(Just committing this now to a temp branch so that I can continue working on this
from another machine later. This is a re-based+squashed, re-pushed version of what
I just pushed earlier, but now based on current 2.8 code, not from several days ago)
Rationale:
The Spring team needs a way to hide objects from the viewport, so that parts of
the rig can be enabled/disabled per shot. An example of this is how the cornea
meshes are typically hidden from the viewport so that the animators can see
the irises, and hence, where the character is looking.
(Another reason we may want this in future is to make it so that a bunch of
objects/rigs can be keyframed together in the same action, making it easier
to manage their actions)
Status:
* Currently all necessary data and animation editor support changes should be
in place and working. Hopefully I haven't missed any - the checklist may need
updating for 2.8
* Depsgraph support however is still incomplete. We still need to figure out what
needs to happen with the animated values to make objects actually appear/disappear
when triggered via the animation system, just like they do now from the UIwip
By default when moving a edge of the screen it always snaps to an invisible grid with unit of 4 pixels.
This was also affecting the snap to the midpoint and adjacent.
The solution was to make the snap to areagrid optional and use values of `origmin` and `origsize` that match the transformations in screen_edit.c.
The fix bit is the split.
But since we are using col.separator() left and right we need this as well.
I still don't think the separators are the way to go, yet may as well be
consistent with the current design in place, thus the extra separator here too.
This commit restores support for Motion Path drawing in 2.8 (as it wasn't ported over
to the new draw engines earlier, and the existing space_view3d/drawanimviz.c code was
removed during the Blender Internal removal).
Notes:
* Motion Paths are now implemented as an overlay (enabled by default).
Therefore, you can turn all of them on/off from the "Overlays" popover
* By and large, we have kept the same draw style as was used in 2.7
Further changes can happen later following further design work.
* One change from 2.7 is that thicker lines are used by default (2px vs 1px)
Todo's:
* There are some bad-level calls introduced here (i.e. the actgroup_to_keylist() stuff).
These were introduced to optimise drawing performance (by avoiding full keyframes -> keylist
conversion step on each drawcall). Instead, this has been moved to the calculation step
(in blenkernel). Soon, there will be some cleanups/improvements with those functions,
so until then, we'll keep the bad level calls.
Credits:
* Clément Foucault (fclem) - Draw Engine magic + Shader Conversion/Optimisation
* Joshua Leung (Aligorith) - COW fixes, UI integration, etc.
Revision History:
See "tmp-b28-motionpath_drawing" branch (rBa12ab5b2ef49ccacae091ccb54d72de0d63f990d)
Since the viewport header now supports transparency, text on pulldowns
can be hard to read if their color matches the viewport content.
Background is drawn using the 'inner' theme color, that was unused until now.
In some heavy rigs matrix inverse can be 10% of computation time. This
reduces it to 2% by using Eigen's optimized 4x4 matrix inverse and SSE
matrix multiplication.
