applying patch, fixes #10523

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

diff --git a/src/common/imagjpeg.cpp b/src/common/imagjpeg.cpp
index 64cc2b859d3a688e9b6522eebaaaad1ceadb5e23..f14027cb78d4bd0ed122b7e051eef07a2e646759 100644 (file)
--- a/src/common/imagjpeg.cpp
+++ b/src/common/imagjpeg.cpp
@@ -57,10 +57,6 @@ typedef boolean wxjpeg_boolean;
 // For JPEG library error handling
 #include <setjmp.h>
 
-#ifdef __SALFORDC__
-#undef FAR
-#endif
-
 // ----------------------------------------------------------------------------
 // types
 // ----------------------------------------------------------------------------
@@ -100,6 +96,9 @@ typedef struct {
 
 typedef wx_source_mgr * wx_src_ptr;
 
+extern "C"
+{
+
 CPP_METHODDEF(void) wx_init_source ( j_decompress_ptr WXUNUSED(cinfo) )
 {
 }
@@ -149,14 +148,11 @@ CPP_METHODDEF(void) wx_term_source ( j_decompress_ptr cinfo )
 
 // JPEG error manager:
 
-struct wx_error_mgr {
-  struct jpeg_error_mgr pub;    /* "public" fields */
-
+struct wx_error_mgr : public jpeg_error_mgr
+{
   jmp_buf setjmp_buffer;    /* for return to caller */
 };
 
-typedef struct wx_error_mgr * wx_error_ptr;
-
 /*
  * Here's the routine that will replace the standard error_exit method:
  */
@@ -164,14 +160,14 @@ typedef struct wx_error_mgr * wx_error_ptr;
 CPP_METHODDEF(void) wx_error_exit (j_common_ptr cinfo)
 {
   /* cinfo->err really points to a wx_error_mgr struct, so coerce pointer */
-  wx_error_ptr myerr = (wx_error_ptr) cinfo->err;
+  wx_error_mgr * const jerr = (wx_error_mgr *) cinfo->err;
 
   /* Always display the message. */
   /* We could postpone this until after returning, if we chose. */
   (*cinfo->err->output_message) (cinfo);
 
   /* Return control to the setjmp point */
-  longjmp(myerr->setjmp_buffer, 1);
+  longjmp(jerr->setjmp_buffer, 1);
 }
 
 /*
@@ -206,6 +202,8 @@ 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];
@@ -230,13 +228,19 @@ static inline void wx_cmyk_to_rgb(unsigned char* rgb, const unsigned char* cmyk)
 
 bool wxJPEGHandler::LoadFile( wxImage *image, wxInputStream& stream, bool verbose, int WXUNUSED(index) )
 {
+    wxCHECK_MSG( image, false, "NULL image pointer" );
+
     struct jpeg_decompress_struct cinfo;
-    struct wx_error_mgr jerr;
+    wx_error_mgr jerr;
     unsigned char *ptr;
 
+    // save this before calling Destroy()
+    const unsigned maxWidth = image->GetOptionInt(wxIMAGE_OPTION_MAX_WIDTH),
+                   maxHeight = image->GetOptionInt(wxIMAGE_OPTION_MAX_HEIGHT);
     image->Destroy();
-    cinfo.err = jpeg_std_error( &jerr.pub );
-    jerr.pub.error_exit = wx_error_exit;
+
+    cinfo.err = jpeg_std_error( &jerr );
+    jerr.error_exit = wx_error_exit;
 
     if (!verbose)
         cinfo.err->output_message = wx_ignore_message;
@@ -270,9 +274,20 @@ bool wxJPEGHandler::LoadFile( wxImage *image, wxInputStream& stream, bool verbos
         bytesPerPixel = 3;
     }
 
+    // scale the picture to fit in the specified max size if necessary
+    if ( maxWidth > 0 || maxHeight > 0 )
+    {
+        unsigned& scale = cinfo.scale_denom;
+        while ( (maxWidth && (cinfo.image_width / scale > maxWidth)) ||
+                    (maxHeight && (cinfo.image_height / scale > maxHeight)) )
+        {
+            scale *= 2;
+        }
+    }
+
     jpeg_start_decompress( &cinfo );
 
-    image->Create( cinfo.image_width, cinfo.image_height );
+    image->Create( cinfo.output_width, cinfo.output_height );
     if (!image->Ok()) {
         jpeg_finish_decompress( &cinfo );
         jpeg_destroy_decompress( &cinfo );
@@ -305,6 +320,17 @@ 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 +347,9 @@ 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;
@@ -369,16 +398,18 @@ 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;
-    struct wx_error_mgr jerr;
+    wx_error_mgr jerr;
     JSAMPROW row_pointer[1];    /* pointer to JSAMPLE row[s] */
     JSAMPLE *image_buffer;
     int stride;                /* physical row width in image buffer */
 
-    cinfo.err = jpeg_std_error(&jerr.pub);
-    jerr.pub.error_exit = wx_error_exit;
+    cinfo.err = jpeg_std_error(&jerr);
+    jerr.error_exit = wx_error_exit;
 
     if (!verbose)
         cinfo.err->output_message = wx_ignore_message;