arcFrom

arcFrom is a term used in geometry and computer graphics to describe a construction or function that creates an arc connecting two points under a specified constraint, typically a given radius or tangent directions. The exact meaning and signature of arcFrom vary by library or context, but it generally yields a curved path segment rather than a straight line.

In geometric terms, arcFrom refers to forming a circular arc that passes through two endpoints A and B with a prescribed radius r. If the distance AB is greater than 2r, no such arc exists. If AB equals 2r, there is a unique arc whose center lies at the midpoint of AB. If AB is less than 2r, there are typically two possible centers on the perpendicular bisector of AB, yielding two possible arcs; a choice of orientation or sweep determines which arc is produced.

In software, arcFrom often denotes a function that returns a path segment or arc command given inputs such as start point, end point, radius, and optional flags for sweep or large-arc. Some implementations may also accept tangential directions or allow selection among multiple solutions. The resulting object is typically a representation of a portion of a circle used in vector graphics, charting, or CAD tools.

Common use cases include smoothing polyline corners, constructing rounded connections between segments, drawing circular segments in diagrams, and generating toolpaths in design and manufacturing workflows. Because arcFrom is not standardized across libraries, developers should consult specific documentation for parameter names and behavior. See also arc, circle, ellipse, and SVG arc commands.