A Static Code Analysis in C++ for Bullet Physics


Hello folks! I’m here again this time to talk about static analysis. If you are a developer with little to no knowledge on the subject this is the right article for you. Static analysis is the process of analyzing the code of a program without actually running it as opposed to dynamic analysis where code is analysed at run time. This process helps developers to identify potential design issues, bugs, to improve performances and to ensure conformance to coding guidelines.Running static analysis regularly is a good practice and if it’s done regularly it helps identifying issues at an early phase of the software development life cycle. It is mainly used on strongly-typed, static languages like C/C++, C# or Java and there are plenty of products out there, either free and commercial. Have a look at this wikipedia article.

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Unity and Reflection – Optimising Memory using Caching on iOS


I really love reflection. Reflection is a technique used for obtaining type information at run-time. It’s not only that, with reflection is possible to examine and change information of objects, to generate (technically to emit IL) new classes, methods and so on still at runtime. It’s a powerful technique but it is known, under certain circumstances, for being slow. If you are a game developer and you are targeting mobile devices (iOS or Android for instance) using Unity, you definitely want to preserve your memory and save precious clock cycles. Moreover, with AOT (Ahead of Time compilation)  IL cannot be emitted at run-time as it is pre-generated at compile time. Therefore a large part of reflection, e.g. expression trees, anonymous types etc., is just not available.

The Problem

Recently I have worked on a dynamic prefab serializer and I needed to use reflection to retrieve types from their string representations. In general to retrieve a type in C# you have three options:

  • typeof(MyClass), which is an operator to obtain a type known at compile-time.
  • GetType() is a method you call on individual objects, to get the execution-time type of the object.
  • Type.GetType(“Namespace.MyClass, MyAssembly”) gives you a type from its string representation at runtime.

typeof is converted into a constant at compile time and GetType  returns a reference to the run-time type of your object. But what about Type.GetType(string)???

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Deploying Assimp Using Visual Studio and Android NDK for Tegra Devices

Hello folks, welcome back to my blog, hope you are ready for a new adventure. This time I promise it is going to be an adventure with the capital A. I’ve been working on a finite element method algorithm using C++ (and later CUDA) to prove that the latest generation of mobile devices (more specifically the Kepler architecture in the Shield Tablet) is capable of running such complex algorithms.

The Shield is shipped with Android Kit-Kat 4.4 thus using C++ or Java and OpenGL ES 2.0 is not a problem…well not just yet 😀

Setting up the environment is not too difficult too. I used the Tegra Android Development Pack, that installs, all the tools you need to start developing on Android (including extensions for Visual Studio and the whole Eclipse IDE). After a few clicks you have everything up and running.

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C++ Tail Recursion Using 64-bit variables – Part 2

In my previous post I talked about recursion problems in a Fibonacci function using 64-bit variables as function parameters, compiled using the Microsoft Visual C++ compiler. It turned out that while tail recursion was enabled by the compiler using 32-bit types it didn’t really when switching to 64-bit ones. Just as a reminder, Tail Recursion is an optimization performed by the compiler. It is the process of transforming certain types of tail calls into jumps instead of function calls. More about tail recursion here.

My conclusion was that tail recursion is not handled properly by the Visual C++ compiler and a possible explanation could be the presence of a bug.

The calculation of Fibonacci sequences of big integers is not an everyday task but it can still be a reliable example to show how tail calls are implemented.

Not happy with my conclusions and following several suggestions of users’ comments (here on the blog, on Reddit and on StackOverflow) I wanted to understand more about this issue and to explore other solutions using different compilers.

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