Managed DirectX Tutorial Part 1 - The Title Screen

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• Download demo project - 182 Kb

Introduction

Welcome to my first tutorial on Managed DirectX, included with DirectX 9 SDK. Most C# developers were waiting for this release. Before Managed DirectX, C# developers were using DirectX via COM Interop of DirectX 7 or 8 VB component. The new Managed DirectX components offers best performance and easier programming over DirectX COM Interop. This tutorial is for newcomers in DirectX development, like me, or for people who were using COM Interop for DirectX development.

In this tutorial, we will make a clone of Super Metroid game called Managed Metroid. We will try to use all the components of Managed DirectX (DirectDraw, DirectSound, DirectInput, Direct3D, DirectPlay and AudioVideoPlayback). In part 1, we will start with basic DirectDraw implementation by showing the title screen and text in full screen.

Requirements

These articles require some knowledge of C#. Also a basic game development background would be useful.

Software requirements:

• Microsoft Windows NT4 SP6, Windows 2000, Windows XP Pro (for compiling only)
• Visual C# .NET or Visual Studio .NET
• DirectX 9 SDK Full or only C# Part (available from Microsoft
• Image editing tool (optional but useful)
• SNES Emulator with Super Metroid ROM (optional)

The Title Screen

Adding DirectX namespaces to the project

Add the references to Microsoft.DirectX.dll and Microsoft.DirectX.DirectDraw.dll to your project and add these namespaces to the project.

using Microsoft.DirectX;
using Microsoft.DirectX.DirectDraw;

Adding DirectX variables

First of all, we need to create a DirectDraw device. After that, we create the Surfaces. A Surface is a part of memory where you draw the needed stuff; it also acts like a layer. The Clipper is the boundaries you set to the device, so the device will not draw over the Clipper. The back Surface represents the BackBuffer. The title and text represents the layers of the title screen. Finally, the titlescreen string point to the bitmap to load into title Surface.

// The DirectDraw Device, used in all the application
private Device display;
// The Front Surface
private Surface front = null;
// The Back Surface
private Surface back = null;
// Surface to store the title screen
private Surface title = null;
// Surface to store the text
private Surface text = null;
// The Clipper
private Clipper clip = null;
string titlescreen = Application.StartupPath + "\\title.bmp";

Initialize DirectDraw

For initializing any Managed DirectX component, I suggest you to create methods for each component you use. Here is the method I used to init my DirectDraw stuff.

private void InitDirectDraw()
{
    // Used to describe a Surface
    SurfaceDescription description = new SurfaceDescription();
    // Init the Device
    display = new Device();
#if DEBUG
    display.SetCooperativeLevel(this, CooperativeLevelFlags.Normal);
#else
    // Set the Cooperative Level and parent, 
    //Setted to Full Screen Exclusive to the form)
    display.SetCooperativeLevel(this, 
        CooperativeLevelFlags.FullscreenExclusive);
    // Set the resolution and color depth 
    //used in full screen(640x480, 16 bit color)
    display.SetDisplayMode(640, 480, 16, 0, false);
#endif

// Define the attributes for the front Surface
description.SurfaceCaps.PrimarySurface = true;

#if DEBUG
    front = new Surface(description, display);
#else
    description.SurfaceCaps.Flip = true;
    description.SurfaceCaps.Complex = true;

    // Set the Back Buffer count
    description.BackBufferCount = 1;

    // Create the Surface with specifed description and device)
    front = new Surface(description, display);
#endif
    description.Clear();
#if DEBUG
    description.Width = front.SurfaceDescription.Width;
    description.Height = front.SurfaceDescription.Height;
    description.SurfaceCaps.OffScreenPlain = true;
    back = new Surface(description, display);
#else
    // A Caps is a set of attributes used by most of DirectX components
    SurfaceCaps caps = new SurfaceCaps();
    // Yes, we are using a back buffer
    caps.BackBuffer = true;

    // Associate the front buffer to back buffer with specified caps
    back = front.GetAttachedSurface(caps);
#endif

    // Create the Clipper
    clip = new Clipper(display);
    /// Set the region to this form
    clip.Window = this;
    // Set the clipper for the front Surface
    front.Clipper = clip;

    // Reset the description
    description.Clear();
    // Create the title screen
    title = new Surface(titlescreen, description, display);

    description.Clear();
    // Set the height and width of the text.
    description.Width = 600;
    description.Height = 16;
    // OffScreenPlain means that this Surface 
    //is not a front, back, alpha Surface.
    description.SurfaceCaps.OffScreenPlain = true;

    // Create the text Surface
    text = new Surface(description, display);
    // Set the backgroup color
    text.ColorFill(Color.Black);
    // Set the fore color of the text
    text.ForeColor = Color.White;
    // Draw the Text to the Surface to coords (0,0)
    text.DrawText(0, 0, 
        "Managned DirectX Tutorial 1 - Press Enter or Escape to exit", 
        true);
}

The Draw method

The Draw is called each time we need to draw the content of the Surface to the screen.

private void Draw()
{
    // If the front isn't create, ignore this function
    if (front == null)
    {
        return;
    }

    // If the form is minimized, ignore this function
    if(this.WindowState == FormWindowState.Minimized)
    {
        return;
    }
    try
    {
        // Draw the title to the back buffer using source copy blit
        back.DrawFast(0, 0, title, DrawFastFlags.Wait);

        // Draw the text also to the back buffer using source copy blit
        back.DrawFast(10, 10, text, DrawFastFlags.Wait);

#if DEBUG
        // Draw all this to the front
        front.Draw(back, DrawFlags.Wait);
#else
        // Doing a flip to transfer back buffer to the front, faster
        front.Flip(back, FlipFlags.Wait);
#endif
    }

    catch(WasStillDrawingException)
    {
        return;
    }
    catch(SurfaceLostException)
    {
        // If we lost the surfaces, restore the surfaces
        RestoreSurfaces();
    }
}

The RestoreSurfaces method

The RestoreSurfaces method is called when the user defocus the application and then refocus the application (like an Alt-Tab switch).

private void RestoreSurfaces()
{
    // Used to describe a Surface
    SurfaceDescription description = new SurfaceDescription();

    // Restore al the surface associed with the device
    display.RestoreAllSurfaces();
    // Redraw the text
    text.ColorFill(Color.Black);
    text.DrawText(0, 0, 
        "Managned DirectX Tutorial 1 - Press Enter or Escape to exit", 
        true);

    // For the title screen, we need to 
    //dispose it first and then re-create it
    title.Dispose();
    title = null;
    title = new Surface(titlescreen,  description, display);
    return;
}

The Final touch

At last, add the method InitDirectDraw to the constructor. Also implement the main loop of the application where the Draw method is used. Application.DoEvents() makes the application, process the messages event if the application is in a loop.

public Tutorial1()
{
    //
    // Required for Windows Form Designer support
    //
    InitializeComponent();
    // Initialize DirectDraw stuffs
    InitDirectDraw();
    // Remove the cursor
    this.Cursor.Dispose();
    // Show the form if isn't already do
    this.Show();
    // The main loop
    while(Created)
    {
        Draw();
        // Make sure that the application 
        //process the messages
        Application.DoEvents();
    }
}

Made a change to the Main method. Application.Run method doesn't work in this context. You need to create the form by yourself.

static void Main() 
{
    Tutorial1 app = new Tutorial1();
    Application.Exit();
}

The KeyUp event, is used to quit the Tutorial.

private void Tutorial1_KeyUp(object sender, 
                System.Windows.Forms.KeyEventArgs e)
{
    // If the user press Escape or Enter, the tutorial exits
    if(e.KeyCode == Keys.Escape || e.KeyCode == Keys.Enter)
        this.Close();
}

Conclusion

In this tutorial, we learned how to show a bitmap in full screen using DirectDraw with Managed DirectX. The next tutorial will be on sprite animation and background music with AudioVideoPlayback. If you have any comments, suggestions, code corrections, please make me a remark in the bottom of the article.

History

Update 1.1

• Fixed drawing on slower machines
• Separated code for Debug and Release, suggestion by kalme
• Release version more faster, doing a flip instead of a drawing

Update 1.0

• First Release of Part 1