Use 3x3 PMV matrices rather than 4x4 in the GL2 engine

QGraphicsView based applications will set a new transform for every
item before it's painted. This leads to lots of updates to the PMV
matrix. So switching to a 3x3 rather than a 4x4 gives us less data
to pass to GL for each QGraphicsItem which gets rendered. It also
means the vertex shader is more efficient. However, this patch only
gives a maximum 2.5% speed improvement on the SGX, which seems to be
only due to the faster vertex shader rather than the reduced amount
of data we pass to GL.

Reviewed-By: Kim

1 files changed, 1 insertions, 1 deletions

diff --git a/src/opengl/gl2paintengineex/qpaintengineex_opengl2_p.h b/src/opengl/gl2paintengineex/qpaintengineex_opengl2_p.h
index 33ce24d..f1ec6e6 100644
--- a/src/opengl/gl2paintengineex/qpaintengineex_opengl2_p.h
+++ b/src/opengl/gl2paintengineex/qpaintengineex_opengl2_p.h
@@ -254,7 +254,7 @@ public:
     GLfloat staticVertexCoordinateArray[8];
     GLfloat staticTextureCoordinateArray[8];
 
-    GLfloat pmvMatrix[4][4];
+    GLfloat pmvMatrix[3][3];
 
     QGLEngineShaderManager* shaderManager;