OCCT-Light: 3D curve representation in the topology graph. More...

#include <stddef.h>
#include <stdint.h>
#include "occtl_core.h"
#include "occtl_curves_common.h"
#include "occtl_geom.h"

Include dependency graph for occtl_curves.h:

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Go to the source code of this file.

Classes
struct	occtl_curve_bspline_create_info

struct	occtl_curve_bezier_create_info

struct	occtl_curve_offset_create_info

struct	occtl_curve_bspline

struct	occtl_curve_airfoil_naca4_info

struct	occtl_curve_interpolated_info

struct	occtl_curve_approximated_info

struct	occtl_curve_intersection_point

Macros
#define	OCCTL_CURVE_BSPLINE_CREATE_INFO_VERSION_1 1u

#define	OCCTL_CURVE_BSPLINE_CREATE_INFO_INIT {OCCTL_CURVE_BSPLINE_CREATE_INFO_VERSION_1, NULL, NULL, 0, NULL, NULL, NULL, 0, 0, 0}

#define	OCCTL_CURVE_BEZIER_CREATE_INFO_VERSION_1 1u

#define	OCCTL_CURVE_BEZIER_CREATE_INFO_INIT {OCCTL_CURVE_BEZIER_CREATE_INFO_VERSION_1, NULL, NULL, 0, NULL}

#define	OCCTL_CURVE_OFFSET_CREATE_INFO_VERSION_1 1u

#define	OCCTL_CURVE_OFFSET_CREATE_INFO_INIT {OCCTL_CURVE_OFFSET_CREATE_INFO_VERSION_1, NULL, {0}, {0.0, 0.0, 1.0}, 0.0}

#define	OCCTL_CURVE_BSPLINE_VERSION_1 1u

#define	OCCTL_CURVE_BSPLINE_INIT {OCCTL_CURVE_BSPLINE_VERSION_1, NULL, 0, 0, 0, 0, 0, 0, 0, 0, NULL, NULL, NULL, NULL, NULL}

#define	OCCTL_CURVE_AIRFOIL_NACA4_INFO_VERSION_1 1u

#define	OCCTL_CURVE_AIRFOIL_NACA4_INFO_INIT {OCCTL_CURVE_AIRFOIL_NACA4_INFO_VERSION_1, NULL, 0.0, 0.0, 0.12, 1.0, 50, 0, 3, 8, 1.0e-5}

#define	OCCTL_CURVE_INTERPOLATED_INFO_VERSION_1 1u

#define	OCCTL_CURVE_INTERPOLATED_INFO_INIT {OCCTL_CURVE_INTERPOLATED_INFO_VERSION_1, NULL, NULL, 0, 0, 0.0}

#define	OCCTL_CURVE_APPROXIMATED_INFO_VERSION_1 1u

#define	OCCTL_CURVE_APPROXIMATED_INFO_INIT {OCCTL_CURVE_APPROXIMATED_INFO_VERSION_1, NULL, NULL, 0, 1, 3, 1e-3, 0}

Typedefs
typedef struct occtl_curve_bspline_create_info	occtl_curve_bspline_create_info_t

typedef struct occtl_curve_bezier_create_info	occtl_curve_bezier_create_info_t

typedef struct occtl_curve_offset_create_info	occtl_curve_offset_create_info_t

typedef struct occtl_curve_bspline	occtl_curve_bspline_t

typedef struct occtl_curve_airfoil_naca4_info	occtl_curve_airfoil_naca4_info_t

typedef struct occtl_curve_interpolated_info	occtl_curve_interpolated_info_t

typedef struct occtl_curve_approximated_info	occtl_curve_approximated_info_t

typedef struct occtl_curve_intersection_point	occtl_curve_intersection_point_t

Functions
occtl_status_t	occtl_curve_create_line (occtl_graph_t graph, occtl_geom_line_t line, occtl_rep_id_t out_id)

occtl_status_t	occtl_curve_create_circle (occtl_graph_t graph, occtl_geom_circle_t circle, occtl_rep_id_t out_id)

occtl_status_t	occtl_curve_create_ellipse (occtl_graph_t graph, occtl_geom_ellipse_t ellipse, occtl_rep_id_t out_id)

occtl_status_t	occtl_curve_create_hyperbola (occtl_graph_t graph, occtl_geom_hyperbola_t hyperbola, occtl_rep_id_t out_id)

occtl_status_t	occtl_curve_create_parabola (occtl_graph_t graph, occtl_geom_parabola_t parabola, occtl_rep_id_t out_id)

void	occtl_curve_bspline_create_info_init (occtl_curve_bspline_create_info_t *info)

occtl_status_t	occtl_curve_create_bspline (occtl_graph_t graph, const occtl_curve_bspline_create_info_t info, occtl_rep_id_t *out_id)

void	occtl_curve_bezier_create_info_init (occtl_curve_bezier_create_info_t *info)

occtl_status_t	occtl_curve_create_bezier (occtl_graph_t graph, const occtl_curve_bezier_create_info_t info, occtl_rep_id_t *out_id)

occtl_status_t	occtl_curve_create_trimmed (occtl_graph_t graph, const occtl_curve_trimmed_create_info_t info, occtl_rep_id_t *out_id)

void	occtl_curve_offset_create_info_init (occtl_curve_offset_create_info_t *info)

occtl_status_t	occtl_curve_create_offset (occtl_graph_t graph, const occtl_curve_offset_create_info_t info, occtl_rep_id_t *out_id)

occtl_status_t	occtl_curve_reverse (occtl_graph_t graph, occtl_rep_id_t curve_id, occtl_rep_id_t out_id)

occtl_status_t	occtl_curve_transformed (occtl_graph_t graph, occtl_rep_id_t curve_id, occtl_transform_t transform, occtl_rep_id_t out_id)

occtl_status_t	occtl_curve_translated (occtl_graph_t graph, occtl_rep_id_t curve_id, occtl_vector3_t delta, occtl_rep_id_t out_id)

occtl_status_t	occtl_curve_rotated (occtl_graph_t graph, occtl_rep_id_t curve_id, occtl_axis1_placement_t axis, double angle, occtl_rep_id_t out_id)

occtl_status_t	occtl_curve_scaled (occtl_graph_t graph, occtl_rep_id_t curve_id, occtl_point3_t origin, double factor, occtl_rep_id_t out_id)

occtl_status_t	occtl_curve_length (const occtl_graph_t graph, occtl_rep_id_t curve_id, double out_length)

occtl_status_t	occtl_curve_project_point (const occtl_graph_t graph, occtl_rep_id_t curve_id, occtl_point3_t point, double out_param, double *out_distance)

occtl_status_t	occtl_curve_parameter_of_point (const occtl_graph_t graph, occtl_rep_id_t curve_id, occtl_point3_t point, double out_param)

occtl_status_t	occtl_curve_kind (const occtl_graph_t graph, occtl_rep_id_t curve_id, occtl_curve_kind_t out_kind)

occtl_status_t	occtl_curve_is_periodic (const occtl_graph_t graph, occtl_rep_id_t curve_id, int32_t out_is_periodic)

occtl_status_t	occtl_curve_is_closed (const occtl_graph_t graph, occtl_rep_id_t curve_id, int32_t out_is_closed)

occtl_status_t	occtl_curve_continuity (const occtl_graph_t graph, occtl_rep_id_t curve_id, occtl_geom_continuity_t out_continuity)

occtl_status_t	occtl_curve_parameter_range (const occtl_graph_t graph, occtl_rep_id_t curve_id, double out_u_min, double *out_u_max)

occtl_status_t	occtl_curve_as_line (const occtl_graph_t graph, occtl_rep_id_t curve_id, occtl_geom_line_t out_line)

occtl_status_t	occtl_curve_as_circle (const occtl_graph_t graph, occtl_rep_id_t curve_id, occtl_geom_circle_t out_circle)

occtl_status_t	occtl_curve_as_ellipse (const occtl_graph_t graph, occtl_rep_id_t curve_id, occtl_geom_ellipse_t out_ellipse)

occtl_status_t	occtl_curve_as_hyperbola (const occtl_graph_t graph, occtl_rep_id_t curve_id, occtl_geom_hyperbola_t out_hyperbola)

occtl_status_t	occtl_curve_as_parabola (const occtl_graph_t graph, occtl_rep_id_t curve_id, occtl_geom_parabola_t out_parabola)

occtl_status_t	occtl_curve_as_trimmed (const occtl_graph_t graph, occtl_rep_id_t curve_id, double out_u_first, double *out_u_last)

occtl_status_t	occtl_curve_as_offset (const occtl_graph_t graph, occtl_rep_id_t curve_id, double out_offset, occtl_vector3_t *out_offset_dir)

occtl_status_t	occtl_curve_bspline_degree (const occtl_graph_t graph, occtl_rep_id_t curve_id, int32_t out_degree)

occtl_status_t	occtl_curve_bspline_pole_count (const occtl_graph_t graph, occtl_rep_id_t curve_id, size_t out_count)

occtl_status_t	occtl_curve_bspline_knot_count (const occtl_graph_t graph, occtl_rep_id_t curve_id, size_t out_count)

occtl_status_t	occtl_curve_bspline_is_rational (const occtl_graph_t graph, occtl_rep_id_t curve_id, int32_t out_is_rational)

occtl_status_t	occtl_curve_bezier_degree (const occtl_graph_t graph, occtl_rep_id_t curve_id, int32_t out_degree)

occtl_status_t	occtl_curve_bezier_pole_count (const occtl_graph_t graph, occtl_rep_id_t curve_id, size_t out_count)

occtl_status_t	occtl_curve_bezier_is_rational (const occtl_graph_t graph, occtl_rep_id_t curve_id, int32_t out_is_rational)

occtl_status_t	occtl_curve_bspline_poles (const occtl_graph_t graph, occtl_rep_id_t curve_id, occtl_point3_t out_buf, size_t capacity, size_t *out_count)

occtl_status_t	occtl_curve_bspline_knots (const occtl_graph_t graph, occtl_rep_id_t curve_id, double out_buf, size_t capacity, size_t *out_count)

occtl_status_t	occtl_curve_bspline_multiplicities (const occtl_graph_t graph, occtl_rep_id_t curve_id, int32_t out_buf, size_t capacity, size_t *out_count)

occtl_status_t	occtl_curve_bspline_weights (const occtl_graph_t graph, occtl_rep_id_t curve_id, double out_buf, size_t capacity, size_t *out_count)

occtl_status_t	occtl_curve_bspline_poles_view (const occtl_graph_t graph, occtl_rep_id_t curve_id, const occtl_point3_t out_data, size_t out_count)

occtl_status_t	occtl_curve_bspline_flat_knots (const occtl_graph_t graph, occtl_rep_id_t curve_id, double out_buf, size_t capacity, size_t *out_count)

void	occtl_curve_bspline_init (occtl_curve_bspline_t *out)

occtl_status_t	occtl_curve_as_bspline (const occtl_graph_t graph, occtl_rep_id_t curve_id, occtl_curve_bspline_t out)

occtl_status_t	occtl_curve_eval_d0 (const occtl_graph_t graph, occtl_rep_id_t curve_id, double u, occtl_point3_t out_point)

occtl_status_t	occtl_curve_eval_d1 (const occtl_graph_t graph, occtl_rep_id_t curve_id, double u, occtl_point3_t out_point, occtl_vector3_t *out_d1)

occtl_status_t	occtl_curve_eval_d2 (const occtl_graph_t graph, occtl_rep_id_t curve_id, double u, occtl_point3_t out_point, occtl_vector3_t out_d1, occtl_vector3_t out_d2)

occtl_status_t	occtl_curve_eval_d3 (const occtl_graph_t graph, occtl_rep_id_t curve_id, double u, occtl_point3_t out_point, occtl_vector3_t out_d1, occtl_vector3_t out_d2, occtl_vector3_t *out_d3)

occtl_status_t	occtl_curve_eval_dn (const occtl_graph_t graph, occtl_rep_id_t curve_id, double u, int32_t n, occtl_vector3_t out_derivative)

void	occtl_curve_airfoil_naca4_info_init (occtl_curve_airfoil_naca4_info_t *info)

occtl_status_t	occtl_curve_create_airfoil_naca4 (occtl_graph_t graph, const occtl_curve_airfoil_naca4_info_t info, occtl_rep_id_t *out_id)

occtl_status_t	occtl_curve_create_arc_of_circle_3pt (occtl_graph_t graph, occtl_point3_t p1, occtl_point3_t p2, occtl_point3_t p3, occtl_rep_id_t out_id)

void	occtl_curve_interpolated_info_init (occtl_curve_interpolated_info_t *info)

occtl_status_t	occtl_curve_create_interpolated (occtl_graph_t graph, const occtl_curve_interpolated_info_t info, occtl_rep_id_t *out_id)

void	occtl_curve_approximated_info_init (occtl_curve_approximated_info_t *info)

occtl_status_t	occtl_curve_create_approximated (occtl_graph_t graph, const occtl_curve_approximated_info_t info, occtl_rep_id_t *out_id)

occtl_status_t	occtl_curve_to_bezier_segments (occtl_graph_t graph, occtl_rep_id_t curve_id, const occtl_curve_bezier_segments_options_t options, occtl_rep_id_t *out_ids, size_t out_count)

void	occtl_curve_free_bezier_segments (occtl_rep_id_t *ids)

occtl_status_t	occtl_curve_intersect (occtl_graph_t graph, occtl_rep_id_t curve_id_a, occtl_rep_id_t curve_id_b, const occtl_curve_intersection_point_t out_results, size_t out_count)

void	occtl_curve_free_intersection_points (occtl_curve_intersection_point_t *results)

Detailed Description

OCCT-Light: 3D curve representation in the topology graph.

A curve is stored as an occtl_rep_id_t inside an occtl_graph_t. Every curve function takes a graph pointer and a rep id. The kind is available via occtl_curve_kind for O(1) introspection.

This file covers construction, introspection, data extraction, and parametric evaluation of 3D curve representations.

Typedef Documentation

◆ occtl_curve_airfoil_naca4_info_t

typedef struct occtl_curve_airfoil_naca4_info occtl_curve_airfoil_naca4_info_t

Versioned create-info for a NACA 4-digit airfoil profile curve.

The generated profile lies in the XY plane with the leading edge at (0,0,0) and the chord along +X. Use curve transforms to place or scale it after construction.

◆ occtl_curve_approximated_info_t

typedef struct occtl_curve_approximated_info occtl_curve_approximated_info_t

Versioned create-info struct for curve approximation (fitting).

Fits a B-spline curve to the given points within the specified tolerance using OCCT's GeomAPI_PointsToBSpline. The resulting curve does not necessarily pass through the points; it approximates them.

◆ occtl_curve_bezier_create_info_t

typedef struct occtl_curve_bezier_create_info occtl_curve_bezier_create_info_t

Versioned create-info struct for Bezier curve construction.

◆ occtl_curve_bspline_create_info_t

typedef struct occtl_curve_bspline_create_info occtl_curve_bspline_create_info_t

Versioned create-info struct for B-spline curve construction.

Knots are in compact form (distinct values + multiplicities), which is OCCT's canonical representation. Arrays are borrowed for the duration of the occtl_curve_create_bspline call; they are not retained afterwards.

For a non-rational B-spline set weights to NULL. For a rational B-spline (NURBS) provide weights with pole_count entries; all values must be > 0.

◆ occtl_curve_bspline_t

typedef struct occtl_curve_bspline occtl_curve_bspline_t

Aggregate inspection view of a B-spline curve.

Read-only snapshot of every field a caller typically needs in the same pass: scalars (degree, periodicity, continuity, counts) plus borrowed pointers into the underlying OCCT storage for poles, weights, distinct knots, multiplicities, and the expanded flat knot sequence. One call replaces ~10 atomized accessors; pair with occtl_curve_as_bspline.

Pointers in out borrow from the graph rep and are valid until the rep is removed from the graph.

The caller declares the layout version they understand in struct_version before the call; the library fills only fields up to that version. The weights pointer is set to NULL when is_rational is 0.

◆ occtl_curve_interpolated_info_t

typedef struct occtl_curve_interpolated_info occtl_curve_interpolated_info_t

Versioned create-info struct for curve interpolation.

Interpolates a B-spline curve passing through the given points. Uses OCCT's GeomAPI_Interpolate internally, which computes uniform parameters and creates a C2 continuous cubic B-spline.

◆ occtl_curve_intersection_point_t

typedef struct occtl_curve_intersection_point occtl_curve_intersection_point_t

Describes a single intersection point between two curves.

◆ occtl_curve_offset_create_info_t

typedef struct occtl_curve_offset_create_info occtl_curve_offset_create_info_t

Versioned create-info struct for an offset curve.

The constructor makes an internal deep copy of the basis curve.

Function Documentation

◆ occtl_curve_airfoil_naca4_info_init()

void occtl_curve_airfoil_naca4_info_init ( occtl_curve_airfoil_naca4_info_t * info )

Runtime initialiser for occtl_curve_airfoil_naca4_info_t.

Parameters

[out] info Borrows it. NULL-tolerant; no-op when NULL.

\par Thread Safety Yes.

See also: occtl_curve_create_airfoil_naca4

◆ occtl_curve_approximated_info_init()

void occtl_curve_approximated_info_init ( occtl_curve_approximated_info_t * info )

Runtime initialiser for occtl_curve_approximated_info_t.

Parameters

[out] info Borrows it. NULL-tolerant; no-op when NULL.

\par Thread Safety Yes.

See also: occtl_curve_create_approximated

◆ occtl_curve_as_bspline()

occtl_status_t occtl_curve_as_bspline	(	const occtl_graph_t *	graph,
		occtl_rep_id_t	curve_id,
		occtl_curve_bspline_t *	out
	)

Fills a caller-allocated occtl_curve_bspline_t with a complete read-only inspection view of the underlying B-spline curve.

Pointers in out borrow from the graph rep and are valid until the rep is removed from the graph.

Parameters

[in]	graph	Owning graph. Must be non-NULL.
[in]	curve_id	Curve to inspect; kind must be `OCCTL_CURVE_KIND_BSPLINE`.
[in,out]	out	Borrows it. Caller-allocated; must be non-NULL. The caller sets `struct_version` on entry; the library fills the remaining fields on success and leaves them unchanged on failure.

Return values

OCCTL_OK	On success.
OCCTL_INVALID_ARGUMENT	`graph` or `out` is NULL.
OCCTL_VERSION_MISMATCH	`out->struct_version` is not supported.
OCCTL_WRONG_KIND	Curve is not a B-spline curve.

\par Thread Safety Yes (read-only).

See also: occtl_curve_bspline_init, occtl_curve_bspline_poles_view, occtl_curve_bspline_degree, occtl_curve_bspline_pole_count

◆ occtl_curve_as_circle()

occtl_status_t occtl_curve_as_circle	(	const occtl_graph_t *	graph,
		occtl_rep_id_t	curve_id,
		occtl_geom_circle_t *	out_circle
	)

Extracts circle data from a curve representation.

Parameters

[in]	graph	Owning graph. Must be non-NULL.
[in]	curve_id	Curve to extract; kind must be `OCCTL_CURVE_KIND_CIRCLE`.
[out]	out_circle	Borrows it (caller-allocated slot). Must be non-NULL.

Return values

OCCTL_OK	On success.
OCCTL_INVALID_ARGUMENT	`graph` or `out_circle` is NULL.
OCCTL_WRONG_KIND	Curve is not a circle.

\par Thread Safety Yes.

See also: occtl_curve_kind

◆ occtl_curve_as_ellipse()

occtl_status_t occtl_curve_as_ellipse	(	const occtl_graph_t *	graph,
		occtl_rep_id_t	curve_id,
		occtl_geom_ellipse_t *	out_ellipse
	)

Extracts ellipse data from a curve representation.

Parameters

[in]	graph	Owning graph. Must be non-NULL.
[in]	curve_id	Curve to extract; kind must be `OCCTL_CURVE_KIND_ELLIPSE`.
[out]	out_ellipse	Borrows it (caller-allocated slot). Must be non-NULL.

Return values

OCCTL_OK	On success.
OCCTL_INVALID_ARGUMENT	`graph` or `out_ellipse` is NULL.
OCCTL_WRONG_KIND	Curve is not an ellipse.

\par Thread Safety Yes.

See also: occtl_curve_kind

◆ occtl_curve_as_hyperbola()

occtl_status_t occtl_curve_as_hyperbola	(	const occtl_graph_t *	graph,
		occtl_rep_id_t	curve_id,
		occtl_geom_hyperbola_t *	out_hyperbola
	)

Extracts hyperbola data from a curve representation.

Parameters

[in]	graph	Owning graph. Must be non-NULL.
[in]	curve_id	Curve to extract; kind must be `OCCTL_CURVE_KIND_HYPERBOLA`.
[out]	out_hyperbola	Borrows it (caller-allocated slot). Must be non-NULL.

Return values

OCCTL_OK	On success.
OCCTL_INVALID_ARGUMENT	`graph` or `out_hyperbola` is NULL.
OCCTL_WRONG_KIND	Curve is not a hyperbola.

\par Thread Safety Yes.

See also: occtl_curve_kind

◆ occtl_curve_as_line()

occtl_status_t occtl_curve_as_line	(	const occtl_graph_t *	graph,
		occtl_rep_id_t	curve_id,
		occtl_geom_line_t *	out_line
	)

Extracts line data from a curve representation.

Parameters

[in]	graph	Owning graph. Must be non-NULL.
[in]	curve_id	Curve to extract; kind must be `OCCTL_CURVE_KIND_LINE`.
[out]	out_line	Borrows it (caller-allocated slot). Must be non-NULL.

Return values

OCCTL_OK	On success.
OCCTL_INVALID_ARGUMENT	`graph` or `out_line` is NULL.
OCCTL_WRONG_KIND	Curve is not a line.

\par Thread Safety Yes.

See also: occtl_curve_kind

◆ occtl_curve_as_offset()

occtl_status_t occtl_curve_as_offset	(	const occtl_graph_t *	graph,
		occtl_rep_id_t	curve_id,
		double *	out_offset,
		occtl_vector3_t *	out_offset_dir
	)

Extracts the scalar offset and reference direction of an offset curve.

Parameters

[in]	graph	Owning graph. Must be non-NULL.
[in]	curve_id	Curve to extract; kind must be `OCCTL_CURVE_KIND_OFFSET`.
[out]	out_offset	Signed offset distance. May be NULL.
[out]	out_offset_dir	Reference direction (unit length). May be NULL.

Return values

OCCTL_OK	On success.
OCCTL_INVALID_ARGUMENT	`graph` is NULL.
OCCTL_WRONG_KIND	Curve is not an offset curve.

\par Thread Safety Yes.

See also: occtl_curve_kind

◆ occtl_curve_as_parabola()

occtl_status_t occtl_curve_as_parabola	(	const occtl_graph_t *	graph,
		occtl_rep_id_t	curve_id,
		occtl_geom_parabola_t *	out_parabola
	)

Extracts parabola data from a curve representation.

Parameters

[in]	graph	Owning graph. Must be non-NULL.
[in]	curve_id	Curve to extract; kind must be `OCCTL_CURVE_KIND_PARABOLA`.
[out]	out_parabola	Borrows it (caller-allocated slot). Must be non-NULL.

Return values

OCCTL_OK	On success.
OCCTL_INVALID_ARGUMENT	`graph` or `out_parabola` is NULL.
OCCTL_WRONG_KIND	Curve is not a parabola.

\par Thread Safety Yes.

See also: occtl_curve_kind

◆ occtl_curve_as_trimmed()

occtl_status_t occtl_curve_as_trimmed	(	const occtl_graph_t *	graph,
		occtl_rep_id_t	curve_id,
		double *	out_u_first,
		double *	out_u_last
	)

Extracts the parameter bounds of a trimmed curve.

The reported u_first / u_last are the parameter bounds the trimmed curve was constructed with (already adjusted for any sense flip at construction time), so reconstructing via occtl_curve_create_trimmed with sense=1 reproduces an equivalent curve.

Parameters

[in]	graph	Owning graph. Must be non-NULL.
[in]	curve_id	Curve to extract; kind must be `OCCTL_CURVE_KIND_TRIMMED`.
[out]	out_u_first	First parameter. May be NULL.
[out]	out_u_last	Last parameter. May be NULL.

Return values

OCCTL_OK	On success.
OCCTL_INVALID_ARGUMENT	`graph` is NULL.
OCCTL_WRONG_KIND	Curve is not a trimmed curve.

\par Thread Safety Yes.

See also: occtl_curve_kind

◆ occtl_curve_bezier_create_info_init()

void occtl_curve_bezier_create_info_init ( occtl_curve_bezier_create_info_t * info )

Runtime initialiser for occtl_curve_bezier_create_info_t.

Parameters

[out] info Borrows it. NULL-tolerant; no-op when NULL.

\par Thread Safety Yes.

See also: occtl_curve_create_bezier

◆ occtl_curve_bezier_degree()

occtl_status_t occtl_curve_bezier_degree	(	const occtl_graph_t *	graph,
		occtl_rep_id_t	curve_id,
		int32_t *	out_degree
	)

Returns the polynomial degree of a Bezier curve.

Equivalent to pole_count - 1 but exposed for symmetry with occtl_curve_bspline_degree.

Parameters

[in]	graph	Owning graph. Must be non-NULL.
[in]	curve_id	Curve to query; kind must be `OCCTL_CURVE_KIND_BEZIER`.
[out]	out_degree	Receives the degree. Must be non-NULL.

Return values

OCCTL_OK	On success.
OCCTL_INVALID_ARGUMENT	`graph` or `out_degree` is NULL.
OCCTL_WRONG_KIND	Curve is not a Bezier curve.

\par Thread Safety Yes.

See also: occtl_curve_create_bezier

◆ occtl_curve_bezier_is_rational()

occtl_status_t occtl_curve_bezier_is_rational	(	const occtl_graph_t *	graph,
		occtl_rep_id_t	curve_id,
		int32_t *	out_is_rational
	)

Returns non-zero if the Bezier curve is rational (has per-pole weights).

Parameters

[in]	graph	Owning graph. Must be non-NULL.
[in]	curve_id	Curve to query; kind must be `OCCTL_CURVE_KIND_BEZIER`.
[out]	out_is_rational	Receives 1 if rational, 0 otherwise. Must be non-NULL.

Return values

OCCTL_OK	On success.
OCCTL_INVALID_ARGUMENT	`graph` or `out_is_rational` is NULL.
OCCTL_WRONG_KIND	Curve is not a Bezier curve.

\par Thread Safety Yes.

See also: occtl_curve_create_bezier

◆ occtl_curve_bezier_pole_count()

occtl_status_t occtl_curve_bezier_pole_count	(	const occtl_graph_t *	graph,
		occtl_rep_id_t	curve_id,
		size_t *	out_count
	)

Returns the pole count of a Bezier curve.

Parameters

[in]	graph	Owning graph. Must be non-NULL.
[in]	curve_id	Curve to query; kind must be `OCCTL_CURVE_KIND_BEZIER`.
[out]	out_count	Receives the pole count. Must be non-NULL.

Return values

OCCTL_OK	On success.
OCCTL_INVALID_ARGUMENT	`graph` or `out_count` is NULL.
OCCTL_WRONG_KIND	Curve is not a Bezier curve.

\par Thread Safety Yes.

See also: occtl_curve_create_bezier

◆ occtl_curve_bspline_create_info_init()

void occtl_curve_bspline_create_info_init ( occtl_curve_bspline_create_info_t * info )

Runtime initialiser for occtl_curve_bspline_create_info_t.

Sets struct_version and zeroes all other fields. Use instead of the _INIT macro when C macros are not available (e.g. C# P/Invoke).

Parameters

[out] info Borrows it. NULL-tolerant; no-op when NULL.

\par Thread Safety Yes.

See also: occtl_curve_create_bspline

◆ occtl_curve_bspline_degree()

occtl_status_t occtl_curve_bspline_degree	(	const occtl_graph_t *	graph,
		occtl_rep_id_t	curve_id,
		int32_t *	out_degree
	)

Returns the polynomial degree of a B-spline curve.

Parameters

[in]	graph	Owning graph. Must be non-NULL.
[in]	curve_id	Curve to query; kind must be `OCCTL_CURVE_KIND_BSPLINE`.
[out]	out_degree	Receives the degree. Must be non-NULL.

Return values

OCCTL_OK	On success.
OCCTL_INVALID_ARGUMENT	`graph` or `out_degree` is NULL.
OCCTL_WRONG_KIND	Curve is not a B-spline.

\par Thread Safety Yes.

See also: occtl_curve_create_bspline

◆ occtl_curve_bspline_flat_knots()

occtl_status_t occtl_curve_bspline_flat_knots	(	const occtl_graph_t *	graph,
		occtl_rep_id_t	curve_id,
		double *	out_buf,
		size_t	capacity,
		size_t *	out_count
	)

Extracts the expanded (flat) knot sequence of a B-spline curve.

The flat knot sequence repeats each distinct knot value by its multiplicity, which is the form most numerical libraries (NumPy, etc.) expect. The total count equals the sum of multiplicities.

Two-call pattern: same as occtl_curve_bspline_poles.

Parameters

[in]	graph	Owning graph. Must be non-NULL.
[in]	curve_id	Curve to extract; kind must be `OCCTL_CURVE_KIND_BSPLINE`.
[out]	out_buf	Buffer to receive flat knot values. May be NULL on sizing call.
[in]	capacity	Capacity of `out_buf` in elements.
[out]	out_count	Required count. Must be non-NULL.

Return values

OCCTL_OK	On success.
OCCTL_INVALID_ARGUMENT	`graph` or `out_count` is NULL.
OCCTL_WRONG_KIND	Curve is not a B-spline.
OCCTL_BUFFER_TOO_SMALL	Buffer too small.

\par Thread Safety Yes.

See also: occtl_curve_create_bspline

◆ occtl_curve_bspline_init()

void occtl_curve_bspline_init ( occtl_curve_bspline_t * out )

Runtime initialiser for occtl_curve_bspline_t.

Sets struct_version and zeroes all other fields. Use instead of the _INIT macro when C macros are not available (e.g. C# P/Invoke).

Parameters

[out] out Borrows it. NULL-tolerant; no-op when NULL.

\par Thread Safety Yes.

See also: occtl_curve_as_bspline

◆ occtl_curve_bspline_is_rational()

occtl_status_t occtl_curve_bspline_is_rational	(	const occtl_graph_t *	graph,
		occtl_rep_id_t	curve_id,
		int32_t *	out_is_rational
	)

Returns non-zero if the B-spline curve is rational (has per-pole weights).

Parameters

[in]	graph	Owning graph. Must be non-NULL.
[in]	curve_id	Curve to query; kind must be `OCCTL_CURVE_KIND_BSPLINE`.
[out]	out_is_rational	Receives 1 if rational, 0 otherwise. Must be non-NULL.

Return values

OCCTL_OK	On success.
OCCTL_INVALID_ARGUMENT	`graph` or `out_is_rational` is NULL.
OCCTL_WRONG_KIND	Curve is not a B-spline.

\par Thread Safety Yes.

See also: occtl_curve_create_bspline

◆ occtl_curve_bspline_knot_count()

occtl_status_t occtl_curve_bspline_knot_count	(	const occtl_graph_t *	graph,
		occtl_rep_id_t	curve_id,
		size_t *	out_count
	)

Returns the knot count (number of distinct knot values) of a B-spline curve.

Parameters

[in]	graph	Owning graph. Must be non-NULL.
[in]	curve_id	Curve to query; kind must be `OCCTL_CURVE_KIND_BSPLINE`.
[out]	out_count	Receives the knot count. Must be non-NULL.

Return values

OCCTL_OK	On success.
OCCTL_INVALID_ARGUMENT	`graph` or `out_count` is NULL.
OCCTL_WRONG_KIND	Curve is not a B-spline.

\par Thread Safety Yes.

See also: occtl_curve_create_bspline

◆ occtl_curve_bspline_knots()

occtl_status_t occtl_curve_bspline_knots	(	const occtl_graph_t *	graph,
		occtl_rep_id_t	curve_id,
		double *	out_buf,
		size_t	capacity,
		size_t *	out_count
	)

Extracts the distinct knot values of a B-spline curve.

Two-call pattern: same as occtl_curve_bspline_poles.

Parameters

[in]	graph	Owning graph. Must be non-NULL.
[in]	curve_id	Curve to extract; kind must be `OCCTL_CURVE_KIND_BSPLINE`.
[out]	out_buf	Buffer to receive knot values. May be NULL on sizing call.
[in]	capacity	Capacity of `out_buf` in elements.
[out]	out_count	Required count. Must be non-NULL.

Return values

OCCTL_OK	On success.
OCCTL_INVALID_ARGUMENT	`graph` or `out_count` is NULL.
OCCTL_WRONG_KIND	Curve is not a B-spline.
OCCTL_BUFFER_TOO_SMALL	Buffer too small.

\par Thread Safety Yes.

See also: occtl_curve_create_bspline

◆ occtl_curve_bspline_multiplicities()

occtl_status_t occtl_curve_bspline_multiplicities	(	const occtl_graph_t *	graph,
		occtl_rep_id_t	curve_id,
		int32_t *	out_buf,
		size_t	capacity,
		size_t *	out_count
	)

Extracts the knot multiplicities of a B-spline curve.

Two-call pattern: same as occtl_curve_bspline_poles.

Parameters

[in]	graph	Owning graph. Must be non-NULL.
[in]	curve_id	Curve to extract; kind must be `OCCTL_CURVE_KIND_BSPLINE`.
[out]	out_buf	Buffer to receive multiplicity values. May be NULL on sizing call.
[in]	capacity	Capacity of `out_buf` in elements.
[out]	out_count	Required count. Must be non-NULL.

Return values

OCCTL_OK	On success.
OCCTL_INVALID_ARGUMENT	`graph` or `out_count` is NULL.
OCCTL_WRONG_KIND	Curve is not a B-spline.
OCCTL_BUFFER_TOO_SMALL	Buffer too small.

\par Thread Safety Yes.

See also: occtl_curve_create_bspline

◆ occtl_curve_bspline_pole_count()

occtl_status_t occtl_curve_bspline_pole_count	(	const occtl_graph_t *	graph,
		occtl_rep_id_t	curve_id,
		size_t *	out_count
	)

Returns the pole count of a B-spline curve.

Parameters

[in]	graph	Owning graph. Must be non-NULL.
[in]	curve_id	Curve to query; kind must be `OCCTL_CURVE_KIND_BSPLINE`.
[out]	out_count	Receives the pole count. Must be non-NULL.

Return values

OCCTL_OK	On success.
OCCTL_INVALID_ARGUMENT	`graph` or `out_count` is NULL.
OCCTL_WRONG_KIND	Curve is not a B-spline.

\par Thread Safety Yes.

See also: occtl_curve_create_bspline

◆ occtl_curve_bspline_poles()

occtl_status_t occtl_curve_bspline_poles	(	const occtl_graph_t *	graph,
		occtl_rep_id_t	curve_id,
		occtl_point3_t *	out_buf,
		size_t	capacity,
		size_t *	out_count
	)

Extracts the poles of a B-spline curve into a caller-supplied buffer.

Two-call pattern: call with out_buf == NULL to learn the required count in out_count, allocate, then call again with a buffer of at least that size.

Parameters

[in]	graph	Owning graph. Must be non-NULL.
[in]	curve_id	Curve to extract; kind must be `OCCTL_CURVE_KIND_BSPLINE`.
[out]	out_buf	Buffer to receive pole data. May be NULL on the sizing call.
[in]	capacity	Number of elements `out_buf` can hold.
[out]	out_count	Required count. Must be non-NULL.

Return values

OCCTL_OK	On success (poles written).
OCCTL_INVALID_ARGUMENT	`graph` or `out_count` is NULL.
OCCTL_WRONG_KIND	Curve is not a B-spline.
OCCTL_BUFFER_TOO_SMALL	`out_buf` is non-NULL but `capacity` < *`out_count`.

\par Thread Safety Yes.

See also: occtl_curve_create_bspline

◆ occtl_curve_bspline_poles_view()

occtl_status_t occtl_curve_bspline_poles_view	(	const occtl_graph_t *	graph,
		occtl_rep_id_t	curve_id,
		const occtl_point3_t **	out_data,
		size_t *	out_count
	)

Zero-copy view of the poles array of a B-spline curve.

Returns a direct pointer into the OCCT internal storage. Valid only while the graph rep is alive and no mutating call has been made on it.

Parameters

[in]	graph	Owning graph. Must be non-NULL.
[in]	curve_id	Curve to view; kind must be `OCCTL_CURVE_KIND_BSPLINE`.
[out]	out_data	Receives a borrowed pointer to the pole array. Must be non-NULL.
[out]	out_count	Receives the pole count. Must be non-NULL.

Return values

OCCTL_OK	On success.
OCCTL_INVALID_ARGUMENT	`graph`, `out_data`, or `out_count` is NULL.
OCCTL_WRONG_KIND	Curve is not a B-spline.

\par Thread Safety Yes (read-only).

See also: occtl_curve_create_bspline

◆ occtl_curve_bspline_weights()

occtl_status_t occtl_curve_bspline_weights	(	const occtl_graph_t *	graph,
		occtl_rep_id_t	curve_id,
		double *	out_buf,
		size_t	capacity,
		size_t *	out_count
	)

Extracts the per-pole weights of a rational B-spline curve.

Returns OCCTL_WRONG_KIND if the curve is non-rational. Check occtl_curve_bspline_is_rational before calling this function.

Two-call pattern: same as occtl_curve_bspline_poles.

Parameters

[in]	graph	Owning graph. Must be non-NULL.
[in]	curve_id	Curve to extract; kind must be `OCCTL_CURVE_KIND_BSPLINE`; curve must be rational.
[out]	out_buf	Buffer to receive weight values. May be NULL on sizing call.
[in]	capacity	Capacity of `out_buf` in elements.
[out]	out_count	Required count. Must be non-NULL.

Return values

OCCTL_OK	On success.
OCCTL_INVALID_ARGUMENT	`graph` or `out_count` is NULL.
OCCTL_WRONG_KIND	Curve is not a B-spline, or B-spline is non-rational.
OCCTL_BUFFER_TOO_SMALL	Buffer too small.

\par Thread Safety Yes.

See also: occtl_curve_create_bspline

◆ occtl_curve_continuity()

occtl_status_t occtl_curve_continuity	(	const occtl_graph_t *	graph,
		occtl_rep_id_t	curve_id,
		occtl_geom_continuity_t *	out_continuity
	)

Returns the continuity class of the curve.

Parameters

[in]	graph	Owning graph. Must be non-NULL.
[in]	curve_id	Curve to query.
[out]	out_continuity	Receives the continuity class. Must be non-NULL.

Return values

OCCTL_OK	On success.
OCCTL_INVALID_ARGUMENT	`graph` or `out_continuity` is NULL.

\par Thread Safety Yes.

See also: occtl_curve_create_line

◆ occtl_curve_create_airfoil_naca4()

occtl_status_t occtl_curve_create_airfoil_naca4	(	occtl_graph_t *	graph,
		const occtl_curve_airfoil_naca4_info_t *	info,
		occtl_rep_id_t *	out_id
	)

Creates a B-spline curve approximating a NACA 4-digit airfoil profile.

The wrapper generates cosine-spaced NACA profile samples and delegates curve fitting to OCCT's GeomAPI_PointsToBSpline. For a standard NACA 2412 profile, set max_camber=0.02, camber_position=0.4, and thickness=0.12.

Parameters

[in]	graph	Owning graph. Must be non-NULL.
[in]	info	Borrows it. Versioned airfoil parameters; must be non-NULL.
[out]	out_id	Receives the new rep id. Must be non-NULL.

Return values

OCCTL_OK	On success.
OCCTL_INVALID_ARGUMENT	`graph`, `out_id`, or `info` is NULL, `p_next` is non-NULL, a 0/1 flag is invalid, or a numeric parameter is outside its valid range.
OCCTL_VERSION_MISMATCH	Unsupported `struct_version`.
OCCTL_GEOMETRY_INVALID	OCCT rejected the generated point fit.
OCCTL_OUT_OF_MEMORY	Allocation failed.

\par Thread Safety No (mutates graph).

See also: occtl_curve_airfoil_naca4_info_init, occtl_curve_create_approximated

◆ occtl_curve_create_approximated()

occtl_status_t occtl_curve_create_approximated	(	occtl_graph_t *	graph,
		const occtl_curve_approximated_info_t *	info,
		occtl_rep_id_t *	out_id
	)

Fits a B-spline curve to the given points within tolerance.

Uses OCCT's GeomAPI_PointsToBSpline. The resulting curve approximates the points; it does not necessarily pass through them.

Parameters

[in]	graph	Owning graph. Must be non-NULL.
[in]	info	Versioned create-info. Must be non-NULL.
[out]	out_id	Receives the new rep id. Must be non-NULL.

Return values

OCCTL_OK	On success.
OCCTL_INVALID_ARGUMENT	`graph`, `out_id`, or `info` is NULL, or required fields are NULL / zero.
OCCTL_VERSION_MISMATCH	Unsupported `struct_version`.
OCCTL_GEOMETRY_INVALID	Approximation failed.
OCCTL_OUT_OF_MEMORY	Allocation failed.

\par Thread Safety No (mutates graph).

See also: occtl_curve_approximated_info_init

◆ occtl_curve_create_arc_of_circle_3pt()

occtl_status_t occtl_curve_create_arc_of_circle_3pt	(	occtl_graph_t *	graph,
		occtl_point3_t	p1,
		occtl_point3_t	p2,
		occtl_point3_t	p3,
		occtl_rep_id_t *	out_id
	)

Creates a trimmed circular arc through three 3D points.

The arc runs from p1 through p2 to p3. The three points must not be collinear and must be distinct.

Parameters

[in]	graph	Owning graph. Must be non-NULL.
[in]	p1	First point.
[in]	p2	Second point (intermediate).
[in]	p3	Third point.
[out]	out_id	Receives the new rep id. Must be non-NULL.

Return values

OCCTL_OK	On success.
OCCTL_INVALID_ARGUMENT	`graph` or `out_id` is NULL.
OCCTL_GEOMETRY_INVALID	The three points are collinear or cannot define a unique circle.

\par Thread Safety Yes.

See also: occtl_curve_create_circle, occtl_curve_create_trimmed

◆ occtl_curve_create_bezier()

occtl_status_t occtl_curve_create_bezier	(	occtl_graph_t *	graph,
		const occtl_curve_bezier_create_info_t *	info,
		occtl_rep_id_t *	out_id
	)

Creates a 3D curve representation from a Bezier definition.

Parameters

[in]	graph	Owning graph. Must be non-NULL.
[in]	info	Versioned create-info. Must be non-NULL.
[out]	out_id	Receives the new rep id. Must be non-NULL.

Return values

OCCTL_OK	On success.
OCCTL_INVALID_ARGUMENT	`graph`, `out_id`, or `info` is NULL.
OCCTL_VERSION_MISMATCH	Unsupported `struct_version`.
OCCTL_GEOMETRY_INVALID	OCCT rejected the pole count or weights.
OCCTL_OUT_OF_MEMORY	Allocation failed.

\par Thread Safety No (mutates graph).

◆ occtl_curve_create_bspline()

occtl_status_t occtl_curve_create_bspline	(	occtl_graph_t *	graph,
		const occtl_curve_bspline_create_info_t *	info,
		occtl_rep_id_t *	out_id
	)

Creates a 3D curve representation from a B-spline definition.

Parameters

[in]	graph	Owning graph. Must be non-NULL.
[in]	info	Versioned create-info struct. Must be non-NULL. Arrays inside are borrowed; they need not remain valid after the call returns.
[out]	out_id	Receives the new rep id. Must be non-NULL.

Return values

OCCTL_OK	On success.
OCCTL_INVALID_ARGUMENT	`graph`, `out_id`, or `info` is NULL; or required array fields are NULL.
OCCTL_VERSION_MISMATCH	`info->struct_version` is not supported.
OCCTL_GEOMETRY_INVALID	OCCT rejected the knot/pole/degree combination.
OCCTL_OUT_OF_MEMORY	Allocation failed.

\par Thread Safety No (mutates graph).

See also: occtl_curve_bspline_degree, occtl_curve_bspline_poles

◆ occtl_curve_create_circle()

occtl_status_t occtl_curve_create_circle	(	occtl_graph_t *	graph,
		occtl_geom_circle_t	circle,
		occtl_rep_id_t *	out_id
	)

Creates a 3D curve representation from a circle.

Parameters

[in]	graph	Owning graph. Must be non-NULL.
[in]	circle	Circle data (frame + radius). `radius` must be > 0.
[out]	out_id	Receives the new rep id. Must be non-NULL.

Return values

OCCTL_OK	On success.
OCCTL_INVALID_ARGUMENT	`graph` or `out_id` is NULL.
OCCTL_GEOMETRY_INVALID	`circle.radius` is not positive.
OCCTL_OUT_OF_MEMORY	Allocation failed.

\par Thread Safety No (mutates graph).

See also: occtl_curve_as_circle

◆ occtl_curve_create_ellipse()

occtl_status_t occtl_curve_create_ellipse	(	occtl_graph_t *	graph,
		occtl_geom_ellipse_t	ellipse,
		occtl_rep_id_t *	out_id
	)

Creates a 3D curve representation from an ellipse.

Parameters

[in]	graph	Owning graph. Must be non-NULL.
[in]	ellipse	Ellipse data. `major_radius` >= `minor_radius` > 0.
[out]	out_id	Receives the new rep id. Must be non-NULL.

Return values

OCCTL_OK	On success.
OCCTL_INVALID_ARGUMENT	`graph` or `out_id` is NULL.
OCCTL_GEOMETRY_INVALID	Radii are not positive or major < minor.
OCCTL_OUT_OF_MEMORY	Allocation failed.

\par Thread Safety No (mutates graph).

See also: occtl_curve_as_ellipse

◆ occtl_curve_create_hyperbola()

occtl_status_t occtl_curve_create_hyperbola	(	occtl_graph_t *	graph,
		occtl_geom_hyperbola_t	hyperbola,
		occtl_rep_id_t *	out_id
	)

Creates a 3D curve representation from a hyperbola.

Parameters

[in]	graph	Owning graph. Must be non-NULL.
[in]	hyperbola	Hyperbola data. Both radii must be > 0.
[out]	out_id	Receives the new rep id. Must be non-NULL.

Return values

OCCTL_OK	On success.
OCCTL_INVALID_ARGUMENT	`graph` or `out_id` is NULL.
OCCTL_GEOMETRY_INVALID	A radius is not positive.
OCCTL_OUT_OF_MEMORY	Allocation failed.

\par Thread Safety No (mutates graph).

See also: occtl_curve_as_hyperbola

◆ occtl_curve_create_interpolated()

occtl_status_t occtl_curve_create_interpolated	(	occtl_graph_t *	graph,
		const occtl_curve_interpolated_info_t *	info,
		occtl_rep_id_t *	out_id
	)

Creates a B-spline curve that interpolates (passes through) the given points.

Uses OCCT's GeomAPI_Interpolate. The resulting curve is always a C2 continuous cubic B-spline. Set is_periodic to make the curve periodic (first and last points must match within tolerance).

Parameters

[in]	graph	Owning graph. Must be non-NULL.
[in]	info	Versioned create-info. Must be non-NULL.
[out]	out_id	Receives the new rep id. Must be non-NULL.

Return values

OCCTL_OK	On success.
OCCTL_INVALID_ARGUMENT	`graph`, `out_id`, or `info` is NULL, or required fields are NULL / zero.
OCCTL_VERSION_MISMATCH	Unsupported `struct_version`.
OCCTL_GEOMETRY_INVALID	Interpolation failed.
OCCTL_OUT_OF_MEMORY	Allocation failed.

\par Thread Safety No (mutates graph).

See also: occtl_curve_interpolated_info_init

◆ occtl_curve_create_line()

occtl_status_t occtl_curve_create_line	(	occtl_graph_t *	graph,
		occtl_geom_line_t	line,
		occtl_rep_id_t *	out_id
	)

Creates a 3D curve representation from a line.

Parameters

[in]	graph	Owning graph. Must be non-NULL.
[in]	line	Line data (origin + unit direction).
[out]	out_id	Receives the new rep id. Must be non-NULL.

Return values

OCCTL_OK	On success.
OCCTL_INVALID_ARGUMENT	`graph` or `out_id` is NULL.
OCCTL_OUT_OF_MEMORY	Allocation failed.

\par Thread Safety No (mutates graph).

See also: occtl_curve_kind, occtl_curve_as_line

◆ occtl_curve_create_offset()

occtl_status_t occtl_curve_create_offset	(	occtl_graph_t *	graph,
		const occtl_curve_offset_create_info_t *	info,
		occtl_rep_id_t *	out_id
	)

Creates an offset 3D curve.

Parameters

[in]	graph	Owning graph. Must be non-NULL.
[in]	info	Versioned create-info. Must be non-NULL.
[out]	out_id	Receives the new rep id. Must be non-NULL.

Return values

OCCTL_OK	On success.
OCCTL_INVALID_ARGUMENT	`graph`, `out_id`, or `info` is NULL; or `info->basis` is invalid.
OCCTL_VERSION_MISMATCH	Unsupported `struct_version`.
OCCTL_GEOMETRY_INVALID	`offset_dir` has zero length.
OCCTL_OUT_OF_MEMORY	Allocation failed.

\par Thread Safety No (mutates graph).

◆ occtl_curve_create_parabola()

occtl_status_t occtl_curve_create_parabola	(	occtl_graph_t *	graph,
		occtl_geom_parabola_t	parabola,
		occtl_rep_id_t *	out_id
	)

Creates a 3D curve representation from a parabola.

Parameters

[in]	graph	Owning graph. Must be non-NULL.
[in]	parabola	Parabola data. `focal_length` must be > 0.
[out]	out_id	Receives the new rep id. Must be non-NULL.

Return values

OCCTL_OK	On success.
OCCTL_INVALID_ARGUMENT	`graph` or `out_id` is NULL.
OCCTL_GEOMETRY_INVALID	`focal_length` is not positive.
OCCTL_OUT_OF_MEMORY	Allocation failed.

\par Thread Safety No (mutates graph).

See also: occtl_curve_as_parabola

◆ occtl_curve_create_trimmed()

occtl_status_t occtl_curve_create_trimmed	(	occtl_graph_t *	graph,
		const occtl_curve_trimmed_create_info_t *	info,
		occtl_rep_id_t *	out_id
	)

Creates a trimmed 3D curve (bounded section of a basis curve).

Parameters

[in]	graph	Owning graph. Must be non-NULL.
[in]	info	Versioned create-info. Must be non-NULL.
[out]	out_id	Receives the new rep id. Must be non-NULL.

Return values

OCCTL_OK	On success.
OCCTL_INVALID_ARGUMENT	`graph`, `out_id`, or `info` is NULL; or `info->basis` is invalid.
OCCTL_VERSION_MISMATCH	Unsupported `struct_version`.
OCCTL_GEOMETRY_INVALID	`u_last` <= `u_first`, or OCCT rejected the interval.
OCCTL_OUT_OF_MEMORY	Allocation failed.

\par Thread Safety No (mutates graph).

◆ occtl_curve_eval_d0()

occtl_status_t occtl_curve_eval_d0	(	const occtl_graph_t *	graph,
		occtl_rep_id_t	curve_id,
		double	u,
		occtl_point3_t *	out_point
	)

Evaluates the curve at parameter u.

Parameters

[in]	graph	Owning graph. Must be non-NULL.
[in]	curve_id	Curve to evaluate.
[in]	u	Parameter value.
[out]	out_point	Receives the point on the curve. May be NULL.

Return values

OCCTL_OK	On success.
OCCTL_INVALID_ARGUMENT	`graph` is NULL.
OCCTL_OUT_OF_RANGE	`u` is outside the parameter domain.

\par Thread Safety Only when distinct graph instances are used.

See also: occtl_curve_eval_d1, occtl_curve_eval_dn

◆ occtl_curve_eval_d1()

occtl_status_t occtl_curve_eval_d1	(	const occtl_graph_t *	graph,
		occtl_rep_id_t	curve_id,
		double	u,
		occtl_point3_t *	out_point,
		occtl_vector3_t *	out_d1
	)

Evaluates the curve and its first derivative at u.

Parameters

[in]	graph	Owning graph. Must be non-NULL.
[in]	curve_id	Curve to evaluate.
[in]	u	Parameter value.
[out]	out_point	Receives the point. May be NULL.
[out]	out_d1	Receives the first derivative vector. May be NULL.

Return values

OCCTL_OK	On success.
OCCTL_INVALID_ARGUMENT	`graph` is NULL.
OCCTL_OUT_OF_RANGE	`u` is outside the parameter domain.

\par Thread Safety Only when distinct graph instances are used.

See also: occtl_curve_eval_d0, occtl_curve_eval_d2

◆ occtl_curve_eval_d2()

occtl_status_t occtl_curve_eval_d2	(	const occtl_graph_t *	graph,
		occtl_rep_id_t	curve_id,
		double	u,
		occtl_point3_t *	out_point,
		occtl_vector3_t *	out_d1,
		occtl_vector3_t *	out_d2
	)

Evaluates point, first, and second derivatives at u.

Parameters

[in]	graph	Owning graph. Must be non-NULL.
[in]	curve_id	Curve to evaluate.
[in]	u	Parameter value.
[out]	out_point	Receives the point. May be NULL.
[out]	out_d1	Receives the first derivative vector. May be NULL.
[out]	out_d2	Receives the second derivative vector. May be NULL.

Return values

OCCTL_OK	On success.
OCCTL_INVALID_ARGUMENT	`graph` is NULL.
OCCTL_OUT_OF_RANGE	`u` is outside the parameter domain.

\par Thread Safety Only when distinct graph instances are used.

See also: occtl_curve_eval_d1, occtl_curve_eval_d3

◆ occtl_curve_eval_d3()

occtl_status_t occtl_curve_eval_d3	(	const occtl_graph_t *	graph,
		occtl_rep_id_t	curve_id,
		double	u,
		occtl_point3_t *	out_point,
		occtl_vector3_t *	out_d1,
		occtl_vector3_t *	out_d2,
		occtl_vector3_t *	out_d3
	)

Evaluates point and first three derivatives at u.

Parameters

[in]	graph	Owning graph. Must be non-NULL.
[in]	curve_id	Curve to evaluate.
[in]	u	Parameter value.
[out]	out_point	Receives the point. May be NULL.
[out]	out_d1	Receives the first derivative vector. May be NULL.
[out]	out_d2	Receives the second derivative vector. May be NULL.
[out]	out_d3	Receives the third derivative vector. May be NULL.

Return values

OCCTL_OK	On success.
OCCTL_INVALID_ARGUMENT	`graph` is NULL.
OCCTL_OUT_OF_RANGE	`u` is outside the parameter domain.

\par Thread Safety Only when distinct graph instances are used.

See also: occtl_curve_eval_d2, occtl_curve_eval_dn

◆ occtl_curve_eval_dn()

occtl_status_t occtl_curve_eval_dn	(	const occtl_graph_t *	graph,
		occtl_rep_id_t	curve_id,
		double	u,
		int32_t	n,
		occtl_vector3_t *	out_derivative
	)

Returns the N-th derivative vector at u.

Parameters

[in]	graph	Owning graph. Must be non-NULL.
[in]	curve_id	Curve to evaluate.
[in]	u	Parameter value.
[in]	n	Derivative order (0 returns a zero-length vector whose origin is on the curve; 1 returns the first derivative, etc.).
[out]	out_derivative	Receives the derivative vector. Must be non-NULL.

Return values

OCCTL_OK	On success.
OCCTL_INVALID_ARGUMENT	`graph` is NULL.
OCCTL_OUT_OF_RANGE	`u` is outside the parameter domain.

\par Thread Safety Only when distinct graph instances are used.

See also: occtl_curve_eval_d0, occtl_curve_eval_d3

◆ occtl_curve_free_bezier_segments()

void occtl_curve_free_bezier_segments ( occtl_rep_id_t * ids )

Frees the array returned by occtl_curve_to_bezier_segments.

NULL-tolerant; passing NULL is a no-op.

Parameters

[in] ids Owns it. May be NULL.

\par Thread Safety Yes.

See also: occtl_curve_to_bezier_segments

◆ occtl_curve_free_intersection_points()

void occtl_curve_free_intersection_points ( occtl_curve_intersection_point_t * results )

Frees the array returned by occtl_curve_intersect.

NULL-tolerant; passing NULL is a no-op.

Parameters

[in] results Owns it. May be NULL.

\par Thread Safety Yes.

See also: occtl_curve_intersect

◆ occtl_curve_interpolated_info_init()

void occtl_curve_interpolated_info_init ( occtl_curve_interpolated_info_t * info )

Runtime initialiser for occtl_curve_interpolated_info_t.

Parameters

[out] info Borrows it. NULL-tolerant; no-op when NULL.

\par Thread Safety Yes.

See also: occtl_curve_create_interpolated

◆ occtl_curve_intersect()

occtl_status_t occtl_curve_intersect	(	occtl_graph_t *	graph,
		occtl_rep_id_t	curve_id_a,
		occtl_rep_id_t	curve_id_b,
		const occtl_curve_intersection_point_t **	out_results,
		size_t *	out_count
	)

Finds the closest points between two curves.

Uses OCCT's GeomAPI_ExtremaCurveCurve. Returns all extrema points (minima and maxima of distance) between the two curves. When the curves intersect, the distance is zero and the returned points coincide.

The caller owns the returned array and must free it with occtl_curve_free_intersection_points.

Parameters

[in]	graph	Owning graph. Must be non-NULL.
[in]	curve_id_a	First curve.
[in]	curve_id_b	Second curve.
[out]	out_results	Receives a caller-owned array of intersection points. Must be non-NULL. Free with occtl_curve_free_intersection_points.
[out]	out_count	Receives the number of intersection points. Must be non-NULL.

Return values

OCCTL_OK	On success.
OCCTL_INVALID_ARGUMENT	`graph`, `out_results`, or `out_count` is NULL.
OCCTL_OUT_OF_MEMORY	Allocation failed.

\par Thread Safety Yes.

See also: occtl_curve_create_line

◆ occtl_curve_is_closed()

occtl_status_t occtl_curve_is_closed	(	const occtl_graph_t *	graph,
		occtl_rep_id_t	curve_id,
		int32_t *	out_is_closed
	)

Returns non-zero if the curve is closed.

A curve is closed when its start and end points coincide within OCCT's confusion tolerance. Periodic curves are always closed; the converse does not hold.

Parameters

[in]	graph	Owning graph. Must be non-NULL.
[in]	curve_id	Curve to query.
[out]	out_is_closed	Receives 1 if closed, 0 otherwise. Must be non-NULL.

Return values

OCCTL_OK	On success.
OCCTL_INVALID_ARGUMENT	`graph` or `out_is_closed` is NULL.

\par Thread Safety Yes.

See also: occtl_curve_is_periodic

◆ occtl_curve_is_periodic()

occtl_status_t occtl_curve_is_periodic	(	const occtl_graph_t *	graph,
		occtl_rep_id_t	curve_id,
		int32_t *	out_is_periodic
	)

Returns non-zero if the curve is periodic.

Parameters

[in]	graph	Owning graph. Must be non-NULL.
[in]	curve_id	Curve to query.
[out]	out_is_periodic	Receives 1 if periodic, 0 otherwise. Must be non-NULL.

Return values

OCCTL_OK	On success.
OCCTL_INVALID_ARGUMENT	`graph` or `out_is_periodic` is NULL.

\par Thread Safety Yes.

See also: occtl_curve_create_line

◆ occtl_curve_kind()

occtl_status_t occtl_curve_kind	(	const occtl_graph_t *	graph,
		occtl_rep_id_t	curve_id,
		occtl_curve_kind_t *	out_kind
	)

Returns the kind of geometry wrapped by a curve representation.

Parameters

[in]	graph	Owning graph. Must be non-NULL.
[in]	curve_id	Curve to query.
[out]	out_kind	Receives the curve kind. Must be non-NULL.

Return values

OCCTL_OK	On success.
OCCTL_INVALID_ARGUMENT	`graph` or `out_kind` is NULL.

\par Thread Safety Yes.

See also: occtl_curve_as_circle, occtl_curve_as_ellipse

◆ occtl_curve_length()

occtl_status_t occtl_curve_length	(	const occtl_graph_t *	graph,
		occtl_rep_id_t	curve_id,
		double *	out_length
	)

Computes the length of the curve over its full parameter range.

The length is computed by numerical integration using OCCT's GCPnts_AbscissaPoint.

Parameters

[in]	graph	Owning graph. Must be non-NULL.
[in]	curve_id	Curve to measure.
[out]	out_length	Receives the curve length. Must be non-NULL.

Return values

OCCTL_OK	On success.
OCCTL_INVALID_ARGUMENT	`graph` or `out_length` is NULL.

\par Thread Safety Only when distinct graph instances are used.

See also: occtl_curve_create_line

◆ occtl_curve_offset_create_info_init()

void occtl_curve_offset_create_info_init ( occtl_curve_offset_create_info_t * info )

Runtime initialiser for occtl_curve_offset_create_info_t.

Parameters

[out] info Borrows it. NULL-tolerant; no-op when NULL.

\par Thread Safety Yes.

See also: occtl_curve_create_offset

◆ occtl_curve_parameter_of_point()

occtl_status_t occtl_curve_parameter_of_point	(	const occtl_graph_t *	graph,
		occtl_rep_id_t	curve_id,
		occtl_point3_t	point,
		double *	out_param
	)

Returns the parameter on the curve nearest to a given 3D point.

Convenience function equivalent to occtl_curve_project_point with out_distance = NULL.

Parameters

[in]	graph	Owning graph. Must be non-NULL.
[in]	curve_id	Curve to query.
[in]	point	Point to find the parameter for.
[out]	out_param	Receives the parameter. Must be non-NULL.

Return values

OCCTL_OK	On success.
OCCTL_INVALID_ARGUMENT	`graph` or `out_param` is NULL.

\par Thread Safety Only when distinct graph instances are used.

See also: occtl_curve_create_line

◆ occtl_curve_parameter_range()

occtl_status_t occtl_curve_parameter_range	(	const occtl_graph_t *	graph,
		occtl_rep_id_t	curve_id,
		double *	out_u_min,
		double *	out_u_max
	)

Returns the parameter range of the curve.

For analytic infinite curves (lines, parabolas, hyperbolas) OCCT returns -Precision::Infinite() and +Precision::Infinite() (numerically -1e100 and +1e100). Bounded analytic curves (full circles, ellipses) return [0, 2pi]. Trimmed and B-spline curves return their explicit range.

Parameters

[in]	graph	Owning graph. Must be non-NULL.
[in]	curve_id	Curve to query.
[out]	out_u_min	First (start) parameter. May be NULL.
[out]	out_u_max	Last (end) parameter. May be NULL.

Return values

OCCTL_OK	On success.
OCCTL_INVALID_ARGUMENT	`graph` is NULL.

\par Thread Safety Yes.

See also: occtl_curve_create_line

◆ occtl_curve_project_point()

occtl_status_t occtl_curve_project_point	(	const occtl_graph_t *	graph,
		occtl_rep_id_t	curve_id,
		occtl_point3_t	point,
		double *	out_param,
		double *	out_distance
	)

Projects a 3D point onto the curve and returns the closest parameter.

Uses OCCT's GeomAPI_ProjectPointOnCurve. When multiple solutions exist (e.g. a circle), the closest point is returned.

Parameters

[in]	graph	Owning graph. Must be non-NULL.
[in]	curve_id	Curve to project onto.
[in]	point	Point to project.
[out]	out_param	Receives the parameter of the closest point on the curve. Must be non-NULL.
[out]	out_distance	Receives the shortest distance. May be NULL.

Return values

OCCTL_OK	On success.
OCCTL_INVALID_ARGUMENT	`graph` or `out_param` is NULL.

\par Thread Safety Only when distinct graph instances are used.

See also: occtl_curve_create_line

◆ occtl_curve_reverse()

occtl_status_t occtl_curve_reverse	(	occtl_graph_t *	graph,
		occtl_rep_id_t	curve_id,
		occtl_rep_id_t *	out_id
	)

Creates a new curve representation that is the reversed copy of curve_id.

The returned rep owns an independent curve whose parameterisation runs in the opposite direction: reversed(u) = curve(u_last - u).

Parameters

[in]	graph	Owning graph. Must be non-NULL.
[in]	curve_id	Curve to reverse.
[out]	out_id	Receives the new rep id. Must be non-NULL.

Return values

OCCTL_OK	On success.
OCCTL_INVALID_ARGUMENT	`graph` or `out_id` is NULL.
OCCTL_OUT_OF_MEMORY	Allocation failed.

\par Thread Safety No (mutates graph).

See also: occtl_curve_create_line

◆ occtl_curve_rotated()

occtl_status_t occtl_curve_rotated	(	occtl_graph_t *	graph,
		occtl_rep_id_t	curve_id,
		occtl_axis1_placement_t	axis,
		double	angle,
		occtl_rep_id_t *	out_id
	)

Creates a new curve representation by rotating curve_id.

Convenience wrapper equivalent to applying a rotation transform.

Parameters

[in]	graph	Owning graph. Must be non-NULL.
[in]	curve_id	Curve to rotate.
[in]	axis	Rotation axis (origin + direction).
[in]	angle	Rotation angle in radians.
[out]	out_id	Receives the new rep id. Must be non-NULL.

Return values

OCCTL_OK	On success.
OCCTL_INVALID_ARGUMENT	`graph` or `out_id` is NULL.
OCCTL_OUT_OF_MEMORY	Allocation failed.

\par Thread Safety No (mutates graph).

See also: occtl_curve_create_line

◆ occtl_curve_scaled()

occtl_status_t occtl_curve_scaled	(	occtl_graph_t *	graph,
		occtl_rep_id_t	curve_id,
		occtl_point3_t	origin,
		double	factor,
		occtl_rep_id_t *	out_id
	)

Creates a new curve representation by scaling curve_id about origin.

Convenience wrapper equivalent to applying a non-uniform scale transform.

Parameters

[in]	graph	Owning graph. Must be non-NULL.
[in]	curve_id	Curve to scale.
[in]	origin	Origin point for scaling.
[in]	factor	Scale factor; must be non-zero.
[out]	out_id	Receives the new rep id. Must be non-NULL.

Return values

OCCTL_OK	On success.
OCCTL_INVALID_ARGUMENT	`graph` or `out_id` is NULL.
OCCTL_GEOMETRY_INVALID	`factor` is zero.
OCCTL_OUT_OF_MEMORY	Allocation failed.

\par Thread Safety No (mutates graph).

See also: occtl_curve_create_line

◆ occtl_curve_to_bezier_segments()

occtl_status_t occtl_curve_to_bezier_segments	(	occtl_graph_t *	graph,
		occtl_rep_id_t	curve_id,
		const occtl_curve_bezier_segments_options_t *	options,
		occtl_rep_id_t **	out_ids,
		size_t *	out_count
	)

Decomposes a curve into adjacent Bezier curve segments.

The implementation delegates conversion and segmentation to OCCT GeomConvert and GeomConvert_BSplineCurveToBezierCurve. Each output entry is a new rep id of kind OCCTL_CURVE_KIND_BEZIER. Free the returned array with occtl_curve_free_bezier_segments.

Parameters

[in]	graph	Owning graph. Must be non-NULL.
[in]	curve_id	Curve to decompose.
[in]	options	Borrows it. May be NULL for default full-domain options.
[out]	out_ids	Owns it. Receives an allocated array of rep ids. Must be non-NULL. Free with occtl_curve_free_bezier_segments.
[out]	out_count	Borrows it. Receives the number of returned segments. Must be non-NULL.

Return values

OCCTL_OK	On success.
OCCTL_INVALID_ARGUMENT	`graph`, `out_ids`, or `out_count` is NULL; `p_next` is non-NULL; a 0/1 flag is invalid; range/tolerance values are invalid.
OCCTL_VERSION_MISMATCH	Unsupported `options->struct_version`.
OCCTL_GEOMETRY_INVALID	OCCT could not convert or segment the curve.
OCCTL_OUT_OF_MEMORY	Allocation failed.

\par Thread Safety Yes.

See also: occtl_curve_create_bezier, occtl_curve_bezier_segments_options_init

◆ occtl_curve_transformed()

occtl_status_t occtl_curve_transformed	(	occtl_graph_t *	graph,
		occtl_rep_id_t	curve_id,
		occtl_transform_t	transform,
		occtl_rep_id_t *	out_id
	)

Creates a new curve representation by applying a 3D transform to curve_id.

The returned rep owns an independent transformed copy.

Parameters

[in]	graph	Owning graph. Must be non-NULL.
[in]	curve_id	Curve to transform.
[in]	transform	Transform to apply.
[out]	out_id	Receives the new rep id. Must be non-NULL.

Return values

OCCTL_OK	On success.
OCCTL_INVALID_ARGUMENT	`graph` or `out_id` is NULL.
OCCTL_OUT_OF_MEMORY	Allocation failed.

\par Thread Safety No (mutates graph).

See also: occtl_curve_create_line

◆ occtl_curve_translated()

occtl_status_t occtl_curve_translated	(	occtl_graph_t *	graph,
		occtl_rep_id_t	curve_id,
		occtl_vector3_t	delta,
		occtl_rep_id_t *	out_id
	)

Creates a new curve representation by translating curve_id.

Convenience wrapper equivalent to applying a translation transform.

Parameters

[in]	graph	Owning graph. Must be non-NULL.
[in]	curve_id	Curve to translate.
[in]	delta	Translation vector.
[out]	out_id	Receives the new rep id. Must be non-NULL.

Return values

OCCTL_OK	On success.
OCCTL_INVALID_ARGUMENT	`graph` or `out_id` is NULL.
OCCTL_OUT_OF_MEMORY	Allocation failed.

\par Thread Safety No (mutates graph).

See also: occtl_curve_create_line

Classes

Macros

Typedefs

Functions

Detailed Description

Typedef Documentation

◆ occtl_curve_airfoil_naca4_info_t

◆ occtl_curve_approximated_info_t

◆ occtl_curve_bezier_create_info_t

◆ occtl_curve_bspline_create_info_t

◆ occtl_curve_bspline_t

◆ occtl_curve_interpolated_info_t

◆ occtl_curve_intersection_point_t

◆ occtl_curve_offset_create_info_t

Function Documentation

◆ occtl_curve_airfoil_naca4_info_init()

◆ occtl_curve_approximated_info_init()

◆ occtl_curve_as_bspline()

◆ occtl_curve_as_circle()

◆ occtl_curve_as_ellipse()

◆ occtl_curve_as_hyperbola()

◆ occtl_curve_as_line()

◆ occtl_curve_as_offset()

◆ occtl_curve_as_parabola()

◆ occtl_curve_as_trimmed()

◆ occtl_curve_bezier_create_info_init()

◆ occtl_curve_bezier_degree()

◆ occtl_curve_bezier_is_rational()

◆ occtl_curve_bezier_pole_count()

◆ occtl_curve_bspline_create_info_init()

◆ occtl_curve_bspline_degree()

◆ occtl_curve_bspline_flat_knots()

◆ occtl_curve_bspline_init()

◆ occtl_curve_bspline_is_rational()

◆ occtl_curve_bspline_knot_count()

◆ occtl_curve_bspline_knots()

◆ occtl_curve_bspline_multiplicities()

◆ occtl_curve_bspline_pole_count()

◆ occtl_curve_bspline_poles()

◆ occtl_curve_bspline_poles_view()

◆ occtl_curve_bspline_weights()

◆ occtl_curve_continuity()

◆ occtl_curve_create_airfoil_naca4()

◆ occtl_curve_create_approximated()

◆ occtl_curve_create_arc_of_circle_3pt()

◆ occtl_curve_create_bezier()

◆ occtl_curve_create_bspline()

◆ occtl_curve_create_circle()

◆ occtl_curve_create_ellipse()

◆ occtl_curve_create_hyperbola()

◆ occtl_curve_create_interpolated()

◆ occtl_curve_create_line()

◆ occtl_curve_create_offset()

◆ occtl_curve_create_parabola()

◆ occtl_curve_create_trimmed()

◆ occtl_curve_eval_d0()

◆ occtl_curve_eval_d1()

◆ occtl_curve_eval_d2()

◆ occtl_curve_eval_d3()

◆ occtl_curve_eval_dn()

◆ occtl_curve_free_bezier_segments()

◆ occtl_curve_free_intersection_points()

◆ occtl_curve_interpolated_info_init()

◆ occtl_curve_intersect()

◆ occtl_curve_is_closed()

◆ occtl_curve_is_periodic()

◆ occtl_curve_kind()

◆ occtl_curve_length()

◆ occtl_curve_offset_create_info_init()

◆ occtl_curve_parameter_of_point()

◆ occtl_curve_parameter_range()

◆ occtl_curve_project_point()

◆ occtl_curve_reverse()

◆ occtl_curve_rotated()

◆ occtl_curve_scaled()

◆ occtl_curve_to_bezier_segments()

◆ occtl_curve_transformed()

◆ occtl_curve_translated()