Similar to this shaky triangle but with a different offsetting technique.
Created
April 27, 2017 23:58
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Trembling triangle #2
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| <!DOCTYPE html> | |
| <html lang="en"> | |
| <head> | |
| <meta charset="utf-8" /> | |
| </head> | |
| <body> | |
| <canvas width="960" height="500"></canvas> | |
| <script src="https://d3js.org/d3.v4.min.js"></script> | |
| <script> | |
| let context = document.querySelector("canvas").getContext("2d"), | |
| interval = 45000, | |
| triangle = [[480, 50], [680, 450], [280, 450]], | |
| line = d3.line().context(context), | |
| pixelScale = d3.scaleLinear() | |
| .range([2, 8]), | |
| depthScale = d3.scaleLinear() | |
| .rangeRound([3, 7]), | |
| getDistance = d3.randomNormal(0.5, 0.15), | |
| getOffset; | |
| context.globalAlpha = 0.1; | |
| d3.timer(function(t){ | |
| t = Math.min(t % interval / interval, 1 - t % interval / interval) * 2; | |
| getOffset = d3.randomNormal(0, pixelScale(t)); | |
| context.clearRect(0, 0, 960, 500); | |
| context.fillStyle = d3.interpolateWarm(t / 2); | |
| for (let i = 0; i < 10; i++) { | |
| context.beginPath(); | |
| line(tremble(triangle, depthScale(t))); | |
| context.closePath(); | |
| context.fill(); | |
| } | |
| }); | |
| function tremble(shape, depth) { | |
| return shape.reduce((newPoints, val, i) => { | |
| return [...newPoints, val, ...getBetween(val, shape[i + 1] || shape[0], depth)]; | |
| }, []); | |
| } | |
| function getBetween(a, b, depth) { | |
| const midpoint = getMidpoint(a, b); | |
| if (depth === 1) { | |
| return [midpoint]; | |
| } | |
| return [...getBetween(a, midpoint, depth - 1), midpoint, ...getBetween(midpoint, b, depth - 1)]; | |
| } | |
| function getMidpoint(a, b) { | |
| let along = pointAlong(a, b, getDistance()), | |
| distance = distanceBetween(a, b), | |
| offset = getOffset(); | |
| return [ | |
| along[0] + offset * (a[1] - b[1]) / distance, | |
| along[1] - offset * (a[0] - b[0]) / distance | |
| ]; | |
| } | |
| function distanceBetween(a, b) { | |
| return Math.sqrt((a[0] - b[0]) * (a[0] - b[0]) + (a[1] - b[1]) * (a[1] - b[1])); | |
| } | |
| function pointAlong(a, b, pct) { | |
| return [a[0] + (b[0] - a[0]) * pct, a[1] + (b[1] - a[1]) * pct]; | |
| } | |
| </script> |
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