Tutorials/Tips

Qt + Box2D is easy!

Qt SoftwareBox2D is an Open Source rigid body 2D physics engine for C++. It’s currently (2.0.1) released under the MIT license, which is quite permissive. Box2D is used by, among other things, Gluon (http://gluon.tuxfamily.org/), which is a game library from KDE in-the-making.

Integrating Box2D into your Qt application is quite easy, and this blog shows you how to get started. First of all:

  • Step 1: Download Box2D from Google Code: http://code.google.com/p/box2d/
  • Step 2: Build it (I had to insert a few #include <cstring> to get it to build)
  • Step 3: Build and try the test bed application: Box2D/Examples/TestBed/
  • Step 4: Read the manual: http://www.box2d.org/manual.html
  • Step 5: Continue reading this blog to hook up the two frameworks…


The library doesn’t seem to install, so I just compiled it in-source and used it directly.

What I found during my approx 2 hour study today was that Box2D manages a world with bodies, similar to how QGraphicsScene manages items. In short, you create a world object and populate it with elements. Some bodies are static, like the ground, and some dynamic, like a bouncing ball. You can define joints, masses, friction, and other parameters, define a gravity vector, and then start simulating. Box2D doesn’t require a graphics system – any scene graph with elements that you can move and rotate should do fine. Graphics View works quite well. I’ve based this code on the provided “Hello World” example that comes with Box2D.

The world object defines the bounds of the coordinate system and the gravity vector. It feels very similar to QGraphicsScene. The bounds are, according to the docs, not enforced, but I got many run-time aborts when items are outside these bounds so you better make the world large enough to cover all your items. Continue reading

Related Posts

Dual-boot Ubuntu 14.10 and Window 8 on a Toshiba Satellite C55-A The Toshiba Satellite C55-A is a Toshiba laptop with Intel Core i3 processor inside, a 750 GB hard disk drive (HDD) and Windows 8 factory installed. T...
How to enable auto-login and create a guest user account on Fedora 14 Fedora is one of very few distributions that does not have the auto-login feature in its graphical user management tool. Auto-login allows the system ...
Sabayon 5.3 installation guide One of the best features introduced in Sabayon 5.3, the latest upgrade to the Gentoo-based, multi-purpose Linux distribution is the installer. The old...
The best tool for Fantasy Football analytics: Excel or R? In the early days, I used Excel for basic stuff, but I've been playing with R for some fun and funky data crunching. It's a nice tool to know how to u...
Configure LVM in Mandriva Linux Free 2009 Mandriva Free is one of the editions of desktop Linux distros published by Mandriva, the French Linux solutions provider. The others being Mandriva ...
How to install Cinnamon 1.3.1 in Ubuntu 11.10 Cinnamon 1.3.1 is the latest version of Cinnamon, a new desktop environment forked from GNOME 3 by the developers of Linux Mint. Given the need for a ...

We Recommend These Vendors and Free Offers

Launch an SSD VPS in Europe, USA, Asia & Australia on Vultr's KVM-based Cloud platform starting at $5:00/month (15 GB SSD, 768 MB of RAM).

Deploy an SSD Cloud server in 55 seconds on DigitalOcean. Built for developers and starting at $5:00/month (20 GB SSD, 512 MB of RAM).

Want to become an expert ethical hacker and penetration tester? Request your free video training course of Online Penetration Testing and Ethical Hacking

Whether you're new to Linux or are a Linux guru, you can learn a lot more about the Linux kernel by requesting your free ebook of Linux Kernel In A Nutshell.


2 Comments

  1. this is so LOL. Delete or redo right please

  2. Pingback: Links 27/2/2010: Kolivas’ New Patches, Predictions for Sub-notebooks with ARM | Boycott Novell

Leave a Comment

Your email address will not be published. Required fields are marked *

*