Created
August 16, 2015 19:07
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Fun with ndarray and canvas
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| <!DOCTYPE html> | |
| <html> | |
| <body> | |
| <canvas id="canvas" width="300" height="300"></canvas> | |
| <script src="https://jspm.io/system@0.16.js"></script> | |
| <script> | |
| System.import('npm:ndarray').then(function(ndarray) { | |
| System.import('npm:ndarray-warp').then(function(warp) { | |
| var canvas = document.getElementById('canvas') | |
| var w = canvas.width | |
| var h = canvas.height | |
| var ctx = canvas.getContext('2d') | |
| ctx.fillStyle = 'white' | |
| ctx.fillRect(0, 0, w, h) | |
| var imgData = ctx.getImageData(0, 0, w, h) | |
| var rgba = ndarray(imgData.data, [h, w, 4]) | |
| function random() { | |
| for (var y = 0; y < h; y++) { | |
| for (var x = 0; x < w; x++) { | |
| // create random noise | |
| rgba.set(y, x, 0, Math.random() * 255) | |
| rgba.set(y, x, 1, Math.random() * 255) | |
| rgba.set(y, x, 2, Math.random() * 255) | |
| } | |
| } | |
| ctx.putImageData(imgData, 0, 0) | |
| } | |
| function foo() { | |
| warp(rgba, rgba, function(out, inp) { | |
| var dx = inp[0] - w/2 | |
| var dy = inp[1] - h/2 | |
| var r = Math.sqrt(dx * dx + dy * dy) | |
| var theta = Math.atan2(dy, dx) | |
| out[0] = 0.98 * r * Math.cos(theta + 0.01 * r) + w/2 | |
| out[1] = 0.98 * r * Math.sin(theta + 0.01 * r) + h/2 | |
| out[2] = inp[2] | |
| }) | |
| ctx.putImageData(imgData, 0, 0) | |
| requestAnimationFrame(foo) | |
| } | |
| random() | |
| setTimeout(function() {requestAnimationFrame(foo)}, 1000) | |
| setInterval(function() {requestAnimationFrame(random)}, 5000) | |
| }) | |
| }) | |
| </script> | |
| </body> | |
| </html> |
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