using System;
using System.Drawing;
using OpenTK;
using OpenTK.Fonts;
using OpenTK.OpenGL;
using OpenTK.OpenGL.Enums;

namespace Example
{
    public class TKFontTest : GameWindow
    {
        TextureFont textureFont = new TextureFont(new Font(FontFamily.GenericSerif, 24.0f));
        TextHandle textHandle;
        ITextPrinter textPrinter = new TextPrinter();

        string text = "ABCD abcd To whom it may concern:";

        public TKFontTest() : base(new DisplayMode(570, 55), "TKFontTest")
        { }

        public override void OnLoad(EventArgs e)
        {
            GL.ClearColor(Color.Black);
            textPrinter.Prepare(text, textureFont, out textHandle);
        }

        public override void OnUnload(EventArgs e)
        {
            textHandle.Dispose();
            textureFont.Dispose();
        }

        float[] viewport = new float[6];
        protected override void OnResize(OpenTK.Platform.ResizeEventArgs e)
        {
            GL.Viewport(0, 0, Width, Height);
            GL.GetFloat(GetPName.Viewport, viewport);
            GL.MatrixMode(MatrixMode.Projection);
            GL.LoadIdentity();
            GL.Ortho(viewport[0], viewport[2], viewport[3], viewport[1], 0.0, 1.0);

            GL.MatrixMode(MatrixMode.Modelview);
            GL.LoadIdentity();
        }

        public override void OnRenderFrame(RenderFrameEventArgs e)
        {
            GL.Clear(ClearBufferMask.ColorBufferBit);

            float width;
            float height;
            textureFont.MeasureString(text, out width, out height);
            GL.Color3(0.25f, 0.25f, 0.25f);
            GL.Rect(10.0f, 10, 10+width, 10 + height);

            textPrinter.Begin();
            {
                GL.Color3(1.0f, 1.0f, 1.0f);
                GL.Translate(10.0f, 10, 0.0f);
                textPrinter.Draw(textHandle);
            }
            textPrinter.End();

            SwapBuffers();
        }

        [STAThread]
        public static void Main()
        {
            using (TKFontTest tkFontTest = new TKFontTest())
            {
                tkFontTest.Run(30.0, 0.0);
            }
        }
    }
}