This improves the OpenGL ES support to extend it to version 3.0.
A number of new features are available in glesv3 including creation of
multi-sampled renderbuffers. These renderbuffers can be blitted to
single sample textures (but not the other way around). Other features
such as PBO for image uploading, are left as followon work.
For this preliminary implementation, glesv3 backends always create
renderbuffers, which can be set as single sample or multisample. The
renderbuffer's content is blitted to the texture only when used as a
source or a mask.
Images uploaded to a texture stay there until the surface is used as a
rendering target, at which point its painted to the renderbuffer.
This patch is heavily based off of Henry Song's initial GLESv3 patch
6f7f3795 from his cairogles fork of Cairo, and incorporates subsequent
fixes and pertinent refactorings from his trunk and review feedback from
Uli.
This implements the *functional* support for glesv3, excluding the
various optimization work to utilize its features. Rendering and
performance should not be expected to improve notably from pure glesv2.
As the GL backend for Cairo remains "experimental", these changes should
likewise be considered as such.
Signed-off-by: Bryce Harrington <bryce@osg.samsung.com>
To support differentiating between GLES v2 and v3, rename the flavor
enum to be version specific, as CAIRO_GL_FLAVOR_ES2.
Then, when GLES v3 support is introduced we can add it as a distinct
flavor enum (i.e. CAIRO_GL_FLAVOR_ES3).
Signed-off-by: Bryce Harrington <bryce@osg.samsung.com>
In strictly conforming EGL implementations, eglGetProcAddress() can be used
only to get extension functions, but some of the functions we want belong to
core GL(ES). If the *GetProcAddress function provided by the context fails,
try to get the address of the wanted GL function using standard system
facilities (eg dlsym() in *nix systems).
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Some GL functions can be called using different names depending on the
GL version and available extensions (ARB, EXT). The dispatch table
abstracts these differences and provides a uniform API for dealing with
these functions.
