Blender Git Loki

Sculpt dyntopo: Roughed out skeleton of new brush engine API

Command Lists

* The new system will be based on command lists
generated by (eventually) a node editor.
* For now, the lists will be hardcoded.
* Idea is to make a minimal viable
brush engine that won't cause file breakage
when the upgrade to node-based brushes happen.

Brush Channels

* Wrote new structures and API to wrange
brush parameters: BrushChannel.
* Supports, floats, ints, enums, bitmasks,
with plans for vec3 and vec4.
* This will replace UnifiedPaintStruct,
most of the members of Brush and the
DynTopoSettings struct.
* Brush channels can
be mapped to various input device
channels (e.g. pen pressure); each
mapping has its own associated curve
(CurveMapping instance) and bounds.

Brush channel inheritence chaining

* Brush channels can form inheritence chains
* Channel sets are stored in three places:
in the scene toolsettings, in Brush, and in
individual brush commands.
* Node groups will also have a channel set.
* Channels in each set can be flagged to
inherit from the parent set.
* Inheritence happens in seperate merged
channel sets at runtime. The final
Brush channels live in Brush->channels_final,
while the final command channels live in
BrushCommand->params_final.