X-Git-Url: http://git.itanic.dy.fi/?p=mandelbrot;a=blobdiff_plain;f=mandelbrot.c;fp=mandelbrot.c;h=35dc6c64b0405cd64ce4e0afa540a2201203bbf7;hp=ae05fbd50f9591edb9d2cda85785b062adc6d66a;hb=bb75ed1d012e139423d99e179d9680513273f9f8;hpb=10394fae32c1a947bc2e000003c87b41599571ea

diff --git a/mandelbrot.c b/mandelbrot.c
index ae05fbd..35dc6c6 100644
--- a/mandelbrot.c
+++ b/mandelbrot.c
@@ -34,16 +34,19 @@ int get_mandelbrot_iterations(double x0, double y0)
 	return iteration;
 }
 
-int draw_mandelbrot(struct SDL_Surface *screen)
+int draw_mandelbrot(struct SDL_Surface *screen, double x1, double x2,
+		double y1, double y2)
 {
-	double x0, y0;
-	int iteration, xs,ys;
+	double x0, y0, xlen, ylen, xstep, ystep;
+	int iteration, xs, ys;
 
-	for (ys = 0, y0 = -1; ys < screen->h;
-	     y0 += 2 / (double)screen->h, ys++) {
-		for (xs = 0, x0 = -2.5; xs < screen->w;
-		     x0 += 3 / (double)screen->w, xs++) {
+	xlen = x2 - x1;
+	ylen = y2 - y1;
+	xstep = xlen / (double)screen->w;
+	ystep = ylen / (double)screen->h;
 
+	for (ys = 0, y0 = y1; ys < screen->h; y0 += ystep, ys++) {
+		for (xs = 0, x0 = x1; xs < screen->w; x0 += xstep, xs++) {
 			iteration = get_mandelbrot_iterations(x0, y0);
 
 			if (iteration == MAX_ITERATION)
@@ -52,6 +55,7 @@ int draw_mandelbrot(struct SDL_Surface *screen)
 				putpixel(screen, xs, ys,
 					iteration, 0, 0);
 		}
+
 		SDL_Flip(screen);
 	}
 
@@ -81,7 +85,7 @@ int main(int argc, char *argv[])
 
 	SDL_WM_SetCaption(argv[0], NULL);
 
-	draw_mandelbrot(screen);
+	draw_mandelbrot(screen, -2.5, 1, -1, 1);
 
 	yres = read(0, &xres, 1);