Book Image

XNA 4.0 Game Development by Example: Beginner's Guide

By : Kurt Jaegers
Book Image

XNA 4.0 Game Development by Example: Beginner's Guide

By: Kurt Jaegers

Overview of this book

XNA Game Studio enables hobbyists and independent game developers to easily create video games. It gives you the power to bring your creations to life on Windows, the Xbox 360, the Zune, and the Windows Phone platforms. But before you give life to your creativity with XNA, you need to gain a solid understanding of some game development concepts.This book covers both the concepts and the implementations necessary to get you started on bringing your own creations to life with XNA. It details the creation of four games, all in different styles, from start to finish using the Microsoft XNA Framework, including a puzzler, space shooter, multi-axis shoot-'em-up, and a jump-and-run platform game. Each game introduces new concepts and techniques to build a solid foundation for your own ideas and creativity. Beginning with the basics of drawing images to the screen, the book then incrementally introduces sprite animation, particles, sound effects, tile-based maps, and path finding. It then explores combining XNA with Windows Forms to build an interactive map editor, and builds a platform-style game using the editor-generated maps. Finally, the book covers the considerations necessary for deploying your games to the Xbox 360 platform.By the end of the book, you will have a solid foundation of game development concepts and techniques as well as working sample games to extend and innovate upon. You will have the knowledge necessary to create games that you can complete without an army of fellow game developers at your back.
Table of Contents (15 chapters)
XNA 4.0 Game Development by Example Beginner's Guide
Credits
About the Author
About the Reviewers
Preface
4
Asteroid Belt Assault – Lost in Space
Index

Time for action – waypoint management


  1. Add the AddWaypoint() method to the Enemy class:

    public void AddWaypoint(Vector2 waypoint)
    {
        waypoints.Enqueue(waypoint);
    }
  2. Add the WaypointReached() method to the Enemy class:

    public bool WaypointReached()
    {
        if (Vector2.Distance(EnemySprite.Location, currentWaypoint) < 
            (float)EnemySprite.Source.Width/2)
        {
            return true;
        }
        else
        {
            return false;
        }
    }
  3. Add the IsActive() method to the Enemy class:

    public bool IsActive()
    {
        if (Destroyed)
        {
            return false;
        }
    
        if (waypoints.Count > 0)
        {
            return true;
        }
    
        if (WaypointReached())
        {
            return false;
        }
    
        return true;
    }

What just happened?

When a new waypoint is added to the enemy's route, it is enqueued to the waypoints queue. When WaypointReached() is called, the function checks to see if the distance between the sprite's current location and the current waypoint is less than half of the sprite width. If...