diff options
| -rw-r--r-- | vcl/quartz/salbmp.cxx | 28 |
1 files changed, 27 insertions, 1 deletions
diff --git a/vcl/quartz/salbmp.cxx b/vcl/quartz/salbmp.cxx index afd65d863370..ab435c0acdfc 100644 --- a/vcl/quartz/salbmp.cxx +++ b/vcl/quartz/salbmp.cxx @@ -560,7 +560,33 @@ CGImageRef QuartzSalBitmap::CreateColorMask( int nX, int nY, int nWidth, sal_uInt32 x = nWidth; while( x-- ) { - *pDest++ = (pSourcePixels->readPixel() == 0) ? nColor : 0; + // Fix failure to generate the correct color mask + // OutputDevice::ImplDrawRotateText() draws black text but + // that will generate gray pixels due to antialiasing so + // count dark gray the same as black, light gray the same + // as white, and the rest as medium gray. + // The results are not smooth since LibreOffice appears to + // redraw these semi-transparent masks repeatedly without + // clearing the background so the semi-transparent pixels + // will grow darker with repeatedly redraws due to + // cumulative blending. But it is now better than before. + sal_uInt8 nAlpha = 255 - pSourcePixels->readPixel().GetRed(); + sal_uInt32 nPremultColor = nColor; + if ( nAlpha < 192 ) + { + if ( nAlpha < 64 ) + { + nPremultColor = 0; + } + else + { + reinterpret_cast<sal_uInt8*>(&nPremultColor)[0] /= 2; + reinterpret_cast<sal_uInt8*>(&nPremultColor)[1] /= 2; + reinterpret_cast<sal_uInt8*>(&nPremultColor)[2] /= 2; + reinterpret_cast<sal_uInt8*>(&nPremultColor)[3] /= 2; + } + } + *pDest++ = nPremultColor; } pSource += mnBytesPerRow; } |