RFC/WIP: Texture dumping support for GLES

[Alexandros Frantzis]

Hi all,

thanks to recent patches, apitrace now has basic EGL/GLES(2) support.
Unfortunately, as GLES(2) lacks a way to read texture parameters and
directly read texture contents, the current texture dumping code does
not work.

The branch at:

http://git.linaro.org/gitweb?p=people/afrantzis/apitrace.git;a=shortlog;h=refs/heads/gles-teximage-wip

explores a way to add texture dumping functionality by manually tracking
basic texture state while retracing, and using FBOs to read actual
texture content.

The patchset is still in an experimental state. It only supports the
base texture level, and hardcodes decisions on what methods to use to
access texture information and contents. However, it does work, and it
illustrates the result I am aiming for.

Ideally, the retracer would track the currently bound API (GL vs
GLES(2)), and decide which method to use based on that. If the overhead
of manually tracking state is considered high, we could skip the
relevant snippets when producing code for the non-EGL retracers.

Comments?

Thanks,
Alexandros