Disclaimer

This code is sample code that I wrote to help out a reader. It's not commented well, and it hasn't been extensively debugged. I post it here for illustrative purposes only. Hope you find it helpful.

This code shows how to render an image to the screen and then save the same image to a file.

The key to this sample is twofold:

• 1. You must set PresentationParameters.SwapEffect to SwapEffect.Copy orSwapEffect.Flip, otherwise the data in the back buffer will be garbage (that's whatSwapEffect.Discard means).

  2. All the hard work is done by SurfaceLoader.Save.

The Code

using System; using System.Data; using System.Drawing; using System.Drawing.Imaging; using System.Collections; using System.ComponentModel; using System.Windows.Forms; using Microsoft.DirectX; using Microsoft.DirectX.Direct3D; namespace Wangdera.CaptureImage { /// <summary> /// Summary description for Form1. /// </summary> public class Form1 : System.Windows.Forms.Form { private Device _device; private Mesh _mesh; private System.Windows.Forms.Panel _canvas; private System.Windows.Forms.Label label1; private System.Windows.Forms.TrackBar _nudZoom; private System.Windows.Forms.Button _bSaveImage; /// <summary> /// Required designer variable. /// </summary> private System.ComponentModel.Container components = null; public Form1() { // // Required for Windows Form Designer support // InitializeComponent(); InitializeGraphics(); } /// <summary> /// The main entry point for the application. /// </summary> [STAThread] static void Main() { Application.Run(new Form1()); } /// <summary> /// Clean up any resources being used. /// </summary> protected override void Dispose( bool disposing ) { if( disposing ) { if (components != null) { components.Dispose(); } } base.Dispose( disposing ); } #region Windows Form Designer generated code /// <summary> /// Required method for Designer support - do not modify /// the contents of this method with the code editor. /// </summary> private void InitializeComponent() { this._canvas = new System.Windows.Forms.Panel(); this._nudZoom = new System.Windows.Forms.TrackBar(); this.label1 = new System.Windows.Forms.Label(); this._bSaveImage = new System.Windows.Forms.Button(); ((System.ComponentModel.ISupportInitialize)(this._nudZoom)).BeginInit(); this.SuspendLayout(); // // _canvas // this._canvas.Dock = System.Windows.Forms.DockStyle.Top; this._canvas.Location = new System.Drawing.Point(0, 0); this._canvas.Name = "_canvas"; this._canvas.Size = new System.Drawing.Size(880, 464); this._canvas.TabIndex = 0; // // _nudZoom // this._nudZoom.Location = new System.Drawing.Point(120, 496); this._nudZoom.Maximum = -1; this._nudZoom.Minimum = -1000; this._nudZoom.Name = "_nudZoom"; this._nudZoom.TabIndex = 1; this._nudZoom.TickFrequency = 100; this._nudZoom.Value = -100; this._nudZoom.Scroll += new System.EventHandler(this._nudZoom_Scroll); // // label1 // this.label1.Location = new System.Drawing.Point(16, 496); this.label1.Name = "label1"; this.label1.TabIndex = 2; this.label1.Text = "&Zoom:"; this.label1.TextAlign = System.Drawing.ContentAlignment.MiddleRight; // // _bSaveImage // this._bSaveImage.Location = new System.Drawing.Point(248, 496); this._bSaveImage.Name = "_bSaveImage"; this._bSaveImage.Size = new System.Drawing.Size(120, 23); this._bSaveImage.TabIndex = 3; this._bSaveImage.Text = "&Save Image..."; this._bSaveImage.Click += new System.EventHandler(this._bSaveImage_Click); // // Form1 // this.AutoScaleBaseSize = new System.Drawing.Size(5, 13); this.ClientSize = new System.Drawing.Size(880, 581); this.Controls.Add(this._bSaveImage); this.Controls.Add(this.label1); this.Controls.Add(this._nudZoom); this.Controls.Add(this._canvas); this.Name = "Form1"; this.Text = "Form1"; ((System.ComponentModel.ISupportInitialize)(this._nudZoom)).EndInit(); this.ResumeLayout(false); } #endregion protected bool InitializeGraphics() { PresentParameters pres = new PresentParameters(); pres.Windowed = true; pres.SwapEffect = SwapEffect.Copy; pres.EnableAutoDepthStencil = true; pres.AutoDepthStencilFormat = DepthFormat.D16; _device = new Device(0, DeviceType.Hardware, _canvas, CreateFlags.SoftwareVertexProcessing, pres); Material material = new Material(); material.Diffuse = Color.Yellow; material.Specular = Color.White; material.SpecularSharpness = 10.0F; _device.Material = material; _mesh = Mesh.Teapot(_device); SetupLights(); return true; } protected override void OnPaint(PaintEventArgs e) { base.OnPaint (e); Render(); } protected void Render() { _device.Clear(ClearFlags.Target | ClearFlags.ZBuffer, Color.BlueViolet, 1.0F, 0); _device.BeginScene(); SetupMatrices(); _mesh.DrawSubset(0); _device.EndScene(); _device.Present(); } protected void SetupLights() { _device.RenderState.Lighting = true; _device.Lights[0].Diffuse = Color.White; _device.Lights[0].Specular = Color.White; _device.Lights[0].Type = LightType.Directional; _device.Lights[0].Direction = new Vector3(-1, -1, 3); _device.Lights[0].Update(); _device.Lights[0].Enabled = true; _device.RenderState.Ambient = Color.FromArgb(0x00, 0x00, 0x00); } protected void SetupMatrices() { _device.Transform.World = Matrix.Identity; _device.Transform.View = Matrix.LookAtLH(new Vector3(0, 0, _nudZoom.Value / 10.0F), new Vector3(0, 0, 0), new Vector3(0, 1, 0)); _device.Transform.Projection = Matrix.PerspectiveFovLH((float)Math.PI/4.0F, 1.0F, 0.1F, 10000.0F); } private void _nudZoom_Scroll(object sender, System.EventArgs e) { Invalidate(); } private void _bSaveImage_Click(object sender, System.EventArgs e) { SaveFileDialog dialog = new SaveFileDialog(); dialog.Filter = "JPEG (*.jpg)|*.jpg"; if (dialog.ShowDialog() == DialogResult.OK) { // Note that for this to work, you have to have SwapEffect.Flip or SwapEffect.Copy set in // the PresentationParameters set at device creation. SurfaceLoader.Save(dialog.FileName, ImageFileFormat.Jpg, _device.GetBackBuffer(0, 0, BackBufferType.Mono)); } } } }