Tag: Programming

Turns out the German physics educational journal Physik in unserer Zeit (Physics in our time) published a thorough review of one of my Android apps, the Particle Physics Simulator back in January 2014. One of the authors of the article, Jan-Philipp Burde, contacted me a while back to let me know that he was preparing the article and to ask some information on how the code works, which I gladly provided. Then, he kindly contacted me again when the article was published in the January 2014 issue of the journal.

For what I could understand with my still basic German, the article talks about how the app can aid in the teaching of gas dynamics, providing some hints on the configuration set-up (no gravity, elastic collisions, etc.) in order to simulate a gas. For example, it teaches how to illustrate the concept of Brownian motion, removing the gravity and creating several small-sized particles along with one or two big-sized particles.

A couple of posts ago I mentioned I would write a few lines about my experience with the migration of my RTS engine from Slick to Libgdx and that’s what I’ll do in this post. I’ll be talking very lightly on some issues such as the code structure, the rendering process, the camera, etc. If you need a starting tutorial please refer to the official documentation, this is not what you are looking for. I’m just trying to give my impressions in the migration process I had to undertake. But first I want to back up a little and give a quick overview of both libraries.

As you may have noted, I updated the look and feel of the website to a more sober, greenish and polished design. The moon in the header has been replaced by a jumping monkey, which is always likeable. Regarding performance, this new site has less and smaller CSS files and less images and therefore it loads faster. Additionally, it uses HTML5, which is good. I also took the opportunity to update to the latest version of drupal and make use of the newer ZEN base theme.

Today I want to introduce a very different piece of software I have been putting together lately. It is a RTS (real time strategy) engine. I started playing with the idea as a time killer some years ago, kicking off the development with a fast version of the A* pathfinding algorithm backed not by a grid (as usual) but by a quadtree. Quadtrees make pathfinding super-fast because of their hierarchical division of space and their adaptive partition sizes. Even though I used visibility graphs to store the navigable nodes from one given point, quadtrees are also fast for checking the properties/elements of a position’s surroundings, for child nodes are always spatially contained in parent nodes.

The new version 3.6 of the Particle Physics Simulator is now out with customizable star sprites and fading tails. The new tail graphics have an impact on performance with older devices (just like mine), but should be handled with minor fps drops by newer processors. However, if you encounter problems you can disable tails or set them to “short length” in the preferences screen.

I just published the latest version (3.5) of the Particle Physics Simulator, with a fancy new feature that allows for different-sized particles to be shot into the simulation. You’ll notice a frame with a size-changing particle when you hold your touch down for a shoot. The size of that particle at the moment you take the shot is the size of the particle being created. Easy, ain’t it?