GLSL: fix transparency issues on dual source blend. fix issue 6104

Source/Core/VideoCommon/Src/BPStructs.cpp

@@ -213,7 +213,7 @@ void BPWritten(const BPCmd& bp)
 				if (bp.changes & 4)
 					SetDitherMode();
 				// Set Blending Mode
-				if (bp.changes & 0xFE1)
+				if (bp.changes & 0xFF1)
 					SetBlendMode();
 				// Set Color Mask
 				if (bp.changes & 0x18)
@@ -458,11 +458,11 @@ void BPWritten(const BPCmd& bp)
 		break;
 
 	case BPMEM_ZCOMPARE:      // Set the Z-Compare and EFB pixel format
-		g_renderer->SetColorMask(); // alpha writing needs to be disabled if the new pixel format doesn't have an alpha channel
-		g_renderer->SetBlendMode(true);
 		OnPixelFormatChange();
-		if(bp.changes & 3)
+		if(bp.changes & 7) {
 			SetBlendMode(); // dual source could be activated by changing to PIXELFMT_RGBA6_Z24
+			g_renderer->SetColorMask(); // alpha writing needs to be disabled if the new pixel format doesn't have an alpha channel
+		}
 		break;
 
 	case BPMEM_MIPMAP_STRIDE: // MipMap Stride Channel

Source/Plugins/Plugin_VideoOGL/Src/Render.cpp

@@ -882,13 +882,13 @@ void Renderer::ReinterpretPixelData(unsigned int convtype)
 
 void Renderer::SetBlendMode(bool forceUpdate)
 {
-	bool useDstAlpha = !g_ActiveConfig.bDstAlphaPass && bpmem.dstalpha.enable && bpmem.blendmode.alphaupdate
-		&& bpmem.zcontrol.pixel_format == PIXELFMT_RGBA6_Z24;
-	bool useDualSource = useDstAlpha && g_ActiveConfig.backend_info.bSupportsDualSourceBlend;
-
 	// Our render target always uses an alpha channel, so we need to override the blend functions to assume a destination alpha of 1 if the render target isn't supposed to have an alpha channel
 	// Example: D3DBLEND_DESTALPHA needs to be D3DBLEND_ONE since the result without an alpha channel is assumed to always be 1.
 	bool target_has_alpha = bpmem.zcontrol.pixel_format == PIXELFMT_RGBA6_Z24;
+
+	bool useDstAlpha = !g_ActiveConfig.bDstAlphaPass && bpmem.dstalpha.enable && bpmem.blendmode.alphaupdate && target_has_alpha;
+	bool useDualSource = useDstAlpha && g_ActiveConfig.backend_info.bSupportsDualSourceBlend;
+
 	const GLenum glSrcFactors[8] =
 	{
 		GL_ZERO,