Coalescing has only been reachable by hand-editing the INI. It needs to be
switchable per game, because whether it is worth anything depends entirely on
the title: it pays off when a game alternates between two render targets, and
does nothing at all otherwise.
Add the GameDB key coalesceRenderPasses, so a game that benefits can turn it on
by itself, and a checkbox in Graphics > Advanced plus a Full Screen UI toggle
next to the other driver-level GS options, so it can be tried on anything.
It classifies as a user-hack fix, which means enabling Manual Hardware Renderer
Fixes turns it back off - the usual escape hatch, and worth having while this is
new. Note the consequence for A/B testing: GameDB is applied after settings are
loaded, so for a game carrying the key, -set cannot switch it off.
Brian Degenhardt
44e950e7d5