From 52015015343d77f4283f38ee186a29316635e6e7 Mon Sep 17 00:00:00 2001
From: Christoph Oelckers <coelckers@users.noreply.github.com>
Date: Sat, 27 Oct 2018 16:04:28 +0200
Subject: [PATCH] - added lock/unlock methods to the buffer implementations.

These are not interchangeable with Map/Unmap!
Map/Unmap is for mapping a buffer for updating on old hardware, Lock/Unlock are for manually copying some initialization data directly into a static buffer.
---
 src/gl/system/glsys_vertexbuffer.cpp | 55 +++++++++++++++++++++++++++-
 src/gl/system/glsys_vertexbuffer.h   |  4 ++
 src/hwrenderer/data/vertexbuffer.h   |  4 ++
 3 files changed, 61 insertions(+), 2 deletions(-)

diff --git a/src/gl/system/glsys_vertexbuffer.cpp b/src/gl/system/glsys_vertexbuffer.cpp
index 19cc349e0..91d5205f6 100644
--- a/src/gl/system/glsys_vertexbuffer.cpp
+++ b/src/gl/system/glsys_vertexbuffer.cpp
@@ -60,7 +60,7 @@ void GLVertexBuffer::SetData(size_t size, void *data, bool staticdata)
 	}
 	else
 	{
-		mPersistent = screen->BuffersArePersistent();
+		mPersistent = screen->BuffersArePersistent() && !staticdata;
 		if (mPersistent)
 		{
 			glBindBuffer(GL_ARRAY_BUFFER, vbo_id);
@@ -70,7 +70,7 @@ void GLVertexBuffer::SetData(size_t size, void *data, bool staticdata)
 		else
 		{
 			glBindBuffer(GL_ARRAY_BUFFER, vbo_id);
-			glBufferData(GL_ARRAY_BUFFER, size, NULL, GL_STREAM_DRAW);
+			glBufferData(GL_ARRAY_BUFFER, size, NULL, staticdata ? GL_STATIC_DRAW : GL_STREAM_DRAW);
 			map = nullptr;
 		}
 		nomap = false;
@@ -143,6 +143,31 @@ void GLVertexBuffer::Bind(int *offsets)
 	}
 }
 
+//===========================================================================
+//
+//
+//
+//===========================================================================
+
+void *GLVertexBuffer::Lock(unsigned int size)
+{
+	SetData(size, nullptr, true);
+	return glMapBufferRange(GL_ARRAY_BUFFER, 0, size, GL_MAP_WRITE_BIT | GL_MAP_INVALIDATE_BUFFER_BIT | GL_MAP_UNSYNCHRONIZED_BIT);
+}
+
+//===========================================================================
+//
+//
+//
+//===========================================================================
+
+void GLVertexBuffer::Unlock()
+{
+	glBindBuffer(GL_ARRAY_BUFFER, vbo_id);
+	glUnmapBuffer(GL_ARRAY_BUFFER);
+	gl_RenderState.ResetVertexBuffer();
+}
+
 //==========================================================================
 //
 // Index buffer implementation
@@ -180,3 +205,29 @@ void GLIndexBuffer::Bind()
 {
 	glBindBuffer(GL_ELEMENT_ARRAY_BUFFER, ibo_id);
 }
+
+//===========================================================================
+//
+//
+//
+//===========================================================================
+
+void *GLIndexBuffer::Lock(unsigned int size)
+{
+	SetData(size, nullptr, true);
+	return glMapBufferRange(GL_ELEMENT_ARRAY_BUFFER, 0, size, GL_MAP_WRITE_BIT | GL_MAP_INVALIDATE_BUFFER_BIT | GL_MAP_UNSYNCHRONIZED_BIT);
+}
+
+//===========================================================================
+//
+//
+//
+//===========================================================================
+
+void GLIndexBuffer::Unlock()
+{
+	glBindBuffer(GL_ELEMENT_ARRAY_BUFFER, ibo_id);
+	glUnmapBuffer(GL_ELEMENT_ARRAY_BUFFER);
+	gl_RenderState.ResetVertexBuffer();
+}
+
diff --git a/src/gl/system/glsys_vertexbuffer.h b/src/gl/system/glsys_vertexbuffer.h
index d90722ecf..c3c836142 100644
--- a/src/gl/system/glsys_vertexbuffer.h
+++ b/src/gl/system/glsys_vertexbuffer.h
@@ -27,6 +27,8 @@ public:
 	void Bind(int *offsets);
 	void Map() override;
 	void Unmap() override;
+	void *Lock(unsigned int size) override;
+	void Unlock() override;
 };
 
 class GLIndexBuffer : public IIndexBuffer
@@ -38,5 +40,7 @@ public:
 	~GLIndexBuffer();
 	void SetData(size_t size, void *data, bool staticdata) override;
 	void Bind();
+	void *Lock(unsigned int size) override;
+	void Unlock() override;
 };
 
diff --git a/src/hwrenderer/data/vertexbuffer.h b/src/hwrenderer/data/vertexbuffer.h
index 104455a14..d16c3cdbc 100644
--- a/src/hwrenderer/data/vertexbuffer.h
+++ b/src/hwrenderer/data/vertexbuffer.h
@@ -43,6 +43,8 @@ public:
 	virtual ~IVertexBuffer() {}
 	virtual void SetData(size_t size, void *data, bool staticdata = true) = 0;
 	virtual void SetFormat(int numBindingPoints, int numAttributes, size_t stride, const FVertexBufferAttribute *attrs) = 0;
+	virtual void *Lock(unsigned int size) = 0;
+	virtual void Unlock() = 0;
 	virtual void Map() {}		// Only needed by old OpenGL but this needs to be in the interface.
 	virtual void Unmap() {}
 	void *Memory() { assert(map); return map; }
@@ -59,5 +61,7 @@ protected:
 public:
 	virtual ~IIndexBuffer() {}
 	virtual void SetData(size_t size, void *data, bool staticdata = true) = 0;
+	virtual void *Lock(unsigned int size) = 0;
+	virtual void Unlock() = 0;
 };