Functions common to both the Curve Definition and Curve Interrogation modules

• Create and Initialize an Instance of a Curve
• Copy an Instance of a Curve
• Free the Space Occupied by a Curve

Compute the Position and the Left-/Right-hand Derivatives of a Curve
To evaluate and compute the derivatives of a given SISL curve at a given parameter value. The evaluation is either from the left or the right.

Subdivide a Curve at a Given Parameter Value
To subdivide a SISL curve at a given parameter value using the Oslo algorithm.

Insert New Knots into the Description of a Curve
To insert a single or a set of new knots into the representation of a SISL curve using the Oslo algorithm.

Split a Curve into two New Curves
To split a SISL curve in two parts at two specified parameter values. If the curve is open, the last part of the curve between the end and start of the original curve is translated.

Pick a Part of a SISL Curve
To pick one part of a SISL curve and make a new curve of that part. If a part of a closed curve is picked over the joint, the two parts will be joined into one curve. If the end value is less than the start value, the direction of the new curve is changed.

Join Two Curves at Specified Ends or Closest Ends
To join one end of one SISL curve with one end of another, or to join two SISL curves at the ends closest to each other. Curve 1 is always the first part of the curve. The direction of the curve is changed accordingly.

Reverse the Orientation of a Curve
To change the direction of a SISL curve. The start parameter value remains the same.

Extend a Curve
To extend polynomial SISL curve at the start and/or end by continuing the first and/or last polynomial segment of the curve.

Device Dependent Drawing Primitives to Draw a Sequence of Straight Lines
To draw a broken line as a sequence of straight lines described by the array points, in two or three dimensions. Two routines, one to move the graphics cursor and one to draw a line segment, must be interfaced to the host graphics system.