wrlib/xpixmap.c

   1 /* xpixmap.c - Make RImage from Pixmap or XImage
   2  *
   3  *  Raster graphics library
   4  *
   5  *  Copyright (c) 1997 Alfredo K. Kojima
   6  *
   7  *  This library is free software; you can redistribute it and/or
   8  *  modify it under the terms of the GNU Library General Public
   9  *  License as published by the Free Software Foundation; either
  10  *  version 2 of the License, or (at your option) any later version.
  11  *
  12  *  This library is distributed in the hope that it will be useful,
  13  *  but WITHOUT ANY WARRANTY; without even the implied warranty of
  14  *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  15  *  Library General Public License for more details.
  16  *
  17  *  You should have received a copy of the GNU Library General Public
  18  *  License along with this library; if not, write to the Free
  19  *  Software Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
  20  */
  21
  22
  23 #include <config.h>
  24
  25 #include <X11/Xlib.h>
  26 #include <X11/Xutil.h>
  27 #include <stdlib.h>
  28 #include <stdio.h>
  29 #include <string.h>
  30 #include <assert.h>
  31
  32 #include "wraster.h"
  33
  34
  35
  36 static int
  37 get_shifts(unsigned long mask)
  38 {
  39     int i=0;
  40
  41     while (mask) {
  42         mask>>=1;
  43         i++;
  44     }
  45     return i;
  46 }
  47
  48
  49 RImage*
  50 RCreateImageFromXImage(RContext *context, XImage *image, XImage *mask)
  51 {
  52     RImage *img;
  53     int x, y;
  54     unsigned long pixel;
  55     unsigned char *r, *g, *b, *a;
  56     int rshift, gshift, bshift;
  57     int rmask, gmask, bmask;
  58
  59     RErrorString[0] = 0;
  60
  61     assert(image!=NULL);
  62     assert(image->format==ZPixmap);
  63     assert(!mask || mask->format==ZPixmap);
  64
  65     img = RCreateImage(image->width, image->height, mask!=NULL);
  66     if (!img) {
  67         return NULL;
  68     }
  69
  70
  71     /* I don't know why, but XGetImage() for pixmaps don't set the
  72      * {red,green,blue}_mask values correctly. This will not
  73      * work for imageis of depth different than the root window
  74      * one used in wrlib
  75      */
  76     if (context->depth==image->depth) {
  77         rmask = context->visual->red_mask;
  78         gmask = context->visual->green_mask;
  79         bmask = context->visual->blue_mask;
  80     } else {
  81         rmask = image->red_mask;
  82         gmask = image->green_mask;
  83         bmask = image->blue_mask;
  84     }
  85
  86     /* how many bits to shift to normalize the color into 8bpp */
  87     rshift = get_shifts(rmask) - 8;
  88     gshift = get_shifts(gmask) - 8;
  89     bshift = get_shifts(bmask) - 8;
  90
  91     r = img->data[0];
  92     g = img->data[1];
  93     b = img->data[2];
  94     a = img->data[3];
  95
  96 #define NORMALIZE_RED(pixel)    ((rshift>0) ? ((pixel) & rmask) >> rshift \
  97                                         : ((pixel) & rmask) << -rshift)
  98 #define NORMALIZE_GREEN(pixel)  ((gshift>0) ? ((pixel) & gmask) >> gshift \
  99                                         : ((pixel) & gmask) << -gshift)
 100 #define NORMALIZE_BLUE(pixel)   ((bshift>0) ? ((pixel) & bmask) >> bshift \
 101                                         : ((pixel) & bmask) << -bshift)
 102
 103     for (y = 0; y < image->height; y++) {
 104         for (x = 0; x < image->width; x++) {
 105             pixel = XGetPixel(image, x, y);
 106             *(r++) = NORMALIZE_RED(pixel);
 107             *(g++) = NORMALIZE_GREEN(pixel);
 108             *(b++) = NORMALIZE_BLUE(pixel);
 109         }
 110     }
 111
 112     if (mask && a) {
 113         for (y = 0; y < mask->height; y++) {
 114             for (x = 0; x < mask->width; x++) {
 115                 if (XGetPixel(mask, x, y)) {
 116                     *(a++) = 0xff;
 117                 } else {
 118                     *(a++) = 0xff;
 119                 }
 120             }
 121         }
 122     }
 123     return img;
 124 }
 125
 126
 127
 128 RImage*
 129 RCreateImageFromDrawable(RContext *context, Drawable drawable, Pixmap mask)
 130 {
 131     RImage *image;
 132     XImage *pimg, *mimg;
 133     unsigned int w, h, bar;
 134     int foo;
 135     Window baz;
 136
 137     RErrorString[0] = 0;
 138
 139     assert(drawable!=None);
 140
 141     if (!XGetGeometry(context->dpy, drawable, &baz, &foo, &foo,
 142                       &w, &h, &bar, &bar)) {
 143         printf("wrlib:invalid window or pixmap passed to RCreateImageFromPixmap\n");
 144         return NULL;
 145     }
 146     pimg = XGetImage(context->dpy, drawable, 0, 0, w, h, AllPlanes,
 147                      ZPixmap);
 148
 149     if (!pimg) {
 150         sprintf(RErrorString, "could not get image");
 151         return NULL;
 152     }
 153     mimg = NULL;
 154     if (mask) {
 155         if (XGetGeometry(context->dpy, mask, &baz, &foo, &foo,
 156                           &w, &h, &bar, &bar)) {
 157             mimg = XGetImage(context->dpy, mask, 0, 0, w, h, AllPlanes,
 158                              ZPixmap);
 159         }
 160     }
 161
 162     image = RCreateImageFromXImage(context, pimg, mimg);
 163
 164     XDestroyImage(pimg);
 165     if (mimg)
 166       XDestroyImage(mimg);
 167
 168     return image;
 169 }