X-Git-Url: http://git.mutantstargoat.com/user/nuclear/?p=dosdemo;a=blobdiff_plain;f=src%2Ffract.c;h=a17550b9752c27588036e182009b15e538473807;hp=15da79db549eda1c87434e393f0c440a53ddc303;hb=21c4bd88e7ddd930ac83c54cbe7399af0e188b67;hpb=aefd23e483457daa7eeb4987827e72df83886eaa

diff --git a/src/fract.c b/src/fract.c
index 15da79d..a17550b 100644
--- a/src/fract.c
+++ b/src/fract.c
@@ -12,7 +12,6 @@ static int init(void);
 static void destroy(void);
 static void draw(void);
 static int julia(long x, long y, long cx, long cy, int max_iter);
-static int calc_walk(struct vec2x *path, long x, long y, int max_steps);
 
 static struct screen scr = {
 	"fract",
@@ -49,9 +48,8 @@ static void destroy(void)
 
 static void draw(void)
 {
-	int i, j, len, x, y;
-	unsigned short *pixels = fb_pixels;
-	struct vec2x walkpos[WALK_SIZE];
+	int i, j;
+	unsigned short *pixels = vmem_back;
 
 	cx = mouse_x;
 	cy = mouse_y;
@@ -63,29 +61,9 @@ static void draw(void)
 		}
 	}
 
-	pixels = fb_pixels;
-
-	if((len = calc_walk(walkpos, mouse_x, mouse_y, WALK_SIZE))) {
-		x = walkpos[0].x >> 16;
-		y = walkpos[0].y >> 16;
-
-		for(i=1; i<len; i++) {
-			int x0 = x;
-			int y0 = y;
-			int x1 = walkpos[i].x >> 16;
-			int y1 = walkpos[i].y >> 16;
-
-			if(clip_line(&x0, &y0, &x1, &y1, 0, 0, fb_width - 1, fb_height - 1)) {
-				draw_line(x0, y0, x1, y1, PACK_RGB16(32, 128, 255));
-			}
-			x = x1;
-			y = y1;
-		}
-	}
-
+	pixels = vmem_back;
 	pixels[mouse_y * fb_width + mouse_x] = 0xffe;
-
-	swap_buffers(fb_pixels);
+	swap_buffers(vmem_back);
 }
 
 static long normalize_coord(long x, long range)
@@ -94,12 +72,6 @@ static long normalize_coord(long x, long range)
 	return (x << 17) / range - 65536;
 }
 
-static long device_coord(long x, long range)
-{
-	/* (x + 1) / 2 * (range - 1) */
-	return ((x + 65536) >> 1) * (range - 1);
-}
-
 static int julia(long x, long y, long cx, long cy, int max_iter)
 {
 	int i;
@@ -124,30 +96,3 @@ static int julia(long x, long y, long cx, long cy, int max_iter)
 
 	return i < max_iter ? (256 * i / max_iter) : 0;
 }
-
-static int calc_walk(struct vec2x *path, long x, long y, int max_steps)
-{
-	int i;
-	long cx, cy;
-
-	/* convert to fixed point roughly [-1, 1] */
-	x = cx = (normalize_coord(x, fb_width) >> 8) * xscale_24x8;
-	y = cy = (normalize_coord(y, fb_height) >> 8) * yscale_24x8;
-
-	for(i=0; i<max_steps; i++) {
-		/* z_n = z_{n-1}**2 + c */
-		long px = x >> 8;
-		long py = y >> 8;
-
-		path[i].x = device_coord((x << 8) / xscale_24x8, fb_width);
-		path[i].y = device_coord((y << 8) / yscale_24x8, fb_height);
-
-		if(px * px + py * py > (4 << 16)) {
-			break;
-		}
-		x = px * px - py * py + cx;
-		y = (px * py << 1) + cy;
-	}
-
-	return i;
-}