Blender Git Loki

Fix: Save off GPencil eraser size earlier, to prevent it from being zeroed if something goes wrong (e.g. locked layers) in the meantime

Fix: Grease Pencil eraser would operate on strokes that were not valid for the current context

For example, if a GP datablock was shared between two different types of editors
(e.g. 3D and Sequencer Preview), even the non-valid (and invisible) strokes would
get affected.

GPencil Layer Management: Lock/Unlock All + Isolate Layer

This commit introduces a few operators to make it easier to perform a few common
layer-manipulation operations. Some of these have been sorely needed for quite
a while now...

* Lock/Unlock All - Just as their names suggest, these operators will lock and unlock
all layers in the GP datablock. This is a quick way to unlock all layers previously
locked. These can be found in the new dropdown which replaces the old "Duplicate"
below the +/- (for adding/removing layers); also featured in the dropdown are
the "Duplicate Layers" operator, as well as the show/hide ones.

* Isolate Layer - This operator makes it easy to focus on just a single layer (e.g. the
outlines for a particular character). The "star" button affects editability, while the
"eye" below it toggles editability + visibility.

If any layer is visible/unlocked, this operator will lock and/or hide all; otherwise,
it will unlock/unhide all (to reverse the previous operation).

GPencil: On second thought, the status indicator doesn't need to be shown at all in the 3D View!

GPencil: Do not show "stroke editing" indicator when in "Only Render" mode in the 3D View

3D View: Object name changes colour on frames with GP keyframes (if no other keyframes are present)

The colour used needs to be tweaked/changed (TH_TIME_GP_KEYFRAME would be ideal,
but since it's probably not initialised in many themes, we'll stick with
TH_CFRAME for now, even if it looks a bit rough)

Fix: Stroke Placement options were not getting shown in the Sequencer

GPencil UI: Spacing tweaks

GPencil Drawing Usability: "Additive Drawing"

This commit adds a new option which will make it easier to use the Grease Pencil
drawing tools for animation. With the "Additive Drawing" option enabled in the
toolshelf (located alongside the "Continuous Drawing" toggle), the active frame's
strokes will be carried over/copied if you start drawing on an empty frame (i.e.
one without any keyframe already). This saves the effort of keeping a dopesshet
open, and to remember to duplicate the current frame before starting to draw the
next pose (or risk managing to draw the perfect pose, but without everything else).

Examples of cases where this comes in handy includes animating facial expressions
(when all outlines are on the same layer), or animating "growing" things (e.g. vines,
or concentric circles growing from a central point).

Note: Even without this option enabled, this is the default behaviour when using
the eraser on an "empty" frame. This makes it easier to do shots where you're just
changing parts of the facial expression, or if you're animating an "eraser" effect.

Note 2: The naming of this feature could do with some work. I struggled with several
alternative names for it, but this one seems the most useful about what it helps users
do. Suggestions welcome!

GPencil: Code Cleanup - Deduplicate code for adding a copy of the active frame (for editing)

GPencil: Moved Stroke Placement settings from GP datablock to tool settings

This commit moves the Stroke Placement settings from being a per-datablock
setting to being stored in tool settings instead. The main reason this was
done was to resolve a usability issue with the old way: in order to set this
setting, you had to first create a GP datablock to be able to see the settings!

Now, by having these as tool settings (as they should have been from the start),
they can be always visible (even when there isn't a datablock yet), meaning that
it will work as expected from the very first stroke.


Implementation Notes:
* There are separate Stroke Placement properties for the different editor types.
e.g. 3D View, Sequencer Preview, Image Editor, and all other 2D Views

* I couldn't get the version patching code working (to port over placement settings
from the GP datablock attached to the active scene), as this was causing crashes
and other general weirdness when loading old files. The code to do this is there,
but #if 0'ed out.

GPencil: Usability Tweaks to "Onion Skins" toggle on header

* The state of this toggle now reflects whether onion skinning is enabled on
any layer, instead of just the active layer. This is handy if there's more than
one GP datablock being shown in the scene, and you need to track down whether it's
the current GP datablock that has a layer with this enabled

* Disabling the toggle now turns off onion skinning on ALL layers at the same time.
This makes it much faster to turn off onion skinning if you've got it enabled
on several layers and would now like to disable it (e.g. for a "clean" pass over
the anim)

* Toggling this button still enables onion skinning for just the active layer,
since that's the one you're most likely to want to see these for (i.e. the character
outlines are on this layer, but some of the background elements are animated, and you
don't really want to see those ghosted)

GPencil Dopesheet: Filtering option to only include GPencil layers related to the active scene

As requested by the Caminandes team, in the "Grease Pencil" mode of the dopesheet,
it is now possible to view only the Grease Pencil blocks+layers which come from the
active scene and/or the objects in that scene. This is useful when working with
multiple scenes, or when there are many other GPencil datablocks in the file for
various editors that aren't visible.

To use, enable the 'Active Only' toggle with the scene icon (located beside the
Summary toggle). By default, this is not enabled, so that backwards comptability
with old files is not affected (i.e. users are less likely to why they are no longer
able to see keyframes that would've previously been easily visible).

GPencil Dopesheet: Layers can now be filtered by name

This can be enabled using the "filter text" settings on the header (magnifying glass)
as in the other Dope Sheet modes.

GPencil DopeSheet Mode: Code cleanup for anim filtering code in preparation for some new features

* Split out the code used to generate channels for a datablock out into its own method.
This will be needed when we do some more useful filtering options

* Pass down dopesheet info

Code cleanup: Minor formatting stuff

Merge branch 'master' into GPencil_Editing_Stage3

GP Sculpt: Attempted fix for bug with Grab brush where some points would randomly get left behind

Fix: Initialise GP Sculpt settings when creating new scenes

Fix compile errors due to recent cleanups in master