This upgrade the drawing code to use latest opengl calls.
Also, it adds a fallback shader for opencolorio.
Reviewers: sergey, brecht
Subscribers: merwin, fclem
Differential Revision: https://developer.blender.org/D2652
This one has been painful, it's doing lots of nifty conditional drawing
of all kind... Also, very nice illustration of how cumbersome it is to
use dashed shader currently, we really need to find a simpler way at
some point imho. But this is not critical issue either, for now we can
live with some uglyness like that. :/
Previous fix did not work for mixed textures. This one will over-allocate
information array, but it's better than not being able to render at all.
Some more cleanup and improvement is coming.
- enabled lights
- alpha test
- texture environment
- point sprites (always enabled in modern GL)
Moved is_clip_plane for better struct packing, no functional change there.
Part of T51164
These parts will not be part of final viewport, but are called indirectly during the transition. To avoid runtime errors on core profile, exit early -- functions effectively do nothing.
I put the early exits inside the functions to avoid cluttering the code that calls these. But (long term) the calling functions need to change.
Basic shader's detect_options function was unused and full of old, so I deleted it.
Part of T51164
GL_LOGIC_OP is a synonym for GL_INDEX_LOGIC_OP, from OpenGL 1.0's indexed color drawing. It's not part of modern GL and causes an error in core profile.
GL_COLOR_LOGIC_OP is still supported in the latest GL. It's the last stage before writing to the framebuffer.
Part of T51164
There are multiple ways to orphan a buffer resource, and this code picks the oldest/safest way no matter which OpenGL version we're running.
TODO: use other (more recent) methods after thorough testing
Follow up to 8e0c57a812
Texturing is always enabled in GLSL. Simply use a sampler in the shader.
Replaced gpu_generate_mipmap with glGenerateMipmap since the former just Enabled/Disabled the texture target and called the latter.
Part of T51164
Note that I also made 'dash anchor point' consistent (the static one,
not the mouse one), in previous code somtimes dashed were anchored to
the static center point, in others, to the moving mouse position, the
later was rather disturbing imho...
