}
// ----------------------------------------------------------------------------
-// SaveFile() helpers
+// SaveFile() palette helpers
// ----------------------------------------------------------------------------
-#if wxUSE_PALETTE
+typedef wxLongToLongHashMap PaletteMap;
-static int PaletteFind(const png_color& clr, const png_color *pal, int palCount)
+static unsigned long PaletteMakeKey(const png_color_8& clr)
{
- for (int i = 0; i < palCount; ++i)
- {
- if ( (clr.red == pal[i].red)
- && (clr.green == pal[i].green)
- && (clr.blue == pal[i].blue))
- {
- return i;
- }
- }
-
- return wxNOT_FOUND;
+ return (wxImageHistogram::MakeKey(clr.red, clr.green, clr.blue) << 8) | clr.alpha;
}
-#endif // wxUSE_PALETTE
+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
// explanation why this line is mandatory
png_set_write_fn( png_ptr, &wxinfo, wx_PNG_stream_writer, NULL);
+ const int iHeight = image->GetHeight();
+ const int iWidth = image->GetWidth();
+
const bool bHasPngFormatOption
= image->HasOption(wxIMAGE_OPTION_PNG_FORMAT);
bool bHasAlpha = image->HasAlpha();
bool bHasMask = image->HasMask();
+ bool bUsePalette = iColorType == wxPNG_TYPE_PALETTE
#if wxUSE_PALETTE
- /*
- Only save as an indexed image if the number of palette entries does not
- exceed libpng's limit (256).
- We assume here that we will need an extra palette entry if there's an
- alpha or mask, regardless of whether a possibly needed conversion from
- alpha to a mask fails (unlikely), or whether the mask colour already
- can be found in the palette (more likely). In the latter case an extra
- palette entry would not be required later on and the image could actually
- be saved as a palettised PNG (instead now it will be saved as true colour).
- A little bit of precision is lost, but at the benefit of a lot more
- simplified code.
- */
- bool bUsePalette =
- (!bHasPngFormatOption || iColorType == wxPNG_TYPE_PALETTE)
- && image->HasPalette()
- && image->GetPalette().GetColoursCount()
- + ((bHasAlpha || bHasMask) ? 1 : 0) <= PNG_MAX_PALETTE_LENGTH;
-
- wxImage temp_image(*image);
- if (bUsePalette && image->HasAlpha() && !bHasMask)
+ || (!bHasPngFormatOption && image->HasPalette() )
+#endif
+ ;
+
+ png_color_8 mask;
+
+ if (bHasMask)
+ {
+ mask.red = image->GetMaskRed();
+ mask.green = image->GetMaskGreen();
+ mask.blue = image->GetMaskBlue();
+ mask.alpha = 0;
+ mask.gray = 0;
+ }
+
+ PaletteMap palette;
+
+ if (bUsePalette)
{
- /*
- Only convert alpha to mask if saving as a palettised image was
- explicitly requested. We don't want to lose alpha's precision
- by converting to a mask just to be able to save palettised.
- */
- if (iColorType == wxPNG_TYPE_PALETTE
- && temp_image.ConvertAlphaToMask())
+ 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)
{
- image = &temp_image;
- bHasMask = true;
- bHasAlpha = image->HasAlpha();
+ // Mask must be first
+ PaletteAdd(&palette, mask);
}
- else
+
+ for (int y = 0; y < iHeight; y++)
{
- bUsePalette = false;
- iColorType = wxPNG_TYPE_COLOUR;
+ 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);
+ }
}
}
-#else
- bool bUsePalette = false;
-#endif // wxUSE_PALETTE
/*
If saving palettised was requested but it was decided we can't use a
bool bUseAlpha = !bUsePalette && (bHasAlpha || bHasMask);
- png_color mask;
- if (bHasMask)
- {
- mask.red = image->GetMaskRed();
- mask.green = image->GetMaskGreen();
- mask.blue = image->GetMaskBlue();
- }
-
-
int iPngColorType;
-#if wxUSE_PALETTE
if (bUsePalette)
{
iPngColorType = PNG_COLOR_TYPE_PALETTE;
iColorType = wxPNG_TYPE_PALETTE;
}
- else
-#endif // wxUSE_PALETTE
- if ( iColorType==wxPNG_TYPE_COLOUR )
+ else if ( iColorType==wxPNG_TYPE_COLOUR )
{
iPngColorType = bUseAlpha ? PNG_COLOR_TYPE_RGB_ALPHA
: PNG_COLOR_TYPE_RGB;
PNG_INTERLACE_NONE, PNG_COMPRESSION_TYPE_BASE,
PNG_FILTER_TYPE_BASE);
-#if wxUSE_PALETTE
- png_colorp palette = NULL;
- int numPalette = 0;
-
- if (bUsePalette)
- {
- const wxPalette& pal = image->GetPalette();
- const int palCount = pal.GetColoursCount();
- palette = (png_colorp) malloc(
- (palCount + 1 /*headroom for trans */) * sizeof(png_color));
-
- if (!palette)
- {
- png_destroy_write_struct( &png_ptr, (png_infopp)NULL );
- if (verbose)
- {
- wxLogError(_("Couldn't save PNG image."));
- }
- return false;
- }
-
- for (int i = 0; i < palCount; ++i)
- {
- pal.GetRGB(i, &palette[i].red, &palette[i].green, &palette[i].blue);
- }
-
- numPalette = palCount;
- if (bHasMask)
- {
- int index = PaletteFind(mask, palette, numPalette);
-
- if (index)
- {
- if (index == wxNOT_FOUND)
- {
- numPalette++;
- index = palCount;
- palette[index] = mask;
- }
-
- wxSwap(palette[0], palette[index]);
- }
-
- png_byte trans = 0;
- png_set_tRNS(png_ptr, info_ptr, &trans, 1, NULL);
- }
-
- png_set_PLTE(png_ptr, info_ptr, palette, numPalette);
- free (palette);
- palette = NULL;
-
- // Let palette point to libpng's copy of the palette.
- (void) png_get_PLTE(png_ptr, info_ptr, &palette, &numPalette);
- }
-#endif // wxUSE_PALETTE
-
int iElements;
png_color_8 sig_bit;
iElements = 1;
}
- if ( iPngColorType & PNG_COLOR_MASK_ALPHA )
+ if ( bUseAlpha )
{
sig_bit.alpha = (png_byte)iBitDepth;
iElements++;
return false;
}
- unsigned char *
- pAlpha = (unsigned char *)(bHasAlpha ? image->GetAlpha() : NULL);
- int iHeight = image->GetHeight();
- int iWidth = image->GetWidth();
+ 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++)
{
- png_color clr;
+ 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 )
{
*pData++ = 0;
break;
-#if wxUSE_PALETTE
case wxPNG_TYPE_PALETTE:
- *pData++ = (unsigned char) PaletteFind(clr,
- palette, numPalette);
+ *pData++ = (unsigned char) PaletteFind(palette, clr);
break;
-#endif // wxUSE_PALETTE
}
if ( bUseAlpha )
CPPUNIT_TEST( SizeImage );
CPPUNIT_TEST( CompareLoadedImage );
CPPUNIT_TEST( CompareSavedImage );
+ CPPUNIT_TEST( SavePNG );
CPPUNIT_TEST( SaveAnimatedGIF );
CPPUNIT_TEST( ReadCorruptedTGA );
CPPUNIT_TEST( GIFComment );
void SizeImage();
void CompareLoadedImage();
void CompareSavedImage();
+ void SavePNG();
void SaveAnimatedGIF();
void ReadCorruptedTGA();
void GIFComment();
CompareImage(*handler, expected24);
CompareImage(*handler, expected32, wxIMAGE_HAVE_ALPHA);
}
+}
+void ImageTestCase::SavePNG()
+{
+ wxImage expected24("horse.png");
+ CPPUNIT_ASSERT( expected24.IsOk() );
+#if wxUSE_PALETTE
+ CPPUNIT_ASSERT( !expected24.HasPalette() );
+#endif // #if wxUSE_PALETTE
- expected8.LoadFile("horse.gif");
- CPPUNIT_ASSERT( expected8.IsOk() );
+ wxImage expected8 = expected24.ConvertToGreyscale();
+
+ /*
+ horse.png converted to greyscale should be saved without a palette.
+ */
+ CompareImage(*wxImage::FindHandler(wxBITMAP_TYPE_PNG), expected8);
+
+ /*
+ But if we explicitly ask for trying to save with a palette, it should work.
+ */
+ expected8.SetOption(wxIMAGE_OPTION_PNG_FORMAT, wxPNG_TYPE_PALETTE);
+
+ CompareImage(*wxImage::FindHandler(wxBITMAP_TYPE_PNG),
+ expected8, wxIMAGE_HAVE_PALETTE);
+
+
+ CPPUNIT_ASSERT( expected8.LoadFile("horse.gif") );
#if wxUSE_PALETTE
CPPUNIT_ASSERT( expected8.HasPalette() );
#endif // #if wxUSE_PALETTE
+ CompareImage(*wxImage::FindHandler(wxBITMAP_TYPE_PNG),
+ expected8, wxIMAGE_HAVE_PALETTE);
+
+ /*
+ Add alpha to the image in such a way that there will still be a maximum
+ of 256 unique RGBA combinations. This should result in a saved
+ PNG image still being palettised and having alpha.
+ */
expected8.SetAlpha();
- width = expected8.GetWidth();
- height = expected8.GetHeight();
+ int x, y;
+ const int width = expected8.GetWidth();
+ const int height = expected8.GetHeight();
for (y = 0; y < height; ++y)
{
for (x = 0; x < width; ++x)
{
- expected8.SetAlpha(x, y, (x*y) & wxIMAGE_ALPHA_OPAQUE);
+ expected8.SetAlpha(x, y, expected8.GetRed(x, y));
}
}
- /*
- Explicitly make known we want a palettised PNG. If we don't then this
- particular image gets saved as a true colour image because there's an
- alpha channel present and the PNG saver prefers to keep the alpha over
- saving as a palettised image that has alpha converted to a mask.
- */
- expected8.SetOption(wxIMAGE_OPTION_PNG_FORMAT, wxPNG_TYPE_PALETTE);
-
- /*
- The image contains 256 indexed colours and needs another palette entry
- for storing the transparency index. This results in wanting 257 palette
- entries but that amount is not supported by PNG, as such this image
- should not contain a palette (but still have alpha) and be stored as a
- true colour image instead.
- */
CompareImage(*wxImage::FindHandler(wxBITMAP_TYPE_PNG),
- expected8, wxIMAGE_HAVE_ALPHA);
+ expected8, wxIMAGE_HAVE_ALPHA|wxIMAGE_HAVE_PALETTE);
-#if wxUSE_PALETTE
/*
- Now do the same test again but remove one (random) palette entry. This
- should result in saving the PNG with a palette.
+ Now change the alpha of the first pixel so that we can't save palettised
+ anymore because there will be 256+1 entries which is beyond PNGs limit
+ of 256 entries.
*/
- unsigned char red[256], green[256], blue[256];
- const wxPalette& pal = expected8.GetPalette();
- const int paletteCount = pal.GetColoursCount();
- for (i = 0; i < paletteCount; ++i)
- {
- expected8.GetPalette().GetRGB(i, &red[i], &green[i], &blue[i]);
- }
- wxPalette newPal(paletteCount - 1, red, green, blue);
- expected8.Replace(
- red[paletteCount-1], green[paletteCount-1], blue[paletteCount-1],
- red[paletteCount-2], green[paletteCount-2], blue[paletteCount-2]);
-
- expected8.SetPalette(newPal);
+ expected8.SetAlpha(0, 0, 1);
- wxImage ref8 = expected8;
+ CompareImage(*wxImage::FindHandler(wxBITMAP_TYPE_PNG),
+ expected8, wxIMAGE_HAVE_ALPHA);
/*
- Convert the alpha channel to a mask like the PNG saver does. Also convert
- the colour used for transparency from 1,0,0 to 2,0,0. The latter gets
- done by the PNG loader in search of an unused colour to use for
- transparency (this should be fixed).
+ Even if we explicitly ask for saving palettised it should not be done.
*/
- ref8.ConvertAlphaToMask();
- ref8.Replace(1, 0, 0, 2, 0, 0);
-
+ expected8.SetOption(wxIMAGE_OPTION_PNG_FORMAT, wxPNG_TYPE_PALETTE);
CompareImage(*wxImage::FindHandler(wxBITMAP_TYPE_PNG),
- expected8, wxIMAGE_HAVE_PALETTE, &ref8);
-#endif
+ expected8, wxIMAGE_HAVE_ALPHA);
+
}
void ImageTestCase::SaveAnimatedGIF()
projects / wxWidgets.git / commitdiff
