number=2
GM_PointArray{size=(2xnumArc+l)=5}
GM_ArcString
Fig. 4.6. GM _AreString
4.3 Spatial schema (ISO 19107)
135
• endPoint:GM_Position
An are (class GM _Are) that eonsists of an are of the eircle is determined by three
points and is therefore defined by the starting point, a point somewhere between the
beginning and the end and the point oftermination. Ifthe 3 points are co-linear, then
the are shall be a 3-point line string, and will not be able to return values for center,
radius, start angle and end angle.
A eircle (class GM _ Circle) is defined by three points that close to form a full eircle.
GM_ArcStringByBulge
An are string by bulge (class GM_AreStringByBulge) eonsists of a sequence of
arcs where eaeh are is eontrolled by its startPoint, its endPoint, and a value determining its bulge. The bulge eontrols the off set of eaeh are's midpoint. The eontrolPoint
sequenee eonsists of the start and the end points of eaeh are. The bulge sequenee
eonsists of the bulge values, which is exaetly one less than the length of the eontrolPoint array.