uf_evalsf.html

/*

uf_evalsf.h
File description:

Open API interface to functions that evaluate surfaces. These functions are
the preferred way for fast evaluation of faces and underlying surfaces.

Note that UF_EVALSF_evaluate and UF_EVALSF_evaluate_array may not properly
handle parameter values returned by UF_EVALSF_find_closest_point or similar
functions for surface types Blend or Trimmed B-surface. The functions
UF_MODL_evaluate_face or UF_MODL_ask_face_props should be called instead.

*******************************************************************************/

#ifndef UF_EVALSF_H_INCLUDED
#define UF_EVALSF_H_INCLUDED

#include <uf_defs.h>
#include <uf_modl_types.h>
#include <libufun_exports.h>

/***************** Data Structure Section ************************************/

/* surface evaluation structure */
typedef struct UF_EVALSF_S *UF_EVALSF_p_t;
typedef const struct UF_EVALSF_S *UF_EVALSF_pc_t;
typedef struct UF_EVALSF_pos3_s UF_EVALSF_pos3_t, *UF_EVALSF_pos3_p_t;

/*
Definition for 3D position
*/
struct UF_EVALSF_pos3_s
{
double distance; /* separation between surface and reference point */
double uv[2]; /* uv-parameter pair */
double pnt3[3]; /* 3D point */
};
typedef const UF_EVALSF_pos3_t UF_EVALSF_pos3_c_t, *UF_EVALSF_pos3_pc_t;

/* By reference components */
#define UF_EVALSF_pos3_UV(r) ((r)->uv)
#define UF_EVALSF_pos3_PNT3(r) ((r)->pnt3)
#define UF_EVALSF_pos3_U(r) ((r)->uv[0])
#define UF_EVALSF_pos3_V(r) ((r)->uv[1])
#define UF_EVALSF_pos3_D(r) ((r)->distance)
#define UF_EVALSF_pos3_X(r) ((r)->pnt3[0])
#define UF_EVALSF_pos3_Y(r) ((r)->pnt3[1])
#define UF_EVALSF_pos3_Z(r) ((r)->pnt3[2])
#define UF_EVALSF_pos3_LIST(r) UF_EVALSF_pos3_U(r), UF_EVALSF_pos3_V(r), UF_EVALSF_pos3_D(r), \
UF_EVALSF_pos3_X(r), UF_EVALSF_pos3_Y(r), UF_EVALSF_pos3_Z(r)
/* By value components */
#define UF_EVALSF_pos3_uv(v) ((v).uv)
#define UF_EVALSF_pos3_pnt3(v) ((v).pnt3)
#define UF_EVALSF_pos3_u(v) ((v).uv[0])
#define UF_EVALSF_pos3_v(v) ((v).uv[1])
#define UF_EVALSF_pos3_d(v) ((v).distance)
#define UF_EVALSF_pos3_x(v) ((v).pnt3[0])
#define UF_EVALSF_pos3_y(v) ((v).pnt3[1])
#define UF_EVALSF_pos3_z(v) ((v).pnt3[2])
#define UF_EVALSF_pos3_list(v) UF_EVALSF_pos3_u(v), UF_EVALSF_pos3_v(v), UF_EVALSF_pos3_d(v), \
UF_EVALSF_pos3_x(v), UF_EVALSF_pos3_y(v), UF_EVALSF_pos3_z(v)

/***************** Function Prototypes Section ********************************/

/******************************************************************************
Computes the u,v parameter space min, max of a face

Environment: Internal and External
See Also:
History:
*****************************************************************************/
extern UFUNEXPORT int UF_EVALSF_ask_face_uv_minmax
(
UF_EVALSF_pc_t evaluator, /* Address of evaluator structure */
double uv_min_max[4] /* <O> [0] - umin
[1] - umax
[2] - vmin
[3] - vmax */
);

/******************************************************************************
Returns the minimum distance parameter and point on the surface of a face
given a reference point.

The surface point is on the portion which is bounded by the edges of the face.

To find the closest point on the extended surface (not within bounding edges)
use UF_EVALSF_find_closest_point

Environment: Internal and External
See Also:
History:
*****************************************************************************/
extern UFUNEXPORT int UF_EVALSF_ask_minimum_face_dist
(
UF_EVALSF_pc_t evaluator, /* Address of evaluator structure */
const double point[3], /* Given point in absolute space */
UF_EVALSF_pos3_p_t srf_pos3 /* <O> Address of point position on surface */
);

/******************************************************************************
Evaluates a point and the derivatives of a face at the given parameter value.

Environment: Internal and External
See Also: UF_MODL_evaluate_face and UF_MODL_ask_face_props
Note that UF_EVALSF_evaluate may not properly handle parameter values
returned by UF_EVALSF_find_closest_point or similar functions for
surface types Blend or Trimmed B-surface. The above functions should be
called instead.
History:
*****************************************************************************/
extern UFUNEXPORT int UF_EVALSF_evaluate
(
UF_EVALSF_pc_t evaluator, /* Address of evaluator structure */
int deriv_flag, /* 
order of the derivative to be computed:
UF_MODL_EVAL - position
UF_MODL_EVAL_DERIV1 - position and 1. partial
UF_MODL_EVAL_DERIV2 - position, 1. and 2. partials
UF_MODL_EVAL_DERIV3 - position, 1., 2. and 3. partials
UF_MODL_EVAL_UNIT_NORMAL - position, 1. partials and
unitized normal.
UF_MODL_EVAL_NORMAL - position, 1. partials and the
ununitized normal.
UF_MODL_EVAL_ALL - position, normals and all the partials
up to the third order.
*/
const double uv_pair[2], /* uv-parameter pair
at which derivatives are to be computed.
The parameter limits for a given face can be found
by calling UF_EVALSF_ask_face_uv_minmax.
*/
UF_MODL_SRF_VALUE_p_t surf_eval /* <O> Address of evaluation result structure
containing position and derivatives:
srf_pos[3] - position
srf_du[3] - d/du
srf_dv[3] - d/dv
srf_unormal[3] - unit normal
srf_d2u[3] - d2/du2
srf_dudv[3] - d2/dudv
srf_d2v[3] - d2/dv2
srf_d3u[3] - d3/du3
srf_d2udv[3] - d3/du2dv
srf_dud2v[3] - d3/dud2v
srf_d3v[3] - d3/dv3
srf_normal[3] - d/du X d/dv
*/
);

/******************************************************************************
Evaluates an array of points and derivatives of a face for a given array of parameter values.

Environment: Internal and External
See Also: UF_MODL_evaluate_face and UF_MODL_ask_face_props
Note that UF_EVALSF_evaluate_array may not properly handle parameter values
returned by UF_EVALSF_find_closest_point or similar functions for
surface types Blend or Trimmed B-surface. The above functions should be
called instead.
History:
*****************************************************************************/
extern UFUNEXPORT int UF_EVALSF_evaluate_array
(
UF_EVALSF_pc_t evaluator, /* Address of evaluator structure */
int deriv_flag, /* 
order of the derivative to be computed:
UF_MODL_EVAL - position
UF_MODL_EVAL_DERIV1 - position and 1. partial
UF_MODL_EVAL_DERIV2 - position, 1. and 2. partials
UF_MODL_EVAL_DERIV3 - position, 1., 2. and 3. partials
UF_MODL_EVAL_UNIT_NORMAL - position, 1. partials and
unitized normal.
UF_MODL_EVAL_NORMAL - position, 1. partials and the
ununitized normal.
UF_MODL_EVAL_ALL - position, normals and all the partials
up to the third order.
*/
int num_points, /* number of points to evaluate */
const double uv_pairs[], /* num_points uv-parameter pairs
The parameter limits for a given face can be found
by calling UF_EVALSF_ask_face_uv_minmax.
*/
UF_MODL_SRF_VALUE_t surf_evals[]/* <O> Address of array of evaluation results
The caller must provide space of
size = sizeof(UF_MODL_SRF_VALUE_t) * num_points
Each structure element contains:
srf_pos[3] - position
srf_du[3] - d/du
srf_dv[3] - d/dv
srf_unormal[3] - unit normal
srf_d2u[3] - d2/du2
srf_dudv[3] - d2/dudv
srf_d2v[3] - d2/dv2
srf_d3u[3] - d3/du3
srf_d2udv[3] - d3/du2dv
srf_dud2v[3] - d3/dud2v
srf_d3v[3] - d3/dv3
srf_normal[3] - d/du X d/dv
*/
);

/******************************************************************************
Finds on the surface the closest point and uv-parameter pair to a given point.

Note that the returned point will be on the underlying surface
but may not be on the portion which is bounded by the edges
of the face.

To find the closest point within bounding edges, use
UF_EVALSF_ask_minimum_face_dist

Environment: Internal and External
See Also:
History:
*****************************************************************************/
extern UFUNEXPORT int UF_EVALSF_find_closest_point
(
UF_EVALSF_pc_t evaluator, /* Address of evaluator structure */
const double point[3], /* Given point in absolute space */
UF_EVALSF_pos3_p_t srf_pos3 /* <O> Address of point position on surface */
);

/******************************************************************************
Frees the evaluator of a face

Environment: Internal and External
See Also:
History:
*****************************************************************************/
extern UFUNEXPORT int UF_EVALSF_free
(
UF_EVALSF_p_t *evaluator /* <O> address of evaluator pointer */
);

/******************************************************************************
Initializes a face evaluator structure

Environment: Internal and External
See Also:
History:
*****************************************************************************/
extern UFUNEXPORT int UF_EVALSF_initialize
(
tag_t face_tag, /* Object identifier of a face */
UF_EVALSF_p_t *evaluator /* <OF> Evaluator structure for this face.
It must be freed by calling UF_EVALFS_free. */
);

#undef EXPORTLIBRARY

#endif /* UF_EVALSF_H_INCLUDED */