Unit Testing and Texture Builder

5 minute read

I'm going to put in extra effort to try and write at least one dev journal entry every week. It should help keep me motivated, which has been a little difficult these days. I usually get home from work and shut my brain off so I can unwind before the next work day.

But I digress. This week's entry will give a quick update on what I've done recently: unit testing and my use of the Builder pattern .

So one of the biggest things I've done since my last update is add a bunch of unit tests for my code, and a couple of performance tests. I made use of the wonderful GoogleMock  library to get me there. I'm not following a pure test-driven development workflow, but I do try my best to add in tests whenever I can. The only thing I'm missing right now, which I may add in the near future, are tests to verify correctness in rendering. If it does happen, I'll compare rendered images against golden images. Rendering images for testing means using a headless/software renderer, which will likely be Mesa  if they ever fix this  issue. I haven't come across any other decent open-source software renderer for OpenGL (perhaps a side project?). In the meantime, I have empty implementations of any OpenGL functions I'm using and link those in for unit tests.

One other significant thing I done was refactor my texture code. I was kind of lazy initially and duplicated a fair amount of code for different types of textures: 2D texture arrays, regular 2D textures, and rectangular textures. My refactoring unified all of these into a single texture class that is constructed from a builder instance. Creating a texture looks something like this now:

1TextureBuilder builder(GL_TEXTURE_2D_ARRAY);
2builder.mipmap()
3       .allocate(128, 128, 3)
4       .fromImage("textures/foo1.png")
5       .fromImage("textures/foo2.png")
6       .fromImage("textures/foo3.png");
7return std::make_shared<Texture>(builder);