b3dGetParent

Returns entity's parent handle (0 if no parent). Takes entity (child entity handle). Returns parent handle as Int (entity handle of parent, 0 if no parent or invalid entity). Validates entity exists and has parent (it->second.parent!=nullptr), returns parent->handle (parent entity's handle), returns 0 if entity doesn't exist or has no parent. Query function for hierarchy relationships.

This function queries parent relationship. Return values: returns parent entity handle (integer, same handle type used in other entity functions), returns 0 if entity has no parent (root-level entity, never parented or detached via b3dSetParent(child, 0)), returns 0 if entity handle invalid (entity doesn't exist in g_entities map). Parent pointer: internally entities store parent as pointer (entity.parent = Entity3D*), function returns parent->handle (parent entity's handle integer), 0 represents nullptr/no parent (sentinel value). Use cases: (1) Hierarchy traversal (walk up parent chain to root), (2) Validation (check if entity parented before operations), (3) Debugging (inspect scene graph structure), (4) Save/load systems (serialize hierarchy relationships), (5) Unparenting (if b3dGetParent(entity)!=0, has parent). Common pattern: parent = b3dGetParent(child), while parent != 0: parent = b3dGetParent(parent) to traverse to root, or if b3dGetParent(entity) == 0: entity is root-level. Typical usage: check parent before hierarchy operations, traverse hierarchy for scene graph visualization, verify parenting after b3dSetParent calls. Root entities: entities created without parents (b3dLoadMesh, b3dCreatePivot, etc.) have parent=nullptr, b3dGetParent returns 0 for root entities. Detached entities: entities detached via b3dSetParent(entity, 0) become root entities (parent=nullptr), subsequent b3dGetParent returns 0. Hierarchy depth: repeatedly call b3dGetParent to find hierarchy depth: depth=0, p=entity, while b3dGetParent(p)!=0: depth++, p=b3dGetParent(p). Performance: O(1) lookup (hash map find, pointer dereference, handle return), fast query. Validation: returns 0 for invalid handles (no error message), safe to call on any integer (won't crash on invalid handles). Related: b3dSetParent establishes parent-child relationships, UpdateEntityWorldMatrix uses parent chain for matrix calculation, entity hierarchy system for grouped transforms.