# SimVulcan

A minimal Vulkan 1.3 / C++20 **3D model editor**: an orbit camera over three
reference grid planes through the origin, with `.obj` model loading and display.

## Features

* Orbit camera — drag to rotate around the centre, wheel to zoom, and Front / Top
  / Side buttons to align the view to the principal planes.
* A 3D editor space: three grid planes (XY, XZ, YZ) and coloured X/Y/Z axes meeting
  at the origin.
* `.obj` loading with three display modes — solid (flat-shaded), wireframe, and
  solid + wireframe overlay.
* ImGui interface — two windows, titled `Viewport` and `Mesh`.

All Vulkan code is isolated in `src/vk/`; the rest of the app is Vulkan-free.

## Targets

* Windows x64 (MSVC)
* Linux x64 (gcc / clang)
* macOS arm64 (Apple Silicon, via MoltenVK)

The presets do not pin a compiler — each inherits whatever the environment provides.

## Prerequisites

* Vulkan SDK 1.3.290+ (`https://vulkan.lunarg.com/`)
* CMake 3.26+
* Ninja
* C++20 compiler (MSVC 19.36+, gcc 11+, clang 14+)

Only CMake 3.26 and C++20 are enforced by the build. `find_package(Vulkan)` carries no
version argument, and the compiler minimums above are recommendations, not checks — the
de-facto SDK floor comes from the pinned volk and vk-bootstrap 1.3.295.

## Build

```sh
cmake --preset windows-msvc-release
cmake --build --preset windows-msvc-release
```

Run from the executable's own directory (`build/<preset>/src/app/`) so it finds
the `spirv/` and `assets/` trees copied next to it.

## Tests

```sh
cmake --build --preset windows-msvc-debug --target simv_tests
ctest --preset windows-msvc-debug
```

## Layout

```
src/
  core/    Logger, Window, App (orchestration, Vulkan-free)
  vk/      All Vulkan: Context, Swapchain, Shader, GpuMesh,
           Renderer (frame loop + depth + ImGui), MeshRenderer, GridRenderer
           (Buffer and Image are also built here but used by nobody — the
            renderers call VMA directly)
  mesh/    CPU mesh: tinyobjloader + welding (no Vulkan)
  editor/  Camera, mouse input, EditorUI + MeshLoadPanel (ImGui, no Vulkan)
  app/     main.cpp
shaders/
  editor/  mesh + grid vertex/fragment shaders (GLSL → SPIR-V at build time)
tests/     Catch2 unit tests (mesh math)
```