Mirror vertically the texture bitmaps for OpenGL

In case of glTF models it saves a Mirror() call.
In case of OpenGL charts it avoid flipped texts.

Change-Id: I1ac980e16bcb5ba6a9a025b638aaac3b08b4aab3

4 files changed, 9 insertions, 8 deletions

diff --git a/avmedia/source/opengl/oglplayer.cxx b/avmedia/source/opengl/oglplayer.cxx
index 917ab2d12c6a..a21d5db403d1 100644
--- a/avmedia/source/opengl/oglplayer.cxx
+++ b/avmedia/source/opengl/oglplayer.cxx
@@ -102,9 +102,8 @@ bool OGLPlayer::create( const OUString& rURL )
                     return false;
                 }
                 BitmapEx aBitmapEx = aGraphic.GetBitmapEx();
-                aBitmapEx.Mirror(BMP_MIRROR_VERT);
                 rFile.buffer = new char[4 * aBitmapEx.GetSizePixel().Width() * aBitmapEx.GetSizePixel().Height()];
-                OpenGLHelper::ConvertBitmapExToRGBABuffer(aBitmapEx, reinterpret_cast<sal_uInt8*>(rFile.buffer));
+                OpenGLHelper::ConvertBitmapExToRGBATextureBuffer(aBitmapEx, reinterpret_cast<sal_uInt8*>(rFile.buffer));
                 rFile.imagewidth = aBitmapEx.GetSizePixel().Width();
                 rFile.imageheight = aBitmapEx.GetSizePixel().Height();
             }
diff --git a/chart2/source/view/main/OpenGLRender.cxx b/chart2/source/view/main/OpenGLRender.cxx
index 42b21cf67b1a..1075b86cc497 100644
--- a/chart2/source/view/main/OpenGLRender.cxx
+++ b/chart2/source/view/main/OpenGLRender.cxx
@@ -699,7 +699,7 @@ int OpenGLRender::CreateTextTexture(const BitmapEx& rBitmapEx, const awt::Point&
 
     boost::shared_array<sal_uInt8> bitmapBuf(new sal_uInt8[4 * rBitmapEx.GetSizePixel().Width() * rBitmapEx.GetSizePixel().Height()]);
 
-    OpenGLHelper::ConvertBitmapExToRGBABuffer(rBitmapEx, bitmapBuf.get());
+    OpenGLHelper::ConvertBitmapExToRGBATextureBuffer(rBitmapEx, bitmapBuf.get());
 
     return CreateTextTexture(bitmapBuf, rBitmapEx.GetSizePixel(),
                              awt::Point(), aSize, rotation, rTrans);
diff --git a/include/vcl/opengl/OpenGLHelper.hxx b/include/vcl/opengl/OpenGLHelper.hxx
index aa9448c2b3b7..8b18964eb5f6 100644
--- a/include/vcl/opengl/OpenGLHelper.hxx
+++ b/include/vcl/opengl/OpenGLHelper.hxx
@@ -22,10 +22,12 @@ public:
     static GLint LoadShaders(const OUString& rVertexShaderName, const OUString& rFragmentShaderName);
 
     /**
-     * Note: The caller is responsible for allocate the memory for the RGBA buffer, before call
-     * this method. RGBA buffer size is assumed to be 4*width*height
+     * The caller is responsible for allocate the memory for the RGBA buffer, before call
+     * this method. RGBA buffer size is assumed to be 4*width*height.
+     * Since OpenGL uses textures flipped relative to BitmapEx storage this method
+     * also mirrors the bitmap vertically.
     **/
-    static void ConvertBitmapExToRGBABuffer(const BitmapEx& rBitmapEx, sal_uInt8* o_pRGBABuffer);
+    static void ConvertBitmapExToRGBATextureBuffer(const BitmapEx& rBitmapEx, sal_uInt8* o_pRGBABuffer);
     static BitmapEx ConvertBGRABufferToBitmapEx(const sal_uInt8* const pBuffer, long nWidth, long nHeight);
     static void renderToFile(long nWidth, long nHeight, const OUString& rFileName);
 
diff --git a/vcl/source/opengl/OpenGLHelper.cxx b/vcl/source/opengl/OpenGLHelper.cxx
index c028246b8b06..16dd5b7a9411 100644
--- a/vcl/source/opengl/OpenGLHelper.cxx
+++ b/vcl/source/opengl/OpenGLHelper.cxx
@@ -146,7 +146,7 @@ GLint OpenGLHelper::LoadShaders(const OUString& rVertexShaderName,const OUString
     return ProgramID;
 }
 
-void OpenGLHelper::ConvertBitmapExToRGBABuffer(const BitmapEx& rBitmapEx, sal_uInt8* o_pRGBABuffer)
+void OpenGLHelper::ConvertBitmapExToRGBATextureBuffer(const BitmapEx& rBitmapEx, sal_uInt8* o_pRGBABuffer)
 {
     long nBmpWidth = rBitmapEx.GetSizePixel().Width();
     long nBmpHeight = rBitmapEx.GetSizePixel().Height();
@@ -156,7 +156,7 @@ void OpenGLHelper::ConvertBitmapExToRGBABuffer(const BitmapEx& rBitmapEx, sal_uI
     Bitmap::ScopedReadAccess pReadAccces( aBitmap );
     AlphaMask::ScopedReadAccess pAlphaReadAccess( aAlpha );
     size_t i = 0;
-    for (long ny = 0; ny < nBmpHeight; ny++)
+    for (long ny = nBmpHeight - 1; ny >= 0; ny--)
     {
         Scanline pAScan = pAlphaReadAccess ? pAlphaReadAccess->GetScanline(ny) : 0;
         for(long nx = 0; nx < nBmpWidth; nx++)