Skip to main content

HMREngine

Location: src/MovieMakerCore/HMREngine/

HMREngine ("HMR" = the original's internal engine prefix) is the rendering core: a scene-graph engine over D3D11 + D2D + DirectWrite, with an X3D/VRML-inspired node system. The original was recovered from RTTI: X3DFieldNode base class, typed field system (SFBool, SFVec3f, MFNode, ...), and a family of grouping/appearance/geometry nodes.

Tree​

HMREngine/
  HMREngine.cpp/.h        # engine facade + (see note) SDK macro redefinition zone
  Engine.cpp/.h           # device/context ownership, frame orchestration
  RenderLoop.cpp/.h       # the render loop
  RenderingList.cpp/.h    # per-frame renderable collection
  ExecutionContext.cpp/.h # per-frame execution state
  DXResources/            # DX11 resource management (textures, buffers, RTVs)
  TextRender/             # DirectWrite text rendering pipeline
  PatternMesh/            # video transition geometry (see below)
  X3DReader / scene impls # X3DNodeImpls, IndexedFaceSet, Material, Texture nodes...
  X3DMath.h               # Vec2/3/4, Rotation4f, Matrix3f/4f, Rgb/Rgba, Frustum (on DirectXMath)
  Browser.cpp/.h          # scene browser/debug surface
  GridImpl, CoordinateImpl, LayerImpl, InterpolatorImpl, EventImpl,
  MetadataImpl, ErrHandler, AsyncWorker, ReloadImageWorker
  d3dx11compat.h/.cpp     # D3DX11 compatibility stub (SDK compatibility)

The X3D node system​

All nodes inherit CComObjectRootEx (COM reference counting) and derive from X3DFieldNode, which owns the typed field system. Node families include:

  • Grouping: Group, Transform, Switch, Billboard
  • Appearance: Material, ImageTexture, Appearance
  • Geometry: Shape, Box, Sphere, Cylinder, Cone, Plane, Mesh (IndexedFaceSet)
  • Sensors: TouchSensor, TimeSensor, ProximitySensor
  • Layers: Layer2D, Layer3D

X3DReader parses scene descriptions (JSON-object syntax) into the node graph — with hard caps: nesting depth 512, node count 100,000, and depth-guarded recursive parsing (hostile-input hardening; see Security).

Scene traversal​

Per frame, Engine → RenderLoop walks the scene graph building a RenderingList. Traversal (Scene::TraverseNode, X3DChildNodeImpl::Traverse, GroupNodeImpl::Traverse, SwitchNodeImpl::TraverseActive, EnumerateNodes::EnumerateRecursive) is depth-capped at 512 to prevent stack exhaustion on hostile graphs — a hardening pass, not original behavior, and one of the few deliberate divergences (documented in the module README).

PatternMesh and transitions​

PatternMesh/ generates the wipe/reveal geometry used by video transitions. Transition animations themselves live in WLXPipetran; HMREngine renders whatever mesh/texture state they produce.

D3DX11 compatibility zone​

The original linked the deprecated D3DX11 Effect Framework. d3dx11compat.h/.cpp re-implements the needed surface (ID3DX11Effect, ID3DX11EffectTechnique, ID3DX11EffectPass, ...) over raw D3D11, returning E_NOTIMPL for unused paths. See SDK Compatibility.

Macro redefinition zone

HMREngine.h (lines ~111–182) temporarily redefines Windows SDK error macros and restores them — matching the original binary's layout. Do not add #include directives inside that span; it breaks the restore logic (Quirk #5).

Error handling — preserved quirks​

  • HMREngine silently swallows non-fatal failures (log-and-continue) — original behavior, Quirk #21.
  • 118 dummy texture codec classes exist purely for RTTI parity (Quirk #13).
  • Local classes nested inside methods appear in RTTI (Quirk #14).