Mandelbrot
/**
* The Mandelbrot Set
* by Daniel Shiffman.
*
* Simple rendering of the Mandelbrot set.
*/
void setup() {
size(640, 360);
noLoop();
background(255);
float w = 4;
float h = (w * height) / width;
float xmin = -w / 2;
float ymin = -h / 2;
loadPixels();
int maxiterations = 100;
float xmax = xmin + w;
float ymax = ymin + h;
float dx = (xmax - xmin) / width;
float dy = (ymax - ymin) / height;
float y = ymin;
for (int j = 0; j < height; j++) {
float x = xmin;
for (int i = 0; i < width; i++) {
float a = x;
float b = y;
int n = 0;
float maxAbs = 4.0;
float absOld = 0.0;
float convergeNumber = maxiterations;
while (n < maxiterations) {
float aa = a * a;
float bb = b * b;
float absVal = sqrt(aa + bb);
if (absVal > maxAbs) {
float diffToLast = absVal - absOld;
float diffToMax = maxAbs - absOld;
convergeNumber = n + diffToMax / diffToLast;
break;
}
float twoab = 2.0 * a * b;
a = aa - bb + x;
b = twoab + y;
n++;
absOld = absVal;
}
if (n == maxiterations) {
pixels[i + j * width] = color(0);
} else {
float norm = map(convergeNumber, 0, maxiterations, 0, 1);
pixels[i + j * width] = color(map(sqrt(norm), 0, 1, 0, 255));
}
x += dx;
}
y += dy;
}
updatePixels();
}
void draw() {}