Superfig/references/layout.md

Layout rules

Cursor flow

Inside \sfrow … \sfrowend, objects are placed from left to right by the cursor. The first object starts on the left rail; every later object reserves the standing gutter.

• Declare the band height once in \sfrow. An object that overflows it is a build warning.
• Use \sfconn for a labelled edge in the flow; the label reserves its own width.
• Do not add magic-number xshifts between flow objects.

Fixed topology

Use \sfnode[at={(x,y)}]{...} only when the diagram is genuinely non-linear: branches, loops, vertical/horizontal stacks, skip edges.

• Keep coordinates on a coarse grid; prefer multiples of \sfgutter or explicit anchors.
• Use \sfarrow between placed nodes. Route edges on the background layer.
• Put edge labels on the edge itself, not floating nearby.

Captions

Use \sflane{row} after \sfrowend to give all captions in that row one shared baseline. Symbol and detail lines are two reserved lanes; do not place other text between them.

Groups

A group outline adds inner padding, so place it after its members. It must not cover unrelated nodes. Members must be adjacent in the semantic sense; the explicit fit list prevents the package from inventing a group around whatever is near. A group must bind at least two members.

After a \sfrow, \sfgroup refits that row so \sflane{row} hangs captions below the outline. Prefer an empty overlay caption and \sfcaption{group}{...}{...}: an overlay at the north-west corner lands on skip edges. A connector that should leave the composite starts on the group node (\sfarrow{block.east}{next.west}), not on a member — otherwise the shaft crosses an outline that is not its endpoint.

Formula

Call \sftopformula after the last \sfrowend. The line is centered on \sfbbox, whose width is only known once the bands exist.

Callouts

\sfcallout hangs off a finished \sfrow band, one per figure. It is not an object in the flow and must not be anchored to a single node.

Meaning box

The meaning box hangs below the full figure bbox (\sfbbox). It is one column, at most three rows. If it is too long, remove content; do not widen it past the figure or shrink type.