#define PNGLINKAGEMODE LINKAGEMODE
#endif
+
+// VS: wxPNGInfoStruct declared below is a hack that needs some explanation.
+// First, let me describe what's the problem: libpng uses jmp_buf in
+// its png_struct structure. Unfortunately, this structure is
+// compiler-specific and may vary in size, so if you use libpng compiled
+// as DLL with another compiler than the main executable, it may not work
+// (this is for example the case with wxMGL port and SciTech MGL library
+// that provides custom runtime-loadable libpng implementation with jmpbuf
+// disabled altogether). Luckily, it is still possible to use setjmp() &
+// longjmp() as long as the structure is not part of png_struct.
+//
+// Sadly, there's no clean way to attach user-defined data to png_struct.
+// There is only one customizable place, png_struct.io_ptr, which is meant
+// only for I/O routines and is set with png_set_read_fn or
+// png_set_write_fn. The hacky part is that we use io_ptr to store
+// a pointer to wxPNGInfoStruct that holds I/O structures _and_ jmp_buf.
+
+struct wxPNGInfoStruct
+{
+ jmp_buf jmpbuf;
+ bool verbose;
+
+ union
+ {
+ wxInputStream *in;
+ wxOutputStream *out;
+ } stream;
+};
+
+#define WX_PNG_INFO(png_ptr) ((wxPNGInfoStruct*)png_get_io_ptr(png_ptr))
+
+
extern "C"
{
void PNGLINKAGEMODE _PNG_stream_reader( png_structp png_ptr, png_bytep data, png_size_t length )
{
- ((wxInputStream*) png_get_io_ptr( png_ptr )) -> Read(data, length);
+ WX_PNG_INFO(png_ptr)->stream.in->Read(data, length);
}
void PNGLINKAGEMODE _PNG_stream_writer( png_structp png_ptr, png_bytep data, png_size_t length )
{
- ((wxOutputStream*) png_get_io_ptr( png_ptr )) -> Write(data, length);
+ WX_PNG_INFO(png_ptr)->stream.out->Write(data, length);
}
// from pngerror.c
// so that the libpng doesn't send anything on stderr
void
-PNGLINKAGEMODE png_silent_error(png_structp png_ptr, png_const_charp WXUNUSED(message))
+PNGLINKAGEMODE wx_png_error(png_structp png_ptr, png_const_charp message)
{
+ wxPNGInfoStruct *info = WX_PNG_INFO(png_ptr);
+ if ( info->verbose )
+ wxLogError(wxString(message));
+
#ifdef USE_FAR_KEYWORD
- {
- jmp_buf jmpbuf;
- png_memcpy(jmpbuf,png_ptr->jmpbuf,sizeof(jmp_buf));
- longjmp(jmpbuf, 1);
- }
+ {
+ jmp_buf jmpbuf;
+ png_memcpy(jmpbuf,info->jmpbuf,sizeof(jmp_buf));
+ longjmp(jmpbuf, 1);
+ }
#else
- longjmp(png_ptr->jmpbuf, 1);
+ longjmp(info->jmpbuf, 1);
#endif
}
void
-PNGLINKAGEMODE png_silent_warning(png_structp WXUNUSED(png_ptr), png_const_charp WXUNUSED(message))
+PNGLINKAGEMODE wx_png_warning(png_structp png_ptr, png_const_charp message)
{
+ wxPNGInfoStruct *info = WX_PNG_INFO(png_ptr);
+ if ( info->verbose )
+ wxLogWarning(wxString(message));
}
} // extern "C"
unsigned char **lines;
unsigned int i;
- png_infop info_ptr = (png_infop) NULL;
+ png_infop info_ptr = (png_infop) NULL;
+ wxPNGInfoStruct wxinfo;
+
+ wxinfo.verbose = verbose;
+ wxinfo.stream.in = &stream;
image->Destroy();
if (!png_ptr)
goto error_nolines;
- // the file example.c explain how to guess if the stream is a png image
- if (!verbose) png_set_error_fn(png_ptr, (png_voidp)NULL, png_silent_error, png_silent_warning);
+ png_set_error_fn(png_ptr, (png_voidp)NULL, wx_png_error, wx_png_warning);
+
+ // NB: please see the comment near wxPNGInfoStruct declaration for
+ // explanation why this line is mandatory
+ png_set_read_fn( png_ptr, &wxinfo, _PNG_stream_reader);
info_ptr = png_create_info_struct( png_ptr );
if (!info_ptr)
goto error_nolines;
- if (setjmp(png_ptr->jmpbuf))
+ if (setjmp(wxinfo.jmpbuf))
goto error_nolines;
if (info_ptr->color_type == PNG_COLOR_TYPE_RGB_ALPHA)
goto error_nolines;
- png_set_read_fn( png_ptr, &stream, _PNG_stream_reader);
-
png_uint_32 width,height;
int bit_depth,color_type,interlace_type;
bool wxPNGHandler::SaveFile( wxImage *image, wxOutputStream& stream, bool verbose )
{
- {
- png_structp png_ptr = png_create_write_struct( PNG_LIBPNG_VER_STRING, NULL, NULL, NULL);
- if (!png_ptr)
- {
- return FALSE;
- }
+ wxPNGInfoStruct wxinfo;
- if (!verbose) png_set_error_fn(png_ptr, (png_voidp)NULL, png_silent_error, png_silent_warning);
+ wxinfo.verbose = verbose;
+ wxinfo.stream.out = &stream;
- png_infop info_ptr = png_create_info_struct(png_ptr);
- if (info_ptr == NULL)
- {
- png_destroy_write_struct( &png_ptr, (png_infopp)NULL );
- return FALSE;
- }
+ png_structp png_ptr = png_create_write_struct( PNG_LIBPNG_VER_STRING, NULL, NULL, NULL);
+ if (!png_ptr)
+ {
+ if (verbose)
+ wxLogError(_("Couldn't save PNG image."));
+ return FALSE;
+ }
- if (setjmp(png_ptr->jmpbuf))
- {
- png_destroy_write_struct( &png_ptr, (png_infopp)NULL );
- return FALSE;
- }
+ png_set_error_fn(png_ptr, (png_voidp)NULL, wx_png_error, wx_png_warning);
- png_set_write_fn( png_ptr, &stream, _PNG_stream_writer, NULL);
+ png_infop info_ptr = png_create_info_struct(png_ptr);
+ if (info_ptr == NULL)
+ {
+ png_destroy_write_struct( &png_ptr, (png_infopp)NULL );
+ if (verbose)
+ wxLogError(_("Couldn't save PNG image."));
+ return FALSE;
+ }
- png_set_IHDR( png_ptr, info_ptr, image->GetWidth(), image->GetHeight(), 8,
- PNG_COLOR_TYPE_RGB_ALPHA, PNG_INTERLACE_NONE,
- PNG_COMPRESSION_TYPE_BASE, PNG_FILTER_TYPE_BASE);
+ if (setjmp(wxinfo.jmpbuf))
+ {
+ png_destroy_write_struct( &png_ptr, (png_infopp)NULL );
+ if (verbose)
+ wxLogError(_("Couldn't save PNG image."));
+ return FALSE;
+ }
- png_color_8 sig_bit;
- sig_bit.red = 8;
- sig_bit.green = 8;
- sig_bit.blue = 8;
- sig_bit.alpha = 8;
- png_set_sBIT( png_ptr, info_ptr, &sig_bit );
- png_write_info( png_ptr, info_ptr );
- png_set_shift( png_ptr, &sig_bit );
- png_set_packing( png_ptr );
+ // NB: please see the comment near wxPNGInfoStruct declaration for
+ // explanation why this line is mandatory
+ png_set_write_fn( png_ptr, &wxinfo, _PNG_stream_writer, NULL);
+
+ png_set_IHDR( png_ptr, info_ptr, image->GetWidth(), image->GetHeight(), 8,
+ PNG_COLOR_TYPE_RGB_ALPHA, PNG_INTERLACE_NONE,
+ PNG_COMPRESSION_TYPE_BASE, PNG_FILTER_TYPE_BASE);
+
+ png_color_8 sig_bit;
+ sig_bit.red = 8;
+ sig_bit.green = 8;
+ sig_bit.blue = 8;
+ sig_bit.alpha = 8;
+ png_set_sBIT( png_ptr, info_ptr, &sig_bit );
+ png_write_info( png_ptr, info_ptr );
+ png_set_shift( png_ptr, &sig_bit );
+ png_set_packing( png_ptr );
- unsigned char *data = (unsigned char *)malloc( image->GetWidth()*4 );
- if (!data)
- {
- png_destroy_write_struct( &png_ptr, (png_infopp)NULL );
- return FALSE;
- }
+ unsigned char *data = (unsigned char *)malloc( image->GetWidth()*4 );
+ if (!data)
+ {
+ png_destroy_write_struct( &png_ptr, (png_infopp)NULL );
+ return FALSE;
+ }
- for (int y = 0; y < image->GetHeight(); y++)
+ for (int y = 0; y < image->GetHeight(); y++)
+ {
+ unsigned char *ptr = image->GetData() + (y * image->GetWidth() * 3);
+ for (int x = 0; x < image->GetWidth(); x++)
{
- unsigned char *ptr = image->GetData() + (y * image->GetWidth() * 3);
- for (int x = 0; x < image->GetWidth(); x++)
+ data[(x << 2) + 0] = *ptr++;
+ data[(x << 2) + 1] = *ptr++;
+ data[(x << 2) + 2] = *ptr++;
+ if (( !image->HasMask() ) || \
+ (data[(x << 2) + 0] != image->GetMaskRed()) || \
+ (data[(x << 2) + 1] != image->GetMaskGreen()) || \
+ (data[(x << 2) + 2] != image->GetMaskBlue()))
{
- data[(x << 2) + 0] = *ptr++;
- data[(x << 2) + 1] = *ptr++;
- data[(x << 2) + 2] = *ptr++;
- if (( !image->HasMask() ) || \
- (data[(x << 2) + 0] != image->GetMaskRed()) || \
- (data[(x << 2) + 1] != image->GetMaskGreen()) || \
- (data[(x << 2) + 2] != image->GetMaskBlue()))
- {
- data[(x << 2) + 3] = 255;
- }
- else
- {
- data[(x << 2) + 3] = 0;
- }
+ data[(x << 2) + 3] = 255;
+ }
+ else
+ {
+ data[(x << 2) + 3] = 0;
}
- png_bytep row_ptr = data;
- png_write_rows( png_ptr, &row_ptr, 1 );
}
-
- free(data);
- png_write_end( png_ptr, info_ptr );
- png_destroy_write_struct( &png_ptr, (png_infopp)&info_ptr );
+ png_bytep row_ptr = data;
+ png_write_rows( png_ptr, &row_ptr, 1 );
}
+
+ free(data);
+ png_write_end( png_ptr, info_ptr );
+ png_destroy_write_struct( &png_ptr, (png_infopp)&info_ptr );
+
return TRUE;
}
{
unsigned char hdr[4];
- stream.Read(hdr, 4);
- stream.SeekI(-4, wxFromCurrent);
- return (hdr[0] == 0x89 && hdr[1] == 'P' && hdr[2] == 'N' && hdr[3] == 'G');
+ if ( !stream.Read(hdr, WXSIZEOF(hdr)) )
+ return FALSE;
+
+ return memcmp(hdr, "\211PNG", WXSIZEOF(hdr)) == 0;
}
#endif // wxUSE_STREAMS
projects / wxWidgets.git / blobdiff