From c10d9ea87a46fe5a86f80ccd896062875056cf5b Mon Sep 17 00:00:00 2001
From: NeoBrainX <NeoBrainX@gmail.com>
Date: Thu, 28 Mar 2013 22:59:42 +0100
Subject: [PATCH] Clean up blending code a bit.

---
 Source/Core/VideoCommon/Src/BPMemory.h        | 11 +++++++++++
 .../Plugins/Plugin_VideoDX11/Src/Render.cpp   |  6 +++---
 Source/Plugins/Plugin_VideoDX9/Src/Render.cpp |  4 ++--
 Source/Plugins/Plugin_VideoOGL/Src/Render.cpp | 19 +++++++++----------
 4 files changed, 25 insertions(+), 15 deletions(-)

diff --git a/Source/Core/VideoCommon/Src/BPMemory.h b/Source/Core/VideoCommon/Src/BPMemory.h
index 1a29439b36..f0d0a502ed 100644
--- a/Source/Core/VideoCommon/Src/BPMemory.h
+++ b/Source/Core/VideoCommon/Src/BPMemory.h
@@ -621,6 +621,17 @@ union X10Y10
 
 // Framebuffer/pixel stuff (incl fog)
 
+#define GX_BL_ZERO         0
+#define GX_BL_ONE          1
+#define GX_BL_SRCCLR       2 // for dst factor
+#define GX_BL_INVSRCCLR    3 // for dst factor
+#define GX_BL_SRCALPHA     4
+#define GX_BL_INVSRCALPHA  5
+#define GX_BL_DSTALPHA     6
+#define GX_BL_INVDSTALPHA  7
+#define GX_BL_DSTCLR       GX_BL_SRCCLR // for src factor
+#define GX_BL_INVDSTCLR    GX_BL_INVSRCCLR // for src factor
+
 union BlendMode
 {
 	struct 
diff --git a/Source/Plugins/Plugin_VideoDX11/Src/Render.cpp b/Source/Plugins/Plugin_VideoDX11/Src/Render.cpp
index 2dcfcd041c..f765b1e920 100644
--- a/Source/Plugins/Plugin_VideoDX11/Src/Render.cpp
+++ b/Source/Plugins/Plugin_VideoDX11/Src/Render.cpp
@@ -715,12 +715,12 @@ void Renderer::SetBlendMode(bool forceUpdate)
 	if (bpmem.blendmode.logicopenable && !forceUpdate)
 		return;
 
-	if (bpmem.blendmode.subtract)  // enable blending src 1 dst 1
+	if (bpmem.blendmode.subtract)
 	{
 		gx_state.blenddc.RenderTarget[0].BlendEnable = true;
 		SetBlendOp(D3D11_BLEND_OP_REV_SUBTRACT);
-		SetSrcBlend(d3dSrcFactors[1]);
-		SetDestBlend(d3dDestFactors[1]);
+		SetSrcBlend(D3D11_BLEND_ONE);
+		SetDestBlend(D3D11_BLEND_ONE);
 	}
 	else
 	{
diff --git a/Source/Plugins/Plugin_VideoDX9/Src/Render.cpp b/Source/Plugins/Plugin_VideoDX9/Src/Render.cpp
index 7a175fd443..fdd29d289b 100644
--- a/Source/Plugins/Plugin_VideoDX9/Src/Render.cpp
+++ b/Source/Plugins/Plugin_VideoDX9/Src/Render.cpp
@@ -691,8 +691,8 @@ void Renderer::SetBlendMode(bool forceUpdate)
 	{
 		D3D::SetRenderState(D3DRS_ALPHABLENDENABLE, true);
 		D3D::SetRenderState(D3DRS_BLENDOP, D3DBLENDOP_REVSUBTRACT);
-		D3D::SetRenderState(D3DRS_SRCBLEND, d3dSrcFactors[1]);
-		D3D::SetRenderState(D3DRS_DESTBLEND, d3dDestFactors[1]);
+		D3D::SetRenderState(D3DRS_SRCBLEND, D3DBLEND_ONE);
+		D3D::SetRenderState(D3DRS_DESTBLEND, D3DBLEND_ONE);
 	}
 	else
 	{
diff --git a/Source/Plugins/Plugin_VideoOGL/Src/Render.cpp b/Source/Plugins/Plugin_VideoOGL/Src/Render.cpp
index 2f2b0b224d..7c950e9e85 100644
--- a/Source/Plugins/Plugin_VideoOGL/Src/Render.cpp
+++ b/Source/Plugins/Plugin_VideoOGL/Src/Render.cpp
@@ -1008,23 +1008,22 @@ void Renderer::SetBlendMode(bool forceUpdate)
 		u32 dstidx = (newval >> 6) & 7;
 		GLenum srcFactor = glSrcFactors[srcidx];
 		GLenum dstFactor = glDestFactors[dstidx];
+
+		// adjust alpha factors
 		if (useDualSource)
 		{
-			srcidx = 1;
-			dstidx = 0;			
+			srcidx = GX_BL_ONE;
+			dstidx = GX_BL_ZERO;
 		}	
 		else
 		{
 			// we can't use GL_DST_COLOR or GL_ONE_MINUS_DST_COLOR for source in alpha channel so use their alpha equivalent instead
-			if (srcidx == 2 || srcidx == 3)
-			{
-				srcidx += 4;
-			}
+			if (srcidx == GX_BL_DSTCLR) srcidx = GX_BL_DSTALPHA;
+			if (srcidx == GX_BL_INVDSTCLR) srcidx = GX_BL_INVDSTALPHA;
+
 			// we can't use GL_SRC_COLOR or GL_ONE_MINUS_SRC_COLOR for destination in alpha channel so use their alpha equivalent instead
-			if (dstidx == 2 || dstidx == 3)
-			{
-				dstidx += 2;
-			}
+			if (dstidx == GX_BL_SRCCLR) dstidx = GX_BL_SRCALPHA;
+			if (dstidx == GX_BL_INVSRCCLR) dstidx = GX_BL_INVSRCALPHA;
 		}		
 		GLenum srcFactorAlpha = glSrcFactors[srcidx];
 		GLenum dstFactorAlpha = glDestFactors[dstidx];