source/graphics/quartz/quartzloader.cpp

   1 #include "quartzloader.h"
   2 #include <algorithm>
   3 #include <ApplicationServices/ApplicationServices.h>
   4
   5 using namespace std;
   6
   7 namespace {
   8
   9 size_t get_bytes(void *info, void *buffer, size_t count)
  10 {
  11         Msp::IO::Seekable *io = reinterpret_cast<Msp::IO::Seekable *>(info);
  12         char *cbuf = reinterpret_cast<char *>(buffer);
  13         return io->read(cbuf, count);
  14 }
  15
  16 off_t skip_forward(void *info, off_t count)
  17 {
  18         Msp::IO::Seekable *io = reinterpret_cast<Msp::IO::Seekable *>(info);
  19
  20         off_t i = 0;
  21         char buf[1024];
  22         while(i<count)
  23                 i += io->read(buf, min<unsigned>(sizeof(buf), count-i));
  24
  25         return i;
  26 }
  27
  28 void rewind(void *info)
  29 {
  30         Msp::IO::Seekable *io = reinterpret_cast<Msp::IO::Seekable *>(info);
  31         io->seek(0, Msp::IO::S_BEG);
  32 }
  33
  34 CGDataProviderSequentialCallbacks callbacks =
  35 {
  36         0,
  37         &get_bytes,
  38         &skip_forward,
  39         &rewind,
  40         0
  41 };
  42
  43 } // namespace
  44
  45
  46 namespace Msp {
  47 namespace Graphics {
  48
  49 struct QuartzLoader::Private
  50 {
  51         CGDataProviderRef provider;
  52         CGImageSourceRef source;
  53 };
  54
  55
  56 QuartzLoader::QuartzLoader(IO::Seekable &io):
  57         priv(new Private)
  58 {
  59         priv->provider = CGDataProviderCreateSequential(&io, &callbacks);
  60         priv->source = CGImageSourceCreateWithDataProvider(priv->provider, 0);
  61 }
  62
  63 QuartzLoader::~QuartzLoader()
  64 {
  65         CFRelease(priv->source);
  66         CFRelease(priv->provider);
  67         delete priv;
  68 }
  69
  70 bool QuartzLoader::detect(const string &sig)
  71 {
  72         CGImageSourceRef source = CGImageSourceCreateIncremental(0);
  73         CFDataRef data = CFDataCreate(0, reinterpret_cast<const UInt8 *>(sig.data()), sig.size());
  74         CGImageSourceUpdateData(source, data, false);
  75         CGImageSourceStatus status = CGImageSourceGetStatus(source);
  76         CFRelease(data);
  77         CFRelease(source);
  78
  79         return status==kCGImageStatusIncomplete || status==kCGImageStatusReadingHeader;
  80 }
  81
  82 void QuartzLoader::load_(Image::Data &data)
  83 {
  84         CGImageRef image = CGImageSourceCreateImageAtIndex(priv->source, 0, 0);
  85         if(!image)
  86                 throw bad_image_data("null image");
  87
  88         try
  89         {
  90                 data.width = CGImageGetWidth(image);
  91                 data.height = CGImageGetHeight(image);
  92                 data.stride = CGImageGetBytesPerRow(image);
  93
  94                 CGColorSpaceRef color = CGImageGetColorSpace(image);
  95                 CGColorSpaceModel model = CGColorSpaceGetModel(color);
  96                 CGImageAlphaInfo alpha = CGImageGetAlphaInfo(image);
  97                 if(model==kCGColorSpaceModelRGB)
  98                 {
  99                         if(alpha==kCGImageAlphaLast)
 100                                 data.fmt = RGBA;
 101                         else if(alpha==kCGImageAlphaNoneSkipLast || alpha==kCGImageAlphaNoneSkipFirst)
 102                                 data.fmt = RGBX;
 103                         else if(alpha==kCGImageAlphaNone)
 104                                 data.fmt = RGB;
 105                         else
 106                                 throw unsupported_image_format("unknown alpha mode");
 107                 }
 108                 else
 109                         throw unsupported_image_format("unknown colorspace");
 110         }
 111         catch(...)
 112         {
 113                 CFRelease(image);
 114                 throw;
 115         }
 116 }
 117
 118 void QuartzLoader::load_(Image::Data &data)
 119 {
 120         CGDataProviderRef dp = CGImageGetDataProvider(image);
 121         CFDataRef image_data = CGDataProviderCopyData(dp);
 122         unsigned offset = (alpha==kCGImageAlphaNoneSkipFirst);
 123         CFRange range = CFRangeMake(offset, CFDataGetLength(image_data)-offset);
 124         CFDataGetBytes(image_data, range, reinterpret_cast<UInt8 *>(data.pixels));
 125         CFRelease(image_data);
 126
 127         CFRelease(image);
 128 }
 129
 130 } // namespace Graphics
 131 } // namespace Msp