Joshua Leung
72a360827b
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)