#region --- License ---
/* Copyright (c) 2006, 2007 Stefanos Apostolopoulos
 * See license.txt for license info
 */
#endregion

#region --- Using Directives ---

using System;
using System.Collections.Generic;
using System.Windows.Forms;

using OpenTK;
using OpenTK.OpenGL;
using OpenTK.Platform;
using Enums = OpenTK.OpenGL.Enums;
using OpenTK.Input;

#endregion

namespace Examples.Tutorial
{
    public class T03_RotatingCube : OpenTK.GameWindow, IExample
    {
        #region --- Fields ---

        /// <summary>
        /// Denotes the cube rotation.
        /// </summary>
        float angle = 0.0f;

        #endregion

        #region --- Constructors ---

        public T03_RotatingCube()
        {
            Context.MakeCurrent();
        
            GL.ClearColor(0.1f, 0.1f, 0.5f, 0.0f);
            GL.Enable(Enums.EnableCap.DEPTH_TEST);

            this.OnResize(new ResizeEventArgs(this.Width, this.Height));
        }

        #endregion
        
        #region Resize event handler

        /// <summary>
        /// Called when the user resizes the window.
        /// </summary>
        /// <param name="e">Contains the new width/height of the window.</param>
        /// <remarks>
        /// You want the OpenGL viewport to match the window. This is the place to do it!
        /// </remarks>
        protected override void OnResize(OpenTK.Platform.ResizeEventArgs e)
        {
            base.OnResize(e);

            GL.Viewport(0, 0, e.Width, e.Height);

            double ratio = e.Width / (double)e.Height;

            GL.MatrixMode(Enums.MatrixMode.PROJECTION);
            GL.LoadIdentity();
            Glu.Perspective(45.0, ratio, 1.0, 64.0);
        }

        #endregion

        #region UpdateFrame function

        /// <summary>
        /// Prepares the next frame for rendering.
        /// </summary>
        /// <remarks>
        /// Place your control logic here. This is the place to respond to user input,
        /// update object positions etc.
        /// </remarks>
        public override void UpdateFrame()
        {
            if (Key.Escape)
            {
                Quit = true;
                return;
            }

            GL.MatrixMode(Enums.MatrixMode.MODELVIEW);
            GL.LoadIdentity();
            Glu.LookAt(
                0.0, 5.0, 5.0,
                0.0, 0.0, 0.0,
                0.0, 1.0, 0.0
            );

            GL.Rotatef(angle, 0.0f, 1.0f, 0.0f);
            angle += 0.5f;
        }

        #endregion

        #region RenderFrame function

        /// <summary>
        /// Place your rendering code here.
        /// </summary>
        public override void RenderFrame()
        {
            GL.Clear(Enums.ClearBufferMask.COLOR_BUFFER_BIT | Enums.ClearBufferMask.DEPTH_BUFFER_BIT);

            DrawCube();

            Context.SwapBuffers();
        }

        #endregion

        #region DrawCube function

        /// <summary>
        /// Draws simple, colored cube.
        /// </summary>
        protected void DrawCube()
        {
            GL.Begin(Enums.BeginMode.QUADS);

            GL.Color3f(1, 0, 0);
            GL.Vertex3f(-1.0f, -1.0f, -1.0f);
            GL.Vertex3f(-1.0f, 1.0f, -1.0f);
            GL.Vertex3f(1.0f, 1.0f, -1.0f);
            GL.Vertex3f(1.0f, -1.0f, -1.0f);

            GL.Color3f(1, 1, 0);
            GL.Vertex3f(-1.0f, -1.0f, -1.0f);
            GL.Vertex3f(1.0f, -1.0f, -1.0f);
            GL.Vertex3f(1.0f, -1.0f, 1.0f);
            GL.Vertex3f(-1.0f, -1.0f, 1.0f);

            GL.Color3f(1, 0, 1);
            GL.Vertex3f(-1.0f, -1.0f, -1.0f);
            GL.Vertex3f(-1.0f, -1.0f, 1.0f);
            GL.Vertex3f(-1.0f, 1.0f, 1.0f);
            GL.Vertex3f(-1.0f, 1.0f, -1.0f);

            GL.Color3f(0, 1, 0);
            GL.Vertex3f(-1.0f, -1.0f, 1.0f);
            GL.Vertex3f(1.0f, -1.0f, 1.0f);
            GL.Vertex3f(1.0f, 1.0f, 1.0f);
            GL.Vertex3f(-1.0f, 1.0f, 1.0f);

            GL.Color3f(0, 0, 1);
            GL.Vertex3f(-1.0f, 1.0f, -1.0f);
            GL.Vertex3f(-1.0f, 1.0f, 1.0f);
            GL.Vertex3f(1.0f, 1.0f, 1.0f);
            GL.Vertex3f(1.0f, 1.0f, -1.0f);

            GL.Color3f(0, 1, 1);
            GL.Vertex3f(1.0f, -1.0f, -1.0f);
            GL.Vertex3f(1.0f, 1.0f, -1.0f);
            GL.Vertex3f(1.0f, 1.0f, 1.0f);
            GL.Vertex3f(1.0f, -1.0f, 1.0f);

            GL.End();
        }

        #endregion

        #region static public void Launch()

        /// <summary>
        /// Launches this example.
        /// </summary>
        /// <remarks>
        /// Provides a simple way for the example launcher to launch the examples.
        /// </remarks>
        static public void Launch()
        {
            using (T03_RotatingCube ex = new T03_RotatingCube())
            {
                ex.Run();
            }
        }

        #endregion
    }
}