Make code reading BMP files more robust.

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

diff --git a/src/common/imagpng.cpp b/src/common/imagpng.cpp
index abe155c880bd0174dfacc9138bc8ea397fd682ad..81c411619bc63132a9e06635cee8096b5dd4ba7b 100644 (file)
--- a/src/common/imagpng.cpp
+++ b/src/common/imagpng.cpp
@@ -25,6 +25,7 @@
 #if wxUSE_IMAGE && wxUSE_LIBPNG
 
 #include "wx/imagpng.h"
 #if wxUSE_IMAGE && wxUSE_LIBPNG
 
 #include "wx/imagpng.h"

+#include "wx/versioninfo.h"

 
 #ifndef WX_PRECOMP
     #include "wx/log.h"
 
 #ifndef WX_PRECOMP
     #include "wx/log.h"


@@ -42,7 +43,7 @@
 // constants
 // ----------------------------------------------------------------------------
 
 // constants
 // ----------------------------------------------------------------------------
 

-// image can not have any transparent pixels at all, have only 100% opaque
+// image cannot 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
 // 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


@@ -115,11 +116,9 @@ IMPLEMENT_DYNAMIC_CLASS(wxPNGHandler,wxImageHandler)
 //     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
 //     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.
+//     as DLL with another compiler than the main executable, it may not work.
+//     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
 //
 //     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


@@ -387,7 +386,7 @@ void CopyDataFromPNG(wxImage *image,
 
                         // must be opaque then as otherwise we shouldn't be
                         // using the mask at all
 
                         // 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
 


@@ -455,7 +454,7 @@ void CopyDataFromPNG(wxImage *image,
                         {
                             // must be opaque then as otherwise we shouldn't be
                             // using the mask at all
                         {
                             // 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


@@ -521,7 +520,7 @@ wxPNGHandler::LoadFile(wxImage *image,
     png_structp png_ptr = png_create_read_struct
                           (
                             PNG_LIBPNG_VER_STRING,
     png_structp png_ptr = png_create_read_struct
                           (
                             PNG_LIBPNG_VER_STRING,

-                            (voidp) NULL,
+                            NULL,

                             wx_png_error,
                             wx_png_warning
                           );
                             wx_png_error,
                             wx_png_warning
                           );


@@ -557,7 +556,7 @@ wxPNGHandler::LoadFile(wxImage *image,
 
     image->Create((int)width, (int)height, (bool) false /* no need to init pixels */);
 
 
     image->Create((int)width, (int)height, (bool) false /* no need to init pixels */);
 

-    if (!image->Ok())
+    if (!image->IsOk())

         goto error;
 
     // initialize all line pointers to NULL to ensure that they can be safely
         goto error;
 
     // initialize all line pointers to NULL to ensure that they can be safely


@@ -568,7 +567,7 @@ wxPNGHandler::LoadFile(wxImage *image,
 
     for (i = 0; i < height; i++)
     {
 
     for (i = 0; i < height; i++)
     {

-        if ((lines[i] = (unsigned char *)malloc( (size_t)(width * (sizeof(unsigned char) * 4)))) == NULL)
+        if ((lines[i] = (unsigned char *)malloc( (size_t)(width * 4))) == NULL)

             goto error;
     }
 
             goto error;
     }
 


@@ -578,25 +577,70 @@ wxPNGHandler::LoadFile(wxImage *image,
 #if wxUSE_PALETTE
     if (color_type == PNG_COLOR_TYPE_PALETTE)
     {
 #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];
+        png_colorp palette = NULL;
+        int numPalette = 0;
+
+        (void) png_get_PLTE(png_ptr, info_ptr, &palette, &numPalette);
+
+        unsigned char* r = new unsigned char[numPalette];
+        unsigned char* g = new unsigned char[numPalette];
+        unsigned char* b = new unsigned char[numPalette];

 
 

-        for (size_t j = 0; j < ncolors; j++)
+        for (int j = 0; j < numPalette; j++)

         {
         {

-            r[j] = info_ptr->palette[j].red;
-            g[j] = info_ptr->palette[j].green;
-            b[j] = info_ptr->palette[j].blue;
+            r[j] = palette[j].red;
+            g[j] = palette[j].green;
+            b[j] = palette[j].blue;

         }
 
         }
 

-        image->SetPalette(wxPalette(ncolors, r, g, b));
+        image->SetPalette(wxPalette(numPalette, r, g, b));

         delete[] r;
         delete[] g;
         delete[] b;
     }
 #endif // wxUSE_PALETTE
 
         delete[] r;
         delete[] g;
         delete[] b;
     }
 #endif // wxUSE_PALETTE
 

+
+    // set the image resolution if it's available
+    png_uint_32 resX, resY;
+    int unitType;
+    if (png_get_pHYs(png_ptr, info_ptr, &resX, &resY, &unitType)
+        == PNG_INFO_pHYs)
+    {
+        wxImageResolution res = wxIMAGE_RESOLUTION_CM;
+
+        switch (unitType)
+        {
+            default:
+                wxLogWarning(_("Unknown PNG resolution unit %d"), unitType);
+                // fall through
+
+            case PNG_RESOLUTION_UNKNOWN:
+                image->SetOption(wxIMAGE_OPTION_RESOLUTIONX, resX);
+                image->SetOption(wxIMAGE_OPTION_RESOLUTIONY, resY);
+
+                res = wxIMAGE_RESOLUTION_NONE;
+                break;
+
+            case PNG_RESOLUTION_METER:
+                /*
+                Convert meters to centimeters.
+                Use a string to not lose precision (converting to cm and then
+                to inch would result in integer rounding error).
+                If an app wants an int, GetOptionInt will convert and round
+                down for them.
+                */
+                image->SetOption(wxIMAGE_OPTION_RESOLUTIONX,
+                    wxString::FromCDouble((double) resX / 100.0, 2));
+                image->SetOption(wxIMAGE_OPTION_RESOLUTIONY,
+                    wxString::FromCDouble((double) resY / 100.0, 2));
+                break;
+        }
+
+        image->SetOption(wxIMAGE_OPTION_RESOLUTIONUNIT, res);
+    }
+
+

     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


@@ -614,7 +658,7 @@ error:
        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->IsOk() )

     {
         image->Destroy();
     }
     {
         image->Destroy();
     }


@@ -640,6 +684,44 @@ error:
     return false;
 }
 
     return false;
 }
 

+// ----------------------------------------------------------------------------
+// SaveFile() palette helpers
+// ----------------------------------------------------------------------------
+
+typedef wxLongToLongHashMap PaletteMap;
+
+static unsigned long PaletteMakeKey(const png_color_8& clr)
+{
+    return (wxImageHistogram::MakeKey(clr.red, clr.green, clr.blue) << 8) | clr.alpha;
+}
+
+static long PaletteFind(const PaletteMap& palette, const png_color_8& clr)
+{
+    unsigned long value = PaletteMakeKey(clr);
+    PaletteMap::const_iterator it = palette.find(value);
+
+    return (it != palette.end()) ? it->second : wxNOT_FOUND;
+}
+
+static long PaletteAdd(PaletteMap *palette, const png_color_8& clr)
+{
+    unsigned long value = PaletteMakeKey(clr);
+    PaletteMap::const_iterator it = palette->find(value);
+    size_t index;
+
+    if (it == palette->end())
+    {
+        index = palette->size();
+        (*palette)[value] = index;
+    }
+    else
+    {
+        index = it->second;
+    }
+
+    return index;
+}
+

 // ----------------------------------------------------------------------------
 // writing PNGs
 // ----------------------------------------------------------------------------
 // ----------------------------------------------------------------------------
 // writing PNGs
 // ----------------------------------------------------------------------------


@@ -692,19 +774,117 @@ 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);
 

-    const int iColorType = image->HasOption(wxIMAGE_OPTION_PNG_FORMAT)
+    const int iHeight = image->GetHeight();
+    const int iWidth = image->GetWidth();
+
+    const bool bHasPngFormatOption
+        = image->HasOption(wxIMAGE_OPTION_PNG_FORMAT);
+
+    int iColorType = bHasPngFormatOption

                             ? image->GetOptionInt(wxIMAGE_OPTION_PNG_FORMAT)
                             : wxPNG_TYPE_COLOUR;
                             ? 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 bHasAlpha = image->HasAlpha();
     bool bHasMask = image->HasMask();

-    bool bUseAlpha = bHasAlpha || bHasMask;
+
+    bool bUsePalette = iColorType == wxPNG_TYPE_PALETTE
+#if wxUSE_PALETTE
+        || (!bHasPngFormatOption && image->HasPalette() )
+#endif
+    ;
+
+    png_color_8 mask = { 0, 0, 0, 0, 0 };
+
+    if (bHasMask)
+    {
+        mask.red   = image->GetMaskRed();
+        mask.green = image->GetMaskGreen();
+        mask.blue  = image->GetMaskBlue();
+    }
+
+    PaletteMap palette;
+
+    if (bUsePalette)
+    {
+        png_color png_rgb  [PNG_MAX_PALETTE_LENGTH];
+        png_byte  png_trans[PNG_MAX_PALETTE_LENGTH];
+
+        const unsigned char *pColors = image->GetData();
+        const unsigned char* pAlpha  = image->GetAlpha();
+
+        if (bHasMask && !pAlpha)
+        {
+            // Mask must be first
+            PaletteAdd(&palette, mask);
+        }
+
+        for (int y = 0; y < iHeight; y++)
+        {
+            for (int x = 0; x < iWidth; x++)
+            {
+                png_color_8 rgba;
+
+                rgba.red   = *pColors++;
+                rgba.green = *pColors++;
+                rgba.blue  = *pColors++;
+                rgba.gray  = 0;
+                rgba.alpha = (pAlpha && !bHasMask) ? *pAlpha++ : 0;
+
+                // save in our palette
+                long index = PaletteAdd(&palette, rgba);
+
+                if (index < PNG_MAX_PALETTE_LENGTH)
+                {
+                    // save in libpng's palette
+                    png_rgb[index].red   = rgba.red;
+                    png_rgb[index].green = rgba.green;
+                    png_rgb[index].blue  = rgba.blue;
+                    png_trans[index]     = rgba.alpha;
+                }
+                else
+                {
+                    bUsePalette = false;
+                    break;
+                }
+            }
+        }
+
+        if (bUsePalette)
+        {
+            png_set_PLTE(png_ptr, info_ptr, png_rgb, palette.size());
+
+            if (bHasMask && !pAlpha)
+            {
+                wxASSERT(PaletteFind(palette, mask) == 0);
+                png_trans[0] = 0;
+                png_set_tRNS(png_ptr, info_ptr, png_trans, 1, NULL);
+            }
+            else if (pAlpha && !bHasMask)
+            {
+                png_set_tRNS(png_ptr, info_ptr, png_trans, palette.size(), NULL);
+            }
+        }
+    }
+
+    /*
+    If saving palettised was requested but it was decided we can't use a
+    palette then reset the colour type to RGB.
+    */
+    if (!bUsePalette && iColorType == wxPNG_TYPE_PALETTE)
+    {
+        iColorType = wxPNG_TYPE_COLOUR;
+    }
+
+    bool bUseAlpha = !bUsePalette && (bHasAlpha || bHasMask);

 
     int iPngColorType;
 
     int iPngColorType;

-    if ( iColorType==wxPNG_TYPE_COLOUR )
+
+    if (bUsePalette)
+    {
+        iPngColorType = PNG_COLOR_TYPE_PALETTE;
+        iColorType = wxPNG_TYPE_PALETTE;
+    }
+    else if ( iColorType==wxPNG_TYPE_COLOUR )

     {
         iPngColorType = bUseAlpha ? PNG_COLOR_TYPE_RGB_ALPHA
                                   : PNG_COLOR_TYPE_RGB;
     {
         iPngColorType = bUseAlpha ? PNG_COLOR_TYPE_RGB_ALPHA
                                   : PNG_COLOR_TYPE_RGB;


@@ -730,6 +910,10 @@ bool wxPNGHandler::SaveFile( wxImage *image, wxOutputStream& stream, bool verbos
     if (image->HasOption(wxIMAGE_OPTION_PNG_COMPRESSION_BUFFER_SIZE))
         png_set_compression_buffer_size( png_ptr, image->GetOptionInt(wxIMAGE_OPTION_PNG_COMPRESSION_BUFFER_SIZE) );
 
     if (image->HasOption(wxIMAGE_OPTION_PNG_COMPRESSION_BUFFER_SIZE))
         png_set_compression_buffer_size( png_ptr, image->GetOptionInt(wxIMAGE_OPTION_PNG_COMPRESSION_BUFFER_SIZE) );
 

+    int iBitDepth = !bUsePalette && image->HasOption(wxIMAGE_OPTION_PNG_BITDEPTH)
+                            ? image->GetOptionInt(wxIMAGE_OPTION_PNG_BITDEPTH)
+                            : 8;
+

     png_set_IHDR( png_ptr, info_ptr, image->GetWidth(), image->GetHeight(),
                   iBitDepth, iPngColorType,
                   PNG_INTERLACE_NONE, PNG_COMPRESSION_TYPE_BASE,
     png_set_IHDR( png_ptr, info_ptr, image->GetWidth(), image->GetHeight(),
                   iBitDepth, iPngColorType,
                   PNG_INTERLACE_NONE, PNG_COMPRESSION_TYPE_BASE,


@@ -751,7 +935,7 @@ bool wxPNGHandler::SaveFile( wxImage *image, wxOutputStream& stream, bool verbos
         iElements = 1;
     }
 
         iElements = 1;
     }
 

-    if ( iPngColorType & PNG_COLOR_MASK_ALPHA )
+    if ( bUseAlpha )

     {
         sig_bit.alpha = (png_byte)iBitDepth;
         iElements++;
     {
         sig_bit.alpha = (png_byte)iBitDepth;
         iElements++;


@@ -781,7 +965,7 @@ bool wxPNGHandler::SaveFile( wxImage *image, wxOutputStream& stream, bool verbos
             break;
 
         default:
             break;
 
         default:

-            wxFAIL_MSG( _T("unsupported image resolution units") );
+            wxFAIL_MSG( wxT("unsupported image resolution units") );

     }
 
     if ( resX && resY )
     }
 
     if ( resX && resY )


@@ -800,45 +984,37 @@ bool wxPNGHandler::SaveFile( wxImage *image, wxOutputStream& stream, bool verbos
         return false;
     }
 
         return false;
     }
 

-    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 )
-    {
-        uchMaskRed = image->GetMaskRed();
-        uchMaskGreen = image->GetMaskGreen();
-        uchMaskBlue = image->GetMaskBlue();
-    }
+    const unsigned char *
+        pAlpha = (const unsigned char *)(bHasAlpha ? image->GetAlpha() : NULL);

 
 

-    unsigned char *pColors = image->GetData();
+    const unsigned char *pColors = image->GetData();

 
     for (int y = 0; y != iHeight; ++y)
     {
         unsigned char *pData = data;
         for (int x = 0; x != iWidth; x++)
         {
 
     for (int y = 0; y != iHeight; ++y)
     {
         unsigned char *pData = data;
         for (int x = 0; x != iWidth; x++)
         {

-            unsigned char uchRed = *pColors++;
-            unsigned char uchGreen = *pColors++;
-            unsigned char uchBlue = *pColors++;
+            png_color_8 clr;
+            clr.red   = *pColors++;
+            clr.green = *pColors++;
+            clr.blue  = *pColors++;
+            clr.gray  = 0;
+            clr.alpha = (bUsePalette && pAlpha) ? *pAlpha++ : 0; // use with wxPNG_TYPE_PALETTE only

 
             switch ( iColorType )
             {
                 default:
 
             switch ( iColorType )
             {
                 default:

-                    wxFAIL_MSG( _T("unknown wxPNG_TYPE_XXX") );
+                    wxFAIL_MSG( wxT("unknown wxPNG_TYPE_XXX") );

                     // fall through
 
                 case wxPNG_TYPE_COLOUR:
                     // fall through
 
                 case wxPNG_TYPE_COLOUR:

-                    *pData++ = uchRed;
+                    *pData++ = clr.red;

                     if ( iBitDepth == 16 )
                         *pData++ = 0;
                     if ( iBitDepth == 16 )
                         *pData++ = 0;

-                    *pData++ = uchGreen;
+                    *pData++ = clr.green;

                     if ( iBitDepth == 16 )
                         *pData++ = 0;
                     if ( iBitDepth == 16 )
                         *pData++ = 0;

-                    *pData++ = uchBlue;
+                    *pData++ = clr.blue;

                     if ( iBitDepth == 16 )
                         *pData++ = 0;
                     break;
                     if ( iBitDepth == 16 )
                         *pData++ = 0;
                     break;


@@ -848,9 +1024,9 @@ bool wxPNGHandler::SaveFile( wxImage *image, wxOutputStream& stream, bool verbos
                         // where do these coefficients come from? maybe we
                         // should have image options for them as well?
                         unsigned uiColor =
                         // 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);
+                            (unsigned) (76.544*(unsigned)clr.red +
+                                        150.272*(unsigned)clr.green +
+                                        36.864*(unsigned)clr.blue);

 
                         *pData++ = (unsigned char)((uiColor >> 8) & 0xFF);
                         if ( iBitDepth == 16 )
 
                         *pData++ = (unsigned char)((uiColor >> 8) & 0xFF);
                         if ( iBitDepth == 16 )


@@ -859,10 +1035,14 @@ bool wxPNGHandler::SaveFile( wxImage *image, wxOutputStream& stream, bool verbos
                     break;
 
                 case wxPNG_TYPE_GREY_RED:
                     break;
 
                 case wxPNG_TYPE_GREY_RED:

-                    *pData++ = uchRed;
+                    *pData++ = clr.red;

                     if ( iBitDepth == 16 )
                         *pData++ = 0;
                     break;
                     if ( iBitDepth == 16 )
                         *pData++ = 0;
                     break;

+
+                case wxPNG_TYPE_PALETTE:
+                    *pData++ = (unsigned char) PaletteFind(palette, clr);
+                    break;

             }
 
             if ( bUseAlpha )
             }
 
             if ( bUseAlpha )


@@ -873,9 +1053,9 @@ bool wxPNGHandler::SaveFile( wxImage *image, wxOutputStream& stream, bool verbos
 
                 if ( bHasMask )
                 {
 
                 if ( bHasMask )
                 {

-                    if ( (uchRed == uchMaskRed)
-                            && (uchGreen == uchMaskGreen)
-                                && (uchBlue == uchMaskBlue) )
+                    if ( (clr.red == mask.red)
+                            && (clr.green == mask.green)
+                                && (clr.blue == mask.blue) )

                         uchAlpha = 0;
                 }
 
                         uchAlpha = 0;
                 }
 


@@ -902,4 +1082,18 @@ bool wxPNGHandler::SaveFile( wxImage *image, wxOutputStream& stream, bool verbos
 
 #endif  // wxUSE_STREAMS
 
 
 #endif  // wxUSE_STREAMS
 

+/*static*/ wxVersionInfo wxPNGHandler::GetLibraryVersionInfo()
+{
+    // The version string seems to always have a leading space and a trailing
+    // new line, get rid of them both.
+    wxString str = png_get_header_version(NULL) + 1;
+    str.Replace("\n", "");
+
+    return wxVersionInfo("libpng",
+                         PNG_LIBPNG_VER_MAJOR,
+                         PNG_LIBPNG_VER_MINOR,
+                         PNG_LIBPNG_VER_RELEASE,
+                         str);
+}
+

 #endif  // wxUSE_LIBPNG
 #endif  // wxUSE_LIBPNG