/* xscreensaver, Copyright (c) 1992, 1993, 1994, 1996, 1997 * Jamie Zawinski * * Permission to use, copy, modify, distribute, and sell this software and its * documentation for any purpose is hereby granted without fee, provided that * the above copyright notice appear in all copies and that both that * copyright notice and this permission notice appear in supporting * documentation. No representations are made about the suitability of this * software for any purpose. It is provided "as is" without express or * implied warranty. */ /* decayscreen * * Based on slidescreen program from the xscreensaver application and the * decay program for Sun framebuffers. This is the comment from the decay.c * file: * decay.c * find the screen bitmap for the console and make it "decay" by * randomly shifting random rectangles by one pixelwidth at a time. * * by David Wald, 1988 * rewritten by Natuerlich! * based on a similar "utility" on the Apollo ring at Yale. * X version by * * Vivek Khera * 5-AUG-1993 * * Hacked by jwz, 28-Nov-97 (sped up and added new motion directions) * R. Schultz * Added "melt" & "stretch" modes 28-Mar-1999 * */ #include "screenhack.h" static int sizex, sizey; static int delay; static GC gc; static int mode; static int iterations=100; #define SHUFFLE 0 #define UP 1 #define LEFT 2 #define RIGHT 3 #define DOWN 4 #define UPLEFT 5 #define DOWNLEFT 6 #define UPRIGHT 7 #define DOWNRIGHT 8 #define IN 9 #define OUT 10 #define MELT 11 #define STRETCH 12 #define FUZZ 13 static void init_decay (Display *dpy, Window window) { XGCValues gcv; XWindowAttributes xgwa; long gcflags; unsigned long bg; char *s = get_string_resource("mode", "Mode"); if (s && !strcmp(s, "shuffle")) mode = SHUFFLE; else if (s && !strcmp(s, "up")) mode = UP; else if (s && !strcmp(s, "left")) mode = LEFT; else if (s && !strcmp(s, "right")) mode = RIGHT; else if (s && !strcmp(s, "down")) mode = DOWN; else if (s && !strcmp(s, "upleft")) mode = UPLEFT; else if (s && !strcmp(s, "downleft")) mode = DOWNLEFT; else if (s && !strcmp(s, "upright")) mode = UPRIGHT; else if (s && !strcmp(s, "downright")) mode = DOWNRIGHT; else if (s && !strcmp(s, "in")) mode = IN; else if (s && !strcmp(s, "out")) mode = OUT; else if (s && !strcmp(s, "melt")) mode = MELT; else if (s && !strcmp(s, "stretch")) mode = STRETCH; else if (s && !strcmp(s, "fuzz")) mode = FUZZ; else { if (s && *s && !!strcmp(s, "random")) fprintf(stderr, "%s: unknown mode %s\n", progname, s); mode = random() % (FUZZ+1); } delay = get_integer_resource ("delay", "Integer"); if (delay < 0) delay = 0; XGetWindowAttributes (dpy, window, &xgwa); gcv.function = GXcopy; gcv.subwindow_mode = IncludeInferiors; if (mode == MELT || mode == STRETCH) { bg = get_pixel_resource ("background", "Background", dpy, xgwa.colormap); gcv.foreground = bg; } gcflags = GCForeground |GCFunction; if (use_subwindow_mode_p(xgwa.screen, window)) /* see grabscreen.c */ gcflags |= GCSubwindowMode; gc = XCreateGC (dpy, window, gcflags, &gcv); sizex = xgwa.width; sizey = xgwa.height; load_random_image (xgwa.screen, window, window, NULL); if (mode == MELT || mode == STRETCH) { /* make sure screen eventually turns background color */ XDrawLine(dpy, window, gc, 0, 0, sizex, 0); /* slow down for smoother melting*/ iterations = 1; } } /* * perform one iteration of decay */ static void decay1 (Display *dpy, Window window) { int left, top, width, height, toleft, totop; #define L 101 #define R 102 #define U 103 #define D 104 static int no_bias[] = { L,L,L,L, R,R,R,R, U,U,U,U, D,D,D,D }; static int up_bias[] = { L,L,L,L, R,R,R,R, U,U,U,U, U,U,D,D }; static int down_bias[] = { L,L,L,L, R,R,R,R, U,U,D,D, D,D,D,D }; static int left_bias[] = { L,L,L,L, L,L,R,R, U,U,U,U, D,D,D,D }; static int right_bias[] = { L,L,R,R, R,R,R,R, U,U,U,U, D,D,D,D }; static int upleft_bias[] = { L,L,L,L, L,R,R,R, U,U,U,U, U,D,D,D }; static int downleft_bias[] = { L,L,L,L, L,R,R,R, U,U,U,D, D,D,D,D }; static int upright_bias[] = { L,L,L,R, R,R,R,R, U,U,U,U, U,D,D,D }; static int downright_bias[] = { L,L,L,R, R,R,R,R, U,U,U,D, D,D,D,D }; static int *bias; switch (mode) { case SHUFFLE: bias = no_bias; break; case UP: bias = up_bias; break; case LEFT: bias = left_bias; break; case RIGHT: bias = right_bias; break; case DOWN: bias = down_bias; break; case UPLEFT: bias = upleft_bias; break; case DOWNLEFT: bias = downleft_bias; break; case UPRIGHT: bias = upright_bias; break; case DOWNRIGHT: bias = downright_bias; break; case IN: bias = no_bias; break; case OUT: bias = no_bias; break; case MELT: bias = no_bias; break; case STRETCH: bias = no_bias; break; case FUZZ: bias = no_bias; break; default: abort(); } #define nrnd(x) (random() % (x)) if (mode == MELT || mode == STRETCH) { left = nrnd(sizex/2); top = nrnd(sizey); width = nrnd( sizex/2 ) + sizex/2 - left; height = nrnd(sizey - top); toleft = left; totop = top+1; } else if (mode == FUZZ) { /* By Vince Levey ; inspired by the "melt" mode of the "scrhack" IrisGL program by Paul Haeberli circa 1991. */ static int toggle = 0; left = nrnd(sizex - 1); top = nrnd(sizey - 1); toggle = !toggle; if (toggle) { totop = top; height = 1; toleft = nrnd(sizex - 1); if (toleft > left) { width = toleft-left; toleft = left; left++; } else { width = left-toleft; left = toleft; toleft++; } } else { toleft = left; width = 1; totop = nrnd(sizey - 1); if (totop > top) { height = totop-top; totop = top; top++; } else { height = top-totop; top = totop; totop++; } } } else { left = nrnd(sizex - 1); top = nrnd(sizey); width = nrnd(sizex - left); height = nrnd(sizey - top); toleft = left; totop = top; if (mode == IN || mode == OUT) { int x = left+(width/2); int y = top+(height/2); int cx = sizex/2; int cy = sizey/2; if (mode == IN) { if (x > cx && y > cy) bias = upleft_bias; else if (x < cx && y > cy) bias = upright_bias; else if (x < cx && y < cy) bias = downright_bias; else /* (x > cx && y < cy)*/ bias = downleft_bias; } else { if (x > cx && y > cy) bias = downright_bias; else if (x < cx && y > cy) bias = downleft_bias; else if (x < cx && y < cy) bias = upleft_bias; else /* (x > cx && y < cy)*/ bias = upright_bias; } } switch (bias[random() % (sizeof(no_bias)/sizeof(*no_bias))]) { case L: toleft = left-1; break; case R: toleft = left+1; break; case U: totop = top-1; break; case D: totop = top+1; break; default: abort(); break; } } if (mode == STRETCH) { XCopyArea (dpy, window, window, gc, 0, sizey-top-2, sizex, top+1, 0, sizey-top-1); } else { XCopyArea (dpy, window, window, gc, left, top, width, height, toleft, totop); } #undef nrnd } char *progclass = "DecayScreen"; char *defaults [] = { "*dontClearRoot: True", #ifdef __sgi /* really, HAVE_READ_DISPLAY_EXTENSION */ "*visualID: Best", #endif "*delay: 10000", "*mode: random", 0 }; XrmOptionDescRec options [] = { { "-delay", ".delay", XrmoptionSepArg, 0 }, { "-mode", ".mode", XrmoptionSepArg, 0 }, { 0, 0, 0, 0 } }; void screenhack (Display *dpy, Window window) { init_decay (dpy, window); while (1) { int i; for (i = 0; i < iterations; i++) decay1 (dpy, window); XSync(dpy, False); screenhack_handle_events (dpy); if (delay) usleep (delay); } }