Game engine

Previously I found a game engine LOVE (Lua language). Then I planned to learn about it. But then I read about Godot, which uses GDScript with similar syntax like Python. So, I choose Godot over LOVE because I have better experience in Python.

I planned to work on edutainment project since long time ago. Since I have extra time recently, so I invested little time on my hobby project. Using Godot, I revived my old project.

Previously, I tried to use zsh when I am working, so that my default bash history will not be filled with project related commands, especially git commands. Because some of my bash history are useful like ffmpeg related commands. So, I tried to distinct project work and non-project work with zsh and bash, so that they have different shell histories.

However, there are two problems when I use zsh,

1. All my projects use the same zsh history. The old history may be lost if I have too many commands (depends on HISTSIZE variable).
2. zsh is slow with git auto-completion.

However, zsh has one thing better than bash, that is, auto-completion navigation. Let’s say your directory has various sub-directories, double tab will bring to directory navigation that can be controlled with arrow keys. This is useful for me to navigate to non-alphabetic directories, like the directory with CJK characters.

In my previous post, I mentioned about DownThemAll on Firefox 56. Now the latest release of Firefox is version 61, but there is no update of DownThemAll for Firefox Quantum support. Using older unsupported version like Firefox 56 is not a good idea, because there will have no security update. Firefox ESR 52 is slower than Firefox 56 as I have mentioned.

Since I have spare time recently, I spent some days to write a Firefox extension, DownloadSelected, to solve my problem.

TDD (test driven development) is widely adopted in modern development such as web development. Because it allows the developers to test the solution robustly in order to produce a more stable product.

Higher level programming languages like JavaScript and Ruby allows the developers to easily mock the functions and data to test the target specification. However, programming language like C++ is not designed for TDD. It will be more complex if you want to mock functions.

My hobby project Med is written in C++. A lot of implementations need to use dynamic memory allocation and instantiation. Because complex data is impractical to be passed by value, like the case of JavaScript object and array. Since C++ doesn’t have garbage collection, it is possible that the developer doesn’t free/delete the dynamically created memory properly.

As in my project Med, the program will retrieve the memory from other process. That means, it needs to make a copy of the scanned memory. And this will involve creating dynamic memory (using new operator). When using the program to filter the memory to get the target result, it needs to get a new copy of memory with the updated values, then compare with the previous copy. The unmatched will need to be discarded (free/delete); the matched will need to replace the old one (also free/delete the old one, because the new one is dynamically allocated).

When we are developing a solution or a system, we are prone to choose a simple solution. Because simple solution is just better than complex solution. However, most of the time, we choose a simple solution inappropriately, and this causes more troubles gradually when the system is growing.

The complexity of a solution, should depend on the complexity of the problem itself, not the other way round. For example, we cannot create an operating system with a single line of programming statement. We also cannot create an operating system with just a single source file. Because an operating system is very complex (managing devices, memory, process, etc), no simple solution can fulfil the requirements.