mandelbrot-core.coffeecoffee/ | |
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this.define () ->
"strict mode"
class MandelbrotCore | |
Constructor | |
Necessarily pretty basic as this class could be used in a webworker or a page | constructor: (@progressCallback) ->
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Public Methods | |
getEscapeTimesGets the escape time for every pixel | getEscapeTimes: (width, height, box, maxIterations) -> |
We want an array of arrays | escapeTimes = []
for row in [0..height] |
Use the fat arrow to bind | do (row) =>
rowTimes = []
for column in [0..width]
do (column) -> |
Get the real and imaginary coordinates corresponding to this pixel | real = interpolate column, box.left, box.right, 0, width
imaginary = interpolate row, box.top, box.bottom, 0, height |
Calculate the escape time and store the result in our row | rowTimes.push (getEscapeTimeAtPoint real, imaginary, maxIterations) |
Store the result for this row | escapeTimes.push rowTimes |
If a progress callback was provided use it to update caller on progress | if this.progressCallback? then this.progressCallback 100*row/height
return escapeTimes
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Private methods | |
interpolateThe linear interpolation function ❤ | interpolate = (x, y0, y1, x0, x1) -> y0 + (x - x0)*((y1 - y0)/(x1-x0))
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getEscapeTimeAtPointBased on the algorithm on wikipedia | getEscapeTimeAtPoint = (real, imaginary, maxIteration) ->
[x, y] = [0, 0]
for iteration in [0..maxIteration]
if x*x + y*y < 2*2
xtemp = x*x - y*y + real
y = 2*x*y + imaginary
x = xtemp
else
break
return iteration
return MandelbrotCore
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