vcl/source/bitmap/bitmap.cxx | 44 ++++++++++++++++++++++++++++++++++++++-----
1 file changed, 39 insertions(+), 5 deletions(-)
New commits:
commit 20854a6715154836e05b98d2e365f994d19ed676
Author: Noel Grandin <noel.gran...@collabora.co.uk>
AuthorDate: Fri Aug 8 15:48:49 2025 +0200
Commit: Noel Grandin <noel.gran...@collabora.co.uk>
CommitDate: Sat Aug 9 11:07:45 2025 +0200
tdf#167867 Start center: transparency is missing in logo (GEN)
regression from
commit 2939f4b52d96ef0bd76896dc857f43d4de402d25
Author: Noel Grandin <noel.gran...@collabora.co.uk>
Date: Tue Aug 5 08:26:05 2025 +0200
BitmapEx->Bitmap in CanvasBitmap
which flushed out the fact that the cairo/gen backend
is being very weird when drawing images with alpha,
which is what we are doing in
Bitmap::Bitmap(const BitmapEx&)
Hit it with a large and ugly hammer for now,
long run we won't need this conversion.
Change-Id: Ia7a09402caf2c8d19833fda828a6b3050cb90604
Reviewed-on: https://gerrit.libreoffice.org/c/core/+/189197
Reviewed-by: Noel Grandin <noel.gran...@collabora.co.uk>
Tested-by: Jenkins
diff --git a/vcl/source/bitmap/bitmap.cxx b/vcl/source/bitmap/bitmap.cxx
index 72a84373d14f..4c261c862857 100644
--- a/vcl/source/bitmap/bitmap.cxx
+++ b/vcl/source/bitmap/bitmap.cxx
@@ -143,11 +143,45 @@ Bitmap::Bitmap(const BitmapEx& rBitmapEx)
mxSalBmp = rBitmapEx.GetBitmap().mxSalBmp;
else
{
- ScopedVclPtrInstance<VirtualDevice> xDev(DeviceFormat::WITH_ALPHA);
- Size aPixelSize = rBitmapEx.GetSizePixel();
- xDev->SetOutputSizePixel(aPixelSize, /*bErase*/true,
/*bAlphaMaskTransparent*/true);
- xDev->DrawBitmapEx(Point(0, 0), aPixelSize, rBitmapEx);
- mxSalBmp = xDev->GetBitmap(Point(0,0), aPixelSize).mxSalBmp;
+ Size aSize = rBitmapEx.GetSizePixel();
+ static const BitmapPalette aPalEmpty;
+ mxSalBmp = ImplGetSVData()->mpDefInst->CreateSalBitmap();
+ mxSalBmp->Create(aSize, vcl::PixelFormat::N32_BPP, aPalEmpty);
+
+ BitmapScopedReadAccess pReadColorAcc(rBitmapEx.GetBitmap());
+ BitmapScopedReadAccess pReadAlphaAcc(rBitmapEx.GetAlphaMask());
+ BitmapScopedWriteAccess pWriteAcc(*this);
+ auto nHeight = pReadColorAcc->Height();
+ auto nWidth = pReadColorAcc->Width();
+ bool bPalette = pReadColorAcc->HasPalette();
+
+ for ( tools::Long nY = 0; nY < nHeight; nY++ )
+ {
+ Scanline pScanlineColor = pReadColorAcc->GetScanline( nY );
+ Scanline pScanlineAlpha = pReadAlphaAcc->GetScanline( nY );
+ Scanline pScanlineWrite = pWriteAcc->GetScanline( nY );
+ for (tools::Long nX = 0; nX < nWidth; ++nX)
+ {
+ BitmapColor aCol;
+ if (bPalette)
+ aCol =
pReadColorAcc->GetPaletteColor(pReadColorAcc->GetIndexFromData(pScanlineColor,
nX));
+ else
+ aCol = pReadColorAcc->GetPixelFromData(pScanlineColor, nX);
+ auto nAlpha = pReadAlphaAcc->GetPixelFromData(pScanlineAlpha,
nX).GetIndex();
+ aCol.SetAlpha(nAlpha);
+ pWriteAcc->SetPixelOnData(pScanlineWrite, nX, aCol);
+ }
+ }
+
+// So.... in theory the following code should work, and be much more
efficient. In practice, the gen/cairo
+// code is doing something weird involving masks that results in alpha not
doing the same thing as on the other
+// backends.
+// ScopedVclPtrInstance<VirtualDevice> xDev(DeviceFormat::WITH_ALPHA);
+// Size aPixelSize = rBitmapEx.GetSizePixel();
+// xDev->SetOutputSizePixel(aPixelSize, /*bErase*/true,
/*bAlphaMaskTransparent*/true);
+// xDev->DrawBitmapEx(Point(0, 0), aPixelSize, rBitmapEx);
+// mxSalBmp = xDev->GetBitmap(Point(0,0), aPixelSize).mxSalBmp;
+
}
}
