source/graphics/imageloader.cpp

   1 #include <msp/core/refptr.h>
   2 #include <msp/io/file.h>
   3 #include <msp/strings/format.h>
   4 #include "imageloader.h"
   5 #ifdef WITH_LIBPNG
   6 #include "png/pngloader.h"
   7 #endif
   8 #ifdef WITH_LIBJPEG
   9 #include "jpeg/jpegloader.h"
  10 #endif
  11 #ifdef WITH_DEVIL
  12 #include "devil/devilloader.h"
  13 #endif
  14 #ifdef WITH_QUARTZ
  15 #include "quartz/quartzloader.h"
  16 #endif
  17
  18 using namespace std;
  19
  20 namespace Msp {
  21 namespace Graphics {
  22
  23 bool ImageLoader::registered_loaders_changed = false;
  24
  25 ImageLoader::ImageLoader():
  26         source(0)
  27 { }
  28
  29 ImageLoader::~ImageLoader()
  30 {
  31         delete source;
  32 }
  33
  34 ImageLoader *ImageLoader::open_file(const string &fn)
  35 {
  36         try
  37         {
  38                 RefPtr<IO::BufferedFile> file = new IO::BufferedFile(fn);
  39                 ImageLoader *loader = open_io(*file);
  40                 loader->source = file.release();
  41                 return loader;
  42         }
  43         catch(const unsupported_image_format &e)
  44         {
  45                 throw unsupported_image_format(format("%s: %s", fn, e.what()));
  46         }
  47 }
  48
  49 ImageLoader *ImageLoader::open_io(IO::Seekable &io)
  50 {
  51 #ifdef WITH_LIBPNG
  52         (void)RegisteredImageLoader<PngLoader>::reg;
  53 #endif
  54 #ifdef WITH_LIBJPEG
  55         (void)RegisteredImageLoader<JpegLoader>::reg;
  56 #endif
  57 #ifdef WITH_DEVIL
  58         (void)RegisteredImageLoader<DevilLoader>::reg;
  59 #endif
  60 #ifdef WITH_QUARTZ
  61         (void)RegisteredImageLoader<QuartzLoader>::reg;
  62 #endif
  63
  64         list<RegisterBase *> &loaders = get_registered_loaders();
  65         if(registered_loaders_changed)
  66         {
  67                 registered_loaders_changed = false;
  68                 loaders.sort(signature_size_compare);
  69         }
  70
  71         if(loaders.empty())
  72                 throw unsupported_image_format("no loaders");
  73
  74         vector<char> sig_buf(loaders.back()->get_signature_size());
  75         unsigned sig_len = io.read(&sig_buf[0], sig_buf.size());
  76         string signature(sig_buf.begin(), sig_buf.end());
  77
  78         ImageLoader *loader = 0;
  79         for(list<RegisterBase *>::const_iterator i=loaders.begin(); (!loader && i!=loaders.end()); ++i)
  80                 if((*i)->detect(signature))
  81                         loader = (*i)->create(io);
  82
  83         io.seek(0, IO::S_BEG);
  84
  85         if(!loader)
  86         {
  87                 string sig_hex;
  88                 for(unsigned i=0; i<sig_len; ++i)
  89                 {
  90                         if(i)
  91                                 sig_hex += ' ';
  92                         sig_hex += format("%02X", static_cast<unsigned char>(sig_buf[i]));
  93                 }
  94                 throw unsupported_image_format(sig_hex);
  95         }
  96
  97         return loader;
  98 }
  99
 100
 101 ImageLoader::RegisterBase::RegisterBase()
 102 {
 103         get_registered_loaders().push_back(this);
 104         registered_loaders_changed = true;
 105 }
 106
 107
 108 list<ImageLoader::RegisterBase *> &ImageLoader::get_registered_loaders()
 109 {
 110         static list<RegisterBase *> regs;
 111         return regs;
 112 }
 113
 114 bool ImageLoader::signature_size_compare(RegisterBase *r1, RegisterBase *r2)
 115 {
 116         return r1->get_signature_size()<r2->get_signature_size();
 117 }
 118
 119 } // namespace Graphics
 120 } // namespace Msp