From 8acc319a4a5ab1530bec1c470ed1735cb30d1039 Mon Sep 17 00:00:00 2001
From: lightningterror <lightningterror@yahoo.com>
Date: Thu, 13 Sep 2018 09:35:42 +0200
Subject: [PATCH] GSdx-d3d: Mask alpha channel on 24bit format.

dfmt is not supported but we can use the variable to select the
frame buffer format and later disable writting to the alpha channel.

MGS3 sees an improvement, and possibly other games as well.
So far didn't spot any regressions.
---
 plugins/GSdx/GSDeviceDX.h       | 3 ++-
 plugins/GSdx/GSRendererDX.cpp   | 6 ++++++
 plugins/GSdx/GSRendererDX11.cpp | 4 ++--
 plugins/GSdx/GSRendererDX9.cpp  | 9 +++++++--
 4 files changed, 17 insertions(+), 5 deletions(-)

diff --git a/plugins/GSdx/GSDeviceDX.h b/plugins/GSdx/GSDeviceDX.h
index 22590701b6..def1ae880f 100644
--- a/plugins/GSdx/GSDeviceDX.h
+++ b/plugins/GSdx/GSDeviceDX.h
@@ -172,6 +172,7 @@ public:
 				// *** Word 1
 				// Format
 				uint32 fmt:4;
+				uint32 dfmt:2;
 				// Alpha extension/Correction
 				uint32 aem:1;
 				uint32 fba:1;
@@ -203,7 +204,7 @@ public:
 				uint32 tcoffsethack:1;
 				uint32 point_sampler:1;
 
-				uint32 _free:32;
+				uint32 _free:30;
 			};
 
 			uint64 key;
diff --git a/plugins/GSdx/GSRendererDX.cpp b/plugins/GSdx/GSRendererDX.cpp
index 80a9a817ef..1088d927c3 100644
--- a/plugins/GSdx/GSRendererDX.cpp
+++ b/plugins/GSdx/GSRendererDX.cpp
@@ -475,6 +475,12 @@ void GSRendererDX::DrawPrims(GSTexture* rt, GSTexture* ds, GSTextureCache::Sourc
 
 	EmulateTextureShuffleAndFbmask();
 
+	if(m_ps_sel.dfmt == 1)
+	{
+		// Disable writing of the alpha channel
+		om_bsel.wa = 0;
+	}
+
 	if(DATE)
 	{
 		if(dev->HasStencil())
diff --git a/plugins/GSdx/GSRendererDX11.cpp b/plugins/GSdx/GSRendererDX11.cpp
index 39b1cb91f7..e63bcedbf4 100644
--- a/plugins/GSdx/GSRendererDX11.cpp
+++ b/plugins/GSdx/GSRendererDX11.cpp
@@ -50,7 +50,7 @@ void GSRendererDX11::EmulateTextureShuffleAndFbmask()
 	// Note: D3D1011 is limited and can't read the current framebuffer so we can't have PS_FBMASK and PS_WRITE_RG shaders ported and working.
 	if (m_texture_shuffle) {
 		m_ps_sel.shuffle = 1;
-		m_ps_sel.fmt = 0;
+		m_ps_sel.dfmt = 0;
 
 		const GIFRegXYOFFSET& o = m_context->XYOFFSET;
 
@@ -154,7 +154,7 @@ void GSRendererDX11::EmulateTextureShuffleAndFbmask()
 		}
 
 	} else {
-		//m_ps_sel.fmt = GSLocalMemory::m_psm[m_context->FRAME.PSM].fmt;
+		m_ps_sel.dfmt = GSLocalMemory::m_psm[m_context->FRAME.PSM].fmt;
 
 		om_bsel.wrgba = ~GSVector4i::load((int)m_context->FRAME.FBMSK).eq8(GSVector4i::xffffffff()).mask();
 	}
diff --git a/plugins/GSdx/GSRendererDX9.cpp b/plugins/GSdx/GSRendererDX9.cpp
index 60cb69fe31..b4827701dc 100644
--- a/plugins/GSdx/GSRendererDX9.cpp
+++ b/plugins/GSdx/GSRendererDX9.cpp
@@ -58,11 +58,16 @@ bool GSRendererDX9::CreateDevice(GSDevice* dev)
 
 void GSRendererDX9::EmulateTextureShuffleAndFbmask()
 {
-	if (m_texture_shuffle) {
+	if (m_texture_shuffle)
+	{
 		// We can do a partial port for D3D9 that skips the draw call to give it a slight improvement.
 		// It's still broken but more bearable. Broken effect is on the screen but fully instead of vertical lines.
 		throw GSDXRecoverableError();
-	} else {
+	} 
+	else
+	{
+		m_ps_sel.dfmt = GSLocalMemory::m_psm[m_context->FRAME.PSM].fmt;
+
 		om_bsel.wrgba = ~GSVector4i::load((int)m_context->FRAME.FBMSK).eq8(GSVector4i::xffffffff()).mask();
 	}
 }