using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Text;
using System.Windows.Forms;
using D3D = Microsoft.DirectX.Direct3D;

namespace Nuclex {

/// <summary>A window that is drawn into using Direct3D</summary>
public partial class Direct3DForm : Form {

  /// <summary>Initializes the window</summary>
  public Direct3DForm() {
    InitializeComponent();
  }

  /// <summary>Gets executed when the form is brought onto the screen</summary>
  /// <param name="e">Not used</param>
  protected override void OnLoad(EventArgs e) {
    base.OnLoad(e);

    // Set up the presentation parameters for our little demonstration
    presentParameters = new D3D.PresentParameters();
    presentParameters.IsWindowed = true;
    presentParameters.SwapEffect = D3D.SwapEffect.Discard;

    presentParameters.EnableAutoDepthStencil = true;
    presentParameters.AutoDepthStencilFormat = D3D.DepthFormat.D16;

    presentParameters.BackBufferFormat = D3D.Format.R5G6B5;
    presentParameters.BackBufferWidth = this.ClientSize.Width;
    presentParameters.BackBufferHeight = this.ClientSize.Height;

    d3dDevice = new D3D.Device(
      0,
      D3D.DeviceType.Hardware,
      this.Handle,
      D3D.CreateFlags.SoftwareVertexProcessing,
      presentParameters
    );
  }

  /// <summary>Executed when the window has been closed for good</summary>
  /// <param name="e">Not used</param>
  protected override void OnClosed(EventArgs e) {
    d3dDevice.Dispose();
  }

  /// <summary>We don't want to paint here to avoid flickering </summary>
  /// <param name="e">Additional parameters that control painting</param>
  protected override void OnPaintBackground(PaintEventArgs e) {}

  /// <summary>Paints the window contents</summary>
  /// <param name="e">Additional parameters that control painting</param>
  protected override void OnPaint(PaintEventArgs e) {
    d3dDevice.BeginScene();
    d3dDevice.Clear(
      D3D.ClearFlags.Target | D3D.ClearFlags.ZBuffer,
      SystemColors.Control,
      1.0f,
      0
    );

    OnRender(EventArgs.Empty);

    d3dDevice.EndScene();
    d3dDevice.Present();
  }

  protected override void OnResize(EventArgs e) {
    base.OnResize(e);

    if(d3dDevice != null) {
      presentParameters.BackBufferWidth = this.ClientSize.Width;
      presentParameters.BackBufferHeight = this.ClientSize.Height;
      d3dDevice.Reset(presentParameters);
    }
  }

  /// <summary>Executed to render the Direct3D scene</summary>
  /// <param name="e">Not used</param>
  protected virtual void OnRender(EventArgs e) {}

  /// <summary>The Direct3D rendering device</summary>
  protected D3D.Device d3dDevice;

  /// <summary>Presentation settings for the active Direct3D device</summary>
  protected D3D.PresentParameters presentParameters;

}

} // namespace Nuclex