1 /* xscreensaver, Copyright (c) 1992 Jamie Zawinski <jwz@lucid.com>
3 * Permission to use, copy, modify, distribute, and sell this software and its
4 * documentation for any purpose is hereby granted without fee, provided that
5 * the above copyright notice appear in all copies and that both that
6 * copyright notice and this permission notice appear in supporting
7 * documentation. No representations are made about the suitability of this
8 * software for any purpose. It is provided "as is" without express or
12 /* Rotate a bitmap using using bitblts.
13 The bitmap must be square, and must be a power of 2 in size.
14 This was translated from SmallTalk code which appeared in the
15 August 1981 issue of Byte magazine.
17 The input bitmap may be non-square, it is padded and centered
18 with the background color. Another way would be to subdivide
19 the bitmap into square components and rotate them independently
20 (and preferably in parallel), but I don't think that would be as
23 It's too bad almost nothing uses blitter hardware these days,
24 or this might actually win.
27 #include "screenhack.h"
32 # ifndef PIXEL_ALREADY_TYPEDEFED
33 # define PIXEL_ALREADY_TYPEDEFED /* Sigh, Xmu/Drawing.h needs this... */
37 #include <X11/Xmu/Drawing.h>
42 static unsigned int size;
43 static Pixmap self, temp, mask;
44 static GC SET, CLR, CPY, IOR, AND, XOR;
46 static int delay, delay2;
50 static void rotate(), init (), display ();
52 #define copy_all_to(from, xoff, yoff, to, gc) \
53 XCopyArea (dpy, (from), (to), (gc), 0, 0, \
54 size-(xoff), size-(yoff), (xoff), (yoff))
56 #define copy_all_from(to, xoff, yoff, from, gc) \
57 XCopyArea (dpy, (from), (to), (gc), (xoff), (yoff), \
58 size-(xoff), size-(yoff), 0, 0)
63 int qwad; /* fuckin' C, man... who needs namespaces? */
64 XFillRectangle (dpy, mask, CLR, 0, 0, size, size);
65 XFillRectangle (dpy, mask, SET, 0, 0, size>>1, size>>1);
66 for (qwad = size>>1; qwad > 0; qwad>>=1)
68 if (delay) usleep (delay);
69 copy_all_to (mask, 0, 0, temp, CPY); /* 1 */
70 copy_all_to (mask, 0, qwad, temp, IOR); /* 2 */
71 copy_all_to (self, 0, 0, temp, AND); /* 3 */
72 copy_all_to (temp, 0, 0, self, XOR); /* 4 */
73 copy_all_from (temp, qwad, 0, self, XOR); /* 5 */
74 copy_all_from (self, qwad, 0, self, IOR); /* 6 */
75 copy_all_to (temp, qwad, 0, self, XOR); /* 7 */
76 copy_all_to (self, 0, 0, temp, CPY); /* 8 */
77 copy_all_from (temp, qwad, qwad, self, XOR); /* 9 */
78 copy_all_to (mask, 0, 0, temp, AND); /* A */
79 copy_all_to (temp, 0, 0, self, XOR); /* B */
80 copy_all_to (temp, qwad, qwad, self, XOR); /* C */
81 copy_all_from (mask, qwad>>1, qwad>>1, mask, AND); /* D */
82 copy_all_to (mask, qwad, 0, mask, IOR); /* E */
83 copy_all_to (mask, 0, qwad, mask, IOR); /* F */
91 XWindowAttributes xgwa;
94 int width, height, xh, yh;
95 unsigned int real_size;
99 XpmAttributes xpmattrs;
103 XGetWindowAttributes (dpy, window, &xgwa);
104 cmap = xgwa.colormap;
107 delay = get_integer_resource ("delay", "Integer");
108 delay2 = get_integer_resource ("delay2", "Integer");
109 if (delay < 0) delay = 0;
110 if (delay2 < 0) delay2 = 0;
111 bitmap_name = get_string_resource ("bitmap", "Bitmap");
114 fprintf (stderr, "%s: no bitmap specified\n", progname);
118 xpmattrs.valuemask = 0;
120 result = XpmReadFileToPixmap (dpy,window, bitmap_name, &bitmap, 0, &xpmattrs);
124 fprintf (stderr, "%s: warning: xpm color substitution performed\n",
128 width = xpmattrs.width;
129 height = xpmattrs.height;
136 fprintf (stderr, "%s: xpm: color allocation failed\n", progname);
139 fprintf (stderr, "%s: xpm: out of memory\n", progname);
142 fprintf (stderr, "%s: xpm: unknown error code %d\n", progname, result);
147 bitmap = XmuLocateBitmapFile (DefaultScreenOfDisplay (dpy), bitmap_name,
148 0, 0, &width, &height, &xh, &yh);
151 fprintf (stderr, "%s: couldn't find bitmap %s\n", progname, bitmap_name);
155 real_size = (width > height) ? width : height;
158 /* semi-sleazy way of doing (setq size (expt 2 (ceiling (log size 2)))). */
159 for (i = 31; i > 0; i--)
160 if (size & (1<<i)) break;
161 if (size & (~(1<<i)))
162 size = (size>>i)<<(i+1);
163 self = XCreatePixmap (dpy, window, size, size, depth);
164 temp = XCreatePixmap (dpy, window, size, size, depth);
165 mask = XCreatePixmap (dpy, window, size, size, depth);
166 gcv.foreground = (depth == 1 ? 1 : (~0));
167 gcv.function=GXset; SET = XCreateGC(dpy,self,GCFunction|GCForeground,&gcv);
168 gcv.function=GXclear;CLR = XCreateGC(dpy,self,GCFunction|GCForeground,&gcv);
169 gcv.function=GXcopy; CPY = XCreateGC(dpy,self,GCFunction|GCForeground,&gcv);
170 gcv.function=GXor; IOR = XCreateGC(dpy,self,GCFunction|GCForeground,&gcv);
171 gcv.function=GXand; AND = XCreateGC(dpy,self,GCFunction|GCForeground,&gcv);
172 gcv.function=GXxor; XOR = XCreateGC(dpy,self,GCFunction|GCForeground,&gcv);
174 XFillRectangle (dpy, self, CLR, 0, 0, size, size);
175 XCopyArea (dpy, bitmap, self, CPY, 0, 0, width, height,
176 (size - width)>>1, (size - height)>>1);
178 gcv.foreground = get_pixel_resource ("foreground", "Foreground", dpy, cmap);
179 gcv.background = get_pixel_resource ("background", "Background", dpy, cmap);
180 gc = XCreateGC (dpy, window, GCForeground|GCBackground, &gcv);
187 XWindowAttributes xgwa;
188 static int last_w = 0, last_h = 0;
189 XGetWindowAttributes (dpy, window, &xgwa);
190 if (xgwa.width != last_w || xgwa.height != last_h)
192 XClearWindow (dpy, window);
194 last_h = xgwa.height;
198 XCopyArea (dpy, pixmap, window, gc, 0, 0, size, size,
199 (xgwa.width-size)>>1, (xgwa.height-size)>>1);
202 XCopyPlane (dpy, pixmap, window, gc, 0, 0, size, size,
203 (xgwa.width-size)>>1, (xgwa.height-size)>>1, 1);
205 XDrawRectangle (dpy, window, gc,
206 ((xgwa.width-size)>>1)-1, ((xgwa.height-size)>>1)-1,
213 char *progclass = "BlitSpin";
215 char *defaults [] = {
216 "*background: black",
217 "*foreground: white",
220 "*bitmap: xlogo64", /* hey, pick something better! */
224 XrmOptionDescRec options [] = {
225 { "-delay", ".delay", XrmoptionSepArg, 0 },
226 { "-delay2", ".delay2", XrmoptionSepArg, 0 },
227 { "-bitmap", ".bitmap", XrmoptionSepArg, 0 }
229 int options_size = (sizeof (options) / sizeof (options[0]));
242 if (delay2) usleep (delay2);