better support for <8 bpp in SkiaSalBitmap

Change-Id: Ife79abfb9c36925405fd0b7da40f5274c0339117

5 files changed, 85 insertions, 9 deletions

diff --git a/vcl/inc/salbmp.hxx b/vcl/inc/salbmp.hxx
index b952c8ce4f61..ecb1a1b7d7bf 100644
--- a/vcl/inc/salbmp.hxx
+++ b/vcl/inc/salbmp.hxx
@@ -105,6 +105,8 @@ protected:
     // helper function to convert data in 1,2,4 bpp formats to a 24bpp format
     static std::unique_ptr< sal_uInt8[] > convertDataTo24Bpp( const sal_uInt8* src,
         int width, int height, int bitCount, int bytesPerRow, const BitmapPalette& palette, bool toBgr );
+    static std::unique_ptr< sal_uInt8[] > convertDataTo32Bpp( const sal_uInt8* src,
+        int width, int height, int bitCount, int bytesPerRow, const BitmapPalette& palette, bool toBgra );
 };
 
 #endif
diff --git a/vcl/inc/skia/salbmp.hxx b/vcl/inc/skia/salbmp.hxx
index 005e83be76fc..63a54a8555be 100644
--- a/vcl/inc/skia/salbmp.hxx
+++ b/vcl/inc/skia/salbmp.hxx
@@ -59,18 +59,26 @@ public:
                          sal_uInt8 nTol) override;
     virtual bool ConvertToGreyscale() override;
 
+    // Accesses the internal SkBitmap. If the bit count is one that Skia does
+    // not support natively, data from the internal buffer is converted
+    // to a 32bpp SkBitmap.
+    const SkBitmap& GetSkBitmap() const;
+
 #ifdef DBG_UTIL
     void dump(const char* file) const;
 #endif
 
 private:
+    void ResetCachedBitmap();
+
     SkBitmap mBitmap;
     BitmapPalette mPalette;
     int mBitCount; // bpp
     Size mSize;
-    std::unique_ptr<sal_uInt8[]> mBuffer; // for 1bpp and 4bpp, Skia doesn't support those
+    // Skia does not natively support 1bpp and 4bpp, so such bitmaps are stored
+    // in a buffer (and converted to 32bpp SkBitmap on-demand using GetSkBitmap()).
+    std::unique_ptr<sal_uInt8[]> mBuffer;
     int mScanlineSize; // size of one row in mBuffer
-    friend class SkiaSalGraphicsImpl; // TODO
 };
 
 #endif // INCLUDED_VCL_INC_OPENGL_SALBMP_H
diff --git a/vcl/skia/gdiimpl.cxx b/vcl/skia/gdiimpl.cxx
index b397abd6af66..a80bf73c0cbe 100644
--- a/vcl/skia/gdiimpl.cxx
+++ b/vcl/skia/gdiimpl.cxx
@@ -228,7 +228,7 @@ void SkiaSalGraphicsImpl::drawBitmap(const SalTwoRect& rPosAry, const SalBitmap&
         return;
     assert(dynamic_cast<const SkiaSalBitmap*>(&rSalBitmap));
     mSurface->getCanvas()->drawBitmapRect(
-        static_cast<const SkiaSalBitmap&>(rSalBitmap).mBitmap,
+        static_cast<const SkiaSalBitmap&>(rSalBitmap).GetSkBitmap(),
         SkRect::MakeXYWH(rPosAry.mnSrcX, rPosAry.mnSrcY, rPosAry.mnSrcWidth, rPosAry.mnSrcHeight),
         SkRect::MakeXYWH(rPosAry.mnDestX, rPosAry.mnDestY, rPosAry.mnDestWidth,
                          rPosAry.mnDestHeight),
@@ -314,11 +314,9 @@ bool SkiaSalGraphicsImpl::drawAlphaBitmap(const SalTwoRect& rPosAry, const SalBi
     SkCanvas canvas(tmpBitmap);
     SkPaint paint;
     paint.setBlendMode(SkBlendMode::kDst);
-    canvas.drawBitmap(static_cast<const SkiaSalBitmap&>(rSourceBitmap).mBitmap, 0, 0,
-                      &paint); // TODO bpp < 8?
+    canvas.drawBitmap(static_cast<const SkiaSalBitmap&>(rSourceBitmap).GetSkBitmap(), 0, 0, &paint);
     paint.setBlendMode(SkBlendMode::kSrcIn);
-    canvas.drawBitmap(static_cast<const SkiaSalBitmap&>(rAlphaBitmap).mBitmap, 0, 0,
-                      &paint); // TODO bpp < 8?
+    canvas.drawBitmap(static_cast<const SkiaSalBitmap&>(rAlphaBitmap).GetSkBitmap(), 0, 0, &paint);
     mSurface->getCanvas()->drawBitmapRect(
         tmpBitmap,
         SkRect::MakeXYWH(rPosAry.mnSrcX, rPosAry.mnSrcY, rPosAry.mnSrcWidth, rPosAry.mnSrcHeight),
diff --git a/vcl/skia/salbmp.cxx b/vcl/skia/salbmp.cxx
index ff0a9ed1897b..88677b6132ad 100644
--- a/vcl/skia/salbmp.cxx
+++ b/vcl/skia/salbmp.cxx
@@ -215,12 +215,13 @@ BitmapBuffer* SkiaSalBitmap::AcquireBuffer(BitmapAccessMode nMode)
 void SkiaSalBitmap::ReleaseBuffer(BitmapBuffer* pBuffer, BitmapAccessMode nMode)
 {
     mPalette = pBuffer->maPalette;
-    (void)nMode; // TODO?
     // Are there any more ground movements underneath us ?
     assert(pBuffer->mnWidth == mSize.Width());
     assert(pBuffer->mnHeight == mSize.Height());
     assert(pBuffer->mnBitCount == mBitCount);
     delete pBuffer;
+    if (nMode == BitmapAccessMode::Write) // TODO something more?
+        ResetCachedBitmap();
 }
 
 bool SkiaSalBitmap::GetSystemData(BitmapSystemData& rData)
@@ -249,10 +250,34 @@ bool SkiaSalBitmap::Replace(const Color& rSearchColor, const Color& rReplaceColo
 
 bool SkiaSalBitmap::ConvertToGreyscale() { return false; }
 
+const SkBitmap& SkiaSalBitmap::GetSkBitmap() const
+{
+    if (mBuffer && mBitmap.drawsNothing())
+    {
+        assert(mBitCount == 1 || mBitCount == 2 || mBitCount == 4);
+        std::unique_ptr<sal_uInt8[]> data = convertDataTo32Bpp(
+            mBuffer.get(), mSize.Width(), mSize.Height(), mBitCount, mScanlineSize, mPalette,
+            kN32_SkColorType == kBGRA_8888_SkColorType); // TODO
+        if (!const_cast<SkBitmap&>(mBitmap).installPixels(
+                SkImageInfo::MakeS32(mSize.Width(), mSize.Height(), kOpaque_SkAlphaType),
+                data.release(), mSize.Width() * 4,
+                [](void* addr, void*) { delete[] static_cast<sal_uInt8*>(addr); }, nullptr))
+            abort();
+    }
+    return mBitmap;
+}
+
+// Reset the cached bitmap allocatd in GetSkBitmap().
+void SkiaSalBitmap::ResetCachedBitmap()
+{
+    if (mBuffer)
+        mBitmap.reset();
+}
+
 #ifdef DBG_UTIL
 void SkiaSalBitmap::dump(const char* file) const
 {
-    sk_sp<SkImage> image = SkImage::MakeFromBitmap(mBitmap);
+    sk_sp<SkImage> image = SkImage::MakeFromBitmap(GetSkBitmap());
     sk_sp<SkData> data = image->encodeToData();
     std::ofstream ostream(file, std::ios::binary);
     ostream.write(static_cast<const char*>(data->data()), data->size());
diff --git a/vcl/source/bitmap/salbmp.cxx b/vcl/source/bitmap/salbmp.cxx
index 0cf6fd3ab93a..c7183e117598 100644
--- a/vcl/source/bitmap/salbmp.cxx
+++ b/vcl/source/bitmap/salbmp.cxx
@@ -184,4 +184,47 @@ std::unique_ptr< sal_uInt8[] > SalBitmap::convertDataTo24Bpp( const sal_uInt8* s
     return data;
 }
 
+std::unique_ptr< sal_uInt8[] > SalBitmap::convertDataTo32Bpp( const sal_uInt8* src,
+    int width, int height, int bitCount, int bytesPerRow, const BitmapPalette& palette, bool toBgra )
+{
+    std::unique_ptr< sal_uInt8[] > data( new sal_uInt8[width * height * 4] );
+    std::unique_ptr<ImplPixelFormat> pSrcFormat(ImplPixelFormat::GetFormat(bitCount, palette));
+
+    const sal_uInt8* pSrcData = src;
+    sal_uInt8* pDstData = data.get();
+
+    sal_uInt32 nY = height;
+    while( nY-- )
+    {
+        pSrcFormat->StartLine( pSrcData );
+
+        sal_uInt32 nX = width;
+        if (toBgra)
+        {
+            while( nX-- )
+            {
+                const BitmapColor& c = pSrcFormat->ReadPixel();
+                *pDstData++ = c.GetBlue();
+                *pDstData++ = c.GetGreen();
+                *pDstData++ = c.GetRed();
+                *pDstData++ = 0xff;
+            }
+        }
+        else // RGBA
+        {
+            while( nX-- )
+            {
+                const BitmapColor& c = pSrcFormat->ReadPixel();
+                *pDstData++ = c.GetRed();
+                *pDstData++ = c.GetGreen();
+                *pDstData++ = c.GetBlue();
+                *pDstData++ = 0xff;
+            }
+        }
+
+        pSrcData += bytesPerRow;
+    }
+    return data;
+}
+
 /* vim:set shiftwidth=4 softtabstop=4 expandtab: */