/* grab-ximage.c --- grab the screen to an XImage for use with OpenGL.
- * xscreensaver, Copyright (c) 2001 Jamie Zawinski <jwz@jwz.org>
+ * xscreensaver, Copyright (c) 2001, 2003 Jamie Zawinski <jwz@jwz.org>
*
* Permission to use, copy, modify, distribute, and sell this software and its
* documentation for any purpose is hereby granted without fee, provided that
#include <GL/gl.h> /* only for GLfloat */
#include "grabscreen.h"
+#include "visual.h"
extern char *progname;
#undef countof
#define countof(x) (sizeof((x))/sizeof((*x)))
-static Bool
-bigendian (void)
-{
- union { int i; char c[sizeof(int)]; } u;
- u.i = 1;
- return !u.c[0];
-}
-
/* return the next larger power of 2. */
static int
to_pow2 (int i)
}
+/* Given a bitmask, returns the position and width of the field.
+ */
+static void
+decode_mask (unsigned int mask, unsigned int *pos_ret, unsigned int *size_ret)
+{
+ int i;
+ for (i = 0; i < 32; i++)
+ if (mask & (1L << i))
+ {
+ int j = 0;
+ *pos_ret = i;
+ for (; i < 32; i++, j++)
+ if (! (mask & (1L << i)))
+ break;
+ *size_ret = j;
+ return;
+ }
+}
+
+
+/* Given a value and a field-width, expands the field to fill out 8 bits.
+ */
+static unsigned char
+spread_bits (unsigned char value, unsigned char width)
+{
+ switch (width)
+ {
+ case 8: return value;
+ case 7: return (value << 1) | (value >> 6);
+ case 6: return (value << 2) | (value >> 4);
+ case 5: return (value << 3) | (value >> 2);
+ case 4: return (value << 4) | (value);
+ case 3: return (value << 5) | (value << 2) | (value >> 2);
+ case 2: return (value << 6) | (value << 4) | (value);
+ default: abort(); break;
+ }
+}
+
+
+static Bool
+bigendian (void)
+{
+ union { int i; char c[sizeof(int)]; } u;
+ u.i = 1;
+ return !u.c[0];
+}
+
+
/* Returns an XImage structure containing an image of the desktop.
- (As a side-effect, that image will be painted onto the given Window.)
+ (As a side-effect, that image *may* be painted onto the given Window.)
This XImage will be 32 bits per pixel, 8 each per R, G, and B, with the
extra byte set to 0xFF.
*/
XImage *
-screen_to_ximage (Screen *screen, Window window)
+screen_to_ximage (Screen *screen, Window window, char **filename_return)
{
Display *dpy = DisplayOfScreen (screen);
+ Pixmap pixmap = 0;
XWindowAttributes xgwa;
int win_width, win_height;
int tex_width, tex_height;
- grab_screen_image (screen, window);
-
XGetWindowAttributes (dpy, window, &xgwa);
win_width = xgwa.width;
win_height = xgwa.height;
+ pixmap = XCreatePixmap(dpy, window, xgwa.width, xgwa.height, xgwa.depth);
+ load_random_image (screen, window, pixmap, filename_return);
+
/* GL texture sizes must be powers of two. */
tex_width = to_pow2(win_width);
tex_height = to_pow2(win_height);
- /* Convert the server-side Drawable to a client-side GL-ordered XImage.
+ /* Convert the server-side Pixmap to a client-side GL-ordered XImage.
*/
{
XImage *ximage1, *ximage2;
+ XColor *colors = 0;
- ximage1 = XGetImage (dpy, window, 0, 0, win_width, win_height, ~0L,
+ ximage1 = XGetImage (dpy, pixmap, 0, 0, win_width, win_height, ~0L,
ZPixmap);
+ XFreePixmap (dpy, pixmap);
+ pixmap = 0;
+
ximage2 = XCreateImage (dpy, xgwa.visual, 32, ZPixmap, 0, 0,
tex_width, tex_height, 32, 0);
ximage2->data = (char *) calloc (tex_height, ximage2->bytes_per_line);
+ {
+ Screen *dscreen = DefaultScreenOfDisplay (dpy);
+ Visual *dvisual = DefaultVisualOfScreen (dscreen);
+ if (visual_class (dscreen, dvisual) == PseudoColor ||
+ visual_class (dscreen, dvisual) == GrayScale)
+ {
+ Colormap cmap = DefaultColormapOfScreen(dscreen);
+ int ncolors = visual_cells (dscreen, dvisual);
+ int i;
+ colors = (XColor *) calloc (sizeof (*colors), ncolors+1);
+ for (i = 0; i < ncolors; i++)
+ colors[i].pixel = i;
+ XQueryColors (dpy, cmap, colors, ncolors);
+ }
+ }
+
/* Translate the server-ordered image to a client-ordered image.
*/
{
int x, y;
- int crpos, cgpos, cbpos, capos; /* bitfield positions */
- int srpos, sgpos, sbpos;
- int srmsk, sgmsk, sbmsk;
- int sdepth = ximage1->depth;
-
- srmsk = ximage1->red_mask;
- sgmsk = ximage1->green_mask;
- sbmsk = ximage1->blue_mask;
- if (sdepth == 32 || sdepth == 24)
- srpos = 16, sgpos = 8, sbpos = 0;
- else /* 15 or 16 */
- srpos = 10, sgpos = 5, sbpos = 0;
+ unsigned int crpos=0, cgpos=0, cbpos=0, capos=0; /* bitfield positions */
+ unsigned int srpos=0, sgpos=0, sbpos=0;
+ unsigned int srmsk=0, sgmsk=0, sbmsk=0;
+ unsigned int srsiz=0, sgsiz=0, sbsiz=0;
+ int i;
+
+ unsigned char spread_map[3][256];
+
+ if (colors == 0) /* truecolor */
+ {
+ srmsk = ximage2->red_mask;
+ sgmsk = ximage2->green_mask;
+ sbmsk = ximage2->blue_mask;
+
+ decode_mask (srmsk, &srpos, &srsiz);
+ decode_mask (sgmsk, &sgpos, &sgsiz);
+ decode_mask (sbmsk, &sbpos, &sbsiz);
+ }
/* Note that unlike X, which is endianness-agnostic (since any XImage
can have its own specific bit ordering, with the server reversing
things as necessary) OpenGL pretends everything is client-side, so
- we need to pack things in the right order for the client machine.
+ we need to pack things in "RGBA" order on the client machine,
+ regardless of its endianness.
*/
if (bigendian())
crpos = 24, cgpos = 16, cbpos = 8, capos = 0;
else
crpos = 0, cgpos = 8, cbpos = 16, capos = 24;
+ if (colors == 0) /* truecolor */
+ {
+ for (i = 0; i < 256; i++)
+ {
+ spread_map[0][i] = spread_bits (i, srsiz);
+ spread_map[1][i] = spread_bits (i, sgsiz);
+ spread_map[2][i] = spread_bits (i, sbsiz);
+ }
+ }
+
for (y = 0; y < win_height; y++)
{
int y2 = (win_height-1-y); /* Texture maps are upside down. */
for (x = 0; x < win_width; x++)
{
unsigned long sp = XGetPixel (ximage1, x, y2);
- unsigned char sr = (sp & srmsk) >> srpos;
- unsigned char sg = (sp & sgmsk) >> sgpos;
- unsigned char sb = (sp & sbmsk) >> sbpos;
+ unsigned char sr, sg, sb;
unsigned long cp;
- if (sdepth < 24) /* spread 5 bits to 8 */
+ if (colors)
+ {
+ sr = colors[sp].red & 0xFF;
+ sg = colors[sp].green & 0xFF;
+ sb = colors[sp].blue & 0xFF;
+ }
+ else
{
- sr = (sr << 3) | (sr >> 2);
- sg = (sg << 3) | (sg >> 2);
- sb = (sb << 3) | (sb >> 2);
+ sr = (sp & srmsk) >> srpos;
+ sg = (sp & sgmsk) >> sgpos;
+ sb = (sp & sbmsk) >> sbpos;
+
+ sr = spread_map[0][sr];
+ sg = spread_map[1][sg];
+ sb = spread_map[2][sb];
}
+
cp = ((sr << crpos) |
(sg << cgpos) |
(sb << cbpos) |
(0xFF << capos));
+
XPutPixel (ximage2, x, y, cp);
}
}
}
+ if (pixmap) XFreePixmap (dpy, pixmap);
+ if (colors) free (colors);
free (ximage1->data);
ximage1->data = 0;
XDestroyImage (ximage1);
projects / xscreensaver / blobdiff