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

0 files changed, 0 insertions, 0 deletions