This moves the compute shaders to run immediately after scene draw,
instead of in the draw() callback, which happens much later. All models
in the scene have been queued by the time, but since it is so early in
the ui drawing, it gives a few more ms for the compute to run before the
result needs to be used to draw the next frame.
This adjusts the draw callbacks api to take in the color of the full
screen overlay the client would have rendered. This is primarily used in
godwars, underwater, darkmeyer, etc. Having them rasterized on the cpu
is slow, especially with gpu on since we additionally have to compute
the alpha per-pixel.
Adjust the mouse highlight overlay to run at the same layers as the
tooltip overlay. It always runs first due to having a lower position.
I think previously tooltips from ui ops were 1 frame behind due to this
being UNDER_WIDGETS.
Additionally change the tooltip overlay to draw after the fullscreen tli
instead of the world map interface. Having it render after the world map
caused tooltips to render after the floating world map too, which is too
early. The fullscreen tli is the root of both the fullscreen world map
and of the welcome screen.
This allows overlays to request draw after any interface or layer. This
allows removal of the ABOVE_MAP layer which can now just be replaced
with requesting draw after the map interface. This also fixes item
overlays from drawing over top of the map by now drawing the item
overlay immediately after the interface and/or layer the item is on is
drawn.
For backwards compatability, ABOVE_WIDGETS is kept as a layer, but
internally just requests draw after the 3 TLIs.
Due to overlays defaulting to the UNDER_WIDGETS layer, a new layer
MANUAL has been added, which is intended for use when requesting draw
after specific interfaces or layers, so that the overlay is otherwise
not drawn a second time due to being UNDER_WIDGETS.
The returned widget isn't actually the viewport widget, but is a layer within the viewport, and only needs to be used within the overlay renderer to position the snapcorners
