From 3f467cae67830c6ba3732cc3f1065bd1f7182bee Mon Sep 17 00:00:00 2001
From: lightningterror <lightningterror@yahoo.com>
Date: Sun, 23 Feb 2020 22:24:32 +0100
Subject: [PATCH] gsdx-d3d11: Always enable sw colclip for BLEND_NO_BAR.

- Free blending and it's faster than standard hdr algo when Blending
Accuracy is disabled.

- Add assert when disabling hw blending, hw blending should only be disabled
on free/no barrier blending. D3D11 lacks other types of blending.

- Use const to get rid of some warnings.
---
 .../GSdx/Renderers/DX11/GSRendererDX11.cpp    | 42 ++++++++++---------
 1 file changed, 23 insertions(+), 19 deletions(-)

diff --git a/plugins/GSdx/Renderers/DX11/GSRendererDX11.cpp b/plugins/GSdx/Renderers/DX11/GSRendererDX11.cpp
index 1fd2673db0..ee8a974e75 100644
--- a/plugins/GSdx/Renderers/DX11/GSRendererDX11.cpp
+++ b/plugins/GSdx/Renderers/DX11/GSRendererDX11.cpp
@@ -496,7 +496,7 @@ void GSRendererDX11::EmulateChannelShuffle(GSTexture** rt, const GSTextureCache:
 
 void GSRendererDX11::EmulateBlending()
 {
-	// Partial port of OGL SW blending. Currently only works for accumulation blend.
+	// Partial port of OGL SW blending. Currently only works for accumulation and no barrier blend.
 	const GIFRegALPHA& ALPHA = m_context->ALPHA;
 	bool sw_blending         = false;
 
@@ -526,43 +526,45 @@ void GSRendererDX11::EmulateBlending()
 		}
 	}
 
-	uint8 blend_index  = uint8(((ALPHA.A * 3 + ALPHA.B) * 3 + ALPHA.C) * 3 + ALPHA.D);
-	int blend_flag = m_dev->GetBlendFlags(blend_index);
-
-	// SW free blend.
-	bool free_blend = !!(blend_flag & (BLEND_NO_BAR|BLEND_ACCU));
+	const uint8 blend_index  = uint8(((ALPHA.A * 3 + ALPHA.B) * 3 + ALPHA.C) * 3 + ALPHA.D);
+	const int blend_flag = m_dev->GetBlendFlags(blend_index);
 
 	// Do the multiplication in shader for blending accumulation: Cs*As + Cd or Cs*Af + Cd
-	bool accumulation_blend = !!(blend_flag & BLEND_ACCU);
+	const bool accumulation_blend = !!(blend_flag & BLEND_ACCU);
+
+	// Blending doesn't require barrier
+	const bool no_barrier_blend = !!(blend_flag & BLEND_NO_BAR);
 
 	switch (m_sw_blending)
 	{
 		case ACC_BLEND_HIGH_D3D11:
 		case ACC_BLEND_MEDIUM_D3D11:
 		case ACC_BLEND_BASIC_D3D11:
-			sw_blending |= free_blend;
+			sw_blending |= accumulation_blend || no_barrier_blend;
 			// fall through
 		default: break;
 	}
 
+	// Color clip
 	if (m_env.COLCLAMP.CLAMP == 0)
 	{
-		if (accumulation_blend)
+		// fprintf(stderr, "%d: COLCLIP Info (Blending: %d/%d/%d/%d)\n", s_n, ALPHA.A, ALPHA.B, ALPHA.C, ALPHA.D);
+		if (no_barrier_blend)
 		{
-			// fprintf(stderr, "%d: COLCLIP HDR mode with accumulation blend\n", s_n);
+			// The fastest algo that requires a single pass
+			// fprintf(stderr, "%d: COLCLIP Free mode ENABLED\n", s_n);
+			m_ps_sel.colclip = 1;
+			sw_blending = true;
+		}
+		else if (accumulation_blend)
+		{
+			// fprintf(stderr, "%d: COLCLIP Fast HDR mode ENABLED\n", s_n);
 			sw_blending = true;
 			m_ps_sel.hdr = 1;
 		}
-		else if (sw_blending)
-		{
-			// So far only BLEND_NO_BAR should hit this path, it's faster than standard HDR algo.
-			// Note: Isolate the code to BLEND_NO_BAR if other blending conditions are added.
-			// fprintf(stderr, "%d: COLCLIP SW ENABLED (blending is %d/%d/%d/%d)\n", s_n, ALPHA.A, ALPHA.B, ALPHA.C, ALPHA.D);
-			m_ps_sel.colclip = 1;
-		}
 		else
 		{
-			// fprintf(stderr, "%d: COLCLIP HDR mode\n", s_n);
+			// fprintf(stderr, "%d: COLCLIP HDR mode ENABLED\n", s_n);
 			m_ps_sel.hdr = 1;
 		}
 	}
@@ -594,8 +596,10 @@ void GSRendererDX11::EmulateBlending()
 		else
 		{
 			// Disable HW blending
-			// Only BLEND_NO_BAR should hit this code path for now.
 			m_om_bsel.abe = 0;
+
+			// Only BLEND_NO_BAR should hit this code path for now
+			ASSERT(no_barrier_blend);
 		}
 
 		// Require the fix alpha vlaue