Riplz.html
· 2.3 KiB · HTML
Bruto
<!doctype html>
<html>
<head>
<meta charset="UTF-8" />
<style>
body, html {
height: 100%;
}
body {
display: flex;
justify-content: center;
align-items: center;
background-color: black;
}
</style>
<title>Riplz</title>
</head>
<body>
<canvas id="canvas" width="1024" height="1024"></canvas>
<script>
const canvas = document.getElementById('canvas');
const ctx = canvas.getContext('2d');
const startTime = performance.now();
(function drawRipple(timestamp) {
const elapsedTimeUnits = (timestamp - startTime) / 50;
const pixelData = ctx.createImageData(canvas.width, canvas.height);
// Step through the array one pixel at a time
for (let i = 0; i < pixelData.data.length; i += 4) {
// We can find our (x, y) position on the canvas by comparing
// our position in the array with the width of the canvas.
let x = Math.floor(i / 4) % canvas.width;
let y = Math.floor(i / (4 * canvas.width));
// We need our origin to be in the center, so lets convert the (x, y)
// from above (the "canvas coordinates") to their "reindexed" values
// (what they would become if the origin were in the center).
let reIndexedX = -((canvas.width - x) - (canvas.width / 2));
let reIndexedY = (canvas.height - y) - (canvas.height / 2);
// Instead of writing our own code for Pythagorean's theorem, we can
// use JavaScript's built-in method to calculate the hypotenuse.
let radialX = Math.hypot(reIndexedX, reIndexedY);
// For reference, see https://www.desmos.com/calculator/bp9t79pfa0
let waveHeight = Math.sin((radialX - elapsedTimeUnits) / 8);
// Normally, a sin wave fluctuates between -1 and 1, but we want ours
// to fluctuate between 0 and 255 instead (the range for RGB values).
let adjustedHeight = (waveHeight * 60 + (255/2));
// Assign the adjustedHeight to R, G, and B equally, to make gray.
pixelData.data[i] = adjustedHeight; // red
pixelData.data[i + 1] = adjustedHeight; // green
pixelData.data[i + 2] = adjustedHeight; // blue
pixelData.data[i + 3] = 255; // opacity
}
ctx.putImageData(pixelData, 0, 0);
requestAnimationFrame(drawRipple);
})(startTime);
</script
</body>
</html>
| 1 | <!doctype html> |
| 2 | <html> |
| 3 | <head> |
| 4 | <meta charset="UTF-8" /> |
| 5 | <style> |
| 6 | body, html { |
| 7 | height: 100%; |
| 8 | } |
| 9 | |
| 10 | body { |
| 11 | display: flex; |
| 12 | justify-content: center; |
| 13 | align-items: center; |
| 14 | background-color: black; |
| 15 | } |
| 16 | </style> |
| 17 | <title>Riplz</title> |
| 18 | </head> |
| 19 | <body> |
| 20 | <canvas id="canvas" width="1024" height="1024"></canvas> |
| 21 | |
| 22 | <script> |
| 23 | const canvas = document.getElementById('canvas'); |
| 24 | const ctx = canvas.getContext('2d'); |
| 25 | const startTime = performance.now(); |
| 26 | |
| 27 | (function drawRipple(timestamp) { |
| 28 | const elapsedTimeUnits = (timestamp - startTime) / 50; |
| 29 | const pixelData = ctx.createImageData(canvas.width, canvas.height); |
| 30 | |
| 31 | // Step through the array one pixel at a time |
| 32 | for (let i = 0; i < pixelData.data.length; i += 4) { |
| 33 | |
| 34 | // We can find our (x, y) position on the canvas by comparing |
| 35 | // our position in the array with the width of the canvas. |
| 36 | let x = Math.floor(i / 4) % canvas.width; |
| 37 | let y = Math.floor(i / (4 * canvas.width)); |
| 38 | |
| 39 | // We need our origin to be in the center, so lets convert the (x, y) |
| 40 | // from above (the "canvas coordinates") to their "reindexed" values |
| 41 | // (what they would become if the origin were in the center). |
| 42 | let reIndexedX = -((canvas.width - x) - (canvas.width / 2)); |
| 43 | let reIndexedY = (canvas.height - y) - (canvas.height / 2); |
| 44 | |
| 45 | // Instead of writing our own code for Pythagorean's theorem, we can |
| 46 | // use JavaScript's built-in method to calculate the hypotenuse. |
| 47 | let radialX = Math.hypot(reIndexedX, reIndexedY); |
| 48 | |
| 49 | // For reference, see https://www.desmos.com/calculator/bp9t79pfa0 |
| 50 | let waveHeight = Math.sin((radialX - elapsedTimeUnits) / 8); |
| 51 | |
| 52 | // Normally, a sin wave fluctuates between -1 and 1, but we want ours |
| 53 | // to fluctuate between 0 and 255 instead (the range for RGB values). |
| 54 | let adjustedHeight = (waveHeight * 60 + (255/2)); |
| 55 | |
| 56 | // Assign the adjustedHeight to R, G, and B equally, to make gray. |
| 57 | pixelData.data[i] = adjustedHeight; // red |
| 58 | pixelData.data[i + 1] = adjustedHeight; // green |
| 59 | pixelData.data[i + 2] = adjustedHeight; // blue |
| 60 | pixelData.data[i + 3] = 255; // opacity |
| 61 | } |
| 62 | |
| 63 | ctx.putImageData(pixelData, 0, 0); |
| 64 | |
| 65 | requestAnimationFrame(drawRipple); |
| 66 | })(startTime); |
| 67 | </script |
| 68 | </body> |
| 69 | </html> |
| 70 | |
| 71 |