Flip surface normals if either rows or columns are descending

If both are descending or ascending, do not flip. Flip is needed
to make specular highlight work correctly.

Task-number: QTRD-3156
Change-Id: Ida256ee4ff96553c6f1cd5bf94e71d2e95ce7cf4
Reviewed-by: Titta Heikkala <titta.heikkala@digia.com>
Reviewed-by: Mika Salmela <mika.salmela@digia.com>

1 files changed, 2 insertions, 1 deletions

diff --git a/src/datavisualization/utils/surfaceobject_p.h b/src/datavisualization/utils/surfaceobject_p.h
index c8f7de95..9c18dcb2 100644
--- a/src/datavisualization/utils/surfaceobject_p.h
+++ b/src/datavisualization/utils/surfaceobject_p.h
@@ -72,10 +72,11 @@ public:
     void clear();
 
 private:
-    QVector3D normal(const QVector3D &a, const QVector3D &b, const QVector3D &c);
+    QVector3D normal(const QVector3D &a, const QVector3D &b, const QVector3D &c, bool flipNormal);
     void createBuffers(const QVector<QVector3D> &vertices, const QVector<QVector2D> &uvs,
                        const QVector<QVector3D> &normals, const GLint *indices,
                        bool changeGeometry);
+    bool checkFlipNormal(const QSurfaceDataArray &array);
 
 private:
     SurfaceType m_surfaceType;