enable picking again

Right now with an ugly work-around. The image is vertically flipped so
we just adapt our access to it.

Change-Id: I0128f54d4a0fbe697dc8726f6e255111ecb8412f

chart2/source/view/charttypes/GL3DBarChart.cxx

@@ -316,7 +316,7 @@ public:
 
 }
 
-void GL3DBarChart::clickedAt(const Point& /*rPos*/, sal_uInt16 nButtons)
+void GL3DBarChart::clickedAt(const Point& rPos, sal_uInt16 nButtons)
 {
     if(mbBlockUserInput)
         return;
@@ -325,13 +325,11 @@ void GL3DBarChart::clickedAt(const Point& /*rPos*/, sal_uInt16 nButtons)
         return;
 
     sal_uInt32 nId = 5;
-    /*
     {
         PickingModeSetter aPickingModeSetter(mpRenderer.get());
         render();
         nId = mpRenderer->GetPixelColorFromPoint(rPos.X(), rPos.Y());
     }
-    */
 
     std::map<sal_uInt32, const BarInformation>::const_iterator itr =
         maBarMap.find(nId);

chart2/source/view/main/GL3DRenderer.cxx

@@ -1662,9 +1662,12 @@ void OpenGL3DRenderer::SetPickingMode(bool bPickingMode)
 
 sal_uInt32 OpenGL3DRenderer::GetPixelColorFromPoint(long nX, long nY)
 {
+    static sal_uInt32 nId = 0;
+    OUString aFileName = OUString("/home/moggi/work/picking_") + OUString::number(nId++) + ".png";
+    OpenGLHelper::renderToFile(m_iWidth, m_iHeight, aFileName);
     boost::scoped_array<sal_uInt8> buf(new sal_uInt8[4]);
-    glReadPixels(nX, nY, 1, 1, GL_BGRA, GL_UNSIGNED_BYTE, buf.get());
-    Color aColor(buf[3], buf[2], buf[1], buf[0]);
+    glReadPixels(nX, m_iHeight-nY, 1, 1, GL_BGRA, GL_UNSIGNED_BYTE, buf.get());
+    Color aColor(255-buf[3], buf[2], buf[1], buf[0]);
     return aColor.GetColor();
 }