Add support for applying alpha in linear space to match Photoshop
behavior in linear mode, and for just overall correctness. The default
setting is still nonlinear to match common user expectation though.
When the slideshow is deactivated (not shown to the stream), makes it so
that it can either continue playing regardless, pause, or restart the
slideshow when the source is activated (shown to the stream) again.
Split from jp9000/obs-studio#976
Adds an option that allows the user to specify the size (or aspect) of
the bounding source size which all the images are then scaled in to.
Acts similarly to "bounding box" of scene items, but for the slide show
and its sub-sources.
If this option is on, the image will unload when the image isn't
displayed anywhere, and then reload it when it's displayed again to
reduce the amount of memory images take up on VRAM at any given time.
If this option is off, then it's always loaded in VRAM regardless of
whether it's displayed or not.
Closes Pull Request #380
(edited by Jim)
