using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Runtime.InteropServices;

using OpenGL4NET;

namespace ZPG_2011_Moulis_Jan_A09B0359P
{
    class SingleObject
    {
        private uint vboData;
        private uint iboData;
        private List<PositionNormalColorTexCoor> listVertex;
        private PositionNormalColorTexCoor[] vertex;
        private List<uint> listIndex;
        private uint[] index;
        private float enlarge;

        public SingleObject(float enlarge)
        {
            this.enlarge = enlarge;
            listVertex = new List<PositionNormalColorTexCoor>();
            listIndex = new List<uint>();
        }

        public void addVertex(float x, float y, float z, float nx, float ny, float nz, float r, float g, float b, float texCoorX, float texCoorY)
        {
            //Console.WriteLine("x: "+x+" ; y: "+y+" ; z: "+z+" ; nx: "+nx+" ; ny: "+ny+" ; nz: "+nz+" ; r: "+r+" ; g: "+g+" ; b: "+b+" ; tcX: "+texCoorX+" ; tcY: "+texCoorY);
            listVertex.Add(new PositionNormalColorTexCoor(enlarge * x, enlarge * y, enlarge * z, nx, ny, nz, r, g, b, texCoorX, texCoorY));
        }

        public void addFace(uint p1, uint p2, uint p3)
        {
            listIndex.Add(p1);
            listIndex.Add(p2);
            listIndex.Add(p3);
        }

        public void createBuffers()
        {
            vertex = listVertex.ToArray();
            index = listIndex.ToArray();

            // Priprava vbo
            vboData = gl.GenBuffer();
            gl.BindBuffer(GL.ARRAY_BUFFER, vboData);
            gl.BufferData(GL.ARRAY_BUFFER, vertex.Length * PositionNormalColorTexCoor.SizeInBytes, vertex, GL.STATIC_DRAW);
            gl.BindBuffer(GL.ARRAY_BUFFER, 0);

            // Priiprava ibo
            iboData = gl.GenBuffer();
            gl.BindBuffer(GL.ELEMENT_ARRAY_BUFFER, iboData);
            gl.BufferData(GL.ELEMENT_ARRAY_BUFFER, index.Length * sizeof(uint), index, GL.STATIC_DRAW);

            gl.BindBuffer(GL.ELEMENT_ARRAY_BUFFER, 0);
            gl.BindBuffer(GL.ARRAY_BUFFER, 0);
        }

        public void render(uint texture)
        {
            gl.ActiveTexture(GL.TEXTURE0);
            gl.Enable(GL.TEXTURE_2D);
            gl.BindTexture(GL.TEXTURE_2D, texture);
            gl.TexEnvf(GL.TEXTURE_ENV, GL.TEXTURE_ENV_MODE, GL.MODULATE);

            gl.BindBuffer(GL.ARRAY_BUFFER, vboData);                                        // NAČTENÍ BUFFERU
            gl.BindBuffer(GL.ELEMENT_ARRAY_BUFFER, iboData);

            gl.ClientActiveTexture(GL.TEXTURE0);
            gl.EnableClientState(GL.TEXTURE_COORD_ARRAY);                                    // TEXTURA
            gl.TexCoordPointer(2, GL.FLOAT, PositionNormalColorTexCoor.SizeInBytes, (IntPtr)36);

            gl.EnableClientState(GL.COLOR_ARRAY);
            gl.ColorPointer(3, GL.FLOAT, PositionNormalColorTexCoor.SizeInBytes, (IntPtr)24);

            gl.EnableClientState(GL.NORMAL_ARRAY);                                            // NORMÁLY
            gl.NormalPointer(GL.FLOAT, PositionNormalColorTexCoor.SizeInBytes, (IntPtr)12);

            gl.EnableClientState(GL.VERTEX_ARRAY);                                           // POZICE BODU
            gl.VertexPointer(3, GL.FLOAT, PositionNormalColorTexCoor.SizeInBytes, (IntPtr)0);

            gl.DrawElements(GL.TRIANGLES, index.Length, GL.UNSIGNED_INT, (IntPtr)0);        // VYKRESLENÍ

            gl.DisableClientState(GL.VERTEX_ARRAY);
            gl.DisableClientState(GL.NORMAL_ARRAY);
            gl.DisableClientState(GL.COLOR_ARRAY);
            gl.DisableClientState(GL.TEXTURE_COORD_ARRAY);

            gl.BindBuffer(GL.ARRAY_BUFFER, 0);
            gl.BindBuffer(GL.ELEMENT_ARRAY_BUFFER, 0);
            gl.BindTexture(GL.TEXTURE_2D, 0);

            gl.ActiveTexture(GL.TEXTURE0);
            gl.Disable(GL.TEXTURE_2D);
            gl.BindTexture(GL.TEXTURE_2D, 0);
        }

        public void destroy()
        {
            gl.DeleteBuffer(vboData);
            gl.DeleteBuffer(iboData);
        }

        [StructLayout(LayoutKind.Sequential)]
        struct PositionNormalColorTexCoor
        {
            public Vector3 position;
            public Vector3 normal;
            public Vector3 color;
            public float texCoorX;
            public float texCoorY;

            /// <summary>
            /// Konstruktor z floatu
            /// </summary>
            /// <param name="x">X</param>
            /// <param name="y">Y</param>
            /// <param name="z">Z</param>
            /// <param name="nx">nX</param>
            /// <param name="ny">nY</param>
            /// <param name="nz">nZ</param>
            /// <param name="r">R</param>
            /// <param name="g">G</param>
            /// <param name="b">B</param>
            /// <param name="texCoorX">texCoorX</param>
            /// <param name="texCoorY">texCoorY</param>
            public PositionNormalColorTexCoor(float x, float y, float z, float nx, float ny, float nz, float r, float g, float b, float texCoorX, float texCoorY)
            {
                position = new Vector3(x, y, z);
                normal = new Vector3(nx, ny, nz);
                color = new Vector3(r, g, b);
                this.texCoorX = texCoorX;
                this.texCoorY = texCoorY;
            }

            /// <summary>
            /// Velikost struktury v bytech
            /// </summary>
            public static int SizeInBytes
            {
                get
                {
                    return Marshal.SizeOf(typeof(PositionNormalColorTexCoor));
                }
            }
        }
    }
}