diff options
Diffstat (limited to 'vcl/source/bitmap/BitmapScaleSuperFilter.cxx')
| -rw-r--r-- | vcl/source/bitmap/BitmapScaleSuperFilter.cxx | 28 |
1 files changed, 21 insertions, 7 deletions
diff --git a/vcl/source/bitmap/BitmapScaleSuperFilter.cxx b/vcl/source/bitmap/BitmapScaleSuperFilter.cxx index 26ea43af44a8..54f22f2dc5d8 100644 --- a/vcl/source/bitmap/BitmapScaleSuperFilter.cxx +++ b/vcl/source/bitmap/BitmapScaleSuperFilter.cxx @@ -1049,10 +1049,12 @@ BitmapEx BitmapScaleSuperFilter::execute(BitmapEx const& rBitmap) const { Bitmap::ScopedReadAccess pReadAccess(aBitmap); - sal_Int16 nTargetBitcount = aBitmap.GetBitCount() == 32 ? 32 : 24; + sal_uInt16 nSourceBitcount = aBitmap.GetBitCount(); - Bitmap aOutBmp(Size(nDstW, nDstH), nTargetBitcount); + Bitmap aOutBmp(Size(nDstW, nDstH), std::max(nSourceBitcount, sal_uInt16(24))); Size aOutSize = aOutBmp.GetSizePixel(); + sal_uInt16 nTargetBitcount = aOutBmp.GetBitCount(); + if (!aOutSize.Width() || !aOutSize.Height()) { SAL_WARN("vcl.gdi", "bmp creation failed"); @@ -1076,7 +1078,10 @@ BitmapEx BitmapScaleSuperFilter::execute(BitmapEx const& rBitmap) const bVMirr, bHMirr ); bool bScaleUp = fScaleX >= fScaleThresh && fScaleY >= fScaleThresh; - if( pReadAccess->HasPalette() ) + // If we have a source bitmap with a palette the scaling converts + // from up to 8 bit image -> 24 bit non-palette, which is then + // adapted back to the same type as original. + if (pReadAccess->HasPalette()) { switch( pReadAccess->GetScanlineFormat() ) { @@ -1090,21 +1095,30 @@ BitmapEx BitmapScaleSuperFilter::execute(BitmapEx const& rBitmap) const break; } } + // Here we know that we are dealing with a non-palette source bitmap. + // The target is either 24 or 32 bit, depending on the image and + // the capabilities of the backend. If for some reason the destination + // is not the same bit-depth as the source, then we can't use + // a fast path, so we always need to process with a general scaler. + else if (nSourceBitcount != nTargetBitcount) + { + pScaleRangeFn = bScaleUp ? scaleUpNonPalleteGeneral : scaleDownNonPalleteGeneral; + } + // If we get here then we can only use a fast path, but let's + // still keep the fallback to the general scaler alive. else { switch( pReadAccess->GetScanlineFormat() ) { case ScanlineFormat::N24BitTcBgr: case ScanlineFormat::N24BitTcRgb: - pScaleRangeFn = bScaleUp ? scaleUp24bit - : scaleDown24bit; + pScaleRangeFn = bScaleUp ? scaleUp24bit : scaleDown24bit; break; case ScanlineFormat::N32BitTcRgba: case ScanlineFormat::N32BitTcBgra: case ScanlineFormat::N32BitTcArgb: case ScanlineFormat::N32BitTcAbgr: - pScaleRangeFn = bScaleUp ? scaleUp32bit - : scaleDown32bit; + pScaleRangeFn = bScaleUp ? scaleUp32bit : scaleDown32bit; break; default: pScaleRangeFn = bScaleUp ? scaleUpNonPalleteGeneral |