X-Git-Url: https://git.saurik.com/wxWidgets.git/blobdiff_plain/4d97d44e14d05f9a6da2c5414209b3858d47a520..673e6120795e4e1f3a49157581925a5ee14bf5a9:/src/common/imagpng.cpp diff --git a/src/common/imagpng.cpp b/src/common/imagpng.cpp index 016e594e2b..1b8e201718 100644 --- a/src/common/imagpng.cpp +++ b/src/common/imagpng.cpp @@ -1,5 +1,5 @@ ///////////////////////////////////////////////////////////////////////////// -// Name: imagepng.cpp +// Name: src/common/imagepng.cpp // Purpose: wxImage PNG handler // Author: Robert Roebling // RCS-ID: $Id$ @@ -7,10 +7,18 @@ // Licence: wxWindows licence ///////////////////////////////////////////////////////////////////////////// +// ============================================================================ +// declarations +// ============================================================================ + #ifdef __GNUG__ #pragma implementation "imagpng.h" #endif +// ---------------------------------------------------------------------------- +// headers +// ---------------------------------------------------------------------------- + // For compilers that support precompilation, includes "wx.h". #include "wx/wxprec.h" @@ -44,55 +52,399 @@ #endif #endif -#ifdef __WXMSW__ -#include -#endif +// ---------------------------------------------------------------------------- +// constants +// ---------------------------------------------------------------------------- -//----------------------------------------------------------------------------- -// wxPNGHandler -//----------------------------------------------------------------------------- +// image can not have any transparent pixels at all, have only 100% opaque +// and/or 100% transparent pixels in which case a simple mask is enough to +// store this information in wxImage or have a real alpha channel in which case +// we need to have it in wxImage as well +enum Transparency +{ + Transparency_None, + Transparency_Mask, + Transparency_Alpha +}; -IMPLEMENT_DYNAMIC_CLASS(wxPNGHandler,wxImageHandler) +// ---------------------------------------------------------------------------- +// local functions +// ---------------------------------------------------------------------------- -#if wxUSE_LIBPNG +// return the kind of transparency needed for this image assuming that it does +// have transparent pixels, i.e. either Transparency_Alpha or Transparency_Mask +static Transparency +CheckTransparency(const unsigned char *ptr, + png_uint_32 x, png_uint_32 y, png_uint_32 w, png_uint_32 h); -#if defined(__VISAGECPP__) -#define PNGLINKAGEMODE _Optlink -#elif defined(__WATCOMC__) && !defined(__DOS__) -#define PNGLINKAGEMODE _cdecl -#else -#define PNGLINKAGEMODE +// init the alpha channel for the image and fill it with 1s up to (x, y) +static unsigned char *InitAlpha(wxImage *image, png_uint_32 x, png_uint_32 y); + +// find a free colour for the mask in the PNG data array +static void +FindMaskColour(unsigned char **lines, png_uint_32 width, png_uint_32 height, + unsigned char& rMask, unsigned char& gMask, unsigned char& bMask); + +// ============================================================================ +// wxPNGHandler implementation +// ============================================================================ + +IMPLEMENT_DYNAMIC_CLASS(wxPNGHandler,wxImageHandler) + +#if wxUSE_STREAMS + +#ifndef PNGLINKAGEMODE + #ifdef __WATCOMC__ + // we need an explicit cdecl for Watcom, at least according to + // + // http://sf.net/tracker/index.php?func=detail&aid=651492&group_id=9863&atid=109863 + // + // more testing is needed for this however, please remove this comment + // if you can confirm that my fix works with Watcom 11 + #define PNGLINKAGEMODE cdecl + #else + #define PNGLINKAGEMODE LINKAGEMODE + #endif #endif -static void PNGLINKAGEMODE _PNG_stream_reader( png_structp png_ptr, png_bytep data, png_size_t length ) + +// 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 { - ((wxInputStream*) png_get_io_ptr( png_ptr )) -> Read(data, length); + jmp_buf jmpbuf; + bool verbose; + + union + { + wxInputStream *in; + wxOutputStream *out; + } stream; +}; + +#define WX_PNG_INFO(png_ptr) ((wxPNGInfoStruct*)png_get_io_ptr(png_ptr)) + +// ---------------------------------------------------------------------------- +// helper functions +// ---------------------------------------------------------------------------- + +extern "C" +{ + +void PNGLINKAGEMODE _PNG_stream_reader( png_structp png_ptr, png_bytep data, png_size_t length ) +{ + WX_PNG_INFO(png_ptr)->stream.in->Read(data, length); } -static void PNGLINKAGEMODE _PNG_stream_writer( png_structp png_ptr, png_bytep data, png_size_t 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::FromAscii(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::FromAscii(message) ); +} + +} // extern "C" + +// ---------------------------------------------------------------------------- +// LoadFile() helpers +// ---------------------------------------------------------------------------- + +Transparency +CheckTransparency(const unsigned char *ptr, + png_uint_32 x, png_uint_32 y, png_uint_32 w, png_uint_32 h) +{ + // suppose that a mask will suffice + Transparency transparency = Transparency_Mask; + + // and check all the remaining alpha values to see if it does + unsigned char a2; + unsigned const char *ptr2 = ptr; + for ( png_uint_32 y2 = y; y2 < h; y2++ ) + { + for ( png_uint_32 x2 = x + 1; x2 < w; x2++ ) + { + // skip the grey byte + a2 = *++ptr2; + + if ( a2 && a2 != 0xff ) + { + // not fully opeaque nor fully transparent, hence need alpha + transparency = Transparency_Alpha; + break; + } + + ++ptr2; + } + + if ( transparency == Transparency_Alpha ) + { + // no need to continue + break; + } + } + + return transparency; +} + +unsigned char *InitAlpha(wxImage *image, png_uint_32 x, png_uint_32 y) +{ + // create alpha channel + image->SetAlpha(); + + unsigned char *alpha = image->GetAlpha(); + + // set alpha for the pixels we had so far + for ( png_uint_32 y2 = 0; y2 <= y; y2++ ) + { + for ( png_uint_32 x2 = 0; x2 < x; x2++ ) + { + // all the previous pixels were opaque + *alpha++ = 0xff; + } + } + + return alpha; +} + +void +FindMaskColour(unsigned char **lines, png_uint_32 width, png_uint_32 height, + unsigned char& rMask, unsigned char& gMask, unsigned char& bMask) +{ + // choosing the colour for the mask is more + // difficult: we need to iterate over the entire + // image for this in order to choose an unused + // colour (this is not very efficient but what else + // can we do?) + wxImageHistogram h; + unsigned nentries = 0; + unsigned char r2, g2, b2; + for ( png_uint_32 y2 = 0; y2 < height; y2++ ) + { + const unsigned char *p = lines[y2]; + for ( png_uint_32 x2 = 0; x2 < width; x2++ ) + { + r2 = *p++; + g2 = *p++; + b2 = *p++; + + wxImageHistogramEntry& + entry = h[wxImageHistogram:: MakeKey(r2, g2, b2)]; + + if ( entry.value++ == 0 ) + entry.index = nentries++; + } + } + + if ( !h.FindFirstUnusedColour(&rMask, &gMask, &bMask) ) + { + wxLogWarning(_("Too many colours in PNG, the image may be slightly blurred.")); + + // use a fixed mask colour and we'll fudge + // the real pixels with this colour (see + // below) + rMask = 0xfe; + gMask = 0; + bMask = 0xff; + } +} + +// ---------------------------------------------------------------------------- +// reading PNGs +// ---------------------------------------------------------------------------- + +bool wxPNGHandler::DoCanRead( wxInputStream& stream ) +{ + unsigned char hdr[4]; + + if ( !stream.Read(hdr, WXSIZEOF(hdr)) ) + return FALSE; + + return memcmp(hdr, "\211PNG", WXSIZEOF(hdr)) == 0; +} + +// convert data from RGB to wxImage format +static +void CopyDataFromPNG(wxImage *image, + unsigned char **lines, + png_uint_32 width, + png_uint_32 height, + int color_type) +{ + Transparency transparency = Transparency_None; + + // only non NULL if transparency == Transparency_Alpha + unsigned char *alpha = NULL; + + // RGB of the mask colour if transparency == Transparency_Mask + // (but init them anyhow to avoid compiler warnings) + unsigned char rMask = 0, + gMask = 0, + bMask = 0; + + unsigned char *ptrDst = image->GetData(); + if ( !(color_type & PNG_COLOR_MASK_COLOR) ) + { + // grey image: GAGAGA... where G == grey component and A == alpha + for ( png_uint_32 y = 0; y < height; y++ ) + { + const unsigned char *ptrSrc = lines[y]; + for ( png_uint_32 x = 0; x < width; x++ ) + { + unsigned char g = *ptrSrc++; + unsigned char a = *ptrSrc++; + + // the first time we encounter a transparent pixel we must + // decide about what to do about them + if ( a != 0xff && transparency == Transparency_None ) + { + // we'll need at least the mask for this image and + // maybe even full alpha channel info: the former is + // only enough if we have alpha values of 0 and 0xff + // only, otherwisewe need the latter + transparency = CheckTransparency(ptrSrc, x, y, + width, height); + + if ( transparency == Transparency_Mask ) + { + // let's choose this colour for the mask: this is + // not a problem here as all the other pixels are + // grey, i.e. R == G == B which is not the case for + // this one so no confusion is possible + rMask = 0xff; + gMask = 0; + bMask = 0xff; + } + else // transparency == Transparency_Alpha + { + alpha = InitAlpha(image, x, y); + } + } + + switch ( transparency ) + { + case Transparency_Alpha: + *alpha++ = a; + // fall through + + case Transparency_None: + *ptrDst++ = g; + *ptrDst++ = g; + *ptrDst++ = g; + break; + + case Transparency_Mask: + *ptrDst++ = rMask; + *ptrDst++ = bMask; + *ptrDst++ = gMask; + } + } + } + } + else // colour image: RGBRGB... + { + for ( png_uint_32 y = 0; y < height; y++ ) + { + const unsigned char *ptrSrc = lines[y]; + for ( png_uint_32 x = 0; x < width; x++ ) + { + unsigned char r = *ptrSrc++; + unsigned char g = *ptrSrc++; + unsigned char b = *ptrSrc++; + unsigned char a = *ptrSrc++; + + // the logic here is the same as for the grey case except + // where noted + if ( a != 0xff && transparency == Transparency_None ) + { + transparency = CheckTransparency(ptrSrc, x, y, + width, height); + + if ( transparency == Transparency_Mask ) + { + FindMaskColour(lines, width, height, + rMask, gMask, bMask); + } + else // transparency == Transparency_Alpha + { + alpha = InitAlpha(image, x, y); + } + + } + + switch ( transparency ) + { + case Transparency_Alpha: + *alpha++ = a; + // fall through + + case Transparency_None: + *ptrDst++ = r; + *ptrDst++ = g; + *ptrDst++ = b; + break; + + case Transparency_Mask: + // if we couldn't find a unique colour for the mask, we + // can have real pixels with the same value as the mask + // and it's better to slightly change their colour than + // to make them transparent + if ( r == rMask && g == gMask && b == bMask ) + { + r++; + } + + *ptrDst++ = rMask; + *ptrDst++ = bMask; + *ptrDst++ = gMask; + } + } + } + } + + if ( transparency == Transparency_Mask ) + { + image->SetMaskColour(rMask, gMask, bMask); + } } // temporarily disable the warning C4611 (interaction between '_setjmp' and @@ -101,14 +453,21 @@ PNGLINKAGEMODE png_silent_warning(png_structp WXUNUSED(png_ptr), png_const_charp #pragma warning(disable:4611) #endif /* VC++ */ -bool wxPNGHandler::LoadFile( wxImage *image, wxInputStream& stream, bool verbose, int WXUNUSED(index) ) +bool +wxPNGHandler::LoadFile(wxImage *image, + wxInputStream& stream, + bool verbose, + int WXUNUSED(index)) { // VZ: as this function uses setjmp() the only fool proof error handling // method is to use goto (setjmp is not really C++ dtors friendly...) - unsigned char **lines; - unsigned int i; + unsigned char **lines = NULL; png_infop info_ptr = (png_infop) NULL; + wxPNGInfoStruct wxinfo; + + wxinfo.verbose = verbose; + wxinfo.stream.in = &stream; image->Destroy(); @@ -117,25 +476,23 @@ bool wxPNGHandler::LoadFile( wxImage *image, wxInputStream& stream, bool verbose (png_error_ptr) NULL, (png_error_ptr) NULL ); if (!png_ptr) - goto error_nolines; + goto error; + + png_set_error_fn(png_ptr, (png_voidp)NULL, wx_png_error, wx_png_warning); - // 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); + // 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; + goto error; - if (setjmp(png_ptr->jmpbuf)) - goto error_nolines; + if (setjmp(wxinfo.jmpbuf)) + goto error; - 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; + png_uint_32 i, width, height; + int bit_depth, color_type, interlace_type; png_read_info( png_ptr, info_ptr ); png_get_IHDR( png_ptr, info_ptr, &width, &height, &bit_depth, &color_type, &interlace_type, (int*) NULL, (int*) NULL ); @@ -143,6 +500,10 @@ bool wxPNGHandler::LoadFile( wxImage *image, wxInputStream& stream, bool verbose if (color_type == PNG_COLOR_TYPE_PALETTE) png_set_expand( png_ptr ); + // Fix for Bug [ 439207 ] Monochrome PNG images come up black + if (bit_depth < 8) + png_set_expand( png_ptr ); + png_set_strip_16( png_ptr ); png_set_packing( png_ptr ); if (png_get_valid( png_ptr, info_ptr, PNG_INFO_tRNS)) @@ -152,11 +513,11 @@ bool wxPNGHandler::LoadFile( wxImage *image, wxInputStream& stream, bool verbose image->Create( (int)width, (int)height ); if (!image->Ok()) - goto error_nolines; + goto error; lines = (unsigned char **)malloc( (size_t)(height * sizeof(unsigned char *)) ); - if (lines == NULL) - goto error_nolines; + if ( !lines ) + goto error; for (i = 0; i < height; i++) { @@ -168,87 +529,20 @@ bool wxPNGHandler::LoadFile( wxImage *image, wxInputStream& stream, bool verbose } } - // loaded successfully! - { - int transp = 0; - png_read_image( png_ptr, lines ); - png_read_end( png_ptr, info_ptr ); - png_destroy_read_struct( &png_ptr, &info_ptr, (png_infopp) NULL ); - unsigned char *ptr = image->GetData(); - if ((color_type == PNG_COLOR_TYPE_GRAY) || - (color_type == PNG_COLOR_TYPE_GRAY_ALPHA)) - { - for (unsigned int y = 0; y < height; y++) - { - unsigned char *ptr2 = lines[y]; - for (unsigned int x = 0; x < width; x++) - { - unsigned char r = *ptr2++; - unsigned char a = *ptr2++; - if (a < 128) - { - *ptr++ = 255; - *ptr++ = 0; - *ptr++ = 255; - transp = 1; - } - else - { - *ptr++ = r; - *ptr++ = r; - *ptr++ = r; - } - } - } - } - else - { - for (unsigned int y = 0; y < height; y++) - { - unsigned char *ptr2 = lines[y]; - for (unsigned int x = 0; x < width; x++) - { - unsigned char r = *ptr2++; - unsigned char g = *ptr2++; - unsigned char b = *ptr2++; - unsigned char a = *ptr2++; - if (a < 128) - { - *ptr++ = 255; - *ptr++ = 0; - *ptr++ = 255; - transp = 1; - } - else - { - if ((r == 255) && (g == 0) && (b == 255)) r = 254; - *ptr++ = r; - *ptr++ = g; - *ptr++ = b; - } - } - } - } + png_read_image( png_ptr, lines ); + png_read_end( png_ptr, info_ptr ); + png_destroy_read_struct( &png_ptr, &info_ptr, (png_infopp) NULL ); - for ( unsigned int j = 0; j < height; j++ ) - free( lines[j] ); - free( lines ); + // loaded successfully, now init wxImage with this data + CopyDataFromPNG(image, lines, width, height, color_type); - if (transp) - { - image->SetMaskColour( 255, 0, 255 ); - } - else - { - image->SetMask( FALSE ); - } - } + for ( i = 0; i < height; i++ ) + free( lines[i] ); + free( lines ); return TRUE; - error_nolines: - lines = NULL; // called from before it was set - error: +error: if (verbose) wxLogError(_("Couldn't load a PNG image - file is corrupted or not enough memory.")); @@ -275,81 +569,97 @@ bool wxPNGHandler::LoadFile( wxImage *image, wxInputStream& stream, bool verbose return FALSE; } +// ---------------------------------------------------------------------------- +// writing PNGs +// ---------------------------------------------------------------------------- + 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; } @@ -357,15 +667,6 @@ bool wxPNGHandler::SaveFile( wxImage *image, wxOutputStream& stream, bool verbos #pragma warning(default:4611) #endif /* VC++ */ -bool wxPNGHandler::DoCanRead( wxInputStream& stream ) -{ - 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'); -} - #endif // wxUSE_STREAMS #endif // wxUSE_LIBPNG