Geometry

All geometry in TXHSTL-R is expressed as curve contours made up of circular arc segments. An endpoint and an amplitude vector define a segment. The start point of the segment is the endpoint of the previous segment. The amplitude vector is defined as the vector from the mid-point of the chord between the two points going perpendicular to the top of the arc. A zero-length amplitude vector gives a line segment. A contour has a start point and a number of segments. For a closed contour like a hole, the curve start point coincides with the curve endpoint.

The circular arcs can be both two-dimensional and three-dimensional. For a two-dimensional curve there is belonging transformation information.