/*
 * Particle.cs
 * Authors: Brian Murphy
 * 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.Collections;
using Microsoft.Xna.Framework;
using Microsoft.Xna.Framework.Graphics;

namespace TACParticleEngine.Particles
{
	/// <summary>
    /// Particle structure for storing various non-graphical information of particles
	/// </summary>
	public struct Particle
	{
        /// <summary>
		/// Bool for whether the paricle is alive or not
        /// </summary>
        public bool alive;

        /// <summary>
        /// The amount of lifetime a particle will live for
        /// </summary>
        public float lifetime;

		/// <summary>
		/// The current lifetime of the particle
		/// </summary>
        public float currentLife;

        /// <summary>
        /// Vector used for the starting size of the particle via two-dimensions
        /// </summary>
		public Vector2 startSize;

		/// <summary>
		/// Vector used for the ending size of the particle via two-dimensions
		/// </summary>
		public Vector2 endSize;
        
        /// <summary>
        /// Vector used for the starting velocity of the particle via two-dimensions
        /// </summary>
		public Vector3 startVelocity;

		/// <summary>
		/// Vector used for the ending velocity of the particle via two-dimensions
		/// </summary>
		public Vector3 endVelocity;
        
        /// <summary>
        /// Vector used for the starting color of the particle via RGBA
        /// </summary>
		public Vector4 startColor;

		/// <summary>
		/// Vector used for the starting color of the particle via RGBA
		/// </summary>
		public Vector4 endColor;
    };

	/// <summary>
	/// Particle structure for storing various graphical information of particles
	/// </summary>
    public struct VertexParticle
    {
        /// <summary>
		/// Vector used for the size of the particle via two-dimensions
        /// </summary>
        public Vector2 size;

        /// <summary>
		/// Current position of the particle via three-dimensions
        /// </summary>
        public Vector3 position;

		/// <summary>
		/// Vector used for the color of the particle via RGBA
		/// </summary>
        public Vector4 color;

        /// <summary>
		/// Describe the layout of this structure for data size for GPU
        /// </summary>
        public static readonly VertexElement[] VertexElements =
        {
            // Size data
            new VertexElement(0, 0, VertexElementFormat.Vector2, VertexElementMethod.Default, VertexElementUsage.PointSize, 0),

            // Position data
            new VertexElement(0, 8, VertexElementFormat.Vector3, VertexElementMethod.Default, VertexElementUsage.Position, 0),

            // Color data
            new VertexElement(0, 20, VertexElementFormat.Vector4, VertexElementMethod.Default, VertexElementUsage.Color, 0)
        };
	}
}