TextureAddressMode

Introduction

The TextureAddressMode controls how Sprites display their texture outside of the 0 - 1 range. TextureAddressMode can be used to create tiles and texture scrolling. TextureAddressMode is usually used in combination with texture coordinates. For more information on texture coordinates, see the texture coordinates page.

Usage Example

The following code creates three sprites. It assumes that the texture star is in scope (such as added to the Screen containing the code);

Sprite wrapSprite = SpriteManager.AddSprite(star);
// BottomTextureCoordinate of 4 means the texture will "wrap" 4 times vertically
wrapSprite.RightTextureCoordinate = 4;
wrapSprite.BottomTextureCoordinate = 4;
wrapSprite.X = -200;
wrapSprite.TextureAddressMode = 
    Microsoft.Xna.Framework.Graphics.TextureAddressMode.Wrap;
wrapSprite.TextureScale = 1;

// notice that TextureScale accounts for texture coordinates.
// This sprite will be taller than the sprite to its left:
Sprite tallSprite = SpriteManager.AddSprite(star);
tallSprite.RightTextureCoordinate = 4;
// wrap 10 times vertically...
tallSprite.BottomTextureCoordinate = 10;
tallSprite.TextureAddressMode =
    Microsoft.Xna.Framework.Graphics.TextureAddressMode.Wrap;
tallSprite.TextureScale = 1;

Sprite clampSprite = SpriteManager.AddSprite(star);
clampSprite.RightTextureCoordinate = 4;
clampSprite.BottomTextureCoordinate = 4;
// default
clampSprite.TextureAddressMode = 
    Microsoft.Xna.Framework.Graphics.TextureAddressMode.Clamp;
clampSprite.X = 200;
clampSprite.TextureScale = 1;

This article uses the TextureScale property to automatically size the Sprites according to their texture coordinates.

Note: The Wrap texture address mode requires that textures are a power of 2 on the Windows Phone.

Simulating Scrolling

Changing a Sprite's texture coordinate values while using TextureAddressMode.Wrap is an easy way to simulate a scrolling background with one Sprite. The following code creates a single Sprite which appears to be scrolling. Add the following using statements:

using Microsoft.Xna.Framework.Graphics;

Add the following in Initialize after initializing FlatRedBall:

mSprite = SpriteManager.AddSprite("redball.bmp");
mSprite.TextureAddressMode = TextureAddressMode.Wrap;
mSprite.ScaleX = SpriteManager.Camera.RelativeXEdgeAt(0);
mSprite.ScaleY = SpriteManager.Camera.RelativeYEdgeAt(0);

Add the following in Update:

float scrollSpeed = 1; // 1 means the background will loop one time per second
mSprite.LeftTextureCoordinate += scrollSpeed * TimeManager.SecondDifference;
mSprite.RightTextureCoordinate += scrollSpeed * TimeManager.SecondDifference;

Scrolling.png