Rules

Every source file belongs to exactly one layer. These rules are enforced by include-path structure — violations are caught in code review.

Rule 1 — Public headers are self-contained

Every file in include/mop/ must compile with only C standard library headers and other include/mop/ headers. No file in include/mop/ may include anything from src/.

Rule 2 — No backend headers in public API

The tokens GL, Vk, EGL, CGL, vulkan, or opengl must never appear in include/mop/.

Rule 3 — Viewport core uses RHI, never backend

Files in src/viewport/ may include src/rhi/rhi.h. They must never include files from src/backend/.

Rule 4 — Backends are isolated

A backend in src/backend/opengl/ must never include files from src/backend/vulkan/ or src/backend/cpu/. Backends share the RHI contract — nothing else.

Rule 5 — Math is a leaf

src/math/math.c depends only on include/mop/types.h and <math.h>.

Verification

# No backend headers in public API
grep -r "opengl\|vulkan\|GL/\|Vk" include/mop/

# No backend includes in viewport core
grep -r "backend/" src/viewport/

# No cross-backend includes
grep -r "opengl" src/backend/vulkan/
grep -r "vulkan" src/backend/opengl/

All commands must produce no output.

Directory → Layer Mapping