Blender Git Loki

Merge remote-tracking branch 'remotes/origin/blender2.8' into soc-2018-npr

Modified UI for chaining.

Fixed c function and glsl file names.

Merge remote-tracking branch 'remotes/origin/blender2.8' into soc-2018-npr

Provide a switch to enable chaining or not.

Chain support line types and levels.
Still bugs in chaining, hard to find, but results good enough in most of the conditions.

Merge and changed GWN APIs into GPU ones.

Merge remote-tracking branch 'remotes/origin/blender2.8' into soc-2018-npr

# Conflicts:
# release/scripts/startup/bl_ui/space_view3d.py
# source/blender/draw/intern/draw_manager.c

Fix render triangle size increment error.

Fix fileread error again.

Fix taper on segment_count==1 situation

Fix detail reducing bugs

Chain first level preview ok. Simplification have bugs.

Intersection chain now ok. (occlude level debug wait until tomorrow)

Fixed not updating normal error. now all lines properly calculated.

Fix occlusion error

Chain works, but occlusion is broken. (memory not cleaned up, drawing function is still the old one)

Fix typo, added to cmake, compile ok.

Chain now accept line segments (multiple occlusion level on one line is possible)

Implementing Chaining. Have problems for half-occluded line. Still thinking for solution.