From 58628b8dd357bd3961e7977ebdbe96ac4b6ceeda Mon Sep 17 00:00:00 2001
From: lightningterror <18107717+lightningterror@users.noreply.github.com>
Date: Sat, 24 Feb 2024 22:26:55 +0100
Subject: [PATCH] GS/HW: Make sure we don't multiply Cs if Ad is corrected.

Another potential to avoid copies.
---
 bin/resources/shaders/dx11/tfx.fx        | 2 +-
 bin/resources/shaders/opengl/tfx_fs.glsl | 2 +-
 bin/resources/shaders/vulkan/tfx.glsl    | 2 +-
 pcsx2/GS/Renderers/Metal/tfx.metal       | 2 +-
 4 files changed, 4 insertions(+), 4 deletions(-)

diff --git a/bin/resources/shaders/dx11/tfx.fx b/bin/resources/shaders/dx11/tfx.fx
index ef4c0450c0..6713fa28f9 100644
--- a/bin/resources/shaders/dx11/tfx.fx
+++ b/bin/resources/shaders/dx11/tfx.fx
@@ -930,7 +930,7 @@ void ps_blend(inout float4 Color, inout float4 As_rgba, float2 pos_xy)
 			Color.rgb = max((float3)0.0f, (Alpha - (float3)1.0f));
 			Color.rgb *= (float3)255.0f;
 		}
-		else if (PS_BLEND_HW == 3)
+		else if (PS_BLEND_HW == 3 && PS_RTA_CORRECTION == 0)
 		{
 			// Needed for Cs*Ad, Cs*Ad + Cd, Cd - Cs*Ad
 			// Multiply Color.rgb by (255/128) to compensate for wrong Ad/255 value when rgb are below 128.
diff --git a/bin/resources/shaders/opengl/tfx_fs.glsl b/bin/resources/shaders/opengl/tfx_fs.glsl
index 5cafc59050..0dcae0d976 100644
--- a/bin/resources/shaders/opengl/tfx_fs.glsl
+++ b/bin/resources/shaders/opengl/tfx_fs.glsl
@@ -910,7 +910,7 @@ float As = As_rgba.a;
 
 	Color.rgb = max(vec3(0.0f), (Alpha - vec3(1.0f)));
 	Color.rgb *= vec3(255.0f);
-#elif PS_BLEND_HW == 3
+#elif PS_BLEND_HW == 3 && PS_RTA_CORRECTION == 0
 	// Needed for Cs*Ad, Cs*Ad + Cd, Cd - Cs*Ad
 	// 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
diff --git a/bin/resources/shaders/vulkan/tfx.glsl b/bin/resources/shaders/vulkan/tfx.glsl
index 1619e70d6c..fcf75efcf0 100644
--- a/bin/resources/shaders/vulkan/tfx.glsl
+++ b/bin/resources/shaders/vulkan/tfx.glsl
@@ -1163,7 +1163,7 @@ void ps_blend(inout vec4 Color, inout vec4 As_rgba)
 
 			Color.rgb = max(vec3(0.0f), (Alpha - vec3(1.0f)));
 			Color.rgb *= vec3(255.0f);
-		#elif PS_BLEND_HW == 3
+		#elif PS_BLEND_HW == 3 && PS_RTA_CORRECTION == 0
 			// Needed for Cs*Ad, Cs*Ad + Cd, Cd - Cs*Ad
 			// 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
diff --git a/pcsx2/GS/Renderers/Metal/tfx.metal b/pcsx2/GS/Renderers/Metal/tfx.metal
index cdd66e79aa..e13c2824d2 100644
--- a/pcsx2/GS/Renderers/Metal/tfx.metal
+++ b/pcsx2/GS/Renderers/Metal/tfx.metal
@@ -991,7 +991,7 @@ struct PSMain
 				float Alpha = PS_BLEND_C == 2 ? cb.alpha_fix : As;
 				Color.rgb = saturate(Alpha - 1.f) * 255.f;
 			}
-			else if (PS_BLEND_HW == 3)
+			else if (PS_BLEND_HW == 3 && PS_RTA_CORRECTION == 0)
 			{
 				// Needed for Cs*Ad, Cs*Ad + Cd, Cd - Cs*Ad
 				// Multiply Color.rgb by (255/128) to compensate for wrong Ad/255 value when rgb are below 128.