From 5d0d26164c95eed2cd04ab46136b66d416bde4f8 Mon Sep 17 00:00:00 2001
From: Glenn Maynard <gmaynard@users.sourceforge.net>
Date: Thu, 22 Mar 2007 19:03:31 +0000
Subject: [PATCH] implement RageTextureLock with PBOs

---
 stepmania/src/RageDisplay_OGL.cpp | 77 +++++++++++++++++++++++++++++++
 stepmania/src/RageDisplay_OGL.h   |  1 +
 2 files changed, 78 insertions(+)

diff --git a/stepmania/src/RageDisplay_OGL.cpp b/stepmania/src/RageDisplay_OGL.cpp
index d04cedda62..9d035943f4 100644
--- a/stepmania/src/RageDisplay_OGL.cpp
+++ b/stepmania/src/RageDisplay_OGL.cpp
@@ -2138,6 +2138,83 @@ unsigned RageDisplay_OGL::CreateTexture(
 	return iTexHandle;
 }
 
+struct RageTextureLock_OGL: public RageTextureLock, public InvalidateObject
+{
+public:
+	RageTextureLock_OGL()
+	{
+		m_iTexHandle = 0;
+		m_iBuffer = 0;
+
+		CreateObject();
+	}
+
+	~RageTextureLock_OGL()
+	{
+		ASSERT( m_iTexHandle == 0 ); // locked!
+		GLExt.glDeleteBuffersARB( 1, &m_iBuffer );
+	}
+
+	/* This is called when our OpenGL context is invalidated. */
+	void Invalidate()
+	{
+		m_iTexHandle = 0;
+	}
+
+	void Lock( unsigned iTexHandle, RageSurface *pSurface )
+	{
+		ASSERT( m_iTexHandle == 0 );
+		ASSERT( pSurface->pixels == NULL );
+
+		CreateObject();
+
+		m_iTexHandle = iTexHandle;
+		GLExt.glBindBufferARB( GL_PIXEL_UNPACK_BUFFER_ARB, m_iBuffer );
+
+		int iSize = pSurface->h * pSurface->pitch;
+		GLExt.glBufferDataARB( GL_PIXEL_UNPACK_BUFFER_ARB, iSize, NULL, GL_STREAM_DRAW );
+
+		void *pSurfaceMemory = GLExt.glMapBufferARB( GL_PIXEL_UNPACK_BUFFER_ARB, GL_WRITE_ONLY );
+		pSurface->pixels = (uint8_t *) pSurfaceMemory;
+		pSurface->pixels_owned = false;
+	}
+
+	void Unlock( RageSurface *pSurface, bool bChanged )
+	{
+		GLExt.glUnmapBufferARB( GL_PIXEL_UNPACK_BUFFER_ARB );
+
+		pSurface->pixels = (uint8_t *) BUFFER_OFFSET(0);
+
+		if( bChanged )
+			DISPLAY->UpdateTexture( m_iTexHandle, pSurface, 0, 0, pSurface->w, pSurface->h );
+
+		pSurface->pixels = NULL;
+
+		m_iTexHandle = 0;
+		GLExt.glBindBufferARB( GL_PIXEL_UNPACK_BUFFER_ARB, 0 );
+	}
+
+private:
+	void CreateObject()
+	{
+		if( m_iBuffer != 0 )
+			return;
+
+		FlushGLErrors();
+		GLExt.glGenBuffersARB( 1, &m_iBuffer );
+		AssertNoGLError();
+	}
+
+	GLuint m_iBuffer;
+
+	unsigned m_iTexHandle;
+};
+
+RageTextureLock *RageDisplay_OGL::CreateTextureLock()
+{
+	return new RageTextureLock_OGL;
+}
+
 void RageDisplay_OGL::UpdateTexture( 
 	unsigned iTexHandle, 
 	RageSurface* pImg,
diff --git a/stepmania/src/RageDisplay_OGL.h b/stepmania/src/RageDisplay_OGL.h
index 1decbe37d4..4df1cb7a6b 100644
--- a/stepmania/src/RageDisplay_OGL.h
+++ b/stepmania/src/RageDisplay_OGL.h
@@ -41,6 +41,7 @@ public:
 		);
 	void DeleteTexture( unsigned iTexHandle );
 	RageSurface *GetTexture( unsigned iTexture );
+	RageTextureLock *CreateTextureLock();
 
 	void ClearAllTextures();
 	int GetNumTextureUnits();