From 379d9e4b88dc528a62bfa8fd10f592fc2fac9c01 Mon Sep 17 00:00:00 2001
From: lightningterror <lightningterror@yahoo.com>
Date: Wed, 3 Oct 2018 07:41:10 +0200
Subject: [PATCH] GSdx-d3d: optimize colclip 0 port from OpenGL.

Commits:
https://github.com/PCSX2/pcsx2/commit/7979dec5b089ef7435f344c7d3eead521efe1f3c
https://github.com/PCSX2/pcsx2/commit/15b934eb2a85b680e9e61dad7fc6138b60321bc7
---
 plugins/GSdx/GSRendererDX.cpp | 11 ++++++++++-
 1 file changed, 10 insertions(+), 1 deletion(-)

diff --git a/plugins/GSdx/GSRendererDX.cpp b/plugins/GSdx/GSRendererDX.cpp
index a3f25cfd1e..e92411f490 100644
--- a/plugins/GSdx/GSRendererDX.cpp
+++ b/plugins/GSdx/GSRendererDX.cpp
@@ -533,7 +533,16 @@ void GSRendererDX::DrawPrims(GSTexture* rt, GSTexture* ds, GSTextureCache::Sourc
 	bool colclip_wrap = m_env.COLCLAMP.CLAMP == 0 && !tex && PRIM->PRIM != GS_POINTLIST;
 	if (colclip_wrap)
 	{
-		m_ps_sel.colclip = 1;
+		if ((m_context->ALPHA.A == m_context->ALPHA.B) || !om_bsel.abe) // Optimize-away colclip
+		{
+			// No addition neither substraction so no risk of overflow the [0:255] range.
+			colclip_wrap = false;
+		}
+		else
+		{
+			m_ps_sel.colclip = 1;
+			// fprintf(stderr, "COLCLIP ENABLED (blending is %d/%d/%d/%d)\n", m_context->ALPHA.A, m_context->ALPHA.B, m_context->ALPHA.C, m_context->ALPHA.D);
+		}
 	}
 
 	m_ps_sel.clr1 = om_bsel.IsCLR1();