Extract code of BitmapEx -> RGBA buffer conversion to OpenGLHelper

Needed by gltf rendering.

Change-Id: I1aa974f3c515c5fb19a07b54ff655331138553cb

chart2/source/view/main/OpenGLRender.cxx

@@ -900,26 +900,7 @@ int OpenGLRender::CreateTextTexture(const BitmapEx& rBitmapEx, const awt::Point&
 
     long bmpWidth = rBitmapEx.GetSizePixel().Width();
     long bmpHeight = rBitmapEx.GetSizePixel().Height();
-
-    Bitmap aBitmap (rBitmapEx.GetBitmap());
-    AlphaMask aAlpha (rBitmapEx.GetAlpha());
-    boost::scoped_array<sal_uInt8> bitmapBuf(new sal_uInt8[4* bmpWidth * bmpHeight ]);
-    Bitmap::ScopedReadAccess pReadAccces( aBitmap );
-    AlphaMask::ScopedReadAccess pAlphaReadAccess( aAlpha );
-
-    size_t i = 0;
-    for (long ny = 0; ny < bmpHeight; ny++)
-    {
-        Scanline pAScan = pAlphaReadAccess->GetScanline(ny);
-        for(long nx = 0; nx < bmpWidth; nx++)
-        {
-            BitmapColor aCol = pReadAccces->GetColor( ny, nx );
-            bitmapBuf[i++] = aCol.GetRed();
-            bitmapBuf[i++] = aCol.GetGreen();
-            bitmapBuf[i++] = aCol.GetBlue();
-            bitmapBuf[i++] = 255 - *pAScan++;
-        }
-    }
+    boost::scoped_array<sal_uInt8> bitmapBuf(OpenGLHelper::ConvertBitmapExToRGBABuffer(rBitmapEx));
 
     TextInfo aTextInfo;
     aTextInfo.rotation = -(double)rotation / 360.0 * 2* GL_PI;

include/vcl/opengl/OpenGLHelper.hxx

@@ -12,6 +12,7 @@
 
 #include <GL/glew.h>
 #include <vcl/vclopengl_dllapi.hxx>
+#include <vcl/bitmapex.hxx>
 
 #include <rtl/ustring.hxx>
 
@@ -20,6 +21,7 @@ class VCLOPENGL_DLLPUBLIC OpenGLHelper
 public:
     static GLint LoadShaders(const OUString& rVertexShaderName, const OUString& rFragmentShaderName);
 
+    static sal_uInt8* ConvertBitmapExToRGBABuffer(const BitmapEx& rBitmapEx);
 };
 
 #endif

vcl/source/opengl/OpenGLHelper.cxx

@@ -12,6 +12,8 @@
 #include <osl/file.hxx>
 #include <rtl/bootstrap.hxx>
 #include <config_folders.h>
+#include <vcl/salbtype.hxx>
+#include <vcl/bmpacc.hxx>
 
 #include <vector>
 
@@ -140,4 +142,30 @@ GLint OpenGLHelper::LoadShaders(const OUString& rVertexShaderName,const OUString
     return ProgramID;
 }
 
+sal_uInt8* OpenGLHelper::ConvertBitmapExToRGBABuffer(const BitmapEx& rBitmapEx)
+{
+    long nBmpWidth = rBitmapEx.GetSizePixel().Width();
+    long nBmpHeight = rBitmapEx.GetSizePixel().Height();
+
+    Bitmap aBitmap (rBitmapEx.GetBitmap());
+    AlphaMask aAlpha (rBitmapEx.GetAlpha());
+    sal_uInt8* pBitmapBuf(new sal_uInt8[4* nBmpWidth * nBmpHeight ]);
+    Bitmap::ScopedReadAccess pReadAccces( aBitmap );
+    AlphaMask::ScopedReadAccess pAlphaReadAccess( aAlpha );
+    size_t i = 0;
+    for (long ny = 0; ny < nBmpHeight; ny++)
+    {
+        Scanline pAScan = pAlphaReadAccess ? pAlphaReadAccess->GetScanline(ny) : 0;
+        for(long nx = 0; nx < nBmpWidth; nx++)
+        {
+            BitmapColor aCol = pReadAccces->GetColor( ny, nx );
+            pBitmapBuf[i++] = aCol.GetRed();
+            pBitmapBuf[i++] = aCol.GetGreen();
+            pBitmapBuf[i++] = aCol.GetBlue();
+            pBitmapBuf[i++] = pAScan ? 255 - *pAScan++ : 255;
+        }
+    }
+    return pBitmapBuf;
+}
+
 /* vim:set shiftwidth=4 softtabstop=4 expandtab: */