Minimalist floating point mandelbrot benchmark

mandel.vt100.c

#include <stdio.h>
#include <time.h>

//              "0123 456789ABCDEF";
char gradient[]=".,-=\"^!:;x+X$#&@";

static void mandel(
	int w, int h,
	float cx0, float cy0,
	float cx1, float cy1
){
	float x,y,x0,y0,x2,y2;
	int px,py,i;
	char c;
	float sx=(cx1-cx0)/(float)w;
	float sy=(cy1-cy0)/(float)h;
	y0=cy0-(sy*.5);
	for(py=0; py<h;++py){
		//puts("");
		fflush(stdout);
		x0=cx0;
		y0+=sy;
		for(px=0; px<w;++px){
			x0+=sx;
			x=0,y=0,x2=0,y2=0;
			for(i=0;i<256;++i){
				y=(x+x)*y+y0;
				x=x2-y2+x0;
				x2=x*x;
				y2=y*y;
				if(x2+y2>4){
					i=i&0xf;
					c=gradient[i];
					goto out;
				}
			}
			c=' ';
out:
			putchar(c);
			//fflush(stdout);
		}
	}
	getchar();
	//puts("");
}

int main(int argc,char* argv[]){
	clock_t ticks=clock();
	mandel(80, 25, -2.05, -1.0, 0.6, 1.0);
	ticks=clock()-ticks;
	printf("%f sec\n",(float)ticks/CLOCKS_PER_SEC);
	return 0;
}