fixing bug 1841377

[wxWidgets.git] / src / common / imagjpeg.cpp

diff --git a/src/common/imagjpeg.cpp b/src/common/imagjpeg.cpp
index c6326116c5752f38d4404d475b58b02f1a79c117..d045596065270a56b7da4401918e00eb83abd49c 100644 (file)
--- a/src/common/imagjpeg.cpp
+++ b/src/common/imagjpeg.cpp
@@ -100,6 +100,9 @@ typedef struct {
 
 typedef wx_source_mgr * wx_src_ptr;
 
+extern "C"
+{
+
 CPP_METHODDEF(void) wx_init_source ( j_decompress_ptr WXUNUSED(cinfo) )
 {
 }
@@ -206,6 +209,8 @@ void wx_jpeg_io_src( j_decompress_ptr cinfo, wxInputStream& infile )
     src->pub.term_source = wx_term_source;
 }
 
+} // extern "C"
+
 static inline void wx_cmyk_to_rgb(unsigned char* rgb, const unsigned char* cmyk)
 {
     register int k = 255 - cmyk[3];
@@ -305,6 +310,17 @@ bool wxJPEGHandler::LoadFile( wxImage *image, wxInputStream& stream, bool verbos
         }
     }
 
+    // set up resolution if available: it's part of optional JFIF APP0 chunk
+    if ( cinfo.saw_JFIF_marker )
+    {
+        image->SetOption(wxIMAGE_OPTION_RESOLUTIONX, cinfo.X_density);
+        image->SetOption(wxIMAGE_OPTION_RESOLUTIONY, cinfo.Y_density);
+
+        // we use the same values for this option as libjpeg so we don't need
+        // any conversion here
+        image->SetOption(wxIMAGE_OPTION_RESOLUTIONUNIT, cinfo.density_unit);
+    }
+
     jpeg_finish_decompress( &cinfo );
     jpeg_destroy_decompress( &cinfo );
     return true;
@@ -321,6 +337,9 @@ typedef wx_destination_mgr * wx_dest_ptr;
 
 #define OUTPUT_BUF_SIZE  4096    /* choose an efficiently fwrite'able size */
 
+extern "C"
+{
+
 CPP_METHODDEF(void) wx_init_destination (j_compress_ptr cinfo)
 {
     wx_dest_ptr dest = (wx_dest_ptr) cinfo->dest;
@@ -369,6 +388,8 @@ GLOBAL(void) wx_jpeg_io_dest (j_compress_ptr cinfo, wxOutputStream& outfile)
     dest->stream = &outfile;
 }
 
+} // extern "C"
+
 bool wxJPEGHandler::SaveFile( wxImage *image, wxOutputStream& stream, bool verbose )
 {
     struct jpeg_compress_struct cinfo;
@@ -414,37 +435,16 @@ bool wxJPEGHandler::SaveFile( wxImage *image, wxOutputStream& stream, bool verbo
         jpeg_set_quality(&cinfo, image->GetOptionInt(wxIMAGE_OPTION_QUALITY), TRUE);
 
     // set the resolution fields in the output file
-    UINT16 resX,
-           resY;
-    if ( image->HasOption(wxIMAGE_OPTION_RESOLUTIONX) &&
-         image->HasOption(wxIMAGE_OPTION_RESOLUTIONY) )
-    {
-        resX = (UINT16)image->GetOptionInt(wxIMAGE_OPTION_RESOLUTIONX);
-        resY = (UINT16)image->GetOptionInt(wxIMAGE_OPTION_RESOLUTIONY);
-    }
-    else if ( image->HasOption(wxIMAGE_OPTION_RESOLUTION) )
-    {
-        resX =
-        resY = (UINT16)image->GetOptionInt(wxIMAGE_OPTION_RESOLUTION);
-    }
-    else
-    {
-        resX =
-        resY = 0;
-    }
-
-    if ( resX && resY )
+    int resX, resY;
+    wxImageResolution res = GetResolutionFromOptions(*image, &resX, &resY);
+    if ( res != wxIMAGE_RESOLUTION_NONE )
     {
         cinfo.X_density = resX;
         cinfo.Y_density = resY;
-    }
 
-    // sets the resolution unit field in the output file
-    // wxIMAGE_RESOLUTION_INCHES for inches
-    // wxIMAGE_RESOLUTION_CM for centimeters
-    if ( image->HasOption(wxIMAGE_OPTION_RESOLUTIONUNIT) )
-    {
-        cinfo.density_unit = (UINT8)image->GetOptionInt(wxIMAGE_OPTION_RESOLUTIONUNIT);
+        // it so happens that wxIMAGE_RESOLUTION_INCHES/CM values are the same
+        // ones as used by libjpeg, so we can assign them directly
+        cinfo.density_unit = res;
     }
 
     jpeg_start_compress(&cinfo, TRUE);