vcl: BlendFrameCache refactor

- split off BlendFrameCache.hxx to own header
- move functionality into constructor

Much of the functionality in createAlphaBlendFrame() just updates the
BlendFrameCache's bitmap frame. Really, this should be done when a
BlendFrameCache is instantiated, so functionality has been moved out of
createAlphaBlendFrame() and into the BlendFrameCache constructor.

Change-Id: Ia53a6f1c058ccb5f0ee4314b7a6e0b02ad7db376
Reviewed-on: https://gerrit.libreoffice.org/c/core/+/177802
Reviewed-by: Michael Weghorn <m.weghorn@posteo.de>
Tested-by: Jenkins

1 files changed, 11 insertions, 108 deletions

diff --git a/vcl/source/bitmap/BitmapEx.cxx b/vcl/source/bitmap/BitmapEx.cxx
index d20954b270dc..0d734eaa1831 100644
--- a/vcl/source/bitmap/BitmapEx.cxx
+++ b/vcl/source/bitmap/BitmapEx.cxx
@@ -40,6 +40,7 @@
 #include <svdata.hxx>
 #include <vcl/BitmapWriteAccess.hxx>
 #include <bitmap/BitmapMaskToAlphaFilter.hxx>
+#include <bitmap/BlendFrameCache.hxx>
 
 #include <o3tl/any.hxx>
 #include <tools/stream.hxx>
@@ -1056,7 +1057,14 @@ BitmapEx createAlphaBlendFrame(
     const Color& rColorBottomRight,
     const Color& rColorBottomLeft)
 {
-    BlendFrameCache* pBlendFrameCache = ImplGetBlendFrameCache();
+    ImplSVData* pSVData = ImplGetSVData();
+    if (!pSVData->mpBlendFrameCache)
+    {
+        pSVData->mpBlendFrameCache.reset(new BlendFrameCache(rSize, nAlpha, rColorTopLeft, rColorTopRight, rColorBottomRight, rColorBottomLeft));
+        return pSVData->mpBlendFrameCache->m_aLastResult;
+    }
+
+    BlendFrameCache* pBlendFrameCache = pSVData->mpBlendFrameCache.get();
 
     if(pBlendFrameCache->m_aLastSize == rSize
         && pBlendFrameCache->m_nLastAlpha == nAlpha
@@ -1068,113 +1076,8 @@ BitmapEx createAlphaBlendFrame(
         return pBlendFrameCache->m_aLastResult;
     }
 
-    pBlendFrameCache->m_aLastSize = rSize;
-    pBlendFrameCache->m_nLastAlpha = nAlpha;
-    pBlendFrameCache->m_aLastColorTopLeft = rColorTopLeft;
-    pBlendFrameCache->m_aLastColorTopRight = rColorTopRight;
-    pBlendFrameCache->m_aLastColorBottomRight = rColorBottomRight;
-    pBlendFrameCache->m_aLastColorBottomLeft = rColorBottomLeft;
-    pBlendFrameCache->m_aLastResult.Clear();
-
-    const tools::Long nW(rSize.Width());
-    const tools::Long nH(rSize.Height());
-
-    if(nW > 1 && nH > 1)
-    {
-        sal_uInt8 aEraseTrans(0xff);
-        Bitmap aContent(rSize, vcl::PixelFormat::N24_BPP);
-        AlphaMask aAlpha(rSize, &aEraseTrans);
-
-        aContent.Erase(COL_BLACK);
-
-        BitmapScopedWriteAccess pContent(aContent);
-        BitmapScopedWriteAccess pAlpha(aAlpha);
-
-        if(pContent && pAlpha)
-        {
-            tools::Long x(0);
-            tools::Long y(0);
-            Scanline pScanContent = pContent->GetScanline( 0 );
-            Scanline pScanAlpha = pContent->GetScanline( 0 );
-
-            // x == 0, y == 0, top-left corner
-            pContent->SetPixelOnData(pScanContent, 0, rColorTopLeft);
-            pAlpha->SetPixelOnData(pScanAlpha, 0, BitmapColor(nAlpha));
-
-            // y == 0, top line left to right
-            for(x = 1; x < nW - 1; x++)
-            {
-                Color aMix(rColorTopLeft);
-
-                aMix.Merge(rColorTopRight, 255 - sal_uInt8((x * 255) / nW));
-                pContent->SetPixelOnData(pScanContent, x, aMix);
-                pAlpha->SetPixelOnData(pScanAlpha, x, BitmapColor(nAlpha));
-            }
-
-            // x == nW - 1, y == 0, top-right corner
-            // #i123690# Caution! When nW is 1, x == nW is possible (!)
-            if(x < nW)
-            {
-                pContent->SetPixelOnData(pScanContent, x, rColorTopRight);
-                pAlpha->SetPixelOnData(pScanAlpha, x, BitmapColor(nAlpha));
-            }
-
-            // x == 0 and nW - 1, left and right line top-down
-            for(y = 1; y < nH - 1; y++)
-            {
-                pScanContent = pContent->GetScanline( y );
-                pScanAlpha = pContent->GetScanline( y );
-                Color aMixA(rColorTopLeft);
-
-                aMixA.Merge(rColorBottomLeft, 255 - sal_uInt8((y * 255) / nH));
-                pContent->SetPixelOnData(pScanContent, 0, aMixA);
-                pAlpha->SetPixelOnData(pScanAlpha, 0, BitmapColor(nAlpha));
-
-                // #i123690# Caution! When nW is 1, x == nW is possible (!)
-                if(x < nW)
-                {
-                    Color aMixB(rColorTopRight);
-
-                    aMixB.Merge(rColorBottomRight, 255 - sal_uInt8((y * 255) / nH));
-                    pContent->SetPixelOnData(pScanContent, x, aMixB);
-                    pAlpha->SetPixelOnData(pScanAlpha, x, BitmapColor(nAlpha));
-                }
-            }
-
-            // #i123690# Caution! When nH is 1, y == nH is possible (!)
-            if(y < nH)
-            {
-                // x == 0, y == nH - 1, bottom-left corner
-                pContent->SetPixelOnData(pScanContent, 0, rColorBottomLeft);
-                pAlpha->SetPixelOnData(pScanAlpha, 0, BitmapColor(nAlpha));
-
-                // y == nH - 1, bottom line left to right
-                for(x = 1; x < nW - 1; x++)
-                {
-                    Color aMix(rColorBottomLeft);
-
-                    aMix.Merge(rColorBottomRight, 255 - sal_uInt8(((x - 0)* 255) / nW));
-                    pContent->SetPixelOnData(pScanContent, x, aMix);
-                    pAlpha->SetPixelOnData(pScanAlpha, x, BitmapColor(nAlpha));
-                }
-
-                // x == nW - 1, y == nH - 1, bottom-right corner
-                // #i123690# Caution! When nW is 1, x == nW is possible (!)
-                if(x < nW)
-                {
-                    pContent->SetPixelOnData(pScanContent, x, rColorBottomRight);
-                    pAlpha->SetPixelOnData(pScanAlpha, x, BitmapColor(nAlpha));
-                }
-            }
-
-            pContent.reset();
-            pAlpha.reset();
-
-            pBlendFrameCache->m_aLastResult = BitmapEx(aContent, aAlpha);
-        }
-    }
-
-    return pBlendFrameCache->m_aLastResult;
+    pSVData->mpBlendFrameCache.reset(new BlendFrameCache(rSize, nAlpha, rColorTopLeft, rColorTopRight, rColorBottomRight, rColorBottomLeft));
+    return pSVData->mpBlendFrameCache->m_aLastResult;
 }
 
 void BitmapEx::Replace(const Color& rSearchColor,