// Do threaded task. DON'T use the Unity API here
protected override void ThreadFunction()
{
double moveX = 0;
double moveY = 0;
hsbPixelMap = new ColourUtility.HSBColour[width, height];
rgbPixelMap = new ColourUtility.RGBColour[width, height];
int x = 0;
int y = 0;
//each iteration, it calculates: new = old*old + c, where c is a constant and old starts at current pixel
double cRe, cIm; //real and imaginary part of the constant c, determinate shape of the Julia Set
double newRe, newIm, oldRe, oldIm; //real and imaginary parts of new and old
//pick some values for the constant c, this determines the shape of the Julia Set
cRe = -0.7;
cIm = 0.27015;
//loop through every pixel
for (x = 0; x < width; x++)
{
for (y = 0; y < height; y++)
{
//calculate the initial real and imaginary part of z, based on the pixel location and zoom and position values
newRe = 1.5 * (x - width / 2) / (0.5 * zoom * width) + moveX;
newIm = (y - height / 2) / (0.5 * zoom * height) + moveY;
//i will represent the number of iterations
int i;
//start the iteration process
for (i = 0; i < maxIterations; i++)
{
//remember value of previous iteration
oldRe = newRe;
oldIm = newIm;
//the actual iteration, the real and imaginary part are calculated
newRe = oldRe * oldRe - oldIm * oldIm + cRe;
newIm = 2 * oldRe * oldIm + cIm;
//if the point is outside the circle with radius 2: stop
if ((newRe * newRe + newIm * newIm) > 4)
{
break;
}
}
//colour black if max iterations exceeded
ColourUtility.HSBColour hsbColour = new ColourUtility.HSBColour(0, 0, 0);
if (i < maxIterations)
{
float hue = ((float)(i % 256)) / 256;
hsbColour.hue = hue;
hsbColour.saturation = 1;
hsbColour.brightness = hue;
}
ColourUtility.RGBColour rgbColour = ColourUtility.rgbFromHSB(hsbColour.hue,
hsbColour.saturation,
hsbColour.brightness);
//set pixel map for colour cycling
hsbPixelMap[x, y] = hsbColour;
rgbPixelMap[x, y] = rgbColour;
}
}
}