Show HN: A PSX/DOS style 3D game written in Rust with a custom software renderer

41 points by mvx64 6 hours ago

So, after years of abandoning Rust after the hello world stage, I finally decided to do something substantial. It started with simple line rendering, but I liked how it was progressing so I figured I could make a reasonably complete PSX style renderer and a game with it.

My only dependency is SDL2; I treat it as my "platform", so it handles windowing, input and audio. This means my Cargo.toml is as simple as:

[dependencies.sdl2] version = "0.35" default-features = false features = ["mixer"]

this pulls around 6-7 other dependencies.

I am doing actual true color 3D rendering (with Z buffer, transforming, lighting and rasterizing each triangle and so on, no special techniques or raycasting), the framebuffer is 320x180 (widescreen 320x240). SDL handles the hardware-accelerated final scaling to the display resolution (if available, for example in VMs it's sometimes not so it's pure software). I do my own physics, quaternion/matrix/vector math, TGA and OBJ loading.

Performance: I have not spent a lot of time on this really, but I am kind of satisfied: FPS ranges from [200-500] on a 2011 i5 Thinkpad to [70-80] on a 2005 Pentium laptop (this could barely run rustc...I had to jump through some hoops to make it work on 32 bit Linux), to [40-50] on a RaspberryPi 3B+. I don't have more modern hardware to test.

All of this is single threaded, no SIMD, no inline asm. Also, implementing interlaced rendering provided a +50% perf boost (and a nice effect).

The Pentium laptop has an ATI (yes) chip which is, maybe not surprisingly, supported perfectly by SDL.

Regarding Rust: I've barely touched the language. I am using it more as a "C with vec!s, borrow checker, pattern matching, error propagation, and traits". I love the syntax of the subset that I use; it's crystal clear, readable, ergonomic. Things like matches/ifs returning values are extremely useful for concise and productive code. However, pro/idiomatic code that I see around, looks unreadable to me. I've written all of the code from scratch on my own terms, so this was not a problem, but still... In any case, the ecosystem and tooling are amazing. All in all, an amazing development experience. I am a bit afraid to switch back to C++ for my next project.

Also, rustup/cargo made things a walk in the park while creating a deployment script that automates the whole process: after a commit, it scans source files for used assets and packages only those, copies dependencies (DLLs for Win), sets up build dependencies depending on the target, builds all 3 targets (Win10_64, Linux32, Linux64), bundles everything into separate zips and uploads them to my local server. I am doing this from a 64bit Lubuntu 18.04 virtual machine.

You can try the game and read all info about it on the linked itch.io page: https://totenarctanz.itch.io/a-scavenging-trip

All assets (audio/images/fonts) where also made by me for this project (you could guess from the low quality).

Development tools: Geany (on Linux), notepad++ (on Windows), both vanilla with no plugins, Blender, Gimp, REAPER.