// declarations
// ============================================================================
-#ifdef __GNUG__
+#if defined(__GNUG__) && !defined(NO_GCC_PRAGMA)
#pragma implementation "imagpng.h"
#endif
// 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);
+CheckTransparency(unsigned char **lines,
+ png_uint_32 x, png_uint_32 y, png_uint_32 w, png_uint_32 h,
+ size_t numColBytes);
// 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);
FindMaskColour(unsigned char **lines, png_uint_32 width, png_uint_32 height,
unsigned char& rMask, unsigned char& gMask, unsigned char& bMask);
+// is the pixel with this value of alpha a fully opaque one?
+static inline
+bool IsOpaque(unsigned char a)
+{
+ return a == 0xff;
+}
+
+// is the pixel with this value of alpha a fully transparent one?
+static inline
+bool IsTransparent(unsigned char a)
+{
+ return !a;
+}
+
// ============================================================================
// wxPNGHandler implementation
// ============================================================================
extern "C"
{
-void PNGLINKAGEMODE _PNG_stream_reader( png_structp png_ptr, png_bytep data, png_size_t length )
+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);
}
-void PNGLINKAGEMODE _PNG_stream_writer( png_structp png_ptr, png_bytep data, png_size_t length )
+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);
}
// from pngerror.c
// so that the libpng doesn't send anything on stderr
void
-PNGLINKAGEMODE wx_png_error(png_structp png_ptr, png_const_charp message)
+PNGLINKAGEMODE wx_png_error(png_structp WXUNUSED(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,info->jmpbuf,sizeof(jmp_buf));
- longjmp(jmpbuf, 1);
- }
-#else
- longjmp(info->jmpbuf, 1);
-#endif
+ wxLogFatalError( wxString::FromAscii(message) );
}
void
PNGLINKAGEMODE wx_png_warning(png_structp png_ptr, png_const_charp message)
{
- wxPNGInfoStruct *info = WX_PNG_INFO(png_ptr);
- if (info->verbose)
+ wxPNGInfoStruct *info = png_ptr ? WX_PNG_INFO(png_ptr) : NULL;
+ if ( !info || info->verbose )
wxLogWarning( wxString::FromAscii(message) );
}
// LoadFile() helpers
// ----------------------------------------------------------------------------
+// determine the kind of transparency we need for this image: if the only alpha
+// values it has are 0 (transparent) and 0xff (opaque) then we can simply
+// create a mask for it, we should be ok with a simple mask but otherwise we
+// need a full blown alpha channel in wxImage
+//
+// parameters:
+// lines raw PNG data
+// x, y starting position
+// w, h size of the image
+// numColBytes number of colour bytes (1 for grey scale, 3 for RGB)
+// (NB: alpha always follows the colour bytes)
Transparency
-CheckTransparency(const unsigned char *ptr,
- png_uint_32 x, png_uint_32 y, png_uint_32 w, png_uint_32 h)
+CheckTransparency(unsigned char **lines,
+ png_uint_32 x, png_uint_32 y, png_uint_32 w, png_uint_32 h,
+ size_t numColBytes)
{
- // 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++ )
+ // suppose that a mask will suffice and check all the remaining alpha
+ // values to see if it does
+ for ( ; y < h; y++ )
{
- for ( png_uint_32 x2 = x + 1; x2 < w; x2++ )
+ // each pixel is numColBytes+1 bytes, offset into the current line by
+ // the current x position
+ unsigned const char *ptr = lines[y] + (x * (numColBytes + 1));
+
+ for ( png_uint_32 x2 = x; x2 < w; x2++ )
{
- // skip the grey byte
- a2 = *++ptr2;
+ // skip the grey or colour byte(s)
+ ptr += numColBytes;
- if ( a2 && a2 != 0xff )
+ unsigned char a2 = *ptr++;
+
+ if ( !IsTransparent(a2) && !IsOpaque(a2) )
{
- // not fully opeaque nor fully transparent, hence need alpha
- transparency = Transparency_Alpha;
- break;
+ // not fully opaque nor fully transparent, hence need alpha
+ return Transparency_Alpha;
}
-
- ++ptr2;
}
- if ( transparency == Transparency_Alpha )
- {
- // no need to continue
- break;
- }
+ // during the next loop iteration check all the pixels in the row
+ x = 0;
}
- return transparency;
+ // mask will be enough
+ return Transparency_Mask;
}
unsigned char *InitAlpha(wxImage *image, png_uint_32 x, png_uint_32 y)
unsigned char *alpha = image->GetAlpha();
// set alpha for the pixels we had so far
- for ( png_uint_32 y2 = 0; y2 <= y; y2++ )
+ png_uint_32 end = y * image->GetWidth() + x;
+ for ( png_uint_32 i = 0; i < end; i++ )
{
- for ( png_uint_32 x2 = 0; x2 < x; x2++ )
- {
- // all the previous pixels were opaque
- *alpha++ = 0xff;
- }
+ // all the previous pixels were opaque
+ *alpha++ = 0xff;
}
return alpha;
unsigned char hdr[4];
if ( !stream.Read(hdr, WXSIZEOF(hdr)) )
- return FALSE;
+ return false;
return memcmp(hdr, "\211PNG", WXSIZEOF(hdr)) == 0;
}
// the first time we encounter a transparent pixel we must
// decide about what to do about them
- if ( a != 0xff && transparency == Transparency_None )
+ if ( !IsOpaque(a) && 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);
+ transparency = CheckTransparency
+ (
+ lines,
+ x, y,
+ width, height,
+ 1
+ );
if ( transparency == Transparency_Mask )
{
switch ( transparency )
{
+ case Transparency_Mask:
+ if ( IsTransparent(a) )
+ {
+ *ptrDst++ = rMask;
+ *ptrDst++ = bMask;
+ *ptrDst++ = gMask;
+ 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") );
+
+ // fall through
+
case Transparency_Alpha:
- *alpha++ = a;
+ if ( alpha )
+ *alpha++ = a;
// fall through
case Transparency_None:
*ptrDst++ = g;
*ptrDst++ = g;
break;
-
- case Transparency_Mask:
- *ptrDst++ = rMask;
- *ptrDst++ = bMask;
- *ptrDst++ = gMask;
}
}
}
// the logic here is the same as for the grey case except
// where noted
- if ( a != 0xff && transparency == Transparency_None )
+ if ( !IsOpaque(a) && transparency == Transparency_None )
{
- transparency = CheckTransparency(ptrSrc, x, y,
- width, height);
+ transparency = CheckTransparency
+ (
+ lines,
+ x, y,
+ width, height,
+ 3
+ );
if ( transparency == Transparency_Mask )
{
switch ( transparency )
{
+ case Transparency_Mask:
+ if ( IsTransparent(a) )
+ {
+ *ptrDst++ = rMask;
+ *ptrDst++ = bMask;
+ *ptrDst++ = gMask;
+ 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") );
+
+ // 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++;
+ }
+ }
+
+ // fall through
+
case Transparency_Alpha:
- *alpha++ = a;
+ if ( alpha )
+ *alpha++ = a;
// fall through
case Transparency_None:
*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;
}
}
}
image->Destroy();
- png_structp png_ptr = png_create_read_struct( PNG_LIBPNG_VER_STRING,
- (voidp) NULL,
- (png_error_ptr) NULL,
- (png_error_ptr) NULL );
+ png_structp png_ptr = png_create_read_struct
+ (
+ PNG_LIBPNG_VER_STRING,
+ (voidp) NULL,
+ wx_png_error,
+ wx_png_warning
+ );
if (!png_ptr)
goto error;
- 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);
+ png_set_read_fn( png_ptr, &wxinfo, wx_PNG_stream_reader);
info_ptr = png_create_info_struct( png_ptr );
if (!info_ptr)
png_set_expand( png_ptr );
png_set_filler( png_ptr, 0xff, PNG_FILLER_AFTER );
- image->Create( (int)width, (int)height );
+ image->Create((int)width, (int)height, (bool) false /* no need to init pixels */);
if (!image->Ok())
goto error;
free( lines[i] );
free( lines );
- return TRUE;
+ return true;
error:
if (verbose)
else
png_destroy_read_struct( &png_ptr, (png_infopp) NULL, (png_infopp) NULL );
}
- return FALSE;
+ return false;
}
// ----------------------------------------------------------------------------
wxinfo.verbose = verbose;
wxinfo.stream.out = &stream;
- png_structp png_ptr = png_create_write_struct( PNG_LIBPNG_VER_STRING, NULL, NULL, NULL);
+ png_structp png_ptr = png_create_write_struct
+ (
+ PNG_LIBPNG_VER_STRING,
+ NULL,
+ wx_png_error,
+ wx_png_warning
+ );
if (!png_ptr)
{
if (verbose)
wxLogError(_("Couldn't save PNG image."));
- return FALSE;
+ return false;
}
- png_set_error_fn(png_ptr, (png_voidp)NULL, wx_png_error, wx_png_warning);
-
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;
+ return false;
}
if (setjmp(wxinfo.jmpbuf))
png_destroy_write_struct( &png_ptr, (png_infopp)NULL );
if (verbose)
wxLogError(_("Couldn't save PNG image."));
- return FALSE;
+ return false;
}
// 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_write_fn( png_ptr, &wxinfo, wx_PNG_stream_writer, NULL);
+
+ 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;
- 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);
+ wxASSERT_MSG( iBitDepth == 8 || iBitDepth == 16,
+ _T("PNG bit depth must be 8 or 16") );
+ 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;
+ }
+
+ 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;
- 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;
+
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;
+ 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();
}
- for (int y = 0; y < image->GetHeight(); y++)
+ unsigned char *pColors = image->GetData();
+
+ for (int y = 0; y != iHeight; ++y)
{
- unsigned char *ptr = image->GetData() + (y * image->GetWidth() * 3);
- for (int x = 0; x < image->GetWidth(); x++)
+ 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->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( _T("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_write_end( png_ptr, info_ptr );
png_destroy_write_struct( &png_ptr, (png_infopp)&info_ptr );
- return TRUE;
+ return true;
}
#ifdef __VISUALC__
projects / wxWidgets.git / blobdiff