Figure-ground /
active-passive
space.

FigureGroundRelation {
  regionId,
  contactObjectRefs[],
  contactLengthByObjectRef,

  uniqueObjectBoundaryLengthPx,
  domainBoundaryLengthPx,
  totalBoundaryLengthPx,

  objectBoundaryFraction,
  domainBoundaryFraction,
  contactObjectCount,

  enclosureClass,
  activePassiveClass,
  confidence,
  provenance
}

{
  "module": "Compo 5.03",
  "name": "figure_ground_and_active_passive_space_relations",
  "version": "1.1-corrective",
  "canonical_main_title": "Figure-ground / active-passive space relations",
  "scope": "BOUNDARY_ATTRIBUTED_FIGURE_GROUND_AND_ACTIVE_PASSIVE_SPACE_RELATIONS",
  "consumes": [
    "Compo5.01.SpaceMaskPairResult / canonical OccupiedMask / FreeMask",
    "Compo5.01.ObjectSupportSet + object-specific support attribution adapter",
    "Compo5.02.EmptyRegionSet / EmptyRegion[]",
    "CompositionSpaceDomain boundary"
  ],
  "provides": [
    "BoundaryAttributionAdapter contract",
    "RegionBoundaryContactDescriptor",
    "RegionObjectAdjacency[]",
    "FigureGroundRelation",
    "ActivePassiveSpaceRelation",
    "MetricResult[space.figureGround.objectBoundaryFraction]",
    "MetricResult[space.figureGround.domainBoundaryFraction]",
    "MetricResult[space.figureGround.contactObjectCount]",
    "MetricResult[space.relation.confidence]",
    "SpaceRelationCorrectionRequest[]"
  ],
  "owns_metrics": [
    "space.figureGround.objectBoundaryFraction",
    "space.figureGround.domainBoundaryFraction",
    "space.figureGround.contactObjectCount",
    "space.relation.confidence"
  ],
  "descriptors_only": [
    "space.figureGround.regionId",
    "space.figureGround.contactObjectRefs[]",
    "space.figureGround.contactLengthByObjectRef",
    "space.figureGround.uniqueObjectBoundaryLengthPx",
    "space.figureGround.domainBoundaryLengthPx",
    "space.figureGround.totalBoundaryLengthPx",
    "space.figureGround.enclosureClass",
    "space.figureGround.activePassiveClass",
    "space.figureGround.boundaryOwnerMultiplicityWarnings[]",
    "space.figureGround.status"
  ],
  "boundary_attribution_contract": {
    "purpose": "attribute free-region boundary to domain boundary or one/more object supports without rebuilding 5.01 union masks",
    "segment_record": {
      "segmentRef": "string",
      "kind": "OBJECT_CONTACT|DOMAIN_CONTACT",
      "lengthPx": "finite >=0",
      "ownerObjectRefs": "[] for domain; one or more refs for object contact",
      "confidence": "0..1",
      "provenance": "object"
    },
    "overlap_rule": "unique geometric boundary length counted once even if overlapping supports expose multiple owner refs",
    "per_object_lengths": "may overlap across owners and must not be summed to reconstruct unique object-boundary length"
  },
  "figure_ground_schema": {
    "regionId": "Compo5.02 EmptyRegion ref",
    "contactObjectRefs": "unique refs",
    "contactLengthByObjectRef": "owner-specific contact lengths; potentially non-additive",
    "uniqueObjectBoundaryLengthPx": "unique free/occupied interface",
    "domainBoundaryLengthPx": "free/domain-outside interface",
    "totalBoundaryLengthPx": "sum of unique object + domain boundary lengths",
    "objectBoundaryFraction": "uniqueObjectBoundaryLengthPx/totalBoundaryLengthPx",
    "domainBoundaryFraction": "domainBoundaryLengthPx/totalBoundaryLengthPx",
    "contactObjectCount": "unique owner refs count",
    "enclosureClass": "OBJECT_ENCLOSED_VOID|DOMAIN_OPEN_REGION|FULL_DOMAIN_FREE|N_A",
    "activePassiveClass": "NEGATIVE_FIGURE_CANDIDATE|BACKGROUND_FIELD_CANDIDATE|ACTIVE_PASSIVE_AMBIGUOUS|N_A",
    "confidence": "0..1",
    "provenance": "object"
  },
  "enclosure_semantics": {
    "OBJECT_ENCLOSED_VOID": "positive object-boundary contact and zero domain-boundary contact",
    "DOMAIN_OPEN_REGION": "positive domain-boundary contact and positive object-boundary contact",
    "FULL_DOMAIN_FREE": "region covers the whole supplied domain, object-boundary contact is zero, and no occupied support exists in that domain",
    "N_A": "missing/invalid attribution or degenerate boundary"
  },
  "active_passive_semantics": {
    "NEGATIVE_FIGURE_CANDIDATE": "OBJECT_ENCLOSED_VOID; bounded negative-space shape can act as a figure candidate",
    "BACKGROUND_FIELD_CANDIDATE": "FULL_DOMAIN_FREE; open field with no object boundary",
    "ACTIVE_PASSIVE_AMBIGUOUS": "DOMAIN_OPEN_REGION; the same free component participates as background field while being shaped by object boundaries",
    "N_A": "insufficient relation evidence",
    "candidate_wording": "classes are structural figure-ground cues, not a perceptual certainty or quality judgment",
    "no_thresholds": "no arbitrary objectBoundaryFraction threshold is used for the canonical class"
  },
  "metric_policy": {
    "objectBoundaryFraction": "relation descriptor only",
    "domainBoundaryFraction": "its algebraic complement on valid attributed boundary",
    "contactObjectCount": "adjacency descriptor only",
    "direct_scoring": "FORBIDDEN in 5.03",
    "independent_vote_warning": "object/domain boundary fractions are one evidence degree of freedom",
    "more_enclosed_is_better": "FORBIDDEN",
    "active_is_better": "FORBIDDEN",
    "target_interpretation": "deferred to 5.04"
  },
  "hard_constraints": [
    "one metric = one owner",
    "5.03 consumes canonical 5.01 masks and 5.02 regions; it must not rebuild either",
    "boundary attribution may inspect object-specific supports but cannot mutate/redefine the union mask",
    "unique object-boundary length is counted once under overlapping owners",
    "per-object contact lengths may overlap and are not additive evidence",
    "objectBoundaryFraction + domainBoundaryFraction = 1 on valid nondegenerate attributed boundary",
    "FULL_DOMAIN_FREE requires region coverage of the entire domain; objectBoundaryLength=0 alone is insufficient",
    "isInteriorPocket remains owned by 5.02 and is not re-published as a 5.03 metric",
    "activePassiveClass is a structural candidate class, not an aesthetic score or semantic importance label",
    "no threshold-based active/passive classification is canonicalized in 5.03",
    "channel/corridor routing is outside canonical Topic5 MAIN scope and remains deferred until explicitly allocated",
    "free-space relation must not become eye-flow",
    "5.04 owns explicit-target scoring",
    "visual mass remains Topic4",
    "canvas normalization/domain ownership remains external/future Topic6",
    "grid occupancy remains Topic8",
    "global balance/hierarchy/eye-flow remain future owners",
    "N/A != 0",
    "no beautyScore"
  ],
  "initial_heuristics": {
    "boundary_length_tolerance_px": {
      "value": 1e-07,
      "provenance": "IMPLEMENTATION_HEURISTIC"
    }
  },
  "correction_policy": {
    "foreign_mask_region_geometry_mutation": "FORBIDDEN",
    "boundary_attribution_missing": "request 5.01 object-support attribution adapter",
    "region_topology_issue": "route to 5.02",
    "desired_figure_ground_change": "emit relation correction intent only; actual geometry/layout belongs to solver/owners",
    "target_preference_issue": "route to 5.04"
  },
  "deferred_inputs": [
    "5.04 explicit-target scoring/corrections/tests",
    "any corridor/channel route model pending explicit MAIN allocation",
    "Topic6 canonical canvas/format normalization",
    "Topic8 grid occupancy",
    "future global balance/hierarchy/eye-flow"
  ],
  "recompute_when": [
    "5.01 occupied/free mask or object-support attribution changes",
    "5.02 EmptyRegionSet changes",
    "CompositionSpaceDomain boundary changes",
    "boundary attribution backend/tolerance changes"
  ],
  "finality": "FIGURE_GROUND_AND_ACTIVE_PASSIVE_RELATIONS_ONLY"
}