From 1382fe9c6c1ff317b9a614f91d5cd52b0c003c6a Mon Sep 17 00:00:00 2001
From: lightningterror <18107717+lightningterror@users.noreply.github.com>
Date: Mon, 6 Mar 2023 02:40:49 +0100
Subject: [PATCH] GS-metal: Automatically adjust color compensation based on
 rgb value for hw blend clr3 case.

Auto adjust when any color is higher than 128 ( 1.0f) to get more accurate color results.
---
 pcsx2/GS/Renderers/Metal/tfx.metal | 9 +++++++--
 1 file changed, 7 insertions(+), 2 deletions(-)

diff --git a/pcsx2/GS/Renderers/Metal/tfx.metal b/pcsx2/GS/Renderers/Metal/tfx.metal
index a12f5e5ff4..441b1e64ea 100644
--- a/pcsx2/GS/Renderers/Metal/tfx.metal
+++ b/pcsx2/GS/Renderers/Metal/tfx.metal
@@ -927,8 +927,13 @@ struct PSMain
 			else if (PS_CLR_HW == 3)
 			{
 				// Needed for Cs*Ad, Cs*Ad + Cd, Cd - Cs*Ad
-				// Multiply Color.rgb by (255/128) to compensate for wrong Ad/255 value
-				Color.rgb *= (255.f / 128.f);
+				// Multiply Color.rgb by (255/128) to compensate for wrong Ad/255 value when rgb are below 128.
+				// When any color channel is higher than 128 then adjust the compensation automatically
+				// to give us more accurate colors, otherwise they will be wrong.
+				// The higher the value (>128) the lower the compensation will be.
+				float max_color = max(max(Color.r, Color.g), Color.b);
+				float color_compensate = 255.f / max(128.f, max_color);
+				Color.rgb *= float3(color_compensate);
 			}
 		}
 	}