From bdffd806c3441e1d640c445ff785f5f1ea10298d Mon Sep 17 00:00:00 2001 From: =?utf8?q?V=C3=A1clav=20Slav=C3=ADk?= Date: Sat, 26 Jan 2002 00:19:53 +0000 Subject: [PATCH] modified wxPNGHandler to not use png_struct.jmpbuf (its size is compiler-dependant, so it wasn't possible to use libpng as a DLL, and that's a problem since MGL exports it's own libpng) git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/trunk@13815 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775 --- src/common/imagpng.cpp | 208 ++++++++++++++++++++++++++--------------- 1 file changed, 132 insertions(+), 76 deletions(-) diff --git a/src/common/imagpng.cpp b/src/common/imagpng.cpp index b41838fa22..9320f2f371 100644 --- a/src/common/imagpng.cpp +++ b/src/common/imagpng.cpp @@ -60,38 +60,77 @@ IMPLEMENT_DYNAMIC_CLASS(wxPNGHandler,wxImageHandler) #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" @@ -109,7 +148,11 @@ bool wxPNGHandler::LoadFile( wxImage *image, wxInputStream& stream, bool verbose 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(); @@ -120,21 +163,22 @@ bool wxPNGHandler::LoadFile( wxImage *image, wxInputStream& stream, bool verbose 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; @@ -278,79 +322,91 @@ bool wxPNGHandler::LoadFile( wxImage *image, wxInputStream& stream, bool verbose 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; } -- 2.45.2