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Code Conventions

The repo has no lint/format tooling by design — match the existing style by eye. This page is the by-eye reference. (The canonical agent-facing version lives in AGENTS.md.)

Language & idiom​

  • C++14, MSVC 11-era idiom dominates: ATL (CAppModule), WTL, HRESULT returns, PascalCase methods, Hungarian-ish members (m_ / g_ / s_ prefixes).
  • Do not modernize wholesale — the code deliberately reads like 2012.

Headers​

  • #pragma once everywhere; include guard additionally in common.h.
  • src/common.h is the de-facto precompiled set (Windows/COM/GDI+/DX/Media Foundation + C++ std).
  • src/MovieMakerCore/pch.h for the engine.

Namespaces & version macros​

  • WMMR for shared reconstruction utilities: WMMR::ComPtr (= CComPtr), WMMR::MovieMakerException, WMMR::CoInitializer, WMMR::GdiplusInit, WMMR::Succeeded/Failed.
  • Most module code uses the original ATL/global style (no namespace) — matching the binaries.
  • Version macros from src/common.h (WMMR_VERSION_*), never hardcoded.

CMake pattern (per module)​

src/WLXVideoTrim/CMakeLists.txt is the template:

project(<Name> LANGUAGES CXX)
add_library(${TARGET} SHARED <sources> <Name>.def)
set_target_properties(${TARGET} PROPERTIES
    OUTPUT_NAME "<Name>"          # no PREFIX/SUFFIX munging
    MSVC_RUNTIME_LIBRARY "MultiThreadedDLL")
target_include_directories(${TARGET} PRIVATE src src/WTL)
target_compile_definitions(...)
target_link_libraries(${TARGET} PRIVATE <explicit system libs>)

Exceptions: the launcher (src/MovieMaker) uses the static runtime and delay-loads MovieMakerCore.dll; helper object libs use $<TARGET_OBJECTS:...>.

Export surface rules​

  • Most modules export via a .def file (Name @ordinal); DmxBici / WLXPhotoBase / WLXPhotoSqm list C++ mangled names; UXCore uses __declspec(dllexport).
  • Every DLL must match the reference export names, ordinals, and decorations — export parity is mandatory. Run tools/diff_exports.py after touching exports.

Error handling​

  • HRESULT from every COM/factory/export surface; check with SUCCEEDED (WMMR::Succeeded/Failed for readability).
  • S_FALSE is intentional for true "no-op / already-correct" outcomes — do not change it arbitrarily.
  • Throw WMMR::MovieMakerException (carries its HRESULT) or ATLASSERT for programmer errors; Base::Throw/ThrowLastError in WLXPhotoBase land.
  • Module-specific HRESULT spaces exist (e.g. WLXVideoTrim's FACILITY_WLXVIDEOTRIM / AVS_E_* codes) — match them.
  • Respect the HMREngine macro-redefinition zone.
  • Never swallow the VEH pattern or the delay-load survival logic.

Comments​

Match the existing "recreation notes" style — reference the original binary where relevant (RTTI name, export ordinal, quirk number). No gratuitous comments.

Submodules & vendoring​

  • Submodule output is never vendored into the parent; submodule changes are committed in the submodule, plus a gitlink bump here.
  • src/WTL/ is vendored third-party — keep pristine.
  • System libs only — no third-party runtime dependencies.