A four-sided region, given as corners or as a rectangle.
Eight numbers name each corner in turn, which is what
CanvasRenderingContext2D.createProjection needs for a shape that is
not a rectangle. Four name a rectangle's edges, and two name a rectangle of
that size at the origin.
A four-sided region, given as corners or as a rectangle.
Eight numbers name each corner in turn, which is what CanvasRenderingContext2D.createProjection needs for a shape that is not a rectangle. Four name a rectangle's edges, and two name a rectangle of that size at the origin.