wrlib/load_magick.c

   1 /* load_magick.c - load image file using ImageMagick
   2  *
   3  * Raster graphics library
   4  *
   5  * Copyright (c) 2014 Window Maker Team
   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., 51 Franklin St, Fifth Floor, Boston,
  20  *  MA 02110-1301, USA.
  21  */
  22
  23 #include "config.h"
  24
  25 #ifdef USE_MAGICK
  26 #if USE_MAGICK < 7
  27 #include <wand/magick_wand.h>
  28 #else
  29 #include <MagickWand/MagickWand.h>
  30 #endif
  31 #endif
  32
  33 #include "wraster.h"
  34 #include "imgformat.h"
  35 #include "wr_i18n.h"
  36
  37
  38 static int RInitMagickIfNeeded(void);
  39
  40
  41 RImage *RLoadMagick(const char *file_name)
  42 {
  43         RImage *image = NULL;
  44         unsigned char *ptr;
  45         unsigned long w,h;
  46         MagickWand *m_wand = NULL;
  47         MagickBooleanType mrc;
  48         MagickBooleanType hasAlfa;
  49         PixelWand *bg_wand = NULL;
  50
  51         if (RInitMagickIfNeeded()) {
  52                 RErrorCode = RERR_BADFORMAT;
  53                 return NULL;
  54         }
  55
  56         /* Create a wand */
  57         m_wand = NewMagickWand();
  58
  59         /* set the default background as transparent */
  60         bg_wand = NewPixelWand();
  61         PixelSetColor(bg_wand, "none");
  62         MagickSetBackgroundColor(m_wand, bg_wand);
  63
  64         /* Read the input image */
  65         if (!MagickReadImage(m_wand, file_name)) {
  66                 RErrorCode = RERR_BADIMAGEFILE;
  67                 goto bye;
  68         }
  69
  70         w = MagickGetImageWidth(m_wand);
  71         h = MagickGetImageHeight(m_wand);
  72
  73         hasAlfa = MagickGetImageAlphaChannel(m_wand);
  74
  75         image = RCreateImage(w, h, (unsigned int) hasAlfa);
  76         if (!image) {
  77                 RErrorCode = RERR_NOMEMORY;
  78                 goto bye;
  79         }
  80
  81         ptr = image->data;
  82         if (hasAlfa == MagickFalse)
  83                 mrc = MagickExportImagePixels(m_wand, 0, 0, (size_t)w, (size_t)h, "RGB", CharPixel, ptr);
  84         else
  85                 mrc = MagickExportImagePixels(m_wand, 0, 0, (size_t)w, (size_t)h, "RGBA", CharPixel, ptr);
  86
  87         if (mrc == MagickFalse) {
  88                 RErrorCode = RERR_BADIMAGEFILE;
  89                 RReleaseImage(image);
  90                 image = NULL;
  91                 goto bye;
  92         }
  93
  94 bye:
  95         /* Tidy up */
  96         DestroyPixelWand(bg_wand);
  97         MagickClearException(m_wand);
  98         DestroyMagickWand(m_wand);
  99
 100         return image;
 101 }
 102
 103 /* Track the state of the library in memory */
 104 static enum {
 105         MW_NotReady,
 106         MW_Ready
 107 } magick_state;
 108
 109 /*
 110  * Initialise MagickWand, but only if it was not already done
 111  *
 112  * Return ok(0) when MagickWand is usable and fail(!0) if not usable
 113  */
 114 static int RInitMagickIfNeeded(void)
 115 {
 116         if (magick_state == MW_NotReady) {
 117                 MagickWandGenesis();
 118                 magick_state = MW_Ready;
 119         }
 120
 121         return 0;
 122 }
 123
 124 void RReleaseMagick(void)
 125 {
 126         if (magick_state == MW_Ready) {
 127                 MagickWandTerminus();
 128                 magick_state = MW_NotReady;
 129         }
 130 }