General interpolationType curve CV_SegmentedCurveCoverage

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11.3.4 Segmentation

The association Segmentation shall link this CV_ValueCurve to the sequence of CV_ValueSegments of which it is composed.

11.3.5 Control

The association Control shall link this CV_ValueCurve to the set of two or more CV_PointValuePairs that provide control values for the interpolation along the CV_ValueCurve.

11.4 CV_ValueSegment

11.4.1 General

The limits of a CV_ValueSegment are specified by two values of the arc-length parameter of the GM_Curve underlying its parent CV_ValueCurve.

11.4.2 startParameter

The attribute startParameter: Distance shall be the value of the arc-length parameter of the parent curve at the start of this CV_ValueSegment.

11.4.3 endParameter

The attribute endParameter: Distance shall be the value of the arc-length parameter of the parent curve at the end of this CV_ValueSegment.

11.4.4 Control

The association Control shall link the CV_ValueSegment to the CV_PointValuePairs that provide control values for interpolation. Linear interpolation requires a minimum of two control values, usually those at the beginning and end of the CV_ValueSegment. Additional control values are required to support interpolation by higher order functions.

11.5 Evaluation

CV_SegmentedCurveCoverage inherits the operation evaluate p: DirectPosition, list: Sequence CharacterString: Record from CV_Coverage. Evaluation of a CV_SegmentedCurveCoverage involves several steps: 1 Invoke the operation curve to find the CV_ValueCurve that contains the input DirectPosition. 2 Invoke the operation CV_ValueCurve.segment to find the CV_ValueSegment that contains the input DirectPosition. 3 If CV_ValueCurve.segment returns a single CV_ValueSegment, use the specified interpolationType to compute feature attribute values from the associated controlValues. 4 If CV_ValueCurve.segment returns a pair of conterminous CV_ValueSegments, compute the feature attribute values according to the rule specified by the attribute commonPointRule inherited from CV_Coverage.