now(); + for (let i = 0; i < pointers.length; i++) { + const p = pointers[i]; + p.color = generateColor(); } } } function step (dt) { + gl.disable(gl.BLEND); gl.viewport(0, 0, simWidth, simHeight); curlProgram.bind(); @@ -714,8 +829,9 @@ function step (dt) { velocity.swap(); gl.viewport(0, 0, dyeWidth, dyeHeight); + if (!ext.supportLinearFiltering) - gl.uniform2f(advectionProgram.uniforms.dyeTexelSize, 1.0 / dyeWidth, 1.0 / dyeWidth); + gl.uniform2f(advectionProgram.uniforms.dyeTexelSize, 1.0 / dyeWidth, 1.0 / dyeHeight); gl.uniform1i(advectionProgram.uniforms.uVelocity, velocity.read.texId); gl.uniform1i(advectionProgram.uniforms.uSource, density.read.texId); gl.uniform1f(advectionProgram.uniforms.dissipation, config.DENSITY_DISSIPATION); @@ -723,12 +839,33 @@ function step (dt) { density.swap(); } -function render () { - let width = gl.drawingBufferWidth; - let height = gl.drawingBufferHeight; +function render (target) { + 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 : dyeWidth; + let height = target == null ? gl.drawingBufferHeight : dyeHeight; gl.viewport(0, 0, width, height); + if (!config.TRANSPARENT) { + colorProgram.bind(); + let bc = config.BACK_COLOR; + gl.uniform4f(colorProgram.uniforms.color, bc.r / 255, bc.g / 255, bc.b / 255, 1); + blit(target); + } + + if (target == null && config.TRANSPARENT) { + backgroundProgram.bind(); + gl.uniform1f(backgroundProgram.uniforms.aspectRatio, canvas.width / canvas.height); + blit(null); + } + if (config.SHADING) { displayShadingProgram.bind(); gl.uniform2f(displayShadingProgram.uniforms.texelSize, 1.0 / width, 1.0 / height); @@ -739,7 +876,7 @@ function render () { gl.uniform1i(displayProgram.uniforms.uTexture, density.read.texId); } - blit(null); + blit(target); } function splat (x, y, dx, dy, color) { @@ -782,7 +919,7 @@ function resizeCanvas () { } } -canvas.addEventListener('mousemove', (e) => { +canvas.addEventListener('mousemove', e => { pointers[0].moved = pointers[0].down; pointers[0].dx = (e.offsetX - pointers[0].x) * 5.0; pointers[0].dy = (e.offsetY - pointers[0].y) * 5.0; @@ -790,7 +927,7 @@ canvas.addEventListener('mousemove', (e) => { pointers[0].y = e.offsetY; }); -canvas.addEventListener('touchmove', (e) => { +canvas.addEventListener('touchmove', e => { e.preventDefault(); const touches = e.targetTouches; for (let i = 0; i < touches.length; i++) { @@ -808,7 +945,7 @@ canvas.addEventListener('mousedown', () => { pointers[0].color = generateColor(); }); -canvas.addEventListener('touchstart', (e) => { +canvas.addEventListener('touchstart', e => { e.preventDefault(); const touches = e.targetTouches; for (let i = 0; i < touches.length; i++) { @@ -827,7 +964,7 @@ window.addEventListener('mouseup', () => { pointers[0].down = false; }); -window.addEventListener('touchend', (e) => { +window.addEventListener('touchend', e => { const touches = e.changedTouches; for (let i = 0; i < touches.length; i++) for (let j = 0; j < pointers.length; j++) @@ -835,10 +972,39 @@ window.addEventListener('touchend', (e) => { pointers[j].down = false; }); +window.addEventListener('keydown', e => { + if (e.key === 'p') + config.PAUSED = !config.PAUSED; +}); + 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: Math.random() * 0.15 + 0.05, - g: Math.random() * 0.15 + 0.05, - b: Math.random() * 0.15 + 0.05 + r, + g, + b }; } \ No newline at end of file