Spiral Galaxy

using System;
using System.Drawing;
using OpenTK;
using graph = OpenTK.Graphics;
using OpenTK.Graphics.OpenGL;
using OpenTK.Input;
 
namespace HelloOpenTK
{
	public static class Fps
	{
		static double _time = 0.0, _frames = 0.0;
		static int _fps = 0;
 
		public static int GetFps(double time) {
			_time += time;
			if (_time < 1.0) {
				_frames++;
				return _fps;
			}
			else {
				_fps = (int)_frames;
				_time = 0.0;
				_frames = 0.0;
				return _fps;
			}
		}
	}
 
	public class Program : GameWindow
	{	
		private IntPtr qdr;
		private float perimeter = 0f;
 
		public Program() : base(800, 600, graph.GraphicsMode.Default, "Hello OpenTK")
		{
			Keyboard.KeyDown += new EventHandler<KeyboardKeyEventArgs>(Keyboard_KeyDown);
		}
 
		void Keyboard_KeyDown(object sender, KeyboardKeyEventArgs e)
		{
			if (e.Key == Key.Escape)
				Exit();
		}
 
		protected override void OnLoad(EventArgs e)
		{
			base.OnLoad(e);
 
			// Set opengl view options
			GL.ClearColor(Color.Black);
			GL.Enable(EnableCap.DepthTest);
 
			// Create a quadric
			qdr = graph.Glu.NewQuadric();
		}
 
		protected override void OnUpdateFrame(FrameEventArgs e)
		{
			base.OnUpdateFrame(e);
 
			perimeter += (float)(1 * e.Time);
			if (perimeter > 360) perimeter = 0;
 
			Title = Fps.GetFps(e.Time).ToString();
		}
 
		protected override void OnResize(EventArgs e)
		{
			// Standard OpenTK code for window resize
			base.OnResize(e);
			GL.Viewport(0, 0, Width, Height);
			Matrix4 projection = Matrix4.CreatePerspectiveFieldOfView((float)Math.PI / 4, Width / (float)Height, 1.0f, 64.0f);
			GL.MatrixMode(MatrixMode.Projection);
			GL.LoadMatrix(ref projection);
		}
 
 
		protected override void OnRenderFrame(FrameEventArgs e)
		{
			base.OnRenderFrame(e);
 
			// Camera
			GL.Clear(ClearBufferMask.ColorBufferBit | ClearBufferMask.DepthBufferBit);
			GL.MatrixMode(MatrixMode.Modelview);
			Matrix4 modelview = Matrix4.RotateY(perimeter);							// Rotate
			modelview *= Matrix4.LookAt(20f, 20f, -20f , 0f, 0f, 0f , 0f, 1f, 0f);	// Set eye and target
			GL.LoadMatrix(ref modelview);
 
			// Display spiral galaxy
			for (int i = 0; i <= 500; i += 5) {
				GL.PushMatrix();
				GL.Translate(Math.Sin(i) * (double)(i / 25), 0f, Math.Cos(i) * (double)(i / 25));
				graph.Glu.Sphere(qdr, 0.2f, 4, 4);
				GL.PopMatrix();
			}
 
			SwapBuffers();
		}
 
		[STAThread]
		public static void Main()
		{
			using (Program p = new Program())
			{
				p.Run(80f);
			}
		}
	}
}