From e8cf4822b123fd371df6acaa14aef3498b9c4c6e Mon Sep 17 00:00:00 2001
From: lightningterror <18107717+lightningterror@users.noreply.github.com>
Date: Mon, 6 Mar 2023 02:40:00 +0100
Subject: [PATCH] GS-d3d: 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.
---
 bin/resources/shaders/dx11/tfx.fx | 10 +++++++---
 1 file changed, 7 insertions(+), 3 deletions(-)

diff --git a/bin/resources/shaders/dx11/tfx.fx b/bin/resources/shaders/dx11/tfx.fx
index 12d93a0b4d..8ab748abb8 100644
--- a/bin/resources/shaders/dx11/tfx.fx
+++ b/bin/resources/shaders/dx11/tfx.fx
@@ -872,9 +872,13 @@ void ps_blend(inout float4 Color, inout float4 As_rgba, float2 pos_xy)
 		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 *= (255.0f / 128.0f);
+			// 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 = 255.0f / max(128.0f, max_color);
+			Color.rgb *= (float3)color_compensate;
 		}
 	}
 }