From 816ee9e54503de0723b46e3d07d45ea2ff7eaa4c Mon Sep 17 00:00:00 2001
From: lightningterror <18107717+lightningterror@users.noreply.github.com>
Date: Fri, 18 Feb 2022 15:35:55 +0100
Subject: [PATCH] GS-hw: Prefer sw blend for clr_blend1_2 on ultra blending.

Opengl/Vulkan: Prefer sw blend over hw for clr_blend1_2 on ultra blending, doing hw is less accurate and will introduce rounding issues.

Direct3D11: Prefer sw blend over hw for clr_blend1_2 only when primitives don't overlap.
---
 pcsx2/GS/Renderers/HW/GSRendererNew.cpp | 9 +++++++--
 1 file changed, 7 insertions(+), 2 deletions(-)

diff --git a/pcsx2/GS/Renderers/HW/GSRendererNew.cpp b/pcsx2/GS/Renderers/HW/GSRendererNew.cpp
index 3d6e4d6be8..f6cf244690 100644
--- a/pcsx2/GS/Renderers/HW/GSRendererNew.cpp
+++ b/pcsx2/GS/Renderers/HW/GSRendererNew.cpp
@@ -579,7 +579,7 @@ void GSRendererNew::EmulateBlending(bool& DATE_PRIMID, bool& DATE_BARRIER)
 	// BLEND_C_CLR1 with Ad, BLEND_C_CLR3  Cs > 0.5f will require sw blend.
 	// BLEND_C_CLR1 with As/F, BLEND_C_CLR2_AF, BLEND_C_CLR2_AS can be done in hw.
 	const bool clr_blend = !!(blend_flag & (BLEND_C_CLR1 | BLEND_C_CLR2_AF | BLEND_C_CLR2_AS | BLEND_C_CLR3));
-	const bool clr_blend1_2 = (blend_flag & (BLEND_C_CLR1 | BLEND_C_CLR2_AF | BLEND_C_CLR2_AS))
+	bool clr_blend1_2 = (blend_flag & (BLEND_C_CLR1 | BLEND_C_CLR2_AF | BLEND_C_CLR2_AS))
 		&& (ALPHA.C != 1)                                                // Make sure it isn't an Ad case
 		&& !m_env.PABE.PABE                                              // No PABE as it will require sw blending.
 		&& (m_env.COLCLAMP.CLAMP)                                        // Let's add a colclamp check too, hw blend will clamp to 0-1.
@@ -604,6 +604,7 @@ void GSRendererNew::EmulateBlending(bool& DATE_PRIMID, bool& DATE_BARRIER)
 		switch (GSConfig.AccurateBlendingUnit)
 		{
 			case AccBlendLevel::Ultra:
+				clr_blend1_2 = false;
 				sw_blending |= true;
 				[[fallthrough]];
 			case AccBlendLevel::Full:
@@ -644,7 +645,11 @@ void GSRendererNew::EmulateBlending(bool& DATE_PRIMID, bool& DATE_BARRIER)
 		switch (GSConfig.AccurateBlendingUnit)
 		{
 			case AccBlendLevel::Ultra:
-				sw_blending |= (m_prim_overlap == PRIM_OVERLAP_NO);
+				if (m_prim_overlap == PRIM_OVERLAP_NO)
+				{
+					clr_blend1_2 = false;
+					sw_blending |= true;
+				}
 				[[fallthrough]];
 			case AccBlendLevel::Full:
 				sw_blending |= ((ALPHA.C == 1 || (blend_mix && (alpha_c2_high_one || alpha_c0_high_max_one))) && (m_prim_overlap == PRIM_OVERLAP_NO));