2 * spotlight - an xscreensaver module
3 * Copyright (c) 1999 Rick Schultz <rick@skapunx.net>
5 * loosely based on the BackSpace module "StefView" by Darcy Brockbank
8 /* modified from a module from the xscreensaver distribution */
11 * xscreensaver, Copyright (c) 1992, 1993, 1994, 1996, 1997, 1998
12 * Jamie Zawinski <jwz@jwz.org>
14 * Permission to use, copy, modify, distribute, and sell this software and its
15 * documentation for any purpose is hereby granted without fee, provided that
16 * the above copyright notice appear in all copies and that both that
17 * copyright notice and this permission notice appear in supporting
18 * documentation. No representations are made about the suitability of this
19 * software for any purpose. It is provided "as is" without express or
25 #include "screenhack.h"
26 #include <X11/Xutil.h>
31 #define X_PERIOD 15000.0
32 #define Y_PERIOD 12000.0
34 static int sizex, sizey; /* screen size */
35 static int delay; /* in case it's too fast... */
40 static GC buffer_gc; /* draw in buffer, then flush to screen
42 static int radius; /* radius of spotlight in pixels */
44 static Pixmap pm; /* pixmap grabbed from screen */
45 static Pixmap clip_pm; /* pixmap for clipping (spotlight shape) */
46 static Pixmap buffer; /* pixmap for the buffer */
48 static GC clip_gc; /* GC for the clip pixmap */
50 static int x, y, s; /* x & y coords of buffer (upper left corner) */
51 /* s is the width of the buffer */
53 static int oldx, oldy, max_x_speed, max_y_speed;
54 /* used to keep the new buffer position
55 over the old spotlight image to make sure
56 the old image is completely erased */
58 /* The path the spotlight follows around the screen is sinusoidal.
59 This function is fed to sin() to get the x & y coords */
63 struct timeval curTime;
64 #ifdef GETTIMEOFDAY_TWO_ARGS
65 struct timezone tz = {0,0};
66 gettimeofday(&curTime, &tz);
68 gettimeofday(&curTime);
70 return curTime.tv_sec*1000 + curTime.tv_usec/1000.0;
75 init_hack (Display *dpy, Window window)
78 XWindowAttributes xgwa;
83 XGetWindowAttributes (dpy, window, &xgwa);
87 fg = get_pixel_resource ("foreground", "Foreground", dpy, cmap);
88 bg = get_pixel_resource ("background", "Background", dpy, cmap);
90 /* read parameters, keep em sane */
91 delay = get_integer_resource ("delay", "Integer");
92 if (delay < 1) delay = 1;
93 radius = get_integer_resource ("radius", "Integer");
94 if (radius < 0) radius = 125;
97 gcv.function = GXcopy;
98 gcv.subwindow_mode = IncludeInferiors;
99 gcflags = GCForeground | GCFunction;
103 if (use_subwindow_mode_p(xgwa.screen, window)) /* see grabscreen.c */
104 gcflags |= GCSubwindowMode;
106 window_gc = XCreateGC(dpy, window, gcflags, &gcv);
109 /* grab screen to window */
110 grab_screen_image(xgwa.screen, window);
112 /* save screen to pixmap for copying later */
113 pm = XCreatePixmap(dpy, window, sizex, sizey, xgwa.depth);
114 XCopyArea(dpy, window, pm, window_gc, 0, 0, sizex, sizey, 0, 0);
117 /* create buffer to reduce flicker */
118 buffer = XCreatePixmap(dpy, window, sizex, sizey, xgwa.depth);
119 buffer_gc = XCreateGC(dpy, buffer, gcflags, &gcv);
120 XFillRectangle(dpy, buffer, buffer_gc, 0, 0, sizex, sizey);
122 /* blank out screen */
123 XFillRectangle(dpy, window, window_gc, 0, 0, sizex, sizey);
124 XSetWindowBackground (dpy, window, bg);
126 /* create clip mask (so it's a circle, not a square) */
127 clip_pm = XCreatePixmap(dpy, window, radius*4, radius*4, 1);
130 clip_gc = XCreateGC(dpy, clip_pm, gcflags, &gcv);
131 XFillRectangle(dpy, clip_pm, clip_gc, 0, 0, radius*4, radius*4);
133 XSetForeground(dpy, clip_gc, 1L);
134 XFillArc(dpy, clip_pm, clip_gc, radius , radius,
135 radius*2, radius*2, 0, 360*64);
137 /* set buffer's clip mask to the one we just made */
138 XSetClipMask(dpy, buffer_gc, clip_pm);
140 /* free everything */
141 XFreeGC(dpy, clip_gc);
142 XFreePixmap(dpy, clip_pm);
145 max_x_speed = max_y_speed = radius;
148 /* create GC with white fg */
150 white_gc = XCreateGC(dpy, window, gcflags, &gcv);
153 /* initialize x and y to avoid initial `jump' across screen */
154 x = ((1 + sin(((float)currentTimeInMs()) / X_PERIOD * 2. * M_PI))/2.0)
155 * (sizex - s/2) -s/4 + MINX;
156 y = ((1 + sin(((float)currentTimeInMs()) / Y_PERIOD * 2. * M_PI))/2.0)
157 * (sizey - s/2) -s/4 + MINY;
163 * perform one iteration
166 onestep (Display *dpy, Window window)
171 XFillRectangle(dpy, buffer, buffer_gc, x, y, s, s);
174 #define nrnd(x) (random() % (x))
179 s = radius *4 ; /* s = width of buffer */
181 now = currentTimeInMs();
184 x = ((1 + sin(((float)now) / X_PERIOD * 2. * M_PI))/2.0)
185 * (sizex - s/2) -s/4 + MINX;
186 y = ((1 + sin(((float)now) / Y_PERIOD * 2. * M_PI))/2.0)
187 * (sizey - s/2) -s/4 + MINY;
189 /* limit change in x and y to buffer width */
190 if ( x < (oldx - max_x_speed) ) x = oldx - max_x_speed;
191 if ( x > (oldx + max_x_speed) ) x = oldx + max_x_speed;
192 if ( y < (oldy - max_y_speed) ) y = oldy - max_y_speed;
193 if ( y > (oldy + max_y_speed) ) y = oldy + max_y_speed;
195 /* copy area of screen image (pm) to buffer
197 XSetClipOrigin(dpy, buffer_gc, x,y);
198 XCopyArea(dpy, pm, buffer, buffer_gc, x, y, s, s, x, y);
199 /* copy buffer to screen (window) */
200 XCopyArea(dpy, buffer, window, window_gc, x , y, s, s, x, y);
203 /* draw a box around the buffer */
204 XDrawLine(dpy, window, white_gc, x, y, x+s, y);
205 XDrawLine(dpy, window, white_gc, x, y, x, y+s);
206 XDrawLine(dpy, window, white_gc, x+s, y, x+s, y+s);
207 XDrawLine(dpy, window, white_gc, x, y+s, x+s, y+s);
213 char *progclass = "Spotlight";
215 char *defaults [] = {
216 "*dontClearRoot: True",
218 #ifdef __sgi /* really, HAVE_READ_DISPLAY_EXTENSION */
227 XrmOptionDescRec options [] = {
228 { "-delay", ".delay", XrmoptionSepArg, 0 },
229 { "-radius", ".radius", XrmoptionSepArg, 0 },
234 screenhack (Display *dpy, Window window)
236 init_hack (dpy, window);
238 onestep(dpy, window);
240 if (delay) usleep (delay);
241 screenhack_handle_events (dpy);