Persist CLUT framebuffer to GS memory

Required by DBZ Budokai Tenkaichi 2 for CLUT rendering of characters
jpd002 · Jun 4, 2021 · ee616e0 · ee616e0
1 parent ac76638
commit ee616e0
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diff --git a/Source/gs/GSH_OpenGL/GSH_OpenGL.cpp b/Source/gs/GSH_OpenGL/GSH_OpenGL.cpp
@@ -1358,6 +1358,32 @@ CGSH_OpenGL::BitmapPtr CGSH_OpenGL::FindOrCreateBitmap(const FramebufferPtr& fra
 	return sharedPtr;
 }
 
+CGSH_OpenGL::FramebufferPtr CGSH_OpenGL::FindSmallestFramebufferAtPtr(uint32 ptr, uint32 psm) const
+{
+	uint32 smallestSize = 0;
+	FramebufferPtr framebufferPtr = nullptr;
+
+	for(const auto& framebuffer : m_framebuffers)
+	{
+		if(framebuffer->m_psm != psm)
+		{
+			continue;
+		}
+
+		if(framebuffer->m_basePtr <= ptr && framebuffer->m_basePtr >= ptr)
+		{
+			uint32 size = framebuffer->m_width * framebuffer->m_height;
+			if(size < smallestSize || smallestSize == 0)
+			{
+				smallestSize = size;
+				framebufferPtr = framebuffer;
+			}
+		}
+	}
+
+	return framebufferPtr;
+}
+
 /////////////////////////////////////////////////////////////
 // Individual Primitives Implementations
 /////////////////////////////////////////////////////////////
@@ -1643,6 +1669,15 @@ void CGSH_OpenGL::FlushVertexBuffer()
 	}
 	DoRenderPass();
 	m_vertexBuffer.clear();
+
+	auto handle = m_renderState.framebufferHandle;
+	auto framebufferIterator = std::find_if(m_framebuffers.begin(), m_framebuffers.end(),
+	                                        [handle](const FramebufferPtr& framebuffer) {
+		                                        return (framebuffer->m_framebuffer == handle);
+	                                        });
+	const auto& framebuffer = (*framebufferIterator);
+
+	framebuffer->copiedToRam = false;
 }
 
 void CGSH_OpenGL::DoRenderPass()
@@ -1897,6 +1932,87 @@ void CGSH_OpenGL::WriteRegisterImpl(uint8 nRegister, uint64 nData)
 	}
 }
 
+void CGSH_OpenGL::SyncCLUT(const TEX0& tex0)
+{
+	if(!ProcessCLD(tex0)) return;
+
+	// If we use a CLUT based texture, its possible that the memory
+	// referenced is inside a framebuffer. In that case, we need
+	// to persist the framebuffer content into the GS RAM.
+
+	const uint32 ptr = tex0.GetCLUTPtr();
+
+	FramebufferPtr framebuffer = FindSmallestFramebufferAtPtr(ptr, PSMCT32);
+	if(framebuffer)
+	{
+		WriteFramebufferToMemory(framebuffer, true);
+	}
+
+	CGSHandler::SyncCLUT(tex0);
+}
+
+void CGSH_OpenGL::WriteFramebufferToMemory(const FramebufferPtr& framebuffer, bool downSample)
+{
+	// If the framebuffer has already been persisted to RAM,
+	// we don't need to do that again.
+	if(framebuffer->copiedToRam)
+	{
+		return;
+	}
+
+	FramebufferPtr targetFramebuffer = framebuffer;
+	uint32 scale = m_fbScale;
+
+	if(downSample && m_fbScale != 1)
+	{
+		auto dstFramebuffer = FramebufferPtr(new CFramebuffer(
+		    framebuffer->m_basePtr,
+		    framebuffer->m_width,
+		    framebuffer->m_height,
+		    framebuffer->m_psm,
+		    1,
+		    m_multisampleEnabled));
+		PopulateFramebuffer(dstFramebuffer);
+
+		glBindFramebuffer(GL_FRAMEBUFFER, dstFramebuffer->m_framebuffer);
+		glBindFramebuffer(GL_READ_FRAMEBUFFER, framebuffer->m_framebuffer);
+
+		//Copy buffers
+		glBlitFramebuffer(
+		    0, 0, framebuffer->m_width * m_fbScale, framebuffer->m_height * m_fbScale,
+		    0, 0, dstFramebuffer->m_width, dstFramebuffer->m_height,
+		    GL_COLOR_BUFFER_BIT, GL_NEAREST);
+		CHECKGLERROR();
+		glBindFramebuffer(GL_READ_FRAMEBUFFER, 0);
+
+		targetFramebuffer = dstFramebuffer;
+		scale = 1;
+	}
+
+	glBindFramebuffer(GL_FRAMEBUFFER, targetFramebuffer->m_framebuffer);
+
+	// ----------------------
+
+	// Read data into ram
+
+	auto imgbuffer = FindOrCreateBitmap(targetFramebuffer, scale);
+	glReadPixels(0, 0, targetFramebuffer->m_width * scale, targetFramebuffer->m_height * scale, GL_RGBA, GL_UNSIGNED_BYTE, imgbuffer->GetPixels());
+
+	CGsPixelFormats::CPixelIndexorPSMCT32 indexor(m_pRAM, targetFramebuffer->m_basePtr, targetFramebuffer->m_width / 64);
+	for(uint32 y = 0; y < targetFramebuffer->m_height; y++)
+	{
+		for(uint32 x = 0; x < targetFramebuffer->m_width; x++)
+		{
+			auto pixel = imgbuffer->GetPixel(x * scale, y * scale);
+			indexor.SetPixel(x, y, MakeColor(pixel.r, pixel.g, pixel.b, pixel.a));
+		}
+	}
+
+	framebuffer->copiedToRam = true;
+
+	glBindFramebuffer(GL_FRAMEBUFFER, m_renderState.framebufferHandle);
+}
+
 void CGSH_OpenGL::VertexKick(uint8 nRegister, uint64 nValue)
 {
 	if(m_nVtxCount == 0) return;

diff --git a/Source/gs/GSH_OpenGL/GSH_OpenGL.h b/Source/gs/GSH_OpenGL/GSH_OpenGL.h
@@ -247,6 +247,8 @@ class CGSH_OpenGL : public CGSHandler
 		bool m_resolveNeeded = false;
 		GLuint m_colorBufferMs = 0;
 
+		bool copiedToRam = false;
+
 		CGsCachedArea m_cachedArea;
 	};
 	typedef std::shared_ptr<CFramebuffer> FramebufferPtr;
@@ -312,6 +314,7 @@ class CGSH_OpenGL : public CGSHandler
 	typedef std::vector<PRIM_VERTEX> VertexBuffer;
 
 	void WriteRegisterImpl(uint8, uint64) override;
+	void SyncCLUT(const TEX0&) override;
 
 	void InitializeRC();
 	void CheckExtensions();
@@ -373,6 +376,8 @@ class CGSH_OpenGL : public CGSHandler
 	FramebufferPtr FindFramebuffer(const FRAME&) const;
 	DepthbufferPtr FindDepthbuffer(const ZBUF&, const FRAME&) const;
 	BitmapPtr FindOrCreateBitmap(const FramebufferPtr&, uint32);
+	FramebufferPtr FindSmallestFramebufferAtPtr(uint32, uint32) const;
+	void WriteFramebufferToMemory(const FramebufferPtr&, bool);
 
 	void DumpTexture(unsigned int, unsigned int, uint32);