Add another test for the insertion point position after SetValue().

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

diff --git a/src/common/imagpng.cpp b/src/common/imagpng.cpp
index 7370823ed95347a87644f09143174163d490aa67..14fd9eddb1bae5669b911390af956e76c83d9942 100644 (file)
--- a/src/common/imagpng.cpp
+++ b/src/common/imagpng.cpp
@@ -1,5 +1,5 @@
 /////////////////////////////////////////////////////////////////////////////
 /////////////////////////////////////////////////////////////////////////////

-// Name:        src/common/imagepng.cpp
+// Name:        src/common/imagpng.cpp

 // Purpose:     wxImage PNG handler
 // Author:      Robert Roebling
 // RCS-ID:      $Id$
 // Purpose:     wxImage PNG handler
 // Author:      Robert Roebling
 // RCS-ID:      $Id$


@@ -11,10 +11,6 @@
 // declarations
 // ============================================================================
 
 // declarations
 // ============================================================================
 

-#if defined(__GNUG__) && !defined(NO_GCC_PRAGMA)
-#pragma implementation "imagpng.h"
-#endif
-

 // ----------------------------------------------------------------------------
 // headers
 // ----------------------------------------------------------------------------
 // ----------------------------------------------------------------------------
 // headers
 // ----------------------------------------------------------------------------


@@ -23,35 +19,25 @@
 #include "wx/wxprec.h"
 
 #ifdef __BORLANDC__
 #include "wx/wxprec.h"
 
 #ifdef __BORLANDC__

-  #pragma hdrstop
-#endif
-
-#ifndef WX_PRECOMP
-  #include "wx/defs.h"
+    #pragma hdrstop

 #endif
 
 #if wxUSE_IMAGE && wxUSE_LIBPNG
 
 #include "wx/imagpng.h"
 #endif
 
 #if wxUSE_IMAGE && wxUSE_LIBPNG
 
 #include "wx/imagpng.h"

-#include "wx/bitmap.h"
-#include "wx/debug.h"
-#include "wx/log.h"
-#include "wx/app.h"
+
+#ifndef WX_PRECOMP
+    #include "wx/log.h"
+    #include "wx/intl.h"
+    #include "wx/palette.h"
+    #include "wx/stream.h"
+#endif
+

 #include "png.h"
 #include "png.h"

-#include "wx/filefn.h"
-#include "wx/wfstream.h"
-#include "wx/intl.h"
-#include "wx/module.h"

 
 // For memcpy
 #include <string.h>
 
 
 // For memcpy
 #include <string.h>
 

-#ifdef __SALFORDC__
-#ifdef FAR
-#undef FAR
-#endif
-#endif
-

 // ----------------------------------------------------------------------------
 // constants
 // ----------------------------------------------------------------------------
 // ----------------------------------------------------------------------------
 // constants
 // ----------------------------------------------------------------------------


@@ -109,7 +95,9 @@ IMPLEMENT_DYNAMIC_CLASS(wxPNGHandler,wxImageHandler)
 #if wxUSE_STREAMS
 
 #ifndef PNGLINKAGEMODE
 #if wxUSE_STREAMS
 
 #ifndef PNGLINKAGEMODE

-    #ifdef __WATCOMC__
+    #ifdef PNGAPI
+        #define PNGLINKAGEMODE PNGAPI
+    #elif defined(__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
         // 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


@@ -160,32 +148,39 @@ struct wxPNGInfoStruct
 extern "C"
 {
 
 extern "C"
 {
 

-void PNGLINKAGEMODE wx_PNG_stream_reader( png_structp png_ptr, png_bytep data,
-                                          png_size_t length )
+static void PNGLINKAGEMODE wx_PNG_stream_reader( png_structp png_ptr, png_bytep data,
+                                                 png_size_t length )

 {
     WX_PNG_INFO(png_ptr)->stream.in->Read(data, length);
 }
 
 {
     WX_PNG_INFO(png_ptr)->stream.in->Read(data, length);
 }
 

-void PNGLINKAGEMODE wx_PNG_stream_writer( png_structp png_ptr, png_bytep data,
-                                          png_size_t length )
+static void PNGLINKAGEMODE wx_PNG_stream_writer( png_structp png_ptr, png_bytep data,
+                                                 png_size_t length )

 {
     WX_PNG_INFO(png_ptr)->stream.out->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 wx_png_error(png_structp WXUNUSED(png_ptr), png_const_charp message)
-{
-    wxLogFatalError( wxString::FromAscii(message) );
-}
-
-void
+static void

 PNGLINKAGEMODE wx_png_warning(png_structp png_ptr, png_const_charp message)
 {
     wxPNGInfoStruct *info = png_ptr ? WX_PNG_INFO(png_ptr) : NULL;
     if ( !info || info->verbose )
 PNGLINKAGEMODE wx_png_warning(png_structp png_ptr, png_const_charp message)
 {
     wxPNGInfoStruct *info = png_ptr ? WX_PNG_INFO(png_ptr) : NULL;
     if ( !info || info->verbose )

+    {

         wxLogWarning( wxString::FromAscii(message) );
         wxLogWarning( wxString::FromAscii(message) );

+    }
+}
+
+// from pngerror.c
+// so that the libpng doesn't send anything on stderr
+static void
+PNGLINKAGEMODE wx_png_error(png_structp png_ptr, png_const_charp message)
+{
+    wx_png_warning(NULL, message);
+
+    // we're not using libpng built-in jump buffer (see comment before
+    // wxPNGInfoStruct above) so we have to return ourselves, otherwise libpng
+    // would just abort
+    longjmp(WX_PNG_INFO(png_ptr)->jmpbuf, 1);

 }
 
 } // extern "C"
 }
 
 } // extern "C"


@@ -278,6 +273,7 @@ FindMaskColour(unsigned char **lines, png_uint_32 width, png_uint_32 height,
             r2 = *p++;
             g2 = *p++;
             b2 = *p++;
             r2 = *p++;
             g2 = *p++;
             b2 = *p++;

+            ++p; // jump over alpha

 
             wxImageHistogramEntry&
                 entry = h[wxImageHistogram:: MakeKey(r2, g2, b2)];
 
             wxImageHistogramEntry&
                 entry = h[wxImageHistogram:: MakeKey(r2, g2, b2)];


@@ -287,7 +283,7 @@ FindMaskColour(unsigned char **lines, png_uint_32 width, png_uint_32 height,
         }
     }
 
         }
     }
 

-    if ( !h.FindFirstUnusedColour(&rMask, &gMask, &bMask, rMask, gMask, bMask) )
+    if ( !h.FindFirstUnusedColour(&rMask, &gMask, &bMask) )

     {
         wxLogWarning(_("Too many colours in PNG, the image may be slightly blurred."));
 
     {
         wxLogWarning(_("Too many colours in PNG, the image may be slightly blurred."));
 


@@ -308,7 +304,7 @@ bool wxPNGHandler::DoCanRead( wxInputStream& stream )
 {
     unsigned char hdr[4];
 
 {
     unsigned char hdr[4];
 

-    if ( !stream.Read(hdr, WXSIZEOF(hdr)) )
+    if ( !stream.Read(hdr, WXSIZEOF(hdr)) )     // it's ok to modify the stream position here

         return false;
 
     return memcmp(hdr, "\211PNG", WXSIZEOF(hdr)) == 0;
         return false;
 
     return memcmp(hdr, "\211PNG", WXSIZEOF(hdr)) == 0;


@@ -383,15 +379,15 @@ void CopyDataFromPNG(wxImage *image,
                         if ( IsTransparent(a) )
                         {
                             *ptrDst++ = rMask;
                         if ( IsTransparent(a) )
                         {
                             *ptrDst++ = rMask;

-                            *ptrDst++ = bMask;

                             *ptrDst++ = gMask;
                             *ptrDst++ = gMask;

+                            *ptrDst++ = bMask;

                             break;
                         }
                         // else: !transparent
 
                         // must be opaque then as otherwise we shouldn't be
                         // using the mask at all
                             break;
                         }
                         // else: !transparent
 
                         // must be opaque then as otherwise we shouldn't be
                         // using the mask at all

-                        wxASSERT_MSG( IsOpaque(a), _T("logic error") );
+                        wxASSERT_MSG( IsOpaque(a), wxT("logic error") );

 
                         // fall through
 
 
                         // fall through
 


@@ -435,14 +431,8 @@ void CopyDataFromPNG(wxImage *image,
 
                     if ( transparency == Transparency_Mask )
                     {
 
                     if ( transparency == Transparency_Mask )
                     {

-                        if ( IsTransparent( a ) && ( ! ( rMask || gMask || bMask ) ) )
-                        {
-                            rMask = r;
-                            gMask = g;
-                            bMask = b;
-
-                            FindMaskColour(lines, width, height, rMask, gMask, bMask );
-                        }  
+                        FindMaskColour(lines, width, height,
+                                       rMask, gMask, bMask);

                     }
                     else // transparency == Transparency_Alpha
                     {
                     }
                     else // transparency == Transparency_Alpha
                     {


@@ -457,15 +447,15 @@ void CopyDataFromPNG(wxImage *image,
                         if ( IsTransparent(a) )
                         {
                             *ptrDst++ = rMask;
                         if ( IsTransparent(a) )
                         {
                             *ptrDst++ = rMask;

-                            *ptrDst++ = bMask;

                             *ptrDst++ = gMask;
                             *ptrDst++ = gMask;

+                            *ptrDst++ = bMask;

                             break;
                         }
                         else // !transparent
                         {
                             // must be opaque then as otherwise we shouldn't be
                             // using the mask at all
                             break;
                         }
                         else // !transparent
                         {
                             // must be opaque then as otherwise we shouldn't be
                             // using the mask at all

-                            wxASSERT_MSG( IsOpaque(a), _T("logic error") );
+                            wxASSERT_MSG( IsOpaque(a), wxT("logic error") );

 
                             // if we couldn't find a unique colour for the
                             // mask, we can have real pixels with the same
 
                             // if we couldn't find a unique colour for the
                             // mask, we can have real pixels with the same


@@ -513,13 +503,16 @@ wxPNGHandler::LoadFile(wxImage *image,
                        bool verbose,
                        int WXUNUSED(index))
 {
                        bool verbose,
                        int WXUNUSED(index))
 {

-    // VZ: as this function uses setjmp() the only fool proof error handling
+    // 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 = NULL;
     png_infop info_ptr = (png_infop) NULL;
     wxPNGInfoStruct wxinfo;
 
     //     method is to use goto (setjmp is not really C++ dtors friendly...)
 
     unsigned char **lines = NULL;
     png_infop info_ptr = (png_infop) NULL;
     wxPNGInfoStruct wxinfo;
 

+    png_uint_32 i, width, height = 0;
+    int bit_depth, color_type, interlace_type;
+

     wxinfo.verbose = verbose;
     wxinfo.stream.in = &stream;
 
     wxinfo.verbose = verbose;
     wxinfo.stream.in = &stream;
 


@@ -546,11 +539,8 @@ wxPNGHandler::LoadFile(wxImage *image,
     if (setjmp(wxinfo.jmpbuf))
         goto error;
 
     if (setjmp(wxinfo.jmpbuf))
         goto error;
 

-    png_uint_32 i, width, height;
-    int bit_depth, color_type, interlace_type;
-

     png_read_info( png_ptr, info_ptr );
     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 );
+    png_get_IHDR( png_ptr, info_ptr, &width, &height, &bit_depth, &color_type, &interlace_type, NULL, NULL );

 
     if (color_type == PNG_COLOR_TYPE_PALETTE)
         png_set_expand( png_ptr );
 
     if (color_type == PNG_COLOR_TYPE_PALETTE)
         png_set_expand( png_ptr );


@@ -570,22 +560,43 @@ wxPNGHandler::LoadFile(wxImage *image,
     if (!image->Ok())
         goto error;
 
     if (!image->Ok())
         goto error;
 

-    lines = (unsigned char **)malloc( (size_t)(height * sizeof(unsigned char *)) );
+    // initialize all line pointers to NULL to ensure that they can be safely
+    // free()d if an error occurs before all of them could be allocated
+    lines = (unsigned char **)calloc(height, sizeof(unsigned char *));

     if ( !lines )
         goto error;
 
     for (i = 0; i < height; i++)
     {
         if ((lines[i] = (unsigned char *)malloc( (size_t)(width * (sizeof(unsigned char) * 4)))) == NULL)
     if ( !lines )
         goto error;
 
     for (i = 0; i < height; i++)
     {
         if ((lines[i] = (unsigned char *)malloc( (size_t)(width * (sizeof(unsigned char) * 4)))) == NULL)

-        {
-            for ( unsigned int n = 0; n < i; n++ )
-                free( lines[n] );

             goto error;
             goto error;

-        }

     }
 
     png_read_image( png_ptr, lines );
     png_read_end( png_ptr, info_ptr );
     }
 
     png_read_image( png_ptr, lines );
     png_read_end( png_ptr, info_ptr );

+
+#if wxUSE_PALETTE
+    if (color_type == PNG_COLOR_TYPE_PALETTE)
+    {
+        const size_t ncolors = info_ptr->num_palette;
+        unsigned char* r = new unsigned char[ncolors];
+        unsigned char* g = new unsigned char[ncolors];
+        unsigned char* b = new unsigned char[ncolors];
+
+        for (size_t j = 0; j < ncolors; j++)
+        {
+            r[j] = info_ptr->palette[j].red;
+            g[j] = info_ptr->palette[j].green;
+            b[j] = info_ptr->palette[j].blue;
+        }
+
+        image->SetPalette(wxPalette(ncolors, r, g, b));
+        delete[] r;
+        delete[] g;
+        delete[] b;
+    }
+#endif // wxUSE_PALETTE
+

     png_destroy_read_struct( &png_ptr, &info_ptr, (png_infopp) NULL );
 
     // loaded successfully, now init wxImage with this data
     png_destroy_read_struct( &png_ptr, &info_ptr, (png_infopp) NULL );
 
     // loaded successfully, now init wxImage with this data


@@ -599,7 +610,9 @@ wxPNGHandler::LoadFile(wxImage *image,
 
 error:
     if (verbose)
 
 error:
     if (verbose)

+    {

        wxLogError(_("Couldn't load a PNG image - file is corrupted or not enough memory."));
        wxLogError(_("Couldn't load a PNG image - file is corrupted or not enough memory."));

+    }

 
     if ( image->Ok() )
     {
 
     if ( image->Ok() )
     {


@@ -608,6 +621,9 @@ error:
 
     if ( lines )
     {
 
     if ( lines )
     {

+        for ( unsigned int n = 0; n < height; n++ )
+            free( lines[n] );
+

         free( lines );
     }
 
         free( lines );
     }
 


@@ -645,7 +661,9 @@ bool wxPNGHandler::SaveFile( wxImage *image, wxOutputStream& stream, bool verbos
     if (!png_ptr)
     {
         if (verbose)
     if (!png_ptr)
     {
         if (verbose)

+        {

            wxLogError(_("Couldn't save PNG image."));
            wxLogError(_("Couldn't save PNG image."));

+        }

         return false;
     }
 
         return false;
     }
 


@@ -654,7 +672,9 @@ bool wxPNGHandler::SaveFile( wxImage *image, wxOutputStream& stream, bool verbos
     {
         png_destroy_write_struct( &png_ptr, (png_infopp)NULL );
         if (verbose)
     {
         png_destroy_write_struct( &png_ptr, (png_infopp)NULL );
         if (verbose)

+        {

            wxLogError(_("Couldn't save PNG image."));
            wxLogError(_("Couldn't save PNG image."));

+        }

         return false;
     }
 
         return false;
     }
 


@@ -662,7 +682,9 @@ bool wxPNGHandler::SaveFile( wxImage *image, wxOutputStream& stream, bool verbos
     {
         png_destroy_write_struct( &png_ptr, (png_infopp)NULL );
         if (verbose)
     {
         png_destroy_write_struct( &png_ptr, (png_infopp)NULL );
         if (verbose)

+        {

            wxLogError(_("Couldn't save PNG image."));
            wxLogError(_("Couldn't save PNG image."));

+        }

         return false;
     }
 
         return false;
     }
 


@@ -670,51 +692,199 @@ bool wxPNGHandler::SaveFile( wxImage *image, wxOutputStream& stream, bool verbos
     //     explanation why this line is mandatory
     png_set_write_fn( png_ptr, &wxinfo, wx_PNG_stream_writer, NULL);
 
     //     explanation why this line is mandatory
     png_set_write_fn( png_ptr, &wxinfo, wx_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);
+    const int iColorType = image->HasOption(wxIMAGE_OPTION_PNG_FORMAT)
+                            ? image->GetOptionInt(wxIMAGE_OPTION_PNG_FORMAT)
+                            : wxPNG_TYPE_COLOUR;
+    const int iBitDepth = image->HasOption(wxIMAGE_OPTION_PNG_BITDEPTH)
+                            ? image->GetOptionInt(wxIMAGE_OPTION_PNG_BITDEPTH)
+                            : 8;
+
+    bool bHasAlpha = image->HasAlpha();
+    bool bHasMask = image->HasMask();
+    bool bUseAlpha = bHasAlpha || bHasMask;
+
+    int iPngColorType;
+    if ( iColorType==wxPNG_TYPE_COLOUR )
+    {
+        iPngColorType = bUseAlpha ? PNG_COLOR_TYPE_RGB_ALPHA
+                                  : PNG_COLOR_TYPE_RGB;
+    }
+    else
+    {
+        iPngColorType = bUseAlpha ? PNG_COLOR_TYPE_GRAY_ALPHA
+                                  : PNG_COLOR_TYPE_GRAY;
+    }
+
+    if (image->HasOption(wxIMAGE_OPTION_PNG_FILTER))
+        png_set_filter( png_ptr, PNG_FILTER_TYPE_BASE, image->GetOptionInt(wxIMAGE_OPTION_PNG_FILTER) );
+
+    if (image->HasOption(wxIMAGE_OPTION_PNG_COMPRESSION_LEVEL))
+        png_set_compression_level( png_ptr, image->GetOptionInt(wxIMAGE_OPTION_PNG_COMPRESSION_LEVEL) );
+
+    if (image->HasOption(wxIMAGE_OPTION_PNG_COMPRESSION_MEM_LEVEL))
+        png_set_compression_mem_level( png_ptr, image->GetOptionInt(wxIMAGE_OPTION_PNG_COMPRESSION_MEM_LEVEL) );

 
 

+    if (image->HasOption(wxIMAGE_OPTION_PNG_COMPRESSION_STRATEGY))
+        png_set_compression_strategy( png_ptr, image->GetOptionInt(wxIMAGE_OPTION_PNG_COMPRESSION_STRATEGY) );
+
+    if (image->HasOption(wxIMAGE_OPTION_PNG_COMPRESSION_BUFFER_SIZE))
+        png_set_compression_buffer_size( png_ptr, image->GetOptionInt(wxIMAGE_OPTION_PNG_COMPRESSION_BUFFER_SIZE) );
+
+    png_set_IHDR( png_ptr, info_ptr, image->GetWidth(), image->GetHeight(),
+                  iBitDepth, iPngColorType,
+                  PNG_INTERLACE_NONE, PNG_COMPRESSION_TYPE_BASE,
+                  PNG_FILTER_TYPE_BASE);
+
+    int iElements;

     png_color_8 sig_bit;
     png_color_8 sig_bit;

-    sig_bit.red = 8;
-    sig_bit.green = 8;
-    sig_bit.blue = 8;
-    sig_bit.alpha = 8;
+
+    if ( iPngColorType & PNG_COLOR_MASK_COLOR )
+    {
+        sig_bit.red =
+        sig_bit.green =
+        sig_bit.blue = (png_byte)iBitDepth;
+        iElements = 3;
+    }
+    else // grey
+    {
+        sig_bit.gray = (png_byte)iBitDepth;
+        iElements = 1;
+    }
+
+    if ( iPngColorType & PNG_COLOR_MASK_ALPHA )
+    {
+        sig_bit.alpha = (png_byte)iBitDepth;
+        iElements++;
+    }
+
+    if ( iBitDepth == 16 )
+        iElements *= 2;
+
+    // save the image resolution if we have it
+    int resX, resY;
+    switch ( GetResolutionFromOptions(*image, &resX, &resY) )
+    {
+        case wxIMAGE_RESOLUTION_INCHES:
+            {
+                const double INCHES_IN_METER = 10000.0 / 254;
+                resX = int(resX * INCHES_IN_METER);
+                resY = int(resY * INCHES_IN_METER);
+            }
+            break;
+
+        case wxIMAGE_RESOLUTION_CM:
+            resX *= 100;
+            resY *= 100;
+            break;
+
+        case wxIMAGE_RESOLUTION_NONE:
+            break;
+
+        default:
+            wxFAIL_MSG( wxT("unsupported image resolution units") );
+    }
+
+    if ( resX && resY )
+        png_set_pHYs( png_ptr, info_ptr, resX, resY, PNG_RESOLUTION_METER );
+

     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 );
 
     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)
+    unsigned char *
+        data = (unsigned char *)malloc( image->GetWidth() * iElements );
+    if ( !data )

     {
         png_destroy_write_struct( &png_ptr, (png_infopp)NULL );
         return false;
     }
 
     {
         png_destroy_write_struct( &png_ptr, (png_infopp)NULL );
         return false;
     }
 

-    for (int y = 0; y < image->GetHeight(); y++)
+    unsigned char *
+        pAlpha = (unsigned char *)(bHasAlpha ? image->GetAlpha() : NULL);
+    int iHeight = image->GetHeight();
+    int iWidth = image->GetWidth();
+
+    unsigned char uchMaskRed = 0, uchMaskGreen = 0, uchMaskBlue = 0;
+
+    if ( bHasMask )

     {
     {

-        unsigned char *ptr = image->GetData() + (y * image->GetWidth() * 3);
-        for (int x = 0; x < image->GetWidth(); x++)
+        uchMaskRed = image->GetMaskRed();
+        uchMaskGreen = image->GetMaskGreen();
+        uchMaskBlue = image->GetMaskBlue();
+    }
+
+    unsigned char *pColors = image->GetData();
+
+    for (int y = 0; y != iHeight; ++y)
+    {
+        unsigned char *pData = data;
+        for (int x = 0; x != iWidth; x++)

         {
         {

-            data[(x << 2) + 0] = *ptr++;
-            data[(x << 2) + 1] = *ptr++;
-            data[(x << 2) + 2] = *ptr++;
-            if ( image->HasAlpha() )
-            {
-                data[(x << 2) + 3] = image->GetAlpha(x, y);
-            }
-            else if (( !image->HasMask() ) || \
-                (data[(x << 2) + 0] != image->GetMaskRed()) || \
-                (data[(x << 2) + 1] != image->GetMaskGreen()) || \
-                (data[(x << 2) + 2] != image->GetMaskBlue()))
+            unsigned char uchRed = *pColors++;
+            unsigned char uchGreen = *pColors++;
+            unsigned char uchBlue = *pColors++;
+
+            switch ( iColorType )

             {
             {

-                data[(x << 2) + 3] = 255;
+                default:
+                    wxFAIL_MSG( wxT("unknown wxPNG_TYPE_XXX") );
+                    // fall through
+
+                case wxPNG_TYPE_COLOUR:
+                    *pData++ = uchRed;
+                    if ( iBitDepth == 16 )
+                        *pData++ = 0;
+                    *pData++ = uchGreen;
+                    if ( iBitDepth == 16 )
+                        *pData++ = 0;
+                    *pData++ = uchBlue;
+                    if ( iBitDepth == 16 )
+                        *pData++ = 0;
+                    break;
+
+                case wxPNG_TYPE_GREY:
+                    {
+                        // where do these coefficients come from? maybe we
+                        // should have image options for them as well?
+                        unsigned uiColor =
+                            (unsigned) (76.544*(unsigned)uchRed +
+                                        150.272*(unsigned)uchGreen +
+                                        36.864*(unsigned)uchBlue);
+
+                        *pData++ = (unsigned char)((uiColor >> 8) & 0xFF);
+                        if ( iBitDepth == 16 )
+                            *pData++ = (unsigned char)(uiColor & 0xFF);
+                    }
+                    break;
+
+                case wxPNG_TYPE_GREY_RED:
+                    *pData++ = uchRed;
+                    if ( iBitDepth == 16 )
+                        *pData++ = 0;
+                    break;

             }
             }

-            else
+
+            if ( bUseAlpha )

             {
             {

-                data[(x << 2) + 3] = 0;
+                unsigned char uchAlpha = 255;
+                if ( bHasAlpha )
+                    uchAlpha = *pAlpha++;
+
+                if ( bHasMask )
+                {
+                    if ( (uchRed == uchMaskRed)
+                            && (uchGreen == uchMaskGreen)
+                                && (uchBlue == uchMaskBlue) )
+                        uchAlpha = 0;
+                }
+
+                *pData++ = uchAlpha;
+                if ( iBitDepth == 16 )
+                    *pData++ = 0;

             }
         }
             }
         }

+

         png_bytep row_ptr = data;
         png_write_rows( png_ptr, &row_ptr, 1 );
     }
         png_bytep row_ptr = data;
         png_write_rows( png_ptr, &row_ptr, 1 );
     }