#region Copyright & License Information
/*
 * Copyright 2007-2010 The OpenRA Developers (see AUTHORS)
 * This file is part of OpenRA, which is free software. It is made 
 * available to you under the terms of the GNU General Public License
 * as published by the Free Software Foundation. For more information,
 * see LICENSE.
 */
#endregion

using System.Drawing;
using OpenRA.FileFormats.Graphics;

namespace OpenRA.Graphics
{
	public class LineRenderer
	{
		Renderer renderer;
		IVertexBuffer<Vertex> vertexBuffer;
		IIndexBuffer indexBuffer;            /* kindof a waste of space, but the GPU likes indexing, oh well */

		const int linesPerBatch = 1024;

		Vertex[] vertices = new Vertex[ 2 * linesPerBatch ];
		ushort[] indices = new ushort[ 2 * linesPerBatch ];
		int lines = 0;
		int nv = 0, ni = 0;

		public LineRenderer( Renderer renderer )
		{
			this.renderer = renderer;
			vertexBuffer = renderer.Device.CreateVertexBuffer(vertices.Length );
			indexBuffer = renderer.Device.CreateIndexBuffer( indices.Length );
		}

		public void Flush()
		{
			if( lines > 0 )
			{
				renderer.LineShader.Render( () =>
				{
					vertexBuffer.SetData( vertices );
					indexBuffer.SetData( indices );
					renderer.DrawBatch( vertexBuffer, indexBuffer,
					nv, ni / 2, PrimitiveType.LineList );
				} );

				nv = 0; ni = 0;
				lines = 0;
			}
		}

		public void DrawLine( float2 start, float2 end, Color startColor, Color endColor )
		{
			indices[ ni++ ] = (ushort)nv;

			vertices[ nv++ ] = new Vertex( start,
			new float2( startColor.R / 255.0f, startColor.G / 255.0f ),
			new float2( startColor.B / 255.0f, startColor.A / 255.0f ) );

			indices[ ni++ ] = (ushort)nv;

			vertices[ nv++ ] = new Vertex( end,
			new float2( endColor.R / 255.0f, endColor.G / 255.0f ),
			new float2( endColor.B / 255.0f, endColor.A / 255.0f ) );

			if( ++lines >= linesPerBatch )
				Flush();
		}
		
		public void FillRect( RectangleF r, Color color )
		{
			for (float y = r.Top; y < r.Bottom; y++)
			{
				DrawLine(new float2(r.Left, y), new float2(r.Right, y), color, color);
			}
		}
	}
}