/*
 * Renderable.cs
 * Authors:     August Zinsser
 * 
 * Copyright August Zinsser 2007
 * This program is distributed under the terms of the GNU General Public License
 */


using System;
using System.Collections.Generic;
using Microsoft.Xna.Framework;
using Microsoft.Xna.Framework.Audio;
using Microsoft.Xna.Framework.Content;
using Microsoft.Xna.Framework.Graphics;
using Microsoft.Xna.Framework.Input;
using Microsoft.Xna.Framework.Storage;


namespace Pina3D
{
    /// <summary>
    /// A PinaObject that can be rendered
    /// </summary>
    public class Renderable : PinaObject
    {
        protected IRenderableSourceData _Type;        // Enforces rendering, but allows each sourceData type to implement it differently


        public Renderable(PinaState spawnState, IRenderableSourceData sourceData)
        {
            mState = new RenderableState(spawnState, sourceData);
            _Type = sourceData;
        }


        /// <summary>
        /// This Material will override the model's default material
        /// </summary>
        public Material Material
        {
            set { ((RenderableState)mState).Material = value; }
            get { return ((RenderableState)mState).Material; }
        }

        internal IRenderableSourceData SourceData
        {
            set { ((RenderableState)mState).SourceData = value; }
            get { return ((RenderableState)mState).SourceData; }
        }


        /// <summary>
        /// Draws to the backbuffer
        /// </summary>
        internal virtual void Render()
        {
            // TODO: Sort all of the renderables by sourceData and then call render on that sourcedata once with multiple PinaStates to optimize rendering

            if (((RenderableState)mState).Shader != null)
                _Type.Render(((RenderableState)mState).SourceData, ((RenderableState)mState).Shader, mState);
        }



        protected class RenderableState : PinaState
        {
            /// <summary>
            /// Only children will know how to interpret this
            /// </summary>
            public IRenderableSourceData SourceData;

            /// <summary>
            /// If assigned, use this material when rendering instead of the Model's default material 
            /// </summary>
            public Material Material
            {
                set
                {
                    mMaterial = value;
                    mShader = new Shader(ref mMaterial);
                }
                get
                {
                    return mMaterial;
                }
            }
            /// <summary>
            /// Used only for rendering, but is based on the Material
            /// </summary>
            public Shader Shader
            {
                get { return mShader; }
            }

            protected Material mMaterial;
            protected Shader mShader;


            public RenderableState(PinaState pinaState, IRenderableSourceData sourceData)
                : base(pinaState.Matrix)
            {
                this.SourceData = sourceData;
                this.mMaterial = null;
                this.mShader = null;
            }
        }
    }


    public interface IRenderableSourceData
    {
        void Render(IRenderableSourceData sourceData, Shader shader, PinaState state);
    }
}