source/graphics/quartz/quartzloader.cpp

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