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#include "fractals.h"
#include "grids.h"
/*
* Computes the number of iterations it takes for a point z0 to diverge
* if the return value is equal to max_iterations, the point lies within the mandelbrot set
* This is an implementation the escape algorithm
*/
size_t mandelbrot(const double complex z0, const size_t max_iterations) {
double complex z = z0;
size_t iteration = 0;
while (cabs(z) <= 2 && iteration < max_iterations) {
z = z * z + z0;
iteration++;
}
return iteration;
}
/*
* Fills a grid with mandelbrot values
*/
void mandelbrot_grid(grid_t* grid, const size_t max_iterations){
const size_t size = grid->size;
size_t* data = grid->data;
for(size_t i = 0; i < size; i++){
data[i] = mandelbrot(grid_to_complex(grid, i), max_iterations);
}
}
/*
* Computes the number of iterations it takes for a point z0 to diverge
* if the return value is equal to max_iterations, the point lies within the multibrot set
* This is implementation closely matches mandelbrot, but uses cpow which might degrade performance.
*/
size_t multibrot(const double complex z0, const size_t max_iterations, const double d){
double complex z = z0;
size_t iteration = 0;
while(cabs(z) <= 2 && iteration < max_iterations){
z = cpowl(z, d) + z0;
iteration++;
}
return iteration;
}
/*
* Fills a grid with multibrot values
*/
void multibrot_grid(grid_t* grid, const size_t max_iterations, const double d){
const size_t size = grid->size;
size_t* data = grid->data;
for(size_t i = 0; i < size; i ++){
data[i] = multibrot(grid_to_complex(grid, i), max_iterations, d);
}
}
/*
* Computes ????? for a julia set
* implementation of https://en.wikipedia.org/wiki/Julia_set#Pseudocode
*/
size_t julia(const double R, const double complex z0, const double complex c, const size_t max_iterations){
//FIXME: I'm notsure if this is currently implemented correctly
if(R*R - R >= cabs(z0)) return 0;
double complex z = z0;
size_t iteration = 0;
while(cabs(z) < R && iteration < max_iterations){
z = z * z + c;
iteration++;
}
return iteration;
}
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