Blender Git Loki

Cleanup: use 'r_' prefix for return arguments in math_color

UI: Drag and Drop Modifiers, Layout Updates

This patch implements the list panel system D7490 for modifiers.
It also moves modifier drawing to a callback in ModifierTypeInfo
in line with the extensible architecture refactoring goal T75724.

This adds a PanelRegister callback and utilities for registering
panels and subpanels. It also adds the callbacks for expansion saving
and drag and drop reordering described in D7490.

These utilities, callbacks, and other common UI elements shared
between modifiers live in MOD_ui_common.c.

Because modifier buttons are now in panels, we can make use of
subpanels for organization. The UI layouts also use the single
column layout style consistently used elsewhere in Blender.
Additionally, the mode-setting buttons are aligned and ordered
consistently with the outliner.

However, the large number of UI changes in this patch may mean
that additional polishing is required in master.

Thanks to William Reynish (@billreynish) who did a fair amount of the
layout work and to Julian Eisel (@Severin) for consistent help.

Differential Revision: https://developer.blender.org/D7498

LibOverride: RNA: Cleanup no more needed property-specific override flags.

Cleanup: use doxy sections for sequencer edit, select

Cleanup: compiler warning

Fix failing assert when dragging panel close to region edge

Forgot to include this change from Julian Eisel @Severin in the
previous commit.

UI: Pan 2D Region When Dragging to Boundary

This adds a modal operator called Edge Pan, which is meant to run invisibly
while something inside a region is being dragged. This patch applies this
to dragging panels, but it can be used elsewhere too.

The speed (which is defined relative to how far the mouse is beyond the
boundary) and delay are easily adjustible. and the speed also increases
smoothly from a start value to a max to make it feel more interactive
and less robotic.

Differential Revision: https://developer.blender.org/D7465

Refactor: use new api in write_customdata

Refactor: use new api for writing modifiers

Refactor: use new api in write_nodetree_nolib

Refactor: use new api in write_animdata

GPencil: Improve Vertex Paint in filled areas

When use the Tint tool, it was very difficult to tint the filled areas if the strokes had very few points or the area was big.

Differential Revision: https://developer.blender.org/D7936

Fix T77396: crash in memfile undo code after recent optimizations.

Optimizations in rBcda15408582e8de5b405 do not guarantee anymore that
consecutive memchunks in two consecutive undo steps are actually about
the same data (and hence can share the same buffer when unchanged).

This buffer sharing can now happen without any particular order, so we
need to change the process when 'merging' two undo memfiles together.

Note that existing code was not logically correct either, even with
previous undo storage code, since it would blindly transfer ownership of
the buffer to the second memchunk, without checking whether the first
one was actually the owner of it or not (a same buffer can be shared by
matching memchunks in many consecutive memfiles/undo steps).

Refactor: use new api in write_iddata

Refactor: use new api for writing object, mesh and particlesettings

Refactor: use new api for writing camera, lattice, vfont and key

Refactor: use new api for writing curve, mball, image, light, world, material and texture

Cleanup: remove unused sequencer marker code from 2.4x

Sequencer: split select side of frame out of the select operator

The select operator was getting overloaded with functionality
unrelated to selecting the strip at the mouse position.

- Don't save settings, allowing the keymap only to include
non-default options.

- Fix selecting strips overlapping the current frame
overwrite all flags.

Refactor: use new api for writing collection, action and gpencil