/*
 * PerspectiveCamera.cs
 * Authors: Bradley Blankenship
 * Copyright (c) 2007-2008 Cornell University

 This program is free software; you can redistribute it and/or
 modify it under the terms of the GNU General Public License
 as published by the Free Software Foundation; either version 2
 of the License, or (at your option) any later version.

 This program is distributed in the hope that it will be useful,
 but WITHOUT ANY WARRANTY; without even the implied warranty of
 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 GNU General Public License for more details.

 You should have received a copy of the GNU General Public License
 along with this program; if not, write to the Free Software
 Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.
*/

using System;
using System.Collections.Generic;
using System.Text;
using Microsoft.Xna.Framework;

namespace tAC_Engine.Graphics.Cameras
{
	/// <summary>
	/// This allows the creation of the default projection camera. This specifies the 
	/// camera for working in a fully 3D world, allowing the camera full 3D range of motion.
	/// </summary>
	public abstract class PerspectiveCamera : Camera
	{
		#region Fields

		/// <summary>
		/// The field of view
		/// </summary>
		protected float mFOV = MathHelper.PiOver4;

		/// <summary>
		/// The aspect ratio of he camera
		/// </summary>
		protected float mAspectRatio = 800.0f / 600.0f;

		/// <summary>
		/// The distance to the near plane
		/// </summary>
		protected float mNear = 1.0f;

		/// <summary>
		/// The distance to the far plane
		/// </summary>
		protected float mFar = 10.0f;

		#endregion

		#region Properties

		/// <summary>
		/// Gets/Sets the field of view
		/// </summary>
		public float FOV
		{
			get { return mFOV; }
			set
			{
				// Check to see if we need to recalculate the camera projection
				if (mFOV != value)
				{
					mFOV = value;
					CreateProjection();
				}
			}
		}

		/// <summary>
		/// Gets/Sets the aspect ratio
		/// </summary>
		public float AspectRatio
		{
			get { return mAspectRatio; }
			set
			{
				// Check to see if we need to recalculate the camera projection
				if (mAspectRatio != value)
				{
					mAspectRatio = value;
					CreateProjection();
				}
			}
		}

		/// <summary>
		/// Gets/Sets the distance to the near plane
		/// </summary>
		public float Near
		{
			get { return mNear; }
			set
			{
				// Check to see if we need to recalculate the camera projection
				if (mNear != value)
				{
					mNear = value;
					CreateProjection();
				}
			}
		}

		/// <summary>
		/// Gets/Sets the distance to the far plane
		/// </summary>
		public float Far
		{
			get { return mFar; }
			set
			{
				// Check to see if we need to recalculate the camera projection
				if (mFar != value)
				{
					mFar = value;
					CreateProjection();
				}
			}
		}

		#endregion
	}
}