A Flash Developer Resource Site














Internet Commerce

Partners & Affiliates














Developer Channel

internet.com


Featured Flash FLA
Gallery Downloads 11249 Flash Movies | 9 New Flash Movies Added
What's New | Top 100

Featured FLA

» Author: kyo
» Title: building estructure
» Description: explosion of building estructure made by swift3D
» More by kyo


Random FLAs | Add Flash Movie
Featured Flash Site
Gallery Downloads 6393 Flash Sites | 0 New Flash Links
What's New | Top 100 Flash Site

Featured Site

» Posted in the Flash Kit Links section
» Title: Webdancer's Web Site
» Comments: Webdancer's, an artistic adventure in 3d graphicsbr>


Random Links | Add your own Flash Related Links
Flash Tutorials 1197 Tutorials 7 New Tutorials Added!
What's New | Top100

» Let Photos Show Your Happy Family this Christmas and Upload YouTube
» PowerPoint show to DVD slide show--- PPS to DVD
» How to burn FLV to DVD for Mac
» How to Create Christmas Flash Greeting Ecard with photos and music
» Getting Started In Flash
» How to convert FLV video to MP3 audio for Mac OS
» Join flv videos together with just a few clicks
» How to convert flv file to avi for mac os x
» How to Create Christmas Flash Greeting eCard without programming skills
» Unknown Tag: Title10
Random Tutorial | Add Site

bbm.netBBM.net is designed to save you time and deliver the highest quality royalty-free music for your multimedia projects. Features include: over 450 Music Loop Packages from some of the best composers in the business, our music search engine to speed your selection process, alternate music versions & bonus sounds to use for rollovers or transitions, free technical support and free consulting.

Click here for details »

Senior Web Designer
Aquent
US-GA-Atlanta

Justtechjobs.com Post A Job | Post A Resume


Tutorials Home What's New Top Rated Submit myTutes Random!

Search Tutorials


Tutorials Tutorials » Games

Categories Building Games in Flash 5 - Part 3 - Enemies and collisions
Author: David Doull | Website: http://www.artifactinteractive.com.au |

 
Page 6
«prev 1 2 3 4 5 6 7 8 9 10 11 12 13 next»

Step 3: Collision detection

We now have one key thing to do to turn this into a game. We need to add in collision detection.

We want to detect when a laser hits an enemy spaceship and consequently make the spaceship explode and disappear. Similarly we want to detect when an enemy spaceship collides with the players spaceship, at which point the game will end.

So how do we detect collisions in flash?

The spaceship, enemies and lasers are all movieclips. So we need a simple way to detect collisions between movieclips.

The answer is hitTest. Flash 5 introduced a method called hitTest which allows us to detect collisions between two movie clips and its really easy to use.

If you have two movieclips with instance names movie1 and movie2 then the code to detect a collision would be movie1.hitTest(movie2).

A few words about hitTest

There are actually two different ways you can use hitTest.

Usage 1: You can use it to detect the collision (or overlap) between two movie clips using the syntax: movie1.hitTest(movie2) This will be true if the bounding boxes of the two movieclips are overlapping.

So what's a bounding box? Think of it as an invisible rectangle drawn around the edge of a movie clip. If you click on a movie clip in flash you will see the bounding box highlighted (see right). hitTest detects when the bounding boxes of two movie clips overlap, not when the graphics overlap.

The image to the left shows the bounding boxes for the spaceship and the enemy. The two bounding boxes are overlapping so if we used hitTest to check for a collision it would be true even though the actual graphics don't overlap.

This isn't really a problem because the spaceship graphics mostly fill the bounding box and because the game moves so fast that players are unlikely to notice this lack of precision.

Usage 2: You can use it to detect a collision between a movie clip and a point. The syntax is movie1.hitTest(x, y, shapeFlag) where x and y are the co-ordinates of the point and shapeFlag is either true or false depending of whether you want to detect a collision between the movie clips graphic (true) or the movie clips bounding box (false). This usage of hitTest can give you a more precise collision detection but its not used much in games because we generally want to detect the collision between two movie clips not a point and a movie clip.

«prev 1 2 3 4 5 6 7 8 9 10 11 12 13 next»

» Level Intermediate

Added: : 2001-05-04
Rating: 8.87 Votes: 506
Hits: 6970
» Author
No details available.
» Download
Download the files used in this tutorial.
Download (416 kb)
Get conversion and unzipping tools for PC and Mac here!

» Forums
More help? Search our boards for quick answers!

Please rate this tutorial, 10 is the top rating, you can also click the comments link to read/write a review.
10 9 8 7 6 5 4 3 2 1
Read or Post Comments
 
   
 

internet.comearthweb.comDevx.commediabistro.comGraphics.com

Search:

Jupitermedia Corporation has two divisions: Jupiterimages and JupiterOnlineMedia

Jupitermedia Corporate Info

Legal Notices, Licensing, Reprints, Permissions, Privacy Policy.
Advertise | Newsletters | Tech Jobs | Shopping | E-mail Offers

Whitepapers and eBooks

Intel Whitepaper: Comparing Two- and Four-Socket Platforms for Server Virtualization
IBM Solutions Brief: Go Green With IBM System xTM And Intel
HP eBook: Simplifying SQL Server Management
IBM Contest: Are You the Next Superstar? Join the "Search for the XML Superstar" Contest to Find Out
Microsoft PDF: Top 10 Reasons to Move to Server Virtualization with Hyper-V
Microsoft PDF: Six Reasons Why Microsoft's Hyper-V Will Overtake Vmware
Microsoft Step-by-Step Guide: Hyper-V and Failover Clustering
Intel PDF: Quad-Core Impacts More Than the Data Center
Intel PDF: Virtualization Delivers Data Center Efficiency
Go Parallel Article: PDC 2008 in Review
Microsoft PDF: Top 11 Reasons to Upgrade to Windows Server 2008
Avaya Article: Communication-Enabled Mashups: Empowering Both Business Owners and IT
Intel Whitepaper: Building a Real-World Model to Assess Virtualization Platforms
  PDF: Intel Centrino Duo Processor Technology with Intel Core2 Duo Processor
Microsoft Article: Build and Run Virtual Machines with Hyper-V Server 2008
Go Parallel Article: Q&A with a TBB Junkie
IBM Whitepaper: Innovative Collaboration to Advance Your Business
Internet.com eBook: Real Life Rails
IBM eBook: The Pros and Cons of Outsourcing
Internet.com eBook: Best Practices for Developing a Web Site
IBM CXO Whitepaper: The 2008 Global CEO Study "The Enterprise of the Future"
Avaya Article: Call Control XML in Action - A CCXML Auto Attendant
IBM CXO Whitepaper: Unlocking the DNA of the Adaptable Workforce--The Global Human Capital Study 2008
Adobe Acrobat Connect Pro: Web Conferencing and eLearning Whitepapers
HP eBook: Guide to Storage Networking
MORE WHITEPAPERS, EBOOKS, AND ARTICLES