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