DirectX-based OGL implementation?

using System;using System.Collections.Generic;using System.Runtime.InteropServices;using Microsoft.DirectX;using Microsoft.DirectX.Direct3D;using Microsoft.DirectX.Generic;namespace Inductor{	internal class VertexStreamer : IDisposable	{		[StructLayout( LayoutKind.Sequential, Pack = 4 )]		private struct VertexData		{			public float X, Y, Z;			public float Nx, Ny, Nz;			public int ColorValue;			public float U, V;			public const VertexFormats Format = VertexFormats.PositionNormal | VertexFormats.Diffuse | VertexFormats.Texture1;			public static int StrideSize			{				get { return Marshal.SizeOf( typeof( VertexData ) ); }			}		};		private Device m_Device;		private VertexBuffer m_Vb;		private VertexData[] m_Vertices;		private bool m_Rendering = false;		private PrimitiveType m_PrimitiveType = PrimitiveType.PointList;		private int m_VertexCount;		public VertexStreamer( Device device )			: this( device, 3000 )		{ }		public VertexStreamer( Device device, int bufferSize )		{			if( device == null )				throw new ArgumentNullException( "device" );			if( bufferSize < 3 )				throw new ArgumentOutOfRangeException( "initialSize", bufferSize, "Buffer size must be at least 3." );			m_Vertices = new VertexData[bufferSize];			m_Device = device;			m_Vb = new VertexBuffer( device, bufferSize * VertexData.StrideSize, Usage.Dynamic | Usage.WriteOnly,				VertexData.Format, Pool.Default, null );		}		#region Private Utility Functions		private static int ComputePrimitiveCount( PrimitiveType primitiveType, int vertexCount )		{			switch( primitiveType )			{				case PrimitiveType.PointList:					return vertexCount;				case PrimitiveType.LineList:					return vertexCount / 2;				case PrimitiveType.LineStrip:					return vertexCount - 1;				case PrimitiveType.TriangleList:					return vertexCount / 3;				case PrimitiveType.TriangleStrip:				case PrimitiveType.TriangleFan:					return vertexCount - 2;				default:					return 0;			}		}		private void RestartRendering()		{			//render what we've got so far			End();			//we may need to re-issue certain vertices			int[] v = { -1, -1 };			switch( m_PrimitiveType )			{				case PrimitiveType.LineStrip:					//re-issue the last vertex					v[0] = m_VertexCount - 1;					break;				case PrimitiveType.LineList:					//re-issue the last vertex if our size is odd					if( m_VertexCount % 2 == 1 )						v[0] = m_VertexCount - 1;					break;				case PrimitiveType.TriangleList:					//re-issue the last 1 or 2 left-over vertices					for( int i = 0; i < m_VertexCount % 3; ++i )					{						v = m_VertexCount - 2 + i;					}					break;				case PrimitiveType.TriangleStrip:					//re-issue the last two vertices					v[0] = m_VertexCount - 2;					v[1] = m_VertexCount - 1;					break;				case PrimitiveType.TriangleFan:					//re-issue the first and last vertices					v[0] = 0;					v[1] = m_VertexCount - 1;					break;			}			//now actually submit the new vertices			Begin( m_PrimitiveType );			foreach( int i in v )			{				if( i > -1 )				{					Normal( m_Vertices.Nx, m_Vertices.Ny, m_Vertices.Nz );					Color( m_Vertices.ColorValue );					TexCoord( m_Vertices.U, m_Vertices.V );					Vertex( m_Vertices.X, m_Vertices.Y, m_Vertices.Z );				}			}		}		#endregion		public void Begin( PrimitiveType primitiveType )		{			if( m_Rendering )				throw new InvalidCallException( "VertexStreamer.Begin() called multiple times." );			//set up a new state			m_PrimitiveType = primitiveType;			m_VertexCount = 0;			m_Rendering = true;		}		public void Color( int colorValue )		{			if( !m_Rendering )				throw new InvalidCallException( "VertexStreamer.Color() called outside of Begin/End pair." );			m_Vertices[m_VertexCount].ColorValue = colorValue;		}		public void Color( System.Drawing.Color color )		{			Color( color.ToArgb() );		}		public void Normal( float nx, float ny, float nz )		{			if( !m_Rendering )				throw new InvalidCallException( "VertexStreamer.Normal() called outside of Begin/End pair." );			m_Vertices[m_VertexCount].Nx = nx;			m_Vertices[m_VertexCount].Ny = ny;			m_Vertices[m_VertexCount].Nz = nz;		}		public void Normal( Vector3 normal )		{			Normal( normal.X, normal.Y, normal.Z );		}		public void TexCoord( float tu, float tv )		{			if( !m_Rendering )				throw new InvalidCallException( "VertexStreamer.TexCoord() called outside of Begin/End pair." );			m_Vertices[m_VertexCount].U = tu;			m_Vertices[m_VertexCount].V = tv;		}		public void Vertex( float x, float y, float z )		{			if( !m_Rendering )				throw new InvalidCallException( "VertexStreamer.Vertex() called outside of Begin/End pair." );			m_Vertices[m_VertexCount].X = x;			m_Vertices[m_VertexCount].Y = y;			m_Vertices[m_VertexCount].Z = z;			++m_VertexCount;			if( m_VertexCount == m_Vertices.Length )				RestartRendering();		}		public void Vertex( Vector3 position )		{			Vertex( position.X, position.Y, position.Z );		}		public void End()		{			if( !m_Rendering )				throw new InvalidCallException( "VertexStreamer.End() called without matching Begin()." );			GraphicsBuffer<VertexData> stream = m_Vb.Lock<VertexData>( 0, 0, LockFlags.Discard );			stream.Write( m_Vertices );			m_Vb.Unlock();			//set up critical device states			m_Device.VertexFormat = VertexData.Format;			m_Device.SetStreamSource( 0, m_Vb, 0, VertexData.StrideSize );			//Get the correct primitive count and issue a draw call			m_Device.DrawPrimitives( m_PrimitiveType, 0, ComputePrimitiveCount( m_PrimitiveType, m_VertexCount ) );			//we're done now			m_Rendering = false;		}		#region IDisposable Members		public void Dispose()		{			m_Vb.Dispose();		}		#endregion	}}