ikarus/benchmarks.larceny/src/mbrot.c

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/* MBROT -- Generation of Mandelbrot set fractal. */
#include <stdio.h>
#define FLOAT double
#define N 75
#define max_count 64
#define radius2 16.0
static int count (FLOAT r, FLOAT i, FLOAT step, int x, int y)
{
FLOAT cr = r + x*step;
FLOAT ci = i + y*step;
FLOAT zr = cr;
FLOAT zi = ci;
int c = 0;
while (c != max_count)
{
FLOAT zr2 = zr*zr;
FLOAT zi2 = zi*zi;
if (zr2+zi2 > radius2)
return c;
zi = 2.0*zr*zi + ci;
zr = (zr2-zi2) + cr;
c++;
}
return c;
}
static void mbrot (int *matrix, FLOAT r, FLOAT i, FLOAT step, int n)
{
int x, y;
for (y=n-1; y>=0; y--)
for (x=n-1; x>=0; x--)
matrix[y*n+x] = count (r, i, step, x, y);
}
static int test ()
{
int matrix[N*N];
mbrot (matrix, -1.0, -0.5, 0.005, N);
return matrix[0];
}
int main (int argc, char *argv[])
{
int i;
int result;
for (i=0; i<100; i++)
result = test ();
if (result != 5)
printf ("*** wrong result ***\n");
return 0;
}