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Pixi circle animation example
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| <html> | |
| <body> | |
| <script src="https://cdnjs.cloudflare.com/ajax/libs/pixi.js/4.5.1/pixi.min.js"></script> | |
| <script src="https://cdnjs.cloudflare.com/ajax/libs/chroma-js/1.3.3/chroma.min.js"></script> | |
| <script> | |
| // init Pixi for fullscreen rendering | |
| const doc = document.body; | |
| const docWidth = window.innerWidth; | |
| const docHeight = window.innerHeight; | |
| const aspectRatio = docHeight / docWidth; | |
| const app = new PIXI.Application(docWidth, docHeight); | |
| const { view, renderer } = app; | |
| doc.style.margin = 0; | |
| view.style.position = 'absolute'; | |
| doc.appendChild(view); | |
| // helper that generates a bitmap texture containing | |
| // a circle of the required radius and color | |
| const generateCircleTexture = (renderer, radius, color) => { | |
| const gfx = new PIXI.Graphics(); | |
| const tileSize = radius * 3; | |
| const texture = PIXI.RenderTexture.create(tileSize, tileSize); | |
| gfx.beginFill(color); | |
| gfx.drawCircle(tileSize / 2, tileSize / 2, radius); | |
| gfx.endFill(); | |
| renderer.render(gfx, texture); | |
| return texture; | |
| } | |
| // create a grid of circles based on screen dimensions | |
| const stage = new PIXI.Container(); | |
| const colCount = 50; | |
| const colWidth = docWidth / colCount; | |
| const rowCount = parseInt(colCount * aspectRatio); | |
| const rowHeight = docHeight / rowCount; | |
| const circleCount = rowCount * colCount; | |
| console.log(circleCount); | |
| const maxRadius = Math.min(colWidth, rowHeight) / 3; | |
| const tileCenter = { | |
| x: maxRadius * 3/2, | |
| y: maxRadius * 3/2 | |
| }; | |
| const circleTexture = generateCircleTexture(renderer, maxRadius, 0xFFFFFF); | |
| const centroids = Array.from(Array(circleCount)).map((d,i) => { | |
| const col = i % colCount; | |
| const row = parseInt(i / colCount); | |
| const x = (col * colWidth) + (colWidth / 2); | |
| const y = (row * rowHeight) + (rowHeight / 2); | |
| return { col, row, x, y }; | |
| }); | |
| const circles = centroids.map(({ x, y }) => { | |
| const circleSprite = new PIXI.Sprite(circleTexture); | |
| circleSprite.x = x; | |
| circleSprite.y = y; | |
| circleSprite.anchor.set(0.5); | |
| stage.addChild(circleSprite); | |
| return circleSprite; | |
| }) | |
| const minScale = 1e-6; | |
| const maxScale = 1; | |
| const randomScale = () => minScale + ((maxScale - minScale) * Math.random()); | |
| const palette = chroma.brewer.YlGnBu; | |
| const paletteRGB = palette.map(c => chroma(c).rgb()) | |
| const randomColor = () => paletteRGB[Math.floor(palette.length * Math.random())]; | |
| // create a series of animation states for each circle | |
| const numStates = 50; | |
| const allStates = circles.map((circle, c) => { | |
| const states = Array(numStates); | |
| for (var i = 0; i < numStates; i++) { | |
| states[i] = [randomScale(), randomColor()]; | |
| }; | |
| return states; | |
| }); | |
| // animate the changes between states over time | |
| const fps = 60; | |
| const tweenTime = 2; | |
| const tweenFrames = fps * tweenTime; | |
| let state = 0, frame = 0, progress = 0; | |
| const animate = () => { | |
| // track circles, states and scales | |
| let circle, c; | |
| let currScale, nextScale, scale; | |
| let currColor, nextColor, color; | |
| let r, g, b; | |
| // track progress as proportion of frames completed | |
| frame = ++frame % tweenFrames; | |
| progress = (frame / tweenFrames) || 1e-6; | |
| // increment state counter once we've looped back around | |
| if (frame === 0) { | |
| state = ++state % numStates; | |
| }; | |
| // update scale and color of all circles by | |
| // interpolating current state and next state | |
| for (c = 0; c < circleCount; c++) { | |
| circle = circles[c]; | |
| [currScale, currColor] = allStates[c][state]; | |
| [nextScale, nextColor] = allStates[c][(state + 1) % numStates]; | |
| r = currColor[0] + ((nextColor[0] - currColor[0]) * progress); | |
| g = currColor[1] + ((nextColor[1] - currColor[1]) * progress); | |
| b = currColor[2] + ((nextColor[2] - currColor[2]) * progress); | |
| scale = currScale + ((nextScale - currScale) * progress); | |
| color = (r << 16) + (g << 8) + b; | |
| circle.scale.set(scale); | |
| circle.tint = color; | |
| }; | |
| // cue up next frame then render the updates | |
| requestAnimationFrame(animate); | |
| renderer.render(stage); | |
| }; | |
| animate(); | |
| </script> | |
| </body> | |
| </html> |
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