Book Image

Windows Phone 7 XNA Cookbook

By : Zheng Yang
Book Image

Windows Phone 7 XNA Cookbook

By: Zheng Yang

Overview of this book

Developing games for Windows Phone 7, a new mobile platform, is your big chance to impact the world of mobile games. The XNA 4.0 for Windows Phone 7 integrates a lot of capabilities from software and hardware for you to create incredible games. The next generation of mobile games will be built by you. Windows Phone 7 XNA Cookbook is the best choice for you to make a game on Windows Phone 7. The book helps you to master the indispensable techniques to create your games using XNA 4.0. From the basics such as animating a 2D sprite and interacting with the customized graphical user interface to the more challenging such as 3D graphic rendering and collision detection. This comprehensive cookbook covers all the essential areas of XNA game development for Windows Phone 7, such as approaches to control the sensors, gestures and typical kinds of cameras. We also have recipes for sprite animation, texture rendering, and graphical user interface development that will give you a powerful tool to work with 2D effects. After this we move onto the more juicy stuff with recipes covering 3D graphic rendering and collision detection, and major ways to improve your loading efficiency. You will also work with Xbox live so you can take your game global. Finally, no mobile game development book would be complete without a look at performance optimization to make your games run faster. Windows Phone 7 XNA Cookbook will equip you with the firepower to rock the game world.
Table of Contents (17 chapters)
Windows Phone 7 XNA Cookbook
Credits
About the Author
About the Reviewers
www.PacktPub.com
Preface

Calculating the normal vectors from a model vertex


In mathematics, normal is the vector perpendicular to a plane or a surface. In computer graphics, normal is often used to calculate the lighting, angle of tilting, and collision detection. In this recipe, you will learn how to calculate the normal from vertices.

Getting ready

The 3D model mesh is made up of triangles and every triangle in a plane has a normal vector and is stored in the vertex. (You can find out more information about normal vectors in any computer graphic or linear algebra books.) Some typical and realistic lighting techniques will use the average normal vector of a vertex shared by several triangles. To calculate the normal of a triangle is not hard. Suppose the triangle has three points: A, B, and C. Choose point A as the root, Vector AB equals B - A; Vector AC equals C - A, and normal Vector N is the cross product of the two vectors AB and AC. Our example will illustrate the actual working code.

How to do it...

The following...