From 7192852da35e6d980a37953f9fa8c836568450ef Mon Sep 17 00:00:00 2001
From: Hugo Locurcio <hugo.locurcio@hugo.pro>
Date: Tue, 25 May 2021 16:25:10 +0200
Subject: =?UTF-8?q?Remove=2016=C3=97=20MSAA=20support=20due=20to=20driver?=
 =?UTF-8?q?=20bugs=20and=20low=20performance?=
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In the `master` branch, 16× MSAA caused the entire system to freeze
on NVIDIA GPUs. This is likely caused by graphics drivers not actually
implementing 16× MSAA, but combining 8× MSAA with 2× SSAA instead.

On top of that, modern shader complexity makes 16× MSAA very difficult
to use while keeping a good framerate. 8× MSAA is hard enough to use
as it is.
---
 doc/classes/RenderingServer.xml | 13 +++++--------
 doc/classes/Viewport.xml        |  5 +----
 2 files changed, 6 insertions(+), 12 deletions(-)

(limited to 'doc')

diff --git a/doc/classes/RenderingServer.xml b/doc/classes/RenderingServer.xml
index df8bfb7e34..1cba71aed5 100644
--- a/doc/classes/RenderingServer.xml
+++ b/doc/classes/RenderingServer.xml
@@ -3788,21 +3788,18 @@
 		<constant name="VIEWPORT_SDF_SCALE_MAX" value="3" enum="ViewportSDFScale">
 		</constant>
 		<constant name="VIEWPORT_MSAA_DISABLED" value="0" enum="ViewportMSAA">
-			Multisample antialiasing is disabled.
+			Multisample antialiasing for 3D is disabled. This is the default value, and also the fastest setting.
 		</constant>
 		<constant name="VIEWPORT_MSAA_2X" value="1" enum="ViewportMSAA">
-			Multisample antialiasing uses 2 samples per pixel.
+			Multisample antialiasing uses 2 samples per pixel for 3D. This has a moderate impact on performance.
 		</constant>
 		<constant name="VIEWPORT_MSAA_4X" value="2" enum="ViewportMSAA">
-			Multisample antialiasing uses 4 samples per pixel.
+			Multisample antialiasing uses 4 samples per pixel for 3D. This has a high impact on performance.
 		</constant>
 		<constant name="VIEWPORT_MSAA_8X" value="3" enum="ViewportMSAA">
-			Multisample antialiasing uses 8 samples per pixel.
+			Multisample antialiasing uses 8 samples per pixel for 3D. This has a very high impact on performance. Likely unsupported on low-end and older hardware.
 		</constant>
-		<constant name="VIEWPORT_MSAA_16X" value="4" enum="ViewportMSAA">
-			Multisample antialiasing uses 16 samples per pixel.
-		</constant>
-		<constant name="VIEWPORT_MSAA_MAX" value="5" enum="ViewportMSAA">
+		<constant name="VIEWPORT_MSAA_MAX" value="4" enum="ViewportMSAA">
 		</constant>
 		<constant name="VIEWPORT_SCREEN_SPACE_AA_DISABLED" value="0" enum="ViewportScreenSpaceAA">
 		</constant>
diff --git a/doc/classes/Viewport.xml b/doc/classes/Viewport.xml
index 2478b71b6a..c79ad2bb32 100644
--- a/doc/classes/Viewport.xml
+++ b/doc/classes/Viewport.xml
@@ -307,10 +307,7 @@
 		<constant name="MSAA_8X" value="3" enum="MSAA">
 			Use 8× Multisample Antialiasing. This has a very high performance cost. The difference between 4× and 8× MSAA may not always be visible in real gameplay conditions. Likely unsupported on low-end and older hardware.
 		</constant>
-		<constant name="MSAA_16X" value="4" enum="MSAA">
-			Use 16× Multisample Antialiasing. This has a very high performance cost. The difference between 8× and 16× MSAA may not always be visible in real gameplay conditions. Likely unsupported on medium and low-end hardware.
-		</constant>
-		<constant name="MSAA_MAX" value="5" enum="MSAA">
+		<constant name="MSAA_MAX" value="4" enum="MSAA">
 			Represents the size of the [enum MSAA] enum.
 		</constant>
 		<constant name="SCREEN_SPACE_AA_DISABLED" value="0" enum="ScreenSpaceAA">
-- 
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