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Mandelbrot fractal in a canvas
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// Ref: http://progur.com/2017/02/create-mandelbrot-fractal-javascript.html | |
(function() { | |
var myCanvas = document.createElement("canvas"); | |
myCanvas.width = 600; | |
myCanvas.height = 600; | |
document.body.appendChild(myCanvas); | |
var ctx = myCanvas.getContext("2d"); | |
var maxIterations = 100; | |
var magnificationFactor = 300; // 2900 | |
var panX = 1.5; // 0.6 | |
var panY = 1; // 0.7 | |
function checkIfBelongsToMandelbrotSet(x, y) { | |
var realComponentOfResult = x; | |
var imaginaryComponentOfResult = y; | |
for (var i = 0; i < maxIterations; i++) { | |
var tempRealComponent = realComponentOfResult * realComponentOfResult | |
- imaginaryComponentOfResult * imaginaryComponentOfResult | |
+ x; | |
var tempImaginaryComponent = 2 * realComponentOfResult * imaginaryComponentOfResult | |
+ y; | |
realComponentOfResult = tempRealComponent; | |
imaginaryComponentOfResult = tempImaginaryComponent; | |
// Return a number as a percentage | |
if (realComponentOfResult * imaginaryComponentOfResult > 5) { | |
return (i / maxIterations * 100); | |
} | |
} | |
return 0; // Return zero if in set | |
} | |
for (var x = 0; x < myCanvas.width; x++) { | |
for (var y = 0; y < myCanvas.height; y++) { | |
var belongsToSet = | |
checkIfBelongsToMandelbrotSet( | |
x / magnificationFactor - panX, | |
y / magnificationFactor - panY | |
); | |
if (belongsToSet) { | |
if (belongsToSet === 0) { | |
ctx.fillStyle = '#000'; | |
ctx.fillRect(x,y, 1,1); // Draw a black pixel | |
} else { | |
ctx.fillStyle = 'hsl(0, 100%, ' + belongsToSet + '%)'; | |
ctx.fillRect(x,y, 1,1); // Draw a colorful pixel | |
} | |
} | |
} | |
} | |
})(); |
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