Feature #1663: Replace game-side color filter / special effect with LensFx
[Doom] Inverted B&W palette for invulnerability
The new "postfx" command can be used to draw the game world with an inverted monochrome shader. This should be used in libdoom as the invulnerability effect instead of drawing a pass that negates all colors.
Renderer|libdoom: Use postfx for invulnerability effect
The “post.fx.monochrome.inverted” shader is used as the
invulnerability effect in libdoom.
The blinking effect when the power-up is going away now conforms to
vanilla in that it toggles between completely on and off.
The “postfx” command was enhanced to allow specifying a manual
opacity factor for the effect.