commit bed03b80139322dc361291eed76345acc8be9e5c
author Patrick Luby <guibmacdev@gmail.com> Thu Jun 27 11:15:52 2024 -0400
committer Patrick Luby <guibomacdev@gmail.com> Fri Jun 28 13:35:36 2024 +0200
tree 1c26536c7d6dbbb709aaab295abc1035a27833b9
parent 5f447e9d4e3781c5950b1e5a50da358dc60b305d

tdf#161498 use COL_ALPHA_OPAQUE for finding opaque pixels

Starting with commit 81994cb2b8b32453a92bcb011830fcb884f22ff3,
pixels now contain an alpha value instead of a transparency
value.

Change-Id: I07dd39859057bbbbd153a21ee38625049039b106
Reviewed-on: https://gerrit.libreoffice.org/c/core/+/169654
Tested-by: Jenkins
Reviewed-by: Noel Grandin <noel.grandin@collabora.co.uk>
Reviewed-by: Patrick Luby <guibomacdev@gmail.com>
(cherry picked from commit 1ac602f6ccd75f3b79d6c7a9d40e64677dd5741a)
Reviewed-on: https://gerrit.libreoffice.org/c/core/+/169666

vcl/source/bitmap/BitmapEx.cxx

diff --git a/vcl/source/bitmap/BitmapEx.cxx b/vcl/source/bitmap/BitmapEx.cxx
index 0d1216b..ebcb7aa 100644
--- a/vcl/source/bitmap/BitmapEx.cxx
+++ b/vcl/source/bitmap/BitmapEx.cxx
@@ -1286,7 +1286,11 @@ tools::Polygon  BitmapEx::GetContour( bool bContourEdgeDetect,
            std::unique_ptr<Point[]> pPoints2;
            tools::Long                nX, nY;
            sal_uInt16              nPolyPos = 0;
            const BitmapColor   aBlack = pAcc->GetBestMatchingColor( COL_BLACK );
            // tdf#161498 use COL_ALPHA_OPAQUE for finding opaque pixels
            // Starting with commit 81994cb2b8b32453a92bcb011830fcb884f22ff3,
            // pixels now contain an alpha value instead of a transparency
            // value.
            const BitmapColor   aTransparencyOpaque = pAcc->GetBestMatchingColor( COL_ALPHA_OPAQUE );

            pPoints1.reset(new Point[ nHeight ]);
            pPoints2.reset(new Point[ nHeight ]);
@@ -1299,7 +1303,7 @@ tools::Polygon  BitmapEx::GetContour( bool bContourEdgeDetect,
                // scan row from left to right
                while( nX < nEndX1 )
                {
                    if( aBlack == pAcc->GetPixelFromData( pScanline, nX ) )
                    if( aTransparencyOpaque == pAcc->GetPixelFromData( pScanline, nX ) )
                    {
                        pPoints1[ nPolyPos ] = Point( nX, nY );
                        nX = nStartX2;
@@ -1307,7 +1311,7 @@ tools::Polygon  BitmapEx::GetContour( bool bContourEdgeDetect,
                        // this loop always breaks eventually as there is at least one pixel
                        while( true )
                        {
                            if( aBlack == pAcc->GetPixelFromData( pScanline, nX ) )
                            if( aTransparencyOpaque == pAcc->GetPixelFromData( pScanline, nX ) )
                            {
                                pPoints2[ nPolyPos ] = Point( nX, nY );
                                break;