TH_BACK was being used when drawing the 3D view even though
there was no way to set the color in the preferences.
The color was zero'd when moving to the new 2.8x theme.
Having both gradient and background colors was confusing,
especially having to use 'TH_HIGH_GRAD' for the 3D view, 'TH_BACK' for
other views.
Move the background color back to 'TH_BACK', 'TH_BACK_GRAD' is used
when gradients are enabled.
RNA is unchanged so presets don't need updating.
There was a problem in the caps start and in some situations, the pixel was wrong.
Also changed the way the caps are detected because use the alpha in negative was a hack that maybe will not work with all drivers.
Even though the fragment shader was already discarding all members of
dof_bokeh_sides when blades was zero, the C code was still trying to
use this for a few divisions leading to runtime asserts.
Those are harmless yet can lead some to waste time while pursuiting
other bugs (namely a near freeze when blades aspect ratio is too low).
The GP_STROKE_RECALC_CACHE identifier was changed to GP_STROKE_RECALC_GEOMETRY because the previous name was confusing and could be confused with the recalculation of the Draw Manager cache.
Object visibility is now handled by the depsgraph iterator, but this API
was incomplete as it made no distinction for visibility of the object itself,
particles and generated instances.
The depsgraph iterator API now includes information about which part of the
object is visible, and this is used by Cycles to replace the old custom logic.
Cycles and EEVEE visibility should now be consistent, which unfortunately does
means some subtle compatibility breakage for both.
Fixes T58956, T58202, T59284.
Differential Revision: https://developer.blender.org/D4109
Has some advantages over existing options.
- Using material links color to rendering with no way to vary colors
if objects share a material.
- Random gives no control, objects may randomly have the same color,
duplicating an object often changes it's color.
Now, the internal data is recalculated when add or remove a point.
The change in the API affect to stroke.points.add() that now requires a datablock parameter. This parameter is required to identify the datablock affected.
For example: stroke.points.add(gpencil, 1) instead of stroke.points.add(1)
This is the second try to fix T59600
