Systems programmer. C and C++ for a living and for fun.
Into OS internals, embedded Linux, real-time rendering, game engines, and profiling.
Outside code: biking/bikepacking.
| Contribution | What I did | How it works |
|---|---|---|
| Intel® Cryptography Primitives #95 | Fixed a redundant pointer assignment in the SHA hashUpdate path |
In a multithreaded environment, writing a shared pointer twice forces other cores to invalidate their caches for that address. The redundant write caused extra cache-line bouncing; removing it gives ~10% less CPU time and ~50% fewer instructions in multithreaded hashing workloads. 21 files changed. |
| FTXUI #938 | Added SliderWithCallback component to FTXUI, merged by maintainer |
Extends Slider with a std::function callback that fires on every value change, so actions can run without polling. 4 files, 90 additions. |
| PagedOut! #6 | Published a technical article | Gynvael Coldwind's free-form hacker/systems-programming zine. |
| Project | What it does |
|---|---|
terminal_animation  |
Converts video, GIFs, and images into colored ASCII art in the terminal at the source frame rate. A decoder thread pulls frames via OpenCV/FFMPEG and converts pixels to RGB-escaped characters; a separate render thread drives the FTXUI TUI. Threads synchronized with mutexes and std::atomic shared state. 27 Google Test unit tests. C++20. |
| vlkn | Vulkan 3D renderer and game engine in C++20. 13+ abstractions over the Vulkan API: physical/logical device, swap chain with auto-resize, multi-pass rendering (opaque geometry + point-light billboards + ImGui overlay), OBJ model loading with vertex deduplication, mipmapped textures with anisotropic filtering, up to 16 dynamic Blinn-Phong point lights, 6-DOF camera at 512 Hz, push constants, descriptor sets, fixed-timestep game loop. |
| gos | x86 OS from scratch. Stage 1 fits inside the 512-byte MBR and loads Stage 2 (a full C program) from disk via LBA-to-CHS conversion with retry logic. Stage 2 has a FAT12 driver (BPB parsing, FAT table traversal, root directory search, cluster-chain following) and loads the kernel. Custom printf, memcpy, memset, and string functions for 16-bit real mode. NASM + C (Watcom compiler). |
| pixelpin + app | Wearable ESP32 e-paper badge. The Flutter app converts an image to RGB565 and streams it over BLE using a custom binary protocol with text-based command framing and raw data streaming. ESP32 firmware accumulates chunks through a state machine into two 1-bit framebuffers, runs Floyd-Steinberg dithering to map each pixel to black, white, or red, then refreshes the 2.9-inch tri-color e-paper display. Enters deep sleep after 5 minutes. C++ + Flutter. |
| espcon | Embedded game console engine on an ESP32-S3. Software 3D rasterizer (no GPU) loads OBJ meshes from on-chip LittleFS, runs model-view-projection, painter's-algorithm depth sorting, dot-product directional lighting, and pushes RGB565 frames to a TFT display over SPI at ~80 MHz. FreeRTOS for task management; GPIO buttons and ADC joystick with deadzone filtering. |
| vectng | 2D game engine built from scratch around an Entity-Component-System (ECS) architecture. Components include TransformComponent, SpriteComponent, Animation, ColliderComponent, GravityComponent (with sweep AABB collision: resolves X and Y axes independently), KeyboardController, ScrollComponent, and TileComponent. 55 unit tests. SDL2 + SDL_image. |
| physics_automata | Interactive falling-sand physics simulation using cellular automata. Each cell carries a feature bitfield (Fluid / Solid / Gas / Moveable / Immovable). Every frame, movable solids fall straight down or diagonally with shuffled direction order; movable gases disperse downward in randomized directions. Mouse drawing with adjustable brush radius. Rendered via raylib OpenGL render texture updated each frame. |