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…
Related Post:  How to install Ansible on your favorite Linux distribution


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.

Related Post:  Why you should disable autofill on your browsers

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

Subscribe to LinuxBSDos.com

Subscribe to receive the latest articles in your Inbox

Trust me, you'll not be spammed...

Please share:

We Recommend These Vendors and Free Offers

Google has got competition, because Presearch is building a blockchain-based search engine controlled by the community. At $0.15 a token, you can participation in Lot 3 of the token sale by clicking here

Open Money is building a solution that will run mainstream software on blockchain tech. Click here to get free tokens that will be the digital currency of the platform

COMSA allows centralized businesses to adopt blockchain technology. The token sale starts soon! Sign up for free by clicking here

Register now for Blockchain & Cryptocurrency Con 2018, international conference on blockchain technnology in Dallas, TX (USA), Feb. 23-24, 2018. Students can register at a 50% discount.

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).


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 *

*