Synopsis
PDX_MSGT gdx_GetCurveNumSegs(long option, void *gdx_curve, long *num_segs)
Purpose
Retrieves the number of segments in u, v for a given curve.
Description
Given a GDX curve, determines the number of segments. If the curve is defined using a base curve, the number of segments is taken from that base curve. Segments are defined as follows:
| GDX entity | Segment Determination |
| – | |
| GDX_CONIC | Hyperbolas and parabolas are considered to be 1 |
| segment. Ellipses are considered to have a segment | |
| for each 90 degrees of the angular span. | |
| GDX_NURB_CURVE | Segments are taken from distinct knot values within |
| the knot vector (taking bounds into consideration) | |
| GDX_ARC | Each quarter circle is considered to be a segment. |
| GDX_SPLINE_CURVE | Segments are taken from the nsegs field. |
| GDX_POLYLINE | The number of segments is set to num_of_points - 1 |
| (a single point will also return a single segment). | |
| GDX_COMP_CURVE | The number of segments will be set to the sum of |
| the number of segments of each constituent curve | |
| GDX_OFFSET_CURVE | The number of segments will be set to that of the |
| base curve. | |
| GDX_TRIM_CURVE | The number of segments will be set to that of the |
| base curve. |
Input
option
Options (not used)
gdx_curve
Entity structure pointer of the GDX Surface
Output
num_segs
The number of u segments
Tolerances
KNOT_TOL
ANGLE_TOL
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Return
GDX_NOERR
Low level error return
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