This adds a table of driver descriptions to cogl-renderer.c in order of
preference and when choosing what driver to use we now iterate the table
instead of repeating boilerplate checks. For handling the "default driver"
that can be specified when building cogl and handling driver overrides
there is a foreach_driver_description() that will make sure to iterate
the default driver first or if an override has been set then nothing but
the override will be considered.
This patch introduces some driver flags that let us broadly categorize
what kind of GL driver we are currently running on. Since there are
numerous OpenGL apis with different broad feature sets and new apis
may be introduced in the future by Khronos then we should tend to
avoid using the driver id to do runtime feature checking. These flags
provide a more stable quantity for broad feature checks.
Reviewed-by: Neil Roberts <neil@linux.intel.com>
(cherry picked from commit e07d0fc7441dddc3f0a2bc33a6a37d62ddc3efc0)
34658ea057