This fractal is a Julia set. Points represent complex numbers, where the v coordinate is the imaginary part. The left and right bounds of the screen map to about -2 and 2, and the top and bottom are mapped similarly in i, to put the origin in the center of the screen.
For each sample, the function f(z) = z * z + c is iterated until the point moves far away from the origin. The initial value for z is the point corresponding to the upper left corner of the patch we are drawing, and c is the constant seed value that you provide. The number of iterations, mod 4, determines the color.