/* * spotlight - an xscreensaver module * Copyright (c) 1999, 2001 Rick Schultz * * loosely based on the BackSpace module "StefView" by Darcy Brockbank */ /* modified from a module from the xscreensaver distribution */ /* * xscreensaver, Copyright (c) 1992, 1993, 1994, 1996, 1997, 1998 * 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. */ /* #define DEBUG */ #include #include "screenhack.h" #include #include #define MINX 0.0 #define MINY 0.0 #define X_PERIOD 15000.0 #define Y_PERIOD 12000.0 static int sizex, sizey; /* screen size */ static int delay; /* in case it's too fast... */ static GC window_gc; #ifdef DEBUG static GC white_gc; #endif static GC buffer_gc; /* draw in buffer, then flush to screen to avoid flicker */ static int radius; /* radius of spotlight in pixels */ static Pixmap pm; /* pixmap grabbed from screen */ static Pixmap clip_pm; /* pixmap for clipping (spotlight shape) */ static Pixmap buffer; /* pixmap for the buffer */ static GC clip_gc; /* GC for the clip pixmap */ static int x, y, s; /* x & y coords of buffer (upper left corner) */ /* s is the width of the buffer */ static int oldx, oldy, max_x_speed, max_y_speed; /* used to keep the new buffer position over the old spotlight image to make sure the old image is completely erased */ /* The path the spotlight follows around the screen is sinusoidal. This function is fed to sin() to get the x & y coords */ static long currentTimeInMs(void) { struct timeval curTime; #ifdef GETTIMEOFDAY_TWO_ARGS struct timezone tz = {0,0}; gettimeofday(&curTime, &tz); #else gettimeofday(&curTime); #endif return curTime.tv_sec*1000 + curTime.tv_usec/1000.0; } static void init_hack (Display *dpy, Window window) { XGCValues gcv; XWindowAttributes xgwa; long gcflags; Colormap cmap; unsigned long fg, bg; XGetWindowAttributes (dpy, window, &xgwa); sizex = xgwa.width; sizey = xgwa.height; cmap = xgwa.colormap; fg = get_pixel_resource ("foreground", "Foreground", dpy, cmap); bg = get_pixel_resource ("background", "Background", dpy, cmap); /* read parameters, keep em sane */ delay = get_integer_resource ("delay", "Integer"); if (delay < 1) delay = 1; radius = get_integer_resource ("radius", "Integer"); if (radius < 0) radius = 125; /* Don't let the spotlight be bigger than 1/4 of the window */ if (radius > xgwa.width / 4) radius = xgwa.width / 4; if (radius > xgwa.height / 4) radius = xgwa.height / 4; /* do the dance */ gcv.function = GXcopy; gcv.subwindow_mode = IncludeInferiors; gcflags = GCForeground | GCFunction; gcv.foreground = bg; #ifdef NOPE if (use_subwindow_mode_p(xgwa.screen, window)) /* see grabscreen.c */ gcflags |= GCSubwindowMode; #endif window_gc = XCreateGC(dpy, window, gcflags, &gcv); /* grab screen to pixmap */ pm = XCreatePixmap(dpy, window, sizex, sizey, xgwa.depth); load_random_image (xgwa.screen, window, pm, NULL); XClearWindow(dpy, window); XFlush (dpy); /* create buffer to reduce flicker */ buffer = XCreatePixmap(dpy, window, sizex, sizey, xgwa.depth); buffer_gc = XCreateGC(dpy, buffer, gcflags, &gcv); XFillRectangle(dpy, buffer, buffer_gc, 0, 0, sizex, sizey); /* blank out screen */ XFillRectangle(dpy, window, window_gc, 0, 0, sizex, sizey); XSetWindowBackground (dpy, window, bg); /* create clip mask (so it's a circle, not a square) */ clip_pm = XCreatePixmap(dpy, window, radius*4, radius*4, 1); gcv.foreground = 0L; clip_gc = XCreateGC(dpy, clip_pm, gcflags, &gcv); XFillRectangle(dpy, clip_pm, clip_gc, 0, 0, radius*4, radius*4); XSetForeground(dpy, clip_gc, 1L); XFillArc(dpy, clip_pm, clip_gc, radius , radius, radius*2, radius*2, 0, 360*64); /* set buffer's clip mask to the one we just made */ XSetClipMask(dpy, buffer_gc, clip_pm); /* free everything */ XFreeGC(dpy, clip_gc); XFreePixmap(dpy, clip_pm); /* avoid remants */ max_x_speed = max_y_speed = radius; #ifdef DEBUG /* create GC with white fg */ gcv.foreground = fg; white_gc = XCreateGC(dpy, window, gcflags, &gcv); #endif /* initialize x and y to avoid initial `jump' across screen */ x = ((1 + sin(((float)currentTimeInMs()) / X_PERIOD * 2. * M_PI))/2.0) * (sizex - s/2) -s/4 + MINX; y = ((1 + sin(((float)currentTimeInMs()) / Y_PERIOD * 2. * M_PI))/2.0) * (sizey - s/2) -s/4 + MINY; } /* * perform one iteration */ static void onestep (Display *dpy, Window window) { long now; /* clear buffer */ XFillRectangle(dpy, buffer, buffer_gc, x, y, s, s); #define nrnd(x) (random() % (x)) oldx = x; oldy = y; s = radius *4 ; /* s = width of buffer */ now = currentTimeInMs(); /* find new x,y */ x = ((1 + sin(((float)now) / X_PERIOD * 2. * M_PI))/2.0) * (sizex - s/2) -s/4 + MINX; y = ((1 + sin(((float)now) / Y_PERIOD * 2. * M_PI))/2.0) * (sizey - s/2) -s/4 + MINY; /* limit change in x and y to buffer width */ if ( x < (oldx - max_x_speed) ) x = oldx - max_x_speed; if ( x > (oldx + max_x_speed) ) x = oldx + max_x_speed; if ( y < (oldy - max_y_speed) ) y = oldy - max_y_speed; if ( y > (oldy + max_y_speed) ) y = oldy + max_y_speed; /* copy area of screen image (pm) to buffer Clip to a circle */ XSetClipOrigin(dpy, buffer_gc, x,y); XCopyArea(dpy, pm, buffer, buffer_gc, x, y, s, s, x, y); /* copy buffer to screen (window) */ XCopyArea(dpy, buffer, window, window_gc, x , y, s, s, x, y); #ifdef DEBUG /* draw a box around the buffer */ XDrawLine(dpy, window, white_gc, x, y, x+s, y); XDrawLine(dpy, window, white_gc, x, y, x, y+s); XDrawLine(dpy, window, white_gc, x+s, y, x+s, y+s); XDrawLine(dpy, window, white_gc, x, y+s, x+s, y+s); #endif } char *progclass = "Spotlight"; char *defaults [] = { ".background: black", ".foreground: white", "*dontClearRoot: True", #ifdef __sgi /* really, HAVE_READ_DISPLAY_EXTENSION */ "*visualID: Best", #endif "*delay: 10000", "*radius: 125", 0 }; XrmOptionDescRec options [] = { { "-delay", ".delay", XrmoptionSepArg, 0 }, { "-radius", ".radius", XrmoptionSepArg, 0 }, { 0, 0, 0, 0 } }; void screenhack (Display *dpy, Window window) { init_hack (dpy, window); while (1) { onestep(dpy, window); XSync(dpy, False); if (delay) usleep (delay); screenhack_handle_events (dpy); } }