Dynamically sized regions in the topbar were flickering due to only updating
their size after redraws. Now there is an optional layout() callback for
all regions in an area to do UI layout first, then refresh the region layout,
and then do the actual drawing for each region.
Task T54753
* 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.
This is to address things like a percentage slider with a fixed soft mininum.
For example, the render resolution ranges from 1% to 100% and it is really
strange to have the slider showing nothing filled when the ui shows 1%.
Now we always fill the slider with a vertical boundary. A bit hard to explain,
but very easy to see the difference.
I split the widget in three parts and used fragment shader discard to remove the
undesired bits. That means all the widget program is doing a bit extra
calculation.
Reviewers: fclem
Subscribers: billreynish
Differential Revision: https://developer.blender.org/D3186
U.ui_scale is the setting from the user preferences and should never be used
for drawing. UI_DPI_FAC is the final scale after DPI from the operating system
is taken into account.
Not really happy with the fix, but it works. With the new window draw method
we are no longer storing the 3D viewport in 4 buffers, by having the GPU
viewport function directly as the 3rd buffer. This means we need to draw the
action zones into it, and so we need to keep the framebuffer bound a little
longer.
Note: Quad-View region overlay drawing is not working because of e01cadd657.
However I tested this patch after reverting that commit locally and this
patch's code seems fine.
Partial revert of 3d62230ed6.
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
