include/vcl/outdev.hxx | 10 --
vcl/source/outdev/bitmap.cxx | 155 +++++++++++++++++++++----------------------
2 files changed, 76 insertions(+), 89 deletions(-)
New commits:
commit 0de1d5e85efb70c2c28eedf783aaab9097460927
Author: Christopher Sherlock <chris.sherloc...@gmail.com>
AuthorDate: Mon Jul 28 16:39:26 2025 +1000
Commit: Noel Grandin <noel.gran...@collabora.co.uk>
CommitDate: Tue Jul 29 13:12:12 2025 +0200
Make function that blends bitmaps be local
Change-Id: I81dc7474b603e3fb1eca2d7606f71999b2f87749
Reviewed-on: https://gerrit.libreoffice.org/c/core/+/188459
Reviewed-by: Noel Grandin <noel.gran...@collabora.co.uk>
Tested-by: Jenkins
diff --git a/include/vcl/outdev.hxx b/include/vcl/outdev.hxx
index 1b4ad3210631..9f9b04b34e93 100644
--- a/include/vcl/outdev.hxx
+++ b/include/vcl/outdev.hxx
@@ -1461,16 +1461,6 @@ private:
tools::Rectangle aDstRect, tools::Rectangle
aBmpRect,
Size const & aOutSz, Point const & aOutPt);
-
- static SAL_DLLPRIVATE Bitmap BlendBitmapWithAlpha(
- Bitmap& aBmp,
- BitmapReadAccess const * pP,
- BitmapReadAccess const * pA,
- const sal_Int32 nDstHeight,
- const sal_Int32 nDstWidth,
- const sal_Int32* pMapX,
- const sal_Int32* pMapY );
-
///@}
diff --git a/vcl/source/outdev/bitmap.cxx b/vcl/source/outdev/bitmap.cxx
index 4205188fab36..9b878363a55b 100644
--- a/vcl/source/outdev/bitmap.cxx
+++ b/vcl/source/outdev/bitmap.cxx
@@ -411,6 +411,81 @@ private:
};
+// Co = Cs + Cd*(1-As) premultiplied alpha -or-
+// Co = (AsCs + AdCd*(1-As)) / Ao
+sal_uInt8 CalcColor( const sal_uInt8 nSourceColor, const sal_uInt8
nSourceAlpha,
+ const sal_uInt8 nDstAlpha, const sal_uInt8
nResAlpha, const sal_uInt8 nDestColor )
+{
+ int c = nResAlpha ? ( static_cast<int>(nSourceAlpha)*nSourceColor +
static_cast<int>(nDstAlpha)*nDestColor -
+
static_cast<int>(nDstAlpha)*nDestColor*nSourceAlpha/255 ) /
static_cast<int>(nResAlpha) : 0;
+ return sal_uInt8( c );
+}
+
+BitmapColor AlphaBlend( int nX, int nY,
+ const tools::Long nMapX,
+ const tools::Long nMapY,
+ BitmapReadAccess const * pP,
+ BitmapReadAccess const * pA,
+ BitmapReadAccess const * pB)
+{
+ BitmapColor aDstCol,aSrcCol;
+ aSrcCol = pP->GetColor( nMapY, nMapX );
+ aDstCol = pB->GetColor( nY, nX );
+
+ const sal_uInt8 nSrcAlpha = pA->GetPixelIndex( nMapY, nMapX );
+ const sal_uInt8 nDstAlpha = aDstCol.GetAlpha();
+
+ // Perform porter-duff compositing 'over' operation
+
+ // Co = Cs + Cd*(1-As)
+ // Ad = As + Ad*(1-As)
+ sal_uInt8 nResAlpha = static_cast<int>(nSrcAlpha) +
static_cast<int>(nDstAlpha)
+ - static_cast<int>(nDstAlpha) * nSrcAlpha / 255;
+ aDstCol.SetAlpha(nResAlpha);
+ aDstCol.SetRed( CalcColor( aSrcCol.GetRed(), nSrcAlpha, nDstAlpha,
nResAlpha, aDstCol.GetRed() ) );
+ aDstCol.SetBlue( CalcColor( aSrcCol.GetBlue(), nSrcAlpha, nDstAlpha,
nResAlpha, aDstCol.GetBlue() ) );
+ aDstCol.SetGreen( CalcColor( aSrcCol.GetGreen(), nSrcAlpha, nDstAlpha,
nResAlpha, aDstCol.GetGreen() ) );
+
+ return aDstCol;
+}
+
+Bitmap lcl_BlendBitmapWithAlpha(
+ Bitmap& aBmp,
+ BitmapReadAccess const * pP,
+ BitmapReadAccess const * pA,
+ const sal_Int32 nDstHeight,
+ const sal_Int32 nDstWidth,
+ const sal_Int32* pMapX,
+ const sal_Int32* pMapY )
+
+{
+ Bitmap res;
+
+ {
+ BitmapScopedWriteAccess pB(aBmp);
+ if (pB && pP && pA)
+ {
+ for( int nY = 0; nY < nDstHeight; nY++ )
+ {
+ const tools::Long nMapY = pMapY[ nY ];
+ Scanline pScanlineB = pB->GetScanline(nY);
+
+ for( int nX = 0; nX < nDstWidth; nX++ )
+ {
+ const tools::Long nMapX = pMapX[ nX ];
+ BitmapColor aDstCol = AlphaBlend(nX, nY, nMapX, nMapY, pP,
pA, pB.get());
+
+ pB->SetPixelOnData(pScanlineB, nX, aDstCol);
+ }
+ }
+ }
+ pB.reset();
+ res = aBmp;
+ }
+
+ return res;
+}
+
} // end anonymous namespace
void OutputDevice::DrawDeviceAlphaBitmapSlowPath(const Bitmap& rBitmap,
@@ -466,7 +541,7 @@ void OutputDevice::DrawDeviceAlphaBitmapSlowPath(const
Bitmap& rBitmap,
{
Bitmap aNewBitmap;
- aNewBitmap = BlendBitmapWithAlpha(
+ aNewBitmap = lcl_BlendBitmapWithAlpha(
aBmp, pBitmapReadAccess.get(), pAlphaReadAccess.get(),
nDstHeight,
nDstWidth,
@@ -514,82 +589,4 @@ void OutputDevice::DrawImage( const Point& rPos, const
Size& rSize,
}
}
-namespace
-{
- // Co = Cs + Cd*(1-As) premultiplied alpha -or-
- // Co = (AsCs + AdCd*(1-As)) / Ao
- sal_uInt8 CalcColor( const sal_uInt8 nSourceColor, const sal_uInt8
nSourceAlpha,
- const sal_uInt8 nDstAlpha, const sal_uInt8
nResAlpha, const sal_uInt8 nDestColor )
- {
- int c = nResAlpha ? ( static_cast<int>(nSourceAlpha)*nSourceColor +
static_cast<int>(nDstAlpha)*nDestColor -
-
static_cast<int>(nDstAlpha)*nDestColor*nSourceAlpha/255 ) /
static_cast<int>(nResAlpha) : 0;
- return sal_uInt8( c );
- }
-
- BitmapColor AlphaBlend( int nX, int nY,
- const tools::Long nMapX,
- const tools::Long nMapY,
- BitmapReadAccess const * pP,
- BitmapReadAccess const * pA,
- BitmapReadAccess const * pB)
- {
- BitmapColor aDstCol,aSrcCol;
- aSrcCol = pP->GetColor( nMapY, nMapX );
- aDstCol = pB->GetColor( nY, nX );
-
- const sal_uInt8 nSrcAlpha = pA->GetPixelIndex( nMapY, nMapX );
- const sal_uInt8 nDstAlpha = aDstCol.GetAlpha();
-
- // Perform porter-duff compositing 'over' operation
-
- // Co = Cs + Cd*(1-As)
- // Ad = As + Ad*(1-As)
- sal_uInt8 nResAlpha = static_cast<int>(nSrcAlpha) +
static_cast<int>(nDstAlpha)
- - static_cast<int>(nDstAlpha) * nSrcAlpha / 255;
- aDstCol.SetAlpha(nResAlpha);
- aDstCol.SetRed( CalcColor( aSrcCol.GetRed(), nSrcAlpha, nDstAlpha,
nResAlpha, aDstCol.GetRed() ) );
- aDstCol.SetBlue( CalcColor( aSrcCol.GetBlue(), nSrcAlpha, nDstAlpha,
nResAlpha, aDstCol.GetBlue() ) );
- aDstCol.SetGreen( CalcColor( aSrcCol.GetGreen(), nSrcAlpha, nDstAlpha,
nResAlpha, aDstCol.GetGreen() ) );
-
- return aDstCol;
- }
-}
-
-Bitmap OutputDevice::BlendBitmapWithAlpha(
- Bitmap& aBmp,
- BitmapReadAccess const * pP,
- BitmapReadAccess const * pA,
- const sal_Int32 nDstHeight,
- const sal_Int32 nDstWidth,
- const sal_Int32* pMapX,
- const sal_Int32* pMapY )
-
-{
- Bitmap res;
-
- {
- BitmapScopedWriteAccess pB(aBmp);
- if (pB && pP && pA)
- {
- for( int nY = 0; nY < nDstHeight; nY++ )
- {
- const tools::Long nMapY = pMapY[ nY ];
- Scanline pScanlineB = pB->GetScanline(nY);
-
- for( int nX = 0; nX < nDstWidth; nX++ )
- {
- const tools::Long nMapX = pMapX[ nX ];
- BitmapColor aDstCol = AlphaBlend(nX, nY, nMapX, nMapY, pP,
pA, pB.get());
-
- pB->SetPixelOnData(pScanlineB, nX, aDstCol);
- }
- }
- }
- pB.reset();
- res = aBmp;
- }
-
- return res;
-}
-
/* vim:set shiftwidth=4 softtabstop=4 expandtab: */
