Similar to this shaky triangle but with a different offsetting technique.
Created
April 27, 2017 23:58
-
-
Save veltman/e8f864c45137b493387a4ebc46ff7da5 to your computer and use it in GitHub Desktop.
Trembling triangle #2
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
<!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> |
Sign up for free
to join this conversation on GitHub.
Already have an account?
Sign in to comment