Blender Git Loki

Refactor `BKE_id_copy` to return the new ID pointer.

No reasons to keep the new ID pointer as parameter here.

Part of T71219.

Refactor `BKE_id_copy_ex` to return the new ID pointer.

Note that possibility to pass the new ID pointer as parameter was kept,
as this is needed for some rather specific cases (like in depsgraph/COW,
when copying into already allocated memory).

Part of T71219.

Volumes: new Volume Displace modifier

This modifier uses a 3D texture to displace a volume.
For now, this can only use the previously existing texture system,
because we do not have a better alternative yet. Still, the results
can be quite good and interesting. See D9075 for some examples.

Reviewers: brecht, simonthommes

Differential Revision: https://developer.blender.org/D9075

UI: Fix Incorrect Workspace Tab Sizing

Changes Workspace tabs so that the text size and tab width are both set by style.widget.points.

Differential Revision: https://developer.blender.org/D9108

Reviewed by Julian Eisel

Fix T81171: Show Alerts at Center in Statusbar

Move position of Alerts and Progress bar back to the center of the Statusbar.

Differential Revision: https://developer.blender.org/D9118

Reviewed by Brecht Van Lommel

Fix T81254: Incorrect calculation of EEVEE Transmittance Volumetrics

Regular rendering uses a custom blend mode, but render passes renders to
2 separate textures. This wasn't configured correctly inside the
fragment shaders. This patch adds a switch to configure the fragment
shader with the correct attachments.

Backport to Blender 2.83.

Reviewed By: Cl�ment Foucault

Differential Revision: https://developer.blender.org/D9038

UV/Image Editor: Overlay Popover

The overlay options in the image/uv editor is hidden in side panels and menus. Sometimes this panel is even hidden, while still useful.
The goal of this task is to introduce an overlay pop-over just like the overlay-popover of the 3d viewport.

Popover has
* UV Stretching (only available in the UV mode, when active object mode is a mesh and in OB_EDIT mode)
* Display As (only available in the UV mode, when active object mode is a mesh and in OB_EDIT mode)
* Show Modified (only available in the UV mode, when active object mode is a mesh and in OB_EDIT mode)
* Show UV Edges (including opacity slider; available UV, View, Paint, when active object mode is a mesh and in OB_EDIT mode)
* Udim tiles when no image is available.

Like the 3d viewport, there will be a editor toggle to enable/disable the overlays

For compatibility reasons the RNA properties are added to both the `SpaceImage.uv_editor` amd `SpaceImage.overlay`. On DNA level they are still stored in the SpaceImage. only new properties are added to the SpaceImageOverlay struct. During the next major release we could remove these options from `SpaceImage.uv_editor`. This should be noted in the Python section of release notes.

Reviewed By: Julian Eisel, Pablo Vazquez

Differential Revision: https://developer.blender.org/D8890

Python API: add volume.grids.save(filepath) to save grids and metadata to disk

Particularly useful now that we can dynamically generate volume using
modifiers. Not exposed in the user interface currently, but it can be used
by add-ons that need to export an entire scene including volumes.

Fix T81490: GPencil merge layer duplicated all strokes

There was a wrong duplication of all strokes and this accumulated all previous data for each frame.

Also a cleanup has been done in order to clarify what means each variable.

PyDoc: Multithread sphinx-build

Compile times went from over 5min to under 2 on my laptop.

PyDoc: Remove workaround for slow sphinx builds

Tesing with newer versions of sphinx to directory `sphinx-build` is
executed has no affect on the build time. Testing even gave a 2-3% speed
boost.

CleanUp: DrawManager Balanced alloc/free of surface_per_mat cache

The alloc was done in the init, but the free was done in the discard.
As discarding can happen more often there were some unneeded if
statements to work around use after free.

This patch moves the free to the `mesh_batch_cache_clear` and removes
the if statements to check for use after free.

CleanUp: Introduce `eMeshBatchDirtyMode` enum

It used to be an `int mode`.

Fix / cleanup panel category tab drawing

The panel category tabs (In the 3D view N-panel) did not look great
when zoomed in or with high DPI screens, with multiple overlapping
outlines, and roundness that didn't match elsewhere in Blender. In
addition, there was some unecessarily low-level drawing code in the
panel code.

This commit uses an existing function `UI_draw_roundbox_4fv`to draw
the tabs instead. There are some slight visual differences, though
these are easily adjusted with theme colors.

Differential Revision: https://developer.blender.org/D9045

Fix T76595: Indicate the Active Keyframe in Graph Editor

In the graph editor there is a panel that says "Active Keyframe" for
numerically editing a keyframe's values, but in the code there is no
concept of the "active keyframe." Since this is a useful concept to
have for some other features anyway, this commit adds an active
keyframe index value to FCurves. It also displays it with a theme
color for the active vertex (which didn't exist before) if the
FCurve is active.

The active keyframe in the graph editor is treated similarly to the
active vertex in the 3D view. It is the keyframe most recently selected
with a single click, and it is always selected.

For now, the only real functional change is that the active keyframe
appears in white and it should be more predictable which keyframe is
being edited in the sidebar panel.

Differential Revision: https://developer.blender.org/D7737

Cleanup: improve integer types

Reviewers: mont29, brecht

Differential Revision: https://developer.blender.org/D9135

UI: Improve labels in "Convert To" menu

Move the information about the type of the source objects to the item
descriptions instead of the names. The extra information in the names
made the labels cluttered, and it's less important information.

Differential Revision: https://developer.blender.org/D8352

UI: Fix capitalization in various places

Follow the MLA style, agreed upon in T79589. This means "from" within UI
labels should be lowercase.

Differential Revision: https://developer.blender.org/D8345

UI: Use property split in various pop-up dialogs

The settings in these popups are not animateable, so also turn off
property decorate. And also use better widths in order to fit the
full text.

Differential Revision: https://developer.blender.org/D9060

UI: Reduce item padding in the gpencil edit context menus

Aligning the columns removes unecessary white space.
The same as in the D8480 / rBb2e0c8f902fa.

Differential Revision: https://developer.blender.org/D9111