PK_ERROR_code_t PK_TOPOL_range_array
(
--- received arguments ---
int n_topols_1, --- no. entities in 1st array
const PK_TOPOL_t topols_1[], --- first topological array
int n_topols_2, --- no. entities in 2nd array
const PK_TOPOL_t topols_2[], --- second topological array
const PK_TOPOL_range_array_o_t *options, --- options structure
--- returned arguments ---
PK_range_result_t *const range_result, --- if range data returned
PK_range_2_r_t *const range --- range data
)
This function finds the global minimum separation between two arrays
of topological entities.
Specific Errors:
PK_ERROR_bad_option_data bad option data given
PK_ERROR_bad_parameter bad parameter given
PK_ERROR_wrong_entity given topology is of the wrong type
PK_ERROR_missing_geom given topology has missing geometry
PK_ERROR_no_closest_approach failed to find closest approach
PK_TOPOL_range_array will find the global closest approach between the two
arrays of topological entities topols_1 and topols_2.
The following entity types are supported:
- vertex, edge, face, and body.
The function also takes an options structure containing the following
optional additional information:
have_tolerance : whether a tolerance value is provided.
tolerance : a tolerance on the accuracy of the minimum distance
measurement. This will allow slacker computation of
minimum distance, when default accuracy is not required.
The default accuracy will be the linear precision
of the modeller.
bound : option structure consisting of:
have_upper_bound: whether an upper bound is supplied.
`upper_bound : an upper bound on the minimum
distance to be computed.
If supplied, the minimum distance
achieved will only be identified
if it is less than the bound.
have_lower_bound: whether a lower bound is supplied.
`lower_bound : a lower bound on the minimum distance.
For this option, if the closest
approach between entities is found
to be less than this bound, no
solution will be determined.
The function returns result which can be one of three values:
PK_range_result_found_c the separation has been successfully found.
PK_range_result_lower_c minimum separation is less than the provided
lower bound.
PK_range_result_upper_c no separation is less than the provided
upper bound.
If result is equal to PK_range_result_found_c, then a range data will
also be returned in range, this consists of a structure of type
PK_range_2_r_t, and contains a double distance, which is the
separation distance between the two arrays of topological entities provided,
and an array of two structures of type PK_range_end_t, which provide
information on each end of the line of separation as follows:
entity : the entity at the end of the separation.
sub_entity : the sub-entity at the end of separation (PK_ENTITY_null if
none is found).
vector : end position.
parameters : an array of two parameters of the end position holding
curve or surface parameter(s). Which parameterisation is
used is firstly dependent upon the geometry of the entity
returned and secondly upon the geometry of the sub-entity
(if identified).
If curve parameterisation is used the 2nd parameter should
be ignored.
The table below indicates which parameterisation is used
and when:
-------------------------------------------------------
| Entity | Identified | Geometry used for |
| | Sub-Entity | solution parameterisation |
|-----------|--------------|----------------------------|
| | | |
| point | none | none |
| curve | none | curve |
| surface | none | surface |
| | | |
| vertex | none | none |
| | | |
| edge | none | curve of the edge |
| edge | vertex | curve of the edge |
| | | |
| face | none | surface of the face |
| face | edge | surface of the face |
| face | vertex | surface of the face |
| | | |
| body | face | surface of the face |
| body | edge | curve of the edge |
| body | vertex | none |
| | | |
-------------------------------------------------------
The curve and surface parameter values returned
will be the same as would be returned by the
parameterisation functions PK_CURVE_parameterise_vector
and PK_SURF_parameterise_vector.
region : a logical value - whether the solution is regional. If
PK_LOGICAL_true, the solution is a regional solution upon
the entity (ie. it is possible to move from solution point
pair without the distance changing )
The identification of such a regional solution is not
guaranteed.
negative : a logical value - for a body only, the distance as being
negative. If PK_LOGICAL_true the solution point on
the other entity lies inside the body
