Blender Git Loki

Cloth refactor: Remove goal springs and some other cleanup

This removes the goal springs, in favor of simply calculating the goal forces on the vertices directly. The vertices already store all the necessary data for the goal forces, thus the springs were redundant, and just defined both ends as being the same vertex.

The main advantage of removing the goal springs, is an increase in flexibility, allowing us to much more nicely do some neat dynamic stuff with the goals/pins, such as animated vertex weights. But this also has the advantage of simpler code, and a slightly reduced memory footprint.

This also removes the `f`, `dfdx` and `dfdv` fields from the `ClothSpring` struct, as that data is only used by the solver, and is re-computed on each step, and thus does not need to be stored throughout the simulation.

Reviewers: sergey

Reviewed By: sergey

Tags: #physics

Differential Revision: https://developer.blender.org/D2514

cleanup use of GPU matrix API

Take advantage of 2D functions, rotation about the X Y or Z axis, uniform scale factors.

We no longer need to call gpuMatrixBegin_legacy() before using the new API locally in functions.

related to T49450

OpenGL: `paint_cursor` port to immediate mode (Part 2)

Part of T49043

Cycles: Fix building for some compilers

Cleanup: remove redundant temp dir init

This is already called by wm_init_userdef, in old code
different initialization methods were used but now it's not needed.

Confusing since prefs are loaded in this function that don't initialize temp.

OpenGL: remove GLU option from build system

Also remove linking in glu libs.

T49042 is now done!

remove mention of GLU from comments

related to T49042

convert last remaining GLU calls in BGE

Focus is on getting rid of GLU. We expect UPBGE to replace current BGE.

Part of T49042

Cleanup: minor wm_homefile_read simplification

Logic in this function is a bit scattered,
minor changes to avoid confusion.

Also rename 'from_memory' to 'use_factory_settings'.

OpenGL: `paint_cursor` port to immediate mode (Part 1)

Part of T49043

Object Mode Engine: New grid drawing.

Move the grid drawing to the Object mode engine and implement a new infinite grid.
Everything is done but it needs better parameters to be intuitive.

Draw Module: Move the Global Ubo block definition to it's own file.

fix redundant assignment

Thanks clang for the warning.

OpenGL: use new API for persp & ortho projection

Still using legacy GL within the GPU library itself, but we'll be able to switch soon.

Part of T49450

Cleanup: remove BLI_getlastdir

Replace with BLI_path_name_at_index

Pydoc: Change Wikipedia links and grammar in mathutils matrix code

OpenGL: load projection matrix with new API

New API does not share legacy OpenGL's concept of matrix modes.

Part of T49450

OpenGL: fix new projection matrix API

Now using the correct GL enum.
Part of T49450

Cleanup/optimization: Simplify some usages of uiItemFullO/_ptr, avoid multiple search of same op.

Cleanup: ignore open-blend as startup/prefs basis

No reason startup/prefs would ever be blend-file relative.