gpath.c File Reference

Functions defining the various types of curves used for specifying flow geometry. More...

#include <math.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include "geom.h"
#include "bezier.h"
#include "gpath.h"

Functions
GPathPolyLine *	gpath_init (struct GPathPolyLine *plp)
	Initializes data structure members and returns a pointer.
int	gpath_add_element (struct GPathPolyLine *plp, int type, int np, struct point_3D p[], int direction)
	Adds a path element to a polyline.
double	gpath_element_length (struct GPathElement *pe)
	Length of the GPathElement.
int	gpath_write_all_elements_to_file (FILE *fp, struct GPathPolyLine *plp)
	Writes the all of the GPathElements of GPathPolyline to the specified file.
int	gpath_write_element_to_file (FILE *fp, struct GPathElement *pe)
	Writes the GPathElement to the specified file.
int	gpath_scan_from_string_and_add_element (char str[], struct GPathPolyLine *plp)
	Scans the GPathElement from a supplied string and appends it to the GPathPolyLine.
int	gpath_append_polyline (struct GPathPolyLine *plp1, struct GPathPolyLine *plp2, int direction)
	Appends another path polyline to a first polyline.
point_3D *	gpath_get_first_point_on_path (struct GPathPolyLine *plp)
	Returns a pointer to the first point on a path.
point_3D *	gpath_get_last_point_on_path (struct GPathPolyLine *plp)
	Returns a pointer to the last point on a path.
int	gpath_polyline_set_subrange (struct GPathPolyLine *plp, double t0, double t1)
	Set the parameter subrange for subsequent evaluations of position.
int	gpath_polyline_eval (struct GPathPolyLine *plp, double t_in_subrange, struct point_3D *loc)
	Evaluate the position on the polyline at given parameter t.
int	gpath_polyline_translate (struct GPathPolyLine *plp, double dx, double dy, double dz)
	Translate the polyline position by dx,dy,dz.
int	coons_patch (struct GPathPolyLine *c1, struct GPathPolyLine *c2, struct GPathPolyLine *c3, struct GPathPolyLine *c4, double r, double s, struct point_3D *d)
	Compute a location on the Coons patch at parameter position (r,s).
int	TFI_3D_no_array (struct GPathPolyLine *c0, struct GPathPolyLine *c1, struct GPathPolyLine *c2, struct GPathPolyLine *c3, struct GPathPolyLine *c4, struct GPathPolyLine *c5, struct GPathPolyLine *c6, struct GPathPolyLine *c7, struct GPathPolyLine *c8, struct GPathPolyLine *c9, struct GPathPolyLine *c10, struct GPathPolyLine *c11, double r, double s, double t, struct point_3D *d)
	Compute a location within the 3D volume at parameter position (r,s,t).
int	TFI_3D (struct GPathPolyLine *c[], double r, double s, double t, struct point_3D *d)
	Compute a location within the 3D volume at parameter position (r,s,t).
int	line_translate (struct point_3D B[], double dx, double dy, double dz)
	Translate the straight-line position by dx,dy,dz.
int	line_eval (struct point_3D B[], double t, struct point_3D *loc)
	Evaluate the straight-line position with parameter t.
double	line_length (struct point_3D B[])
	Returns an estimate of the length of a straight line.
int	arc_translate (struct point_3D B[], double dx, double dy, double dz)
	Translate the arc position by dx,dy,dz.
int	arc_eval_position_and_length (struct point_3D B[], double t, struct point_3D *loc, double *length)
	Evaluate the position on an arc for parameter t and the length of the original arc. (This function does the real work.).
int	arc_eval (struct point_3D B[], double t, struct point_3D *loc)
	Evaluate the position on an arc for parameter t.
double	arc_length (struct point_3D B[])
	Returns an estimate of the length of an arc.

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Detailed Description

Functions defining the various types of curves used for specifying flow geometry.

Author:

PA Jacobs

Version:

1.0 : adapted from bezier.c and extended with straight lines and arcs

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Function Documentation

int arc_eval (  struct point_3D  B[], double  t, struct point_3D *  loc )

Evaluate the position on an arc for parameter t. Returns 0 if everything was OK, -1 if there was a problem. The real work is delegated to a helper function because there is so much common code between the arc_length calculation and the position calculation. Parameters: B  : (pointer to) the array of 3 control points t  : position parameter, 0 <= t <= 1.0 loc  : (pointer to) the computed location in 3D

int arc_eval_position_and_length (  struct point_3D  B[], double  t, struct point_3D *  loc, double *  length )

Evaluate the position on an arc for parameter t and the length of the original arc. (This function does the real work.). Returns 0 if everything was OK, -1 if there was a problem. Parameters: B  : (pointer to) the array of 3 control points t  : position parameter, 0 <= t <= 1.0 loc  : (pointer to) the computed location in 3D length  : (pointer to) the computed arc length

double arc_length (  struct point_3D  B[]  )

Returns an estimate of the length of an arc. The real work is delegated. Parameters: B  : array of 3 control points

int arc_translate (  struct point_3D  B[], double  dx, double  dy, double  dz )

Translate the arc position by dx,dy,dz. Returns 0 if everything was OK, -1 if there was a problem. Parameters: B  : (pointer to) the array of 3 control points dx,dy,dz

int coons_patch (  struct GPathPolyLine *  c1, struct GPathPolyLine *  c2, struct GPathPolyLine *  c3, struct GPathPolyLine *  c4, double  r, double  s, struct point_3D *  d )

Compute a location on the Coons patch at parameter position (r,s). Returns 0 for a normal return, -1 otherwise. Parameters: c1,c2,c3,c4  : pointers to the bounding curves These are normalized GPathPolyLines. c1 and c2 are the South and North boundaries respectively. The parameter 0 <= r <= 1 traverses them West to East. c3 and c4 are the West and East boundaries respectively. Parameter 0 <= s <= 1 traverses them South to North. r  : West to East parameter, 0 <= r <= 1. s  : South to North parameter, 0 <= s <= 1. d  : pointer to the computed location in (x,y,z)-space

int gpath_add_element (  struct GPathPolyLine *  plp, int  type, int  np, struct point_3D  p[], int  direction )

Adds a path element to a polyline. Returns the new number of elements on success, -1 otherwise. Presently, these polylines may consist of disjoint segments. Maybe we should test that the ends of adjacent segments are coincident; maybe we shouldn't. Parameters: plp  : pointer to the polyline type  : type of element as listed in the gpath.h np  : number of control points in the new element. p  : the array of control points direction  : +1 add in points normal order; -1 add in reverse order

int gpath_append_polyline (  struct GPathPolyLine *  plp1, struct GPathPolyLine *  plp2, int  direction )

Appends another path polyline to a first polyline. Returns the new number of elements on success, -1 otherwise. Parameters: plp1  : first polyline to which the other is appended plp2  : polyline to append to first (This one remains unchanged.) direction  : =1 appends the plp2 data in forward direction (of plp2) =-1 appends the plp2 in reverse direction (of plp2)

double gpath_element_length (  struct GPathElement *  pe  )

Length of the GPathElement. Parameters: pe  : pointer to the GPathElement Returns: : the length of the element

struct GPathPolyLine* gpath_init (  struct GPathPolyLine *  plp  )

Initializes data structure members and returns a pointer. Parameters: plp  : pointer to a GPathPolyline structure. < the path is initially empty < length should be always current < default subrange is the whole path < == 0 indicates that the path is open

int gpath_polyline_eval (  struct GPathPolyLine *  plp, double  t_in_subrange, struct point_3D *  loc )

Evaluate the position on the polyline at given parameter t. Returns 0 if everything was OK, -1 if there was a problem. Parameters: bp  : (pointer to) the Bezier polyline data t  : position parameter, 0 <= t <= 1.0 loc  : (pointer to) the computed location in 3D

int gpath_polyline_set_subrange (  struct GPathPolyLine *  plp, double  t0, double  t1 )

Set the parameter subrange for subsequent evaluations of position. Parameters: plp  : pointer to the GPathPolyline structure t0  : start of subrange t1  : end of subrange When a polyline is first created, the subrange defaults to 0.0, 1.0.

int gpath_polyline_translate (  struct GPathPolyLine *  plp, double  dx, double  dy, double  dz )

Translate the polyline position by dx,dy,dz. Returns 0 if everything was OK, -1 if there was a problem. Parameters: plp  : (pointer to) the polyline structure dx,dy,dz

int gpath_scan_from_string_and_add_element (  char  str[], struct GPathPolyLine *  plp )

Scans the GPathElement from a supplied string and appends it to the GPathPolyLine. Returns 0 if successful, -1 otherwise.

int gpath_write_all_elements_to_file (  FILE *  fp, struct GPathPolyLine *  plp )

Writes the all of the GPathElements of GPathPolyline to the specified file. Parameters: fp  : pointer to the open file if NULL, stdout will be used. Returns number of characters written if successful, -1 otherwise.

int gpath_write_element_to_file (  FILE *  fp, struct GPathElement *  pe )

Writes the GPathElement to the specified file. Returns number of characters written if successful, -1 otherwise.

int line_eval (  struct point_3D  B[], double  t, struct point_3D *  loc )

Evaluate the straight-line position with parameter t. Returns 0 if everything was OK, -1 if there was a problem. Parameters: B  : (pointer to) the array of 2 control points t  : position parameter, 0 <= t <= 1.0 loc  : (pointer to) the computed location in 3D

double line_length (  struct point_3D  B[]  )

Returns an estimate of the length of a straight line. Parameters: B  : array of 2 control points

int line_translate (  struct point_3D  B[], double  dx, double  dy, double  dz )

Translate the straight-line position by dx,dy,dz. Returns 0 if everything was OK, -1 if there was a problem. Parameters: B  : (pointer to) the array of 2 control points dx,dy,dz

int TFI_3D (  struct GPathPolyLine *  c[], double  r, double  s, double  t, struct point_3D *  d )

Compute a location within the 3D volume at parameter position (r,s,t). Returns 0 for a normal return, -1 otherwise. Parameters: c[]  : array of pointers to the bounding curves These are normalized GPathPolyLines. See 3D CFD workbook page 27pp 2004. r  : West to East parameter, 0 <= r <= 1. s  : South to North parameter, 0 <= s <= 1. t  : Bottom to Top parameter, 0 <= t <= 1. d  : pointer to the computed location in (x,y,z)-space

int TFI_3D_no_array (  struct GPathPolyLine *  c0, struct GPathPolyLine *  c1, struct GPathPolyLine *  c2, struct GPathPolyLine *  c3, struct GPathPolyLine *  c4, struct GPathPolyLine *  c5, struct GPathPolyLine *  c6, struct GPathPolyLine *  c7, struct GPathPolyLine *  c8, struct GPathPolyLine *  c9, struct GPathPolyLine *  c10, struct GPathPolyLine *  c11, double  r, double  s, double  t, struct point_3D *  d )

Compute a location within the 3D volume at parameter position (r,s,t). This function allows us to specify the edges individually but delegates the actual work to TFI_3D. The point of this function is to allow easy access from Python code.

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