layout

const (
	GridStep         = 10  // Grid alignment step
	DefaultCellW     = 120 // Default node width
	DefaultCellH     = 60  // Default node height
	AspectRatioLimit = 3   // Max node height:width before the aspect rule widens it
	MaxNodeWidth     = 600 // Width-growth cap for the aspect rule (5 * DefaultCellW)
	BoundaryCellSize = 40  // S/E boundary node size
	CharsPerLine     = 12  // For text width estimation
	LinesPerBaseH    = 3   // Lines fitting in base height
	LineHeight       = 20  // Height per extra line
	EventVGap        = 60  // Vertical gap between events
	AuxHGap          = 60  // Horizontal gap between aux nodes (things/concepts) and their anchor event
	TuckEdgeClear    = 12  // Tuck offset past the anchor's center, clearing the vertical flow edge
	ThingHGap        = 120 // Horizontal gap between standalone things (2x AuxHGap)
	ThingVGap        = 40  // Vertical gap between standalone things
	AuxVGap          = 20  // Vertical gap between auxiliary nodes (things/concepts) in VDistribute
	ConceptGap       = 120 // Horizontal gap between concepts (2x AuxHGap)
	BoundaryVGap     = 40  // Gap between boundary and first/last event
	// MaxFanAngleDeg caps the angle SPREAD between the two outermost edges
	// fanning from (or into) one event/boundary: each edge is held within
	// MaxFanAngleDeg/2 of the fan axis, so a wide or distant set of targets
	// is pushed further from the source until the spread closes to at most
	// this — never an obtuse near-flat fan. The required perpendicular gap for
	// a parallel offset dx is dx/tan(MaxFanAngleDeg/2). 150° → each edge within
	// 75° of vertical, min-slope 1/tan75 ≈ 0.27.
	//
	// UNIFIED with MaxBoundaryFanAngleDeg at 150° ("the same
	// angle for both"): interior fork/join fans and S/E boundary fans use ONE
	// angle, so a fork→row→join (or S→row→join) diamond reads as symmetric
	// halves. History: 150° → 130° (tightened) → 150° again (re-unified
	// with the boundary). The two constants are kept as a
	// seam in case they ever need to diverge again.
	MaxFanAngleDeg = 150
	// MaxBoundaryFanAngleDeg caps S/E boundary fans — currently EQUAL to the
	// interior MaxFanAngleDeg (150°, see above): one fan angle everywhere keeps
	// the S→row and row→join halves of a diamond symmetric.
	// 150° → each boundary edge within 75° of vertical (min-slope ≈ 0.27); a
	// wide S/E fan keeps its square BoundaryCellSize marker close to the flow.
	// History: 130° (= interior) → 115° (steepened for the k8s PVC fan) → 130°
	// → 150°. The square marker's fan ports are a bit tighter than a 120px
	// event's (the brief box-widening to mirror them read badly, reverted).
	MaxBoundaryFanAngleDeg = 150
	// BoundaryFanSlopeDen sets the minimum steepness of a LONE start boundary's
	// edge: S lifts until the single S->start edge has |dy| >= |dx|/den. A wide
	// start FAN (>=2 starts) is now capped at MaxFanAngleDeg via v5FanGap — the
	// same rule as the fork/join/E fans — so its S→row gap matches the row→join
	// gap (the old /2 made the start fan 18px taller). This
	// constant only governs the rare offset-lone-start case. The END lone
	// terminal keeps the gentler /5 (terminals converging to E never crowd).
	BoundaryFanSlopeDen = 2
	// MaxCorridorLeverage caps how far the leads-to corridor-clearance pass
	// will relocate a join/member event to slip its incoming edge past a
	// previous-row aux box. The required member push amplifies the box's
	// clearance need by span/den (span = member-to-port horizontal run; den =
	// port-to-blocker-near-edge run). A blocker hugging the port (den << span)
	// otherwise levers a modest box depth into a multi-row near-vertical skew.
	// Past this leverage the blocker is in the port's own corridor — the edge
	// router bends around it instead of the layout relocating the member.
	MaxCorridorLeverage = 2
	GraphGap            = 120        // Gap between disconnected components
	MinNodeGap          = 20         // Minimum gap between non-event nodes during overlap resolution
	StandaloneChainGap  = 40         // Vertical gap for simple standalone node chains like A --> B
	ConceptChainVGap    = 40         // Vertical gap between concepts in a chain (2x MinNodeGap)
	MarginX             = 40         // Canvas margin X
	MarginY             = 40         // Canvas margin Y
	ForkHGap            = 60         // Horizontal gap in fork patterns
	TargetAspectRatio   = 16.0 / 9.0 // Maximum canvas width-to-height ratio before compaction
)