diff options
author | Thorsten Behrens <thorsten.behrens@allotropia.de> | 2023-08-06 01:19:17 +0200 |
---|---|---|
committer | Noel Grandin <noel.grandin@collabora.co.uk> | 2023-08-06 12:23:07 +0200 |
commit | ad1f69d28d31725a22e7e1cbb4d950aa9ad3bea7 (patch) | |
tree | f3c553d612f3db55d778ac5835bd1938799d7173 | |
parent | f454a774053d2f631009612c78713822f6afdbd2 (diff) |
tdf#156540 invert alpha mask when drawing sprites
Due to the switch from transparency to alpha in commit
81994cb2b8b32453a92bcb011830fcb884f22ff3, a sprite's
alpha mask needs to be inverted.
Additionally, fixes an oversight in vcl's alpha.cxx, where manual
blend math got mangled, also in
81994cb2b8b32453a92bcb011830fcb884f22ff3.
Change-Id: I8ebbbc7fe624d8dfc8121d8814d30875c498870d
Reviewed-on: https://gerrit.libreoffice.org/c/core/+/155378
Reviewed-by: Patrick Luby <plubius@neooffice.org>
Tested-by: Jenkins
Reviewed-by: Noel Grandin <noel.grandin@collabora.co.uk>
-rw-r--r-- | canvas/source/vcl/spritehelper.cxx | 6 | ||||
-rw-r--r-- | vcl/source/bitmap/alpha.cxx | 4 |
2 files changed, 6 insertions, 4 deletions
diff --git a/canvas/source/vcl/spritehelper.cxx b/canvas/source/vcl/spritehelper.cxx index 3494a5fbda8f..f188526930a0 100644 --- a/canvas/source/vcl/spritehelper.cxx +++ b/canvas/source/vcl/spritehelper.cxx @@ -134,12 +134,14 @@ namespace vclcanvas // sprite content might contain alpha, create // BmpEx, then. BitmapEx aMask( mpBackBufferMask->getOutDev().GetBitmapEx( aEmptyPoint, - aOutputSize ) ); + aOutputSize ) ); + AlphaMask aAlpha( aMask.GetBitmap() ); + aAlpha.Invert(); // Note: since we retrieved aBmp and aMask // directly from an OutDev, it's already a // 'display bitmap' on windows. - maContent = BitmapEx( aBmp.GetBitmap(), AlphaMask( aMask.GetBitmap()) ); + maContent = BitmapEx( aBmp.GetBitmap(), aAlpha ); } } diff --git a/vcl/source/bitmap/alpha.cxx b/vcl/source/bitmap/alpha.cxx index 8e082c695137..ff0d035d52d1 100644 --- a/vcl/source/bitmap/alpha.cxx +++ b/vcl/source/bitmap/alpha.cxx @@ -118,8 +118,8 @@ void AlphaMask::BlendWith(const AlphaMask& rOther) // Awkward calculation because the original used transparency, and to replicate // the logic we need to translate into transparency, perform the original logic, // then translate back to alpha. - auto tmp = 255 - ((255 - nGrey1) + (255 - nGrey2) - (255 - nGrey1) * (255 - nGrey2)); - *scanline = static_cast<sal_uInt8>(tmp / 255); + auto tmp = 255 - ((255 - nGrey1) + (255 - nGrey2) - (255 - nGrey1) * (255 - nGrey2) / 255); + *scanline = static_cast<sal_uInt8>(tmp); ++scanline; ++otherScanline; } |