X-Git-Url: http://git.hungrycats.org/cgi-bin/gitweb.cgi?a=blobdiff_plain;f=hacks%2Fdistort.c;h=7eed6281c8b9c4d3ecef180c77956506ae080fd9;hb=c31d10b6605cd8dc1a7b61fef4256f06198767e5;hp=a18df51bc598dd5948957b6fa4538b8ce8543293;hpb=ce3185de9d9705e259f2b60dd4b5509007fa17d4;p=xscreensaver

diff --git a/hacks/distort.c b/hacks/distort.c
index a18df51b..7eed6281 100644
--- a/hacks/distort.c
+++ b/hacks/distort.c
@@ -41,11 +41,12 @@ struct coo {
 };
 static struct coo xy_coo[10];
 
-static int delay, radius, speed, number, blackhole, vortex, magnify;
+static int delay, radius, speed, number, blackhole, vortex, magnify, reflect;
 static XWindowAttributes xgwa;
 static GC gc;
 static Window g_window;
-static Display *g_dpy; 
+static Display *g_dpy;
+static unsigned long black_pixel;
 
 static XImage *orig_map, *buffer_map;
 
@@ -56,6 +57,9 @@ static void move_lense(int);
 static void swamp_thing(int);
 static void new_rnd_coo(int);
 static void init_round_lense(void);
+static void (*draw) (int) = NULL;
+static void reflect_draw(int);
+static void plain_draw(int);
 
 static void init_distort(Display *dpy, Window window) 
 {
@@ -66,10 +70,10 @@ static void init_distort(Display *dpy, Window window)
 	g_window=window;
 	g_dpy=dpy;
 
-	delay = get_integer_resource ("delay", "Integer");
-	radius = get_integer_resource ("radius", "Integer");
-	speed = get_integer_resource ("speed", "Integer");
-	number = get_integer_resource ("number", "Integer");
+	delay = get_integer_resource("delay", "Integer");
+	radius = get_integer_resource("radius", "Integer");
+	speed = get_integer_resource("speed", "Integer");
+	number = get_integer_resource("number", "Integer");
 
 #ifdef HAVE_XSHM_EXTENSION
 	use_shm = get_boolean_resource("useSHM", "Boolean");
@@ -78,14 +82,15 @@ static void init_distort(Display *dpy, Window window)
 	blackhole = get_boolean_resource("blackhole", "Boolean");
 	vortex = get_boolean_resource("vortex", "Boolean");
 	magnify = get_boolean_resource("magnify", "Boolean");
+	reflect = get_boolean_resource("reflect", "Boolean");
 	
-	if (get_boolean_resource ("swamp", "Boolean"))
+	if (get_boolean_resource("swamp", "Boolean"))
 		effect = &swamp_thing;
-	if (get_boolean_resource ("bounce", "Boolean"))
+	if (get_boolean_resource("bounce", "Boolean"))
 		effect = &move_lense;
 
 	if (effect == NULL && radius == 0 && speed == 0 && number == 0
-		&& !blackhole && !vortex && !magnify) {
+		&& !blackhole && !vortex && !magnify && !reflect) {
 /* if no cmdline options are given, randomly choose one of:
  * -radius 50 -number 4 -speed 1 -bounce
  * -radius 50 -number 4 -speed 1 -blackhole
@@ -102,9 +107,13 @@ static void init_distort(Display *dpy, Window window)
  * -radius 50 -number 4 -speed 2 -swamp -vortex
  * -radius 50 -number 4 -speed 2 -swamp -vortex -magnify
  * -radius 50 -number 4 -speed 2 -swamp -vortex -magnify -blackhole
+ * -radius 80 -number 1 -speed 2 -reflect
+ * -radius 50 -number 3 -speed 2 -reflect
  */
 		
-		i = (random() % 15);
+		i = (random() % 17);
+
+		draw = &plain_draw;
 
 		switch (i) {
 			case 0:
@@ -149,9 +158,15 @@ static void init_distort(Display *dpy, Window window)
 			case 13:
 				radius=50;number=4;speed=2;vortex=1;magnify=1;
 				effect=&swamp_thing;break;
-			case 14: default:
+			case 14:
 				radius=50;number=4;speed=2;vortex=1;magnify=1;blackhole=1;
 				effect=&swamp_thing;break;
+			case 15:
+				radius=80;number=1;speed=2;reflect=1;
+				draw = &reflect_draw;effect = &move_lense;break;
+			case 16: default:
+				radius=50;number=4;speed=2;reflect=1;
+				draw = &reflect_draw;effect = &move_lense;break;
 		}
 
 	}
@@ -168,8 +183,15 @@ static void init_distort(Display *dpy, Window window)
 		number=1;
 	if (effect == NULL)
 		effect = &move_lense;
+	if (reflect) {
+		draw = &reflect_draw;
+		effect = &move_lense;
+	}
+	if (draw == NULL)
+		draw = &plain_draw;
 
 	XGetWindowAttributes (dpy, window, &xgwa);
+	black_pixel = BlackPixelOfScreen( xgwa.screen );
 
 	gcv.function = GXcopy;
 	gcv.subwindow_mode = IncludeInferiors;
@@ -245,7 +267,10 @@ static void make_round_lense(int radius, int loop)
 		for(j = 0; j < 2*radius+speed+2; j++) {
 			double r, d;
 			r = sqrt ((i-radius)*(i-radius)+(j-radius)*(j-radius));
-			d=r/loop;
+			if (loop == 0)
+			  d=0.0;
+			else
+			  d=r/loop;
 
 			if (r < loop-1) {
 
@@ -256,13 +281,18 @@ static void make_round_lense(int radius, int loop)
 		 * Copyright (C) 1996 Federico Mena Quintero
 		 */
 		/* 2.5 is just a constant used because it looks good :) */
-					angle = 2.5*(1-r/loop)*(1-r/loop);
-
-					from[i][j][0] = radius + cos(angle -
-						atan2(radius-j,-(radius-i)))*r;
-					from[i][j][1] = radius + sin(angle -
-						atan2(radius-j,-(radius-i)))*r;
-
+					angle = 2.5*(1-d)*(1-d);
+
+        /* Avoid atan2: DOMAIN error message */
+					if ((radius-j) == 0.0 && (radius-i) == 0.0) {
+						from[i][j][0] = radius + cos(angle)*r;
+						from[i][j][1] = radius + sin(angle)*r;
+					} else {
+      				  	from[i][j][0] = radius +
+									cos(angle - atan2(radius-j, -(radius-i)))*r;
+			        	from[i][j][1] = radius +
+									sin(angle - atan2(radius-j, -(radius-i)))*r;
+					}
 					if (magnify) {
 						r = sin(d*M_PI_2);
 						if (blackhole && r != 0) /* blackhole effect */
@@ -277,7 +307,7 @@ static void make_round_lense(int radius, int loop)
 	 * distortion, a negative value sucks everything into a black hole
 	 */
 				/*	r = r*r; */
-					if (blackhole) /* blackhole effect */
+					if (blackhole && r != 0) /* blackhole effect */
 						r = 1/r;
 									/* bubble effect (and blackhole) */
 					from[i][j][0] = radius + (i-radius)*r;
@@ -291,6 +321,10 @@ static void make_round_lense(int radius, int loop)
 	}
 }
 
+#ifndef EXIT_FAILURE
+# define EXIT_FAILURE -1
+#endif
+
 static void allocate_lense(void)
 {
 	int i, j;
@@ -343,7 +377,7 @@ static void init_round_lense(void)
 
 
 /* generate an XImage of from[][][] and draw it on the screen */
-void draw(int k)
+void plain_draw(int k)
 {
 	int i, j;
 	for(i = 0 ; i < 2*radius+speed+2; i++) {
@@ -363,6 +397,55 @@ void draw(int k)
 			2*radius+speed+2, 2*radius+speed+2);
 }
 
+/* generate an XImage from the reflect algoritm submitted by
+ * Randy Zack <randy@acucorp.com>
+ * draw really got too big and ugly so I split it up
+ * it should be possible to use the from[][] to speed it up
+ * (once I figure out the algorithm used :)
+ */
+void reflect_draw(int k)
+{
+	int i, j;
+	int	cx, cy;
+	int	ly, lysq, lx, ny, dist, rsq = radius * radius;
+
+	cx = cy = radius;
+	if (xy_coo[k].ymove > 0)
+		cy += speed;
+	if (xy_coo[k].xmove > 0)
+		cx += speed;
+
+	for(i = 0 ; i < 2*radius+speed+2; i++) {
+		ly = i - cy;
+		lysq = ly * ly;
+		ny = xy_coo[k].y + i;
+		for(j = 0 ; j < 2*radius+speed+2 ; j++) {
+			lx = j - cx;
+			dist = lx * lx + lysq;
+			if (dist > rsq ||
+				ly < -radius || ly > radius ||
+				lx < -radius || lx > radius)
+				XPutPixel( buffer_map, j, i,
+						   XGetPixel( orig_map, xy_coo[k].x + j, ny ));
+			else if (dist == 0)
+				XPutPixel( buffer_map, j, i, black_pixel );
+			else {
+				int	x = xy_coo[k].x + cx + (lx * rsq / dist);
+				int	y = xy_coo[k].y + cy + (ly * rsq / dist);
+				if (x < 0 || x > xgwa.width ||
+					y < 0 || y > xgwa.height)
+					XPutPixel( buffer_map, j, i, black_pixel );
+				else
+					XPutPixel( buffer_map, j, i,
+							   XGetPixel( orig_map, x, y ));
+			}
+		}
+	}
+
+	XPutImage(g_dpy, g_window, gc, buffer_map, 0, 0, xy_coo[k].x, xy_coo[k].y,
+			2*radius+speed+2, 2*radius+speed+2);
+}
+
 /* create a new, random coordinate, that won't interfer with any other
  * coordinates, as the drawing routines would be significantly slowed
  * down if they were to handle serveral layers of distortions
@@ -391,11 +474,11 @@ static void move_lense(int k)
 {
 	int i;
 
-	if (xy_coo[k].x + 4*radius/2 >= xgwa.width)
+	if (xy_coo[k].x + 2*radius + speed + 2 >= xgwa.width)
 		xy_coo[k].xmove = -abs(xy_coo[k].xmove);
 	if (xy_coo[k].x <= speed) 
 		xy_coo[k].xmove = abs(xy_coo[k].xmove);
-	if (xy_coo[k].y + 4*radius/2 >= xgwa.height)
+	if (xy_coo[k].y + 2*radius + speed + 2 >= xgwa.height)
 		xy_coo[k].ymove = -abs(xy_coo[k].ymove);
 	if (xy_coo[k].y <= speed)
 		xy_coo[k].ymove = abs(xy_coo[k].ymove);
@@ -406,7 +489,7 @@ static void move_lense(int k)
 	for (i = 0; i < number; i++) {
 		if ((i != k)
 		
-/* This commented test is for rectangular lenses (not presently used) and
+/* This commented test is for rectangular lenses (not currently used) and
  * the one used is for circular ones
 		&& (abs(xy_coo[k].x - xy_coo[i].x) <= 2*radius)
 		&& (abs(xy_coo[k].y - xy_coo[i].y) <= 2*radius)) { */
@@ -471,6 +554,7 @@ char *defaults [] = {
 	"*magnify:			False",
 	"*swamp:			False",
 	"*bounce:			False",
+	"*reflect:			False",
 	"*blackhole:		False",
 #ifdef HAVE_XSHM_EXTENSION
 	"*useSHM:			False",		/* xshm turns out not to help. */
@@ -485,6 +569,7 @@ XrmOptionDescRec options [] = {
 	{ "-number",	".number",	XrmoptionSepArg, 0 },
 	{ "-swamp",	".swamp",	XrmoptionNoArg, "True" },
 	{ "-bounce",	".bounce",	XrmoptionNoArg, "True" },
+	{ "-reflect",	".reflect",	XrmoptionNoArg, "True" },
 	{ "-vortex",	".vortex",	XrmoptionNoArg, "True" },
 	{ "-magnify",	".magnify",	XrmoptionNoArg, "True" },
 	{ "-blackhole",	".blackhole",	XrmoptionNoArg, "True" },