Vulkan Engine

A small Vulkan rendering engine written in Zig, built around a layered architecture (swapchain, renderer and pluggable render systems) that transparently handles window resizes and swapchain recreation.

The project ships two interchangeable application roots; src/main.zig picks which one to run at build time via the -Dapp= build option (see build.zig):

• CustomUiApp (current default) — a minimal app demonstrating a custom immediate-mode UI: a nested flex-style screen-space panel drawn by src/systems/UiRenderSystem.zig, plus the Dear ImGui debug overlay. No 3D scene, camera or lighting.
• TutorialApp — the full 3D scene: it renders GameObjects (two ceramic vases on a flat quad "floor", lit by six colored point lights spinning around the scene and rendered as camera-facing billboards), with the camera driven by a WASD + QE + arrow-key keyboard controller. Model assets are loaded from Wavefront .obj files embedded at build time from the models/ directory and parsed by the C++ tinyobjloader library through a small C-ABI shim under src/wrapper/tinyobj/ — see that directory's README.md for the C↔C++ boundary rationale.

To switch between them, pass the -Dapp= build option: -Dapp=custom (the default) runs CustomUiApp, -Dapp=tutorial runs TutorialApp — e.g. zig build run -Dapp=tutorial.

immediate-mode UI

src/systems/UiRenderSystem.zig is a small custom 2D overlay render system with an immediate-mode API: each frame the caller resets the queue with beginFrame(), pushes filled rectangles in pixel coordinates with rect(x, y, w, h, color) or builds a per-frame nested row/column flex tree with container calls and flexRect(...), then records the draws with render(commandBuffer, extent). No retained widget state is kept between frames. The pipeline binds no vertex buffers — the quad is generated procedurally in shaders/ui.vert from gl_VertexIndex, with the per-rect position/size/color delivered as push constants — and uses alpha blending with depth testing disabled so the UI always draws on top.

local development

Setup using nix

nix develop

Or even

nix develop --command zig build run

tests & spell checking

Run the test suite and the spell checker before pushing changes:

nix develop --command zig build test --summary all
nix develop --command codebook-lsp lint --unique -s .

The spell-check step uses codebook and respects the project dictionary in codebook.toml. CI runs both steps as part of the build test workflow.

tools

lines of code

nix develop --command cloc src shaders models docs

resources

• Vulkan Tutorial
• vulkan game engine tutorials by Brendan Galea with source code
• rift engine