Change destination alpha handling. The blending method introduced in rev 1921 was not the correct way to do it. This way was suggested by hrydgard in October and I should have listened. A simple pixel shader as hrydgard suggested cannot be used because the alpha is not set if the pixel is discarded due to failing depth (after z texture) or alpha (result of tev stages) tests. There is a bit of a performance hit so there should be an option to disable the second render pass which sets the alpha because it is probably not needed most of the time.

git-svn-id: https://dolphin-emu.googlecode.com/svn/trunk@2662 8ced0084-cf51-0410-be5f-012b33b47a6e

Source/Plugins/Plugin_VideoOGL/Src/BPStructs.cpp

@@ -153,7 +153,7 @@ void BPWritten(int addr, int changes, int newval)
             PRIM_LOG("constalpha: alp=%d, en=%d\n", bpmem.dstalpha.alpha, bpmem.dstalpha.enable);
 			SETSTAT(stats.dstAlphaEnable, bpmem.dstalpha.enable);
 			SETSTAT_UINT(stats.dstAlpha, bpmem.dstalpha.alpha);
-			Renderer::SetBlendMode(false);
+            PixelShaderManager::SetDestAlpha(bpmem.dstalpha);
         }
         break;
 

Source/Plugins/Plugin_VideoOGL/Src/PixelShaderCache.cpp

@@ -105,13 +105,14 @@ GLuint PixelShaderCache::GetColorMatrixProgram()
 }
 
 
-FRAGMENTSHADER* PixelShaderCache::GetShader()
+FRAGMENTSHADER* PixelShaderCache::GetShader(bool dstAlphaEnable)
 {
 	DVSTARTPROFILE();
 	PIXELSHADERUID uid;
 	u32 zbufrender = (Renderer::UseFakeZTarget() && bpmem.zmode.updateenable) ? 1 : 0;
 	u32 zBufRenderToCol0 = Renderer::GetRenderMode() != Renderer::RM_Normal;
-	GetPixelShaderId(uid, PixelShaderManager::GetTextureMask(), zbufrender, zBufRenderToCol0);
+    u32 dstAlpha = dstAlphaEnable ? 1 : 0;
+	GetPixelShaderId(uid, PixelShaderManager::GetTextureMask(), zbufrender, zBufRenderToCol0, dstAlpha);
 
 	PSCache::iterator iter = pshaders.find(uid);
 
@@ -128,7 +129,8 @@ FRAGMENTSHADER* PixelShaderCache::GetShader()
 	PSCacheEntry& newentry = pshaders[uid];
 	const char *code = GeneratePixelShader(PixelShaderManager::GetTextureMask(),
 										   Renderer::UseFakeZTarget(),
-										   Renderer::GetRenderMode() != Renderer::RM_Normal);
+										   Renderer::GetRenderMode() != Renderer::RM_Normal,
+                                           dstAlphaEnable);
 
 #if defined(_DEBUG) || defined(DEBUGFAST)
 	if (g_Config.iLog & CONF_SAVESHADERS && code) {	

Source/Plugins/Plugin_VideoOGL/Src/PixelShaderCache.h

@@ -58,7 +58,7 @@ public:
 	static void ProgressiveCleanup();
 	static void Shutdown();
 
-	static FRAGMENTSHADER* GetShader();
+	static FRAGMENTSHADER* GetShader(bool dstAlphaEnable);
 	static bool CompilePixelShader(FRAGMENTSHADER& ps, const char* pstrprogram);
 
 	static GLuint GetColorMatrixProgram();

Source/Plugins/Plugin_VideoOGL/Src/Render.cpp

@@ -111,7 +111,6 @@ static bool s_bATIDrawBuffers = false;
 static bool s_bHaveStencilBuffer = false;
 static bool s_bHaveFramebufferBlit = false;
 static bool s_bHaveCoverageMSAA = false;
-static bool g_bBlendSeparate = false;
 static u32 s_blendMode;
 static bool s_bNativeResolution = false;
 
@@ -206,10 +205,6 @@ bool Renderer::Init()
     INFO_LOG(VIDEO, ptoken);  // write to the log file
     INFO_LOG(VIDEO, "\n");
 
-	if (strstr(ptoken, "GL_EXT_blend_func_separate") != NULL &&
-		strstr(ptoken, "GL_EXT_blend_equation_separate") != NULL)
-        g_bBlendSeparate = true;
-
 	// Checks if it ONLY has the ATI_draw_buffers extension, some have both
     if (GLEW_ATI_draw_buffers && !GLEW_ARB_draw_buffers) 
         s_bATIDrawBuffers = true;
@@ -683,58 +678,35 @@ void Renderer::SetBlendMode(bool forceUpdate)
 {	
 	// blend mode bit mask
 	// 0 - blend enable
-	// 1 - dst alpha enable
 	// 2 - reverse subtract enable (else add)
 	// 3-5 - srcRGB function
 	// 6-8 - dstRGB function
-	// 9-16 - dstAlpha
 
 	u32 newval = bpmem.blendmode.subtract << 2;
 
-	if (g_bBlendSeparate) {
-		newval |= bpmem.dstalpha.enable ? 3 : 0;
-		newval |= bpmem.dstalpha.alpha << 9;
+    if (bpmem.blendmode.subtract) {
+        newval |= 0x0049;   // enable blending src 1 dst 1
+    } else if (bpmem.blendmode.blendenable) {		
+		newval |= 1;    // enable blending
+		newval |= bpmem.blendmode.srcfactor << 3;
+		newval |= bpmem.blendmode.dstfactor << 6;
 	}
-
-	if (bpmem.blendmode.blendenable) {		
-		newval |= 1;
-		if (bpmem.blendmode.subtract) {
-			newval |= 0x0048; // src 1 dst 1
-		} else {
-			newval |= bpmem.blendmode.srcfactor << 3;
-			newval |= bpmem.blendmode.dstfactor << 6;
-		}
-	} else {
-		newval |= 0x0008;	// src 1 dst 0
-	}
-
+	
 	u32 changes = forceUpdate ? 0xFFFFFFFF : newval ^ s_blendMode;
 
 	if (changes & 1) {
+        // blend enable change
 		(newval & 1) ? glEnable(GL_BLEND) : glDisable(GL_BLEND);
 	}
 
-	bool dstAlphaEnable = g_bBlendSeparate && newval & 2;
-
-	if (changes & 6) {		
-		// dst alpha enable or subtract enable change
-		if (dstAlphaEnable)
-			glBlendEquationSeparate(newval & 4 ? GL_FUNC_REVERSE_SUBTRACT : GL_FUNC_ADD, GL_FUNC_ADD);
-		else
-			glBlendEquation(newval & 4 ? GL_FUNC_REVERSE_SUBTRACT : GL_FUNC_ADD);
+	if (changes & 4) {		
+		// subtract enable change
+		glBlendEquation(newval & 4 ? GL_FUNC_REVERSE_SUBTRACT : GL_FUNC_ADD);
 	}
 
-	if (changes & 0x1FA) {
-		// dst alpha enable or blend RGB change
-		if (dstAlphaEnable)
-			glBlendFuncSeparate(glSrcFactors[(newval >> 3) & 7], glDestFactors[(newval >> 6) & 7], GL_CONSTANT_ALPHA, GL_ZERO);
-		else
-			glBlendFunc(glSrcFactors[(newval >> 3) & 7], glDestFactors[(newval >> 6) & 7]);
-	}
-
-	if (dstAlphaEnable && changes & 0x1FE00) {
-		// dst alpha color change
-		glBlendColor(0, 0, 0, (float)bpmem.dstalpha.alpha / 255.0f);
+	if (changes & 0x1F8) {
+		// blend RGB change
+		glBlendFunc(glSrcFactors[(newval >> 3) & 7], glDestFactors[(newval >> 6) & 7]);
 	}
 
 	s_blendMode = newval;

Source/Plugins/Plugin_VideoOGL/Src/VertexManager.cpp

@@ -238,7 +238,7 @@ void Flush()
 		PixelShaderManager::SetTexturesUsed(nonpow2tex);
 	}
 
-	FRAGMENTSHADER* ps = PixelShaderCache::GetShader();
+	FRAGMENTSHADER* ps = PixelShaderCache::GetShader(false);
 	VERTEXSHADER* vs = VertexShaderCache::GetShader(g_nativeVertexFmt->m_components);
 
 	bool bRestoreBuffers = false;
@@ -284,6 +284,31 @@ void Flush()
 		groupStart += s_vertexGroups[i].second;
 	}
 
+    // run through vertex groups again to set alpha
+    if (bpmem.dstalpha.enable && bpmem.blendmode.alphaupdate) {
+        ps = PixelShaderCache::GetShader(true);
+
+        if (ps) glBindProgramARB(GL_FRAGMENT_PROGRAM_ARB, ps->glprogid);
+
+        // only update alpha
+        glColorMask(GL_FALSE, GL_FALSE, GL_FALSE, GL_TRUE);
+
+        groupStart = 0;
+	    for (unsigned i = 0; i < s_vertexGroups.size(); i++)
+	    {
+		    INCSTAT(stats.thisFrame.numDrawCalls);
+		    glMultiDrawArrays(s_vertexGroups[i].first,
+		                      &s_vertexFirstOffset[groupStart],
+		                      &s_vertexGroupSize[groupStart], 
+		                      s_vertexGroups[i].second);
+		    groupStart += s_vertexGroups[i].second;
+	    }
+
+        // restore color mask
+        if (!bRestoreBuffers)
+            Renderer::SetColorMask();
+    }
+
 #if defined(_DEBUG) || defined(DEBUGFAST) 
 	if (g_Config.iLog & CONF_SAVESHADERS) {
 		// save the shaders