XNA Essentials

Game Programming for Xbox 360, PC + Windows Phone

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Microsoft XNA Game Studio 3.0 Unleashed Errata

Microsoft XNA Game Studio 3.0 Unleashed - Errata


Any Chapters not listed here do not have any known errors. The complete list of chapters can be found on the main Microsoft XNA Game Studio 3.0 Unleashed book information page.


If you find an error in the book, please create a new post to this forum.


Introduction


Page 2


Software Requirements


There is outdated information in the introduction. The text should state that Microsoft Visual C# 2008 Express or any Visual Studio 2008 SKU (not Visual C# 2005 Express). It should also state Microsoft XNA Game Studio 3.0 and not Express. Finally, DirectX 9.0c is no longer a requirement to install first. The XNA Game Studio setup will take care of this now. Thanks to alvin for pointing this out in the forums.

Chapter 1


Page 15


Installing XNA Game Studio


The Warning box at the bottom of the page is no longer valid. It is no longer required to run Visual C# Express once before installing XNA Game Studio. This was a requirement early on, but is no longer the case. Thanks to alvin for pointing this out in the forums.

Chapter 3


Code Fix on CD


Chapter 3 was edited with the CTP version of XNA Game Studio 3.0. As a result the XNAPerformanceChecker.csproj file is incorrect. The result is that the assemblies it references cannot load successfully. This can be corrected by either following the steps here or by overwriting the current .csproj file with the updated one: XNAPerformanceChecker.csproj. Thanks to Pelham for pointing this out in the forums.


Pages 42,43


Benchmarking


In the code there are extra > values after the methods TransformVectorByReferenceAndOut() and TransformVectorByReferenceAndOutVectorAdd(). The > needs to be removed. Thanks to Myth for pointing this out in the forums.


Chapter 4


Page 57


Creating a Camera


"We then need to add a call to InitializeCamera in the beginning of our LoadGraphicsContent method." should be "We then need to add a call to InitializeCamera in the beginning of our LoadContent method." Thanks to alvin for pointing this out in the forums.


Page 75


Checking Performance


The assignment of the vertexBuffer should be the following code:


 


vertexBuffer = new VertexBuffer(graphics.GraphicsDevice,
    VertexPositionNormalTexture.SizeInBytes * vertices.Length,
    BufferUsage.WriteOnly);

 


The code listed in the book was not correctly changed from the previous edition. Thanks to Myth for pointing this out in the forums.


Chapter 7


Code Fix on CD


Sound Demo


Much to my dismay there is an issue with the code on the CD. The SoundDemo had test code and didn't include the content.contentproj file. As a result after the Chapter 7 code and assets are copied from the CD onto your hard drive you will need to download and extract two files.

Download Chapter7Fix.zip and extract to the Chapter7 folder. It will overwrite the Game1.cs file in the SoundDemo folder. It will add the missing content.contentproj to the SoundDemo\Content folder.

Chapter 9


Code Fix on CD


Sort Order Demo and Progress Bar Demo


With the change from XNA Game Studio 1.0 Refresh to XNA Game Studio 3.0, Microsoft included a enumeration type for buttons. In the original book we created our own type InputHandler.ButtonType. The built in enum type is simply Buttons. In the Game1.cs files for both the Sort Order Demo and the Progress Bar demo both reference the custom enum type which does not exist in the XELibrary code. The code should reference Buttons instead of InputHandler.ButtonType.
Download Chapter9Fix.zip and extract to the Chapter9 folder. It will overwrite the Game1.cs files in the SortOrderDemo and ProgressBarDemo folders.

Alternatively, you can search and replace (Case Sensative) InputHandler.ButtonType. with Buttons. in the Game1.cs files in both the SortOrderDemo and the ProgressBarDemo solutions.

Pages 179,180,187


Practical Sprite Batches


All instances of code where InputHandler.ButtonType. is found, it should be replaced with Buttons.

Page 178 - 183


Practical Sprite Batches


One Figure image was in the incorrect position. This caused Figures 9.3 to 9.6 to not have the correct images.



Figure 9.3
Figure 9.3 shapes.png




Figure 9.4
Figure 9.4 SpriteSortMode.Deferred does not sort the images drawn and displays them in the order they were drawn in the code.




Figure 9.5
Figure 9.5 SpriteSortMode.BackToFront sorts images based on the layer depth values, with the highest number being farthest from the screen.




Figure 9.6
Figure 9.6 SpriteSortMode.FrontToBack sorts the images based on the layer depth values, with the lowest number being farthest from the screen.

Chad Carter - Saturday, May 2, 2009 @ 11:34 AM
XNA Essentials |

XNA Essentials

Game Programming for Xbox 360, PC + Windows Phone

NAVIGATION - SEARCH

Microsoft XNA Unleashed Errata

Microsoft XNA Unleashed - Errata


This errata page has been a long time coming. I finally took all of the posts from the Amazon forum for the book and compiled them into a single source. I'll update this if any additional errors are found in the book. If something is unclear with this errata page or anything else in the book, please post the question in the book's amazon.com forum.


Any Chapters not listed here do not have any known errors. The complete list of chapters can be found on the main Microsoft XNA Unleashed book information page.


Chapter 2


Page 27


Creating a Test Demo for the Xbox 360


The first segment of code on the page says to use the texture variable when it really should be spriteTexture. Change

    spriteBatch.Draw(texture, new Vector2(titleSafeArea.X, titleSafeArea.Y), Color.White);

to

    spriteBatch.Draw(spriteTexture, new Vector2(titleSafeArea.X, titleSafeArea.Y), Color.White);

Chapter 3


Page 47


Optimization Suggestions


The RotateWithMod method uses 30 in the cameraYaw calculation instead of 360.

Chapter 5


Page 100


Creating a Stationary Camera


The text preceeding the first code fragment suggests it should be added to the demo's Update method. This is incorrect. The code should be added to the demo's Draw method.

The actual code should also be modified. It seems there was a formatting issue when I pasted the code to the text and I became a little too happy with the delete key. The world variable should be changed from 

    world = Matrix.CreateRotationY(Matrix.CreateTranslation(new Vector3(3.0f, 0, 10.0f));

to

    world = Matrix.CreateRotationY(MathHelper.ToRadians(180f)) * 

        Matrix.CreateTranslation(new Vector3(3.0f, 0, 10.0f));

Page 107


Creating a Split Screen


The second player's input controls do not function as they should. The axis are inverted, which may be a nice option but to have it react "normally" the camera2.Orientation property should get the same value as camera.Orientation. So change

    camera2.Orientation = new Vector3(0.0f, 0.0f, 1.0f);

to

    camera2.Orientation = camera.Orientation;

Chapter 8


Page 165


Using the Skybox


It was my intention to have all of the code in the book so you didn't have to refer to the code on the CD. However, I forgot to add a couple of code segments. First, add this line in LoadContent method.

    skybox = Content.Load<Skybox>(@"Content\Skyboxes\skybox");

Second, you actually need to draw the skybox by adding the following two lines of code at the bottom of the Draw method, but right before the base.Draw call:

    world = Matrix.CreateScale(5000.0f);
    skybox.Draw(camera.View, camera.Projection, world);

Chapter 9


Page 172


Sprite Batches


The text at the top of the page as well as Figure 9.1 suggests that for a resolution of 1024 by 768 that X would run from 0 to 1024 and Y would run from 0 to 768. There is an "off by one" error there. X would really run from 0 to 1023 and Y would run from 0 to 767.

Page 177


Splash or Loading Screen Demo


Bottom of the page, the final line of code uses "Contents" when the directory is actually "Content". Change

    splashScreen = content.Load<Texture2D>(@"Contents\Textures\splashScreen");

to

    splashScreen = content.Load<Texture2D>(@"Content\Textures\splashScreen");

Page 184


Progress Bar Demo


The list of private member fields are missing one. It seems when I copied the list from the code, I neglected to grab the very first one. At the top of the list (or where ever you want) add the following variable:

    private Texture2D progressBar;

Chapter 10


Pages 194 - 195


Cel Animation


There are 3 overloaded Draw methods in Listing 10.1 - CelAnimationManager.cs. The final overloaded method never uses the int frame parameter passed to it. Since this the case, the three Draw dethods can be simplified to the following two:

    public void Draw(GameTime gameTime, string animationKey, SpriteBatch batch, Vector2 position)
    {
        Draw(gameTime, animationKey, batch, position, Color.White);
    }

    public void Draw(GameTime gameTime, string animationKey, SpriteBatch batch, Vector2 position, Color color)
    {
        if (!animations.ContainsKey(animationKey))
            return;

        CelAnimation ca = animations[animationKey];

        //first get our x increase amount (add our offset-1 to our current frame)
        int xincrease = (ca.Frame + ca.CelRange.FirstCelX - 1);
        //now we need to wrap the value so it will loop to the next row
        int xwrapped = xincrease % ca.CelsPerRow;
        //finally we need to take the product of our wrapped value and a cel's width
        int x = xwrapped * ca.CelWidth;

        //to determine how much we should increase y, we need to look at how much we
        //increased x and do an integer divide
        int yincrease = xincrease / ca.CelsPerRow;
        //now we can take this increase and add it to our Y offset-1 and multiply the sum by
        //our cel height
        int y = (yincrease + ca.CelRange.FirstCelY - 1) * ca.CelHeight;

        Rectangle cel = new Rectangle(x, y, ca.CelWidth, ca.CelHeight);

        batch.Draw(textures[ca.TextureName], position, cel, color);
    }

Page 196


Cel Animation


The text in the book is incorrect as the code is a normal constructor and not a static Create method. Remove the Create method and replace it with the following:

    public CelAnimation(string textureName, CelRange celRange, int framesPerSecond)
    {
        this.textureName = textureName;
        this.celRange = celRange;
        this.framesPerSecond = framesPerSecond;
        this.timePerFrame = 1.0f / (float)framesPerSecond;
        this.Frame = 0;
    }

Page 201


Cel Animation


After updating the Update method and explaining it, I suggest that we run the code to see the animations. Well, it would be beneficial if we actually added the appropriate draw calls. The following code needs to be added to the Draw method:

    spriteBatch.Begin();
    cam.Draw(gameTime, "enemy1", spriteBatch, new Vector2(50, 50));
    cam.Draw(gameTime, "enemy2", spriteBatch, new Vector2(150, 75));
    cam.Draw(gameTime, "enemy3", spriteBatch, new Vector2(70, 130));

    cam.Draw(gameTime, "complex1", spriteBatch, new Vector2(400, 50));
    cam.Draw(gameTime, "complex2", spriteBatch, new Vector2(400, 150));
    cam.Draw(gameTime, "complex3", spriteBatch, new Vector2(400, 250));
    cam.Draw(gameTime, "complex4", spriteBatch, new Vector2(400, 350));
    spriteBatch.End();

Chapter 11


Page 221


Creating Parallax Scrolling


The ScrollingBackgroundManager class should implement the IScrollingBackgroundManager. The code has this, but the listing neglects to include it. A game service must inherit from a unique interface. Change the class declaration to be:

    public class ScrollingBackgroundManager : Microsoft.Xna.Framework.GameComponent, IScrollingBackgroundManager

Page 222


Creating Parallax Scrolling


The AddBackground method in the book did not modify the ScrollRate property. The entire method can be replaced with the following:

    public void AddBackground(string backgroundKey, string textureName,
        Vector2 position, Rectangle? sourceRect, float scrollRateRatio,
        Color color)
    {
        ScrollingBackground background = new ScrollingBackground(
            textureName, position, sourceRect, scrollRateRatio, color);

        background.ScrollRate = scrollRate * scrollRateRatio;

        if (!textures.ContainsKey(textureName))
        {
            textures.Add(textureName, cGame.Content.Load<Texture2D>(
                contentPath + textureName));
        }

        if (backgrounds.ContainsKey(backgroundKey))
            backgrounds[backgroundKey] = background;
        else
            backgrounds.Add(backgroundKey, background);
     }

Page 223


Creating Parallax Scrolling


There is a typo in the code in the book in Listting 11.1 - ScrollingBackgroundManager.cs. The ScrollRate property has a void return. It should be a float. Change the ScrollRate property to the following:

    public float ScrollRate
    {
        get { return (scrollRate); }
    }

Page 225


Creating Parallax Scrolling


In the constructor of the Background class, the last line of code should be removed. It has no use as we are not utilizing the specific game methods inside of this class. Remove this line:

    simpleGame = (SimpleGame)game;

Chapter 13


Page 276


Vertex Displacement


There is an additional change not mentioned in the book that needs to take place before the code will functoin correctly. The code on the CD included this modification, but the text did not point it out. In the effect file, change 

    output.Position = mul(input.Position, WorldViewProjection);

to

    output.Position = mul(Pos, WorldViewProjection);

Without changing input.Position to Pos none of the changes we made to the position to create the vertex displacement would matter.

 

Chad Carter - Saturday, May 2, 2009 @ 12:57 PM