Zhigang Gong authored Jun 11, 2012 and Emma Anholt committed Dec 18, 2013

This is the first commit to add support for large pixmap.
The large here means a pixmap is larger than the texutre's
size limitation thus can't fit into one single texutre.

The previous implementation will simply fallback to use a
in memory pixmap to contain the large pixmap which is
very slow in practice.

The basic idea here is to use an array of texture to hold
the large pixmap. And when we need to get a specific area
of the pixmap, we just need to compute/clip the correct
region and find the corresponding fbo.

We need to implement some auxiliary routines to clip every
rendering operations into small pieces which can fit into
one texture.

The complex part is the transformation/repeat/repeatReflect
and repeat pad and their comination. We will support all of
them step by step.

This commit just add some necessary data structure to represent
the large pixmap, and doesn't change any rendering process.
This commit doesn't add real large pixmap support.

Signed-off-by: Zhigang Gong <zhigang.gong@linux.intel.com>