move the renderToFile function to the helper to avoid the context

Change-Id: I5493126047179d67b2f2ed0d3d5d936ebbaf4810

include/vcl/opengl/OpenGLHelper.hxx

@@ -23,6 +23,7 @@ public:
 
     static sal_uInt8* ConvertBitmapExToRGBABuffer(const BitmapEx& rBitmapEx);
     static BitmapEx ConvertBGRABufferToBitmapEx(const sal_uInt8* const pBuffer, long nWidth, long nHeight);
+    static void renderToFile(long nWidth, long nHeight, const OUString& rFileName);
 
     static const char* GLErrorString(GLenum errorCode);
 };

vcl/source/opengl/OpenGLContext.cxx

@@ -558,20 +558,9 @@ void OpenGLContext::renderToFile()
 {
     int iWidth = m_aGLWin.Width;
     int iHeight = m_aGLWin.Height;
-    boost::scoped_array<sal_uInt8> buf(new sal_uInt8[iWidth * iHeight * 4]);
-    glReadPixels(0, 0, iWidth, iHeight, GL_BGRA, GL_UNSIGNED_BYTE, buf.get());
-
-    BitmapEx aBmp = OpenGLHelper::ConvertBGRABufferToBitmapEx(buf.get(), iWidth, iHeight);
     static int nIdx = 0;
     OUString aName = OUString( "file:///home/moggi/Documents/work/output" ) + OUString::number( nIdx++ ) + ".png";
-    try {
-        vcl::PNGWriter aWriter( aBmp );
-        SvFileStream sOutput( aName, STREAM_WRITE );
-        aWriter.Write( sOutput );
-        sOutput.Close();
-    } catch (...) {
-        SAL_WARN("vcl.opengl", "Error writing png to " << aName);
-    }
+    OpenGLHelper::renderToFile(iWidth, iHeight, aName);
 }
 
 #if defined( WNT )

vcl/source/opengl/OpenGLHelper.cxx

@@ -14,6 +14,9 @@
 #include <config_folders.h>
 #include <vcl/salbtype.hxx>
 #include <vcl/bmpacc.hxx>
+#include <boost/scoped_array.hpp>
+#include <vcl/pngwrite.hxx>
+#include <vcl/graph.hxx>
 
 #include <vector>
 
@@ -168,6 +171,21 @@ sal_uInt8* OpenGLHelper::ConvertBitmapExToRGBABuffer(const BitmapEx& rBitmapEx)
     return pBitmapBuf;
 }
 
+void OpenGLHelper::renderToFile(long nWidth, long nHeight, const OUString& rFileName)
+{
+    boost::scoped_array<sal_uInt8> pBuffer(new sal_uInt8[nWidth*nHeight*4]);
+    glReadPixels(0, 0, nWidth, nHeight, GL_BGRA, GL_UNSIGNED_BYTE, pBuffer.get());
+    BitmapEx aBitmap = ConvertBGRABufferToBitmapEx(pBuffer.get(), nWidth, nHeight);
+    try {
+        vcl::PNGWriter aWriter( aBitmap );
+        SvFileStream sOutput( rFileName, STREAM_WRITE );
+        aWriter.Write( sOutput );
+        sOutput.Close();
+    } catch (...) {
+        SAL_WARN("vcl.opengl", "Error writing png to " << rFileName);
+    }
+}
+
 BitmapEx OpenGLHelper::ConvertBGRABufferToBitmapEx(const sal_uInt8* const pBuffer, long nWidth, long nHeight)
 {
     assert(pBuffer);