Riemers3DXNA1Terrain01starting

Starting your XNA 4.0 Project

Welcome to the first entry of this 3D XNA Tutorial. This tutorial is aimed at people who haven't done any 3D programming so far and would like to see some results in the shortest possible time. Released in December 2006, XNA is pretty much a new language, built around DirectX, which eases game programming in a lot of ways.

The software required to start writing your own XNA code is completely free:

Windows Phone Developer Tools (free) (link)

With this free software installed, you can start up Visual Studio 2010, which you can find in the start menu. Next, go to the File menu, and select New Project. You should select “XNA Game Studio 4.0” as project type in the list on the left.

As project template, we need Windows Game (4.0). Deploying your game on an Xbox360 will be discussed later. Fill in Series3D1 as name for the project, and hit the OK button!

A small XNA project is being made for you. In the Solution Explorer on the right side of your screen you see your project already contains 2 code files: Game1.cs and Program.cs. You can look at the code in the files by right clicking on them and selecting View code. Your program starts in the Program.cs file, in the Main method. This Main method simply calls up the code in the Game1.cs file. There’s nothing we need to change in the Program.cs file.

Open the code in the Game1.cs file. Although it's littered with comments, we can discover the structure of a XNA game program:

• The constructor method Game1() is called once at startup. It is used to load some variables needed by the XNA framework.
• The Initialize method is also called once on startup. This is the method where we should put our initialization code.
• The (Un)LoadContent method is used for importing media (such as images, objects and audio) as well as data related to the graphics card.
• The Update method is called every frame exactly 60 times. Here we will put the code that needs to be updates throughout the lifetime of our program, such as the code that reads the keyboard and updates the geometry of our scene.
• As often as your computer (and especially your graphics card) allows, the Draw method is called. This is where we should put the code that actually draws our scene to the screen.

As you can see, there is no code needed to open a window, as this will be done automatically for us. When you run your project by pressing F5, you will already get a nice blue window.

Let’s move on, and discuss the graphics device. In short, a ‘device’ is a direct link to your graphical adapter. It is an object that gives you direct access to the piece of hardware inside your computer. This variable is readily available in our code as the GraphicsDevice variable, but as we’ll be using this a lot (really, a lot) we’ll make a shortcut for this. First, we’ll declare this variable, by adding this line to the top of your class, exactly above the Game1() method:

 GraphicsDevice device;

Obviously we need to fill this variable. Add this line to your LoadContent method:

 device = graphics.GraphicsDevice;

Let's put it to use, by making the first line in your Draw method a tiny bit shorter:

 device.Clear(Color.CornflowerBlue);

Next, we’re going to specify some extra stuff related to our window such as its size and title. Add this code to the Initialize method:

 graphics.PreferredBackBufferWidth = 500;
 graphics.PreferredBackBufferHeight = 500;
 graphics.IsFullScreen = false;
 graphics.ApplyChanges();

 Window.Title = "Riemer's XNA Tutorials -- Series 1";

The first line sets the size of our backbuffer, which will contain what will be drawn to the screen. We also indicate we want our program to run in a window, after which we apply the changes. The last line sets the title of our window.

When you run this code, you should see a window of 500x500 pixels, with the title you set, as shown below.

// Status image

After each chapter I will suggest some short exercises, so you practice what you’ve learned in the chapter. After the exercise, the whole code of the chapter is listed, with the changes of the current chapter highlighted. I have stripped away all the comments, so it looks a bit more compact. Also, stuff around the SpriteBatch has been removed, as it’s used only to render 2D graphics.

You can try these exercises to practice what you've learned:

• Instead of creating a windowed game, switch to 800x600 fullscreen mode (use Alt+F4 to terminate your program)

Code so far

 using System;
 using System.Collections.Generic;
 using System.Linq;
 using Microsoft.Xna.Framework;
 using Microsoft.Xna.Framework.Audio;
 using Microsoft.Xna.Framework.Content;
 using Microsoft.Xna.Framework.GamerServices;
 using Microsoft.Xna.Framework.Graphics;
 using Microsoft.Xna.Framework.Input;
 using Microsoft.Xna.Framework.Media;
 
 namespace Series3D1
 {
     public class Game1 : Microsoft.Xna.Framework.Game
     {
         GraphicsDeviceManager graphics;
         SpriteBatch spriteBatch;
         GraphicsDevice device;
 
         public Game1()
         {
             graphics = new GraphicsDeviceManager(this);
             Content.RootDirectory = "Content";
         }
 
         protected override void Initialize()
         {
             graphics.PreferredBackBufferWidth = 500;
             graphics.PreferredBackBufferHeight = 500;
             graphics.IsFullScreen = false;
             graphics.ApplyChanges();
             Window.Title = "Riemer's XNA Tutorials -- 3D Series 1";
 
             base.Initialize();
         }
 
         protected override void LoadContent()
         {
             spriteBatch = new SpriteBatch(GraphicsDevice);
 
             device = graphics.GraphicsDevice;
         }
 
         protected override void UnloadContent()
         {
         }
 
         protected override void Update(GameTime gameTime)
         {
             if (GamePad.GetState(PlayerIndex.One).Buttons.Back == ButtonState.Pressed)
                 this.Exit();
 
             base.Update(gameTime);
         }
 
         protected override void Draw(GameTime gameTime)
         {
             device.Clear(Color.CornflowerBlue);
 
             base.Draw(gameTime);
         }
     }
 }

Next Steps

The effect file