Was using classes to define tools, however this makes it awkward to
dynamically generate them (we can do it, but its not very "Pythonic").
Move to a named tuple.
* This is just moving buttons to get a bit closer to the intended design,
better naming and layout is needed.
* Popovers currently work best when the 3D view header is at the top, with
the most important settings nearest to the mouse. Open design question is
if we should flip (part of) the buttons if header is at the bottom.
* Another question is if selecintg a shading mode enum should immediately
close the popover since those are changed often, unlike the other settings
for which it seems more convenient to keep the popover open.
Having single & multi-column checks inline were becoming unmanageable.
Use a generator to define the layout,
allows for easily adding different layouts in the future.
The problem is that some local path is always returned by
bpy_resource_path. The function does not enforce a check for existence
of the path in the low level code.
Since client code may indeed not care about existence of the directory,
I leave bpy_resource_path alone and patch the python code to check for
existence. An extra argument that enforces the check might be a better
solution, but I will be leaving this to the UI team.
Originally it was nice to have a small list of definitions
with tools inline.
However we need to be able to define drawing functions for tools
which Python can't easily inline.
Use function for keymap definition,
support creating a function from a tuple as well
(handy for simple key-maps).
For Blender 2.8 we had to be compatible with very old OpenGL versions, and
triple buffer was designed to work without offscreen rendering, by copying
the the backbuffer to a texture right before swapping. This way we could
avoid redrawing unchanged regions by copying them from this texture on the
next redraws. Triple buffer used to suffer from poor performance and driver
bugs on specific cards, so alternative draw methods remained available.
Now that we require newer OpenGL, we can have just a single draw method
that draw each region into an offscreen buffer, and then draws those to
the screen. This has some advantages:
* Poor 3D view performance when using Region Overlap should be solved now,
since we can also cache overlapping regions in offscreen buffers.
* Page flip, anaglyph and interlace stereo drawing can be a little faster
by avoiding a copy to an intermediate texture.
* The new 3D view drawing already writes to an offscreen buffer, which we
can draw from directly instead of duplicating it to another buffer.
* Eventually we will be able to remove depth and stencil buffers from the
window and save memory, though at the moment there are still some tools
using it so it's not possible yet.
* This also fixes a bug with Eevee sampling not progressing with stereo
drawing in the 3D viewport.
Differential Revision: https://developer.blender.org/D3061
Both the scene and workspace had an active view layer, and it was confusing
which settings were being used or displayed where. Now we always have one,
so there is no mismatch.
The "View Layers" tab in the properties editor is now "View Layer", no longer
showing a list of layers. Instead view layers can be added and removed with
the workspace view layer selector. They are also listed and selectable in the
outliner.
Single layer rendering uses the active view layer from the workspace.
This fixes bugs where the wrong active view layer was used, but more places
remain that are wrong and are now using the first view layer in the scene.
These are all marked with BKE_view_layer_context_active_PLACEHOLDER.
Use render settings and active view layer will be handled elsewhere.
Also change icon to not be confusing with render layers.
Probably we should get rid of the workspace tab entirely and do it in
the user preferences, but that's for later.
Active tool name needed to be unique from all other tools.
This caused problems since different modes have different tools with the
same name (Armature/Mesh click to extrude for eg).
Tool names now only need to be unique per mode.
