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| <html> | |
| <body> | |
| <canvas id="canvas1" width="500", height="500"> | |
| Random Canvas | |
| </canvas> | |
| <script type="text/javascript"> | |
| element = document.getElementById("canvas1"); | |
| c = element.getContext("2d"); | |
| // read the width and height of the canvas | |
| width = parseInt(element.getAttribute("width")); | |
| height = parseInt(element.getAttribute("height")); | |
| // create a new pixel array | |
| imageData = c.createImageData(width, height); | |
| function setPixel(x, y, r, g, b, a) { | |
| index = (x + (height - 1 - y) * width) * 4; | |
| imageData.data[index+0] = r; | |
| imageData.data[index+1] = g; | |
| imageData.data[index+2] = b; | |
| imageData.data[index+3] = a; | |
| } | |
| function draw() { | |
| // draw random dots | |
| for (i = 0; i < width; i++) { | |
| setPixel(i, 0, parseInt(Math.random() * 256), 0, 0, 0xff); | |
| } | |
| // flame average | |
| for (y1 = height; y1 > 0; y1--) { | |
| for (xi = 1; xi < 50; xi++) { | |
| x1 = parseInt(Math.random() * width); | |
| r1 = imageData.data[((x1 - 1) + (height - y1) * width) * 4]; | |
| r2 = imageData.data[(x1 + (height - y1) * width) * 4]; | |
| r3 = imageData.data[((x1 + 1) + (height - y1) * width) * 4]; | |
| r = (r1 + r2 + r3) / 3; | |
| if (r > 50) { | |
| r = r + parseInt(Math.random() * 100) - 50; | |
| } | |
| setPixel(x1, y1, r, 0, 0, 0xff); | |
| } | |
| } | |
| c.putImageData(imageData, 0, 0); // at coords 0,0 | |
| } | |
| setInterval("draw()", 1); | |
| </script> | |
| </body> | |
| </html> |
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