--- /dev/null
+/* xpm-ximage.c --- converts XPM data to an XImage for use with OpenGL.
+ * xscreensaver, Copyright (c) 1998 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
+ * 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.
+ */
+
+#ifdef HAVE_CONFIG_H
+# include "config.h"
+#endif
+
+#include <stdlib.h>
+#include <stdio.h>
+#include <X11/Intrinsic.h>
+
+extern char *progname;
+
+#ifdef HAVE_XPM /* whole file */
+
+#include <X11/Xutil.h>
+#include <X11/xpm.h>
+
+static Bool
+bigendian (void)
+{
+ union { int i; char c[sizeof(int)]; } u;
+ u.i = 1;
+ return !u.c[0];
+}
+
+
+/* Returns an XImage structure containing the bits of the given XPM image.
+ This XImage will be 32 bits per pixel, 8 each per R, G, and B, with the
+ extra byte set to 0xFF.
+
+ The Display and Visual arguments are used only for creating the XImage;
+ no bits are pushed to the server.
+
+ The Colormap argument is used just for parsing color names; no colors
+ are allocated.
+ */
+XImage *
+xpm_to_ximage (Display *dpy, Visual *visual, Colormap cmap, char **xpm_data)
+{
+ /* All we want to do is get RGB data out of the XPM file built in to this
+ program. This is a pain, because there is no way (as of XPM version
+ 4.6, at least) to get libXpm to make an XImage without also allocating
+ colors with XAllocColor. So, instead, we create an XpmImage and parse
+ out the RGB values of the pixels ourselves; and construct an XImage
+ by hand. Regardless of the depth of the visual we're using, this
+ XImage will have 32 bits per pixel, 8 each per R, G, and B. We put
+ 0xFF in the fourth slot, as GL will interpret that as "alpha".
+ */
+ XImage *ximage = 0;
+ XpmImage xpm_image;
+ XpmInfo xpm_info;
+ int result;
+ int x, y, i;
+ int bpl, wpl;
+ XColor colors[255];
+
+ memset (&xpm_image, 0, sizeof(xpm_image));
+ memset (&xpm_info, 0, sizeof(xpm_info));
+ result = XpmCreateXpmImageFromData (xpm_data, &xpm_image, &xpm_info);
+ if (result != XpmSuccess)
+ {
+ fprintf(stderr, "%s: unable to parse xpm data (%d).\n", progname,
+ result);
+ exit (1);
+ }
+
+ ximage = XCreateImage (dpy, visual, 32, ZPixmap, 0, 0,
+ xpm_image.width, xpm_image.height, 32, 0);
+
+ bpl = ximage->bytes_per_line;
+ wpl = bpl/4;
+
+ ximage->data = (char *) malloc(xpm_image.height * bpl);
+
+ /* Parse the colors in the XPM into RGB values. */
+ for (i = 0; i < xpm_image.ncolors; i++)
+ if (!XParseColor(dpy, cmap, xpm_image.colorTable[i].c_color, &colors[i]))
+ {
+ fprintf(stderr, "%s: unparsable color: %s\n", progname,
+ xpm_image.colorTable[i].c_color);
+ exit(1);
+ }
+
+ /* Translate the XpmImage to an RGB XImage. */
+ {
+ int rpos, gpos, bpos, apos; /* bitfield positions */
+
+ /* 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.
+ */
+ if (bigendian())
+ rpos = 24, gpos = 16, bpos = 8, apos = 0;
+ else
+ rpos = 0, gpos = 8, bpos = 16, apos = 24;
+
+ for (y = 0; y < xpm_image.height; y++)
+ {
+ int y2 = (xpm_image.height-1-y); /* Texture maps are upside down. */
+
+ unsigned int *oline = (unsigned int *) (ximage->data + (y * bpl));
+ unsigned int *iline = (unsigned int *) (xpm_image.data + (y2 * wpl));
+
+ for (x = 0; x < xpm_image.width; x++)
+ {
+ XColor *c = &colors[iline[x]];
+ /* pack it as RGBA */
+ oline[x] = (((c->red >> 8) << rpos) |
+ ((c->green >> 8) << gpos) |
+ ((c->blue >> 8) << bpos) |
+ (0xFF << apos));
+ }
+ }
+ }
+
+ /* I sure hope these only free the contents, and not the args. */
+#if 0 /* Apparently not? Gotta love those well-documented APIs! */
+ XpmFreeXpmImage (&xpm_image);
+ XpmFreeXpmInfo (&xpm_info);
+#endif
+
+ return ximage;
+}
+
+
+#else /* !HAVE_XPM */
+
+XImage *
+xpm_to_ximage (char **xpm_data)
+{
+ fprintf(stderr, "%s: not compiled with XPM support.\n", progname);
+ exit (1);
+}
+
+#endif /* !HAVE_XPM */
projects / xscreensaver / blobdiff