Godot: FXAA mess brightness when using World Environment Tone mapping

[vitorbalbio]

Godot version:
3.2.4 Beta 1

OS/device including version:
Windows 10

Issue description:
FXAA mess your scene brightness when using World Environment Tonemap other than default settings.

Steps to reproduce:
See above

Minimal reproduction project:
TesteFXAA.zip

[clayjohn]

Are you using GLES2 or GLES3?

[volzhs]

looks GLES3 according to driver name on top right corner of gif.

[vitorbalbio]

Are you using GLES2 or GLES3?

GLES3

[clayjohn]

Same bug is in master and 3.2. I think I know what the issue is.

_edit:_ The issue is that FXAA relies on colors being in the 0-1 range (i.e. LDR, not HDR). However, we apply it right before tonemapping so that it can be done in the same render pass as tonemapping. Unfortunately this blows up HDR colors. To be done properly, I think FXAA may need to be in a render pass of its own.

_edit2:_ False alarm. The HDR thing is definitely an issue. But it doesn't cause this bug, it just causes FXAA to be less effective than it should be. The real bug is a misplaced parenthesis :P PR coming shortly.