Faset_Engine/docs/IMPLEMENTATION.md

Implementation checkpoints

This log records working implementation and observed validation. It does not replace the acceptance criteria in PLAN.md. Incomplete platform or workflow checks remain open.

Checkpoint 1 — native foundation and independent subsystems

Implemented:

• C++20 CMake presets, pinned dependency archives with SHA-256 verification, and separate targets.
• Core persistent IDs, SHA-256, atomic file replacement, JSON IO, and project path boundaries.
• Explicit schema registration, document transactions, revisions, retry keys, Undo/Redo, recovery records, unknown extension preservation, migrations, and nested template resolution.
• EnTT runtime with real Box2D/Box3D, fixed ticks, deferred changes, checked handles, interpolation, and statically linked example behaviors.
• GLB/glTF asset import, cooked mesh data, stable source identity, cache generations, reimport conflicts, cancellation, and the optional Blender export add-on.
• Direct Vulkan renderer, Slang shaders, sprites/meshes, basic PBR and directional shadows, texture upload, resize, capture, and SDL input.
• English MkDocs/Material manual and an image prototype for the future retained editor UI.

Observed validation on Linux:

• Integrated headless CTest: authoring, runtime, asset pipeline, Blender bundle, core — 5/5 passed.
• Integrated Clang 21.1.8/Ninja build with Vulkan: 7/7 tests passed, including offscreen GPU rendering.
• Independent runtime and asset AddressSanitizer/UndefinedBehaviorSanitizer checks passed.
• Renderer offscreen/visible tests exercised NVIDIA RTX 2080 Ti with Vulkan validation.
• MkDocs strict build passed with MkDocs 1.6.1 and Material 9.7.7.

The full editor, user-project build pipeline, MCP integration, standalone exports, and Windows acceptance are still being implemented. This checkpoint is not the MVP release.

Known intermediate constraints include box-only physics colliders, root-level physics objects, static glTF triangles/UV0, a conservative serial renderer, and unfinished world-preserving authoring reparent operations. These remain implementation work or explicit profile limits to review during final acceptance.