YAC: src/core/geometry.h File Reference

Searching...

No Matches

#include "config.h"
#include <math.h>
#include <float.h>
#include "yac_types.h"
#include "grids/grid_cell.h"
#include "utils_core.h"

Include dependency graph for geometry.h:

This graph shows which files directly or indirectly include this file:

Go to the source code of this file.

Data Structures
struct	sin_cos_angle

struct	bounding_circle

struct	yac_circle

Macros
#define	YAC_RAD (0.01745329251994329576923690768489)

#define	yac_angle_tol (1e-9)

#define	yac_sq_angle_tol (1e-9 * 1e-9)

#define	yac_cos_angle_tol (0.9999999999999999995)

#define	yac_angle_low_tol (1e-11)

#define	yac_cos_angle_low_tol (1.0)

Enumerations
enum	yac_circle_type { GREAT_CIRCLE = YAC_GREAT_CIRCLE_EDGE , LAT_CIRCLE = YAC_LAT_CIRCLE_EDGE , LON_CIRCLE = YAC_LON_CIRCLE_EDGE , POINT }

Functions
int	yac_point_in_cell (double point_coords[3], struct yac_grid_cell cell)

int	yac_point_in_cell2 (double point_coords[3], struct yac_grid_cell cell, struct bounding_circle bnd_circle)

static double	get_angle (double a_lon, double b_lon)

static double	get_angle_deg (double a_lon, double b_lon)

int	yac_intersect_vec (enum yac_edge_type edge_type_a, double const a[3], double const b[3], enum yac_edge_type edge_type_b, double const c[3], double const d[3], double p[3], double q[3])

void	yac_get_cell_bounding_circle (struct yac_grid_cell cell, struct bounding_circle *bnd_circle)

int	yac_extents_overlap (struct bounding_circle extent_a, struct bounding_circle extent_b)

static double	sq_len_diff_vec (double const a[3], double const b[3])
	computes square of the lenght of the vector ab

static double	compute_sq_crd (struct sin_cos_angle angle)

static int	yac_point_in_bounding_circle_vec (double point_vector[3], struct bounding_circle *bnd_circle)

static double	clamp_abs_one (double val)

static void	compute_sin_cos (double angle, double sin_value, double cos_value)

static void	LLtoXYZ (double lon, double lat, double p_out[])

static void	LLtoXYZ_deg (double lon, double lat, double p_out[])

static void	XYZtoLL (double const p_in[], double lon, double lat)

static void	product_eft (double a, double b, double restrict product, double restrict error)

static void	sum_eft (double a, double b, double restrict sum, double restrict error)

static void	accu_eft (double a, double restrict accu, double restrict error)

static void	accu_product_eft (double a, double b, double restrict accu, double restrict accu_error)

static void	det2_error (double a, double b, double c, double d, double restrict det, double restrict det_error)

static double	det2_kahan (double a, double b, double c, double d)

static void	crossproduct_kahan (double const a[], double const b[], double cross[])

static void	crossproduct_d (const double a[], const double b[], double cross[])

static double	dotproduct_eft (double const a[], double const b[])

static double	get_vector_angle (double const a[3], double const b[3])

static struct sin_cos_angle	sin_cos_angle_new (double sin, double cos)

static struct sin_cos_angle	get_vector_angle_2 (double const a[3], double const b[3])

static int	compare_angles (struct sin_cos_angle a, struct sin_cos_angle b)

static double	sin_cos_angle_to_dble (struct sin_cos_angle angle)

static struct sin_cos_angle	sum_angles_no_check (struct sin_cos_angle a, struct sin_cos_angle b)

static int	sum_angles (struct sin_cos_angle a, struct sin_cos_angle b, struct sin_cos_angle *restrict sum)

static struct sin_cos_angle	sub_angles_no_check (struct sin_cos_angle a, struct sin_cos_angle b)

static int	sub_angles (struct sin_cos_angle a, struct sin_cos_angle b, struct sin_cos_angle *restrict sub)

static double	compute_angle (struct sin_cos_angle angle)
	return angles in the range of [0;2PI[

static struct sin_cos_angle	half_angle (struct sin_cos_angle angle)

static struct sin_cos_angle	quarter_angle (struct sin_cos_angle angle)

static int	points_are_identically (double const a, double const b)

static int	compare_coords (double const a, double const b)

static void	normalise_vector (double v[])

static void	rotate_vector2 (double axis[], struct sin_cos_angle angle, double v_in[], double v_out[])

static void	rotate_vector (double axis[], double angle, double v_in[], double v_out[])

void	yac_triangulate_cell (struct yac_grid_cell cell, size_t start_corner, struct yac_grid_cell *triangles)

void	yac_triangulate_cell_indices (size_t const corner_indices, size_t num_corners, size_t start_corner, size_t(triangle_indices)[3])

void	yac_compute_bnd_triangle (double *vertices, size_t num_vertices, double triangle[][3], size_t num_tests)

int	yac_circle_intersect (struct yac_circle a, struct yac_circle b, double p[3], double q[3])

int	yac_point_on_edge (double p[3], double const a[3], double const b[3], enum yac_circle_type circle_type)

Variables
static const struct sin_cos_angle	SIN_COS_ZERO = {0.0, 1.0}

static const struct sin_cos_angle	SIN_COS_TOL = {yac_angle_tol, yac_cos_angle_tol}

static const struct sin_cos_angle	SIN_COS_LOW_TOL = {yac_angle_low_tol, yac_cos_angle_low_tol}

static const struct sin_cos_angle	SIN_COS_M_PI_2 = {1.0, 0.0}

static const struct sin_cos_angle	SIN_COS_M_PI = {0.0, -1.0}

static const struct sin_cos_angle	SIN_COS_7_M_PI_4 = {-0.707106781186547524401, +0.707106781186547524401}

Macro Definition Documentation

◆ yac_angle_low_tol

#define yac_angle_low_tol (1e-11)

Definition at line 29 of file geometry.h.

◆ yac_angle_tol

#define yac_angle_tol (1e-9)

Definition at line 26 of file geometry.h.

◆ yac_cos_angle_low_tol

#define yac_cos_angle_low_tol (1.0)

Definition at line 30 of file geometry.h.

◆ yac_cos_angle_tol

#define yac_cos_angle_tol (0.9999999999999999995)

Definition at line 28 of file geometry.h.

◆ YAC_RAD

#define YAC_RAD (0.01745329251994329576923690768489)

Definition at line 22 of file geometry.h.

◆ yac_sq_angle_tol

#define yac_sq_angle_tol (1e-9 * 1e-9)

Definition at line 27 of file geometry.h.

Enumeration Type Documentation

◆ yac_circle_type

enum yac_circle_type

Enumerator
GREAT_CIRCLE
LAT_CIRCLE
LON_CIRCLE
POINT

Definition at line 59 of file geometry.h.

Function Documentation

◆ accu_eft()

static void accu_eft	(	double	a,
		double *restrict	accu,
		double *restrict	error )

inlinestatic

accumulates a value with error compensation using error-free transformation (EFT)

based on code by Hongyu Chen (https://github.com/hongyuchen1030/regridding-geom-benchmark)

Parameters

[in]	a	value to accumulate
[in,out]	accu	accumulator variable
[in,out]	error	accumulated rounding error

Definition at line 334 of file geometry.h.

Here is the caller graph for this function:

◆ accu_product_eft()

static void accu_product_eft	(	double	a,
		double	b,
		double *restrict	accu,
		double *restrict	accu_error )

inlinestatic

computes the product of two floating-point numbers and accumulates it with error compensation using error-free transformation (EFT)

This function multiplies a and b, then adds the result to the accumulator while tracking and compensating for rounding errors. This is useful for maintaining numerical precision in summations of products.

based on code by Hongyu Chen (https://github.com/hongyuchen1030/regridding-geom-benchmark)

Parameters

[in]	a	first factor
[in]	b	second factor
[in,out]	accu	accumulator variable
[in,out]	accu_error	accumulated rounding error

Definition at line 357 of file geometry.h.

Here is the call graph for this function:

Here is the caller graph for this function:

◆ clamp_abs_one()

static double clamp_abs_one ( double val )

inlinestatic

Definition at line 208 of file geometry.h.

Here is the caller graph for this function:

◆ compare_angles()

static int compare_angles	(	struct sin_cos_angle	a,
		struct sin_cos_angle	b )

inlinestatic

Definition at line 497 of file geometry.h.

Here is the caller graph for this function:

◆ compare_coords()

static int compare_coords	(	double const *	a,
		double const *	b )

inlinestatic

compares two 3d coordinates (vectors need to have a length of 1.0)

Parameters

[in]	a	coordinates of point a
[in]	b	coordinates of point b

Returns: 0 if points are identical, otherwise -1 or 1 depending on their relation

Definition at line 731 of file geometry.h.

Here is the call graph for this function:

Here is the caller graph for this function:

◆ compute_angle()

static double compute_angle ( struct sin_cos_angle angle )

inlinestatic

return angles in the range of [0;2PI[

Definition at line 641 of file geometry.h.

◆ compute_sin_cos()

static void compute_sin_cos	(	double	angle,
		double *	sin_value,
		double *	cos_value )

inlinestatic

compute the sine and cosine of a provided angle in RAD (avoids values close to zero and ensures that the result is in the range [-1,1])

Parameters

[in]	angle	angle in the range of [-PI;PI]
[out]	sin_value
[out]	cos_value

Definition at line 220 of file geometry.h.

Here is the call graph for this function:

Here is the caller graph for this function:

◆ compute_sq_crd()

static double compute_sq_crd ( struct sin_cos_angle angle )

inlinestatic

Definition at line 185 of file geometry.h.

Here is the caller graph for this function:

◆ crossproduct_d()

static void crossproduct_d	(	const double	a[],
		const double	b[],
		double	cross[] )

inlinestatic

for small angles <= 1e-?8? the crossproduct is inaccurate
use crossproduct_kahan for these cases

Definition at line 420 of file geometry.h.

Here is the caller graph for this function:

◆ crossproduct_kahan()

static void crossproduct_kahan	(	double const	a[],
		double const	b[],
		double	cross[] )

inlinestatic

Definition at line 405 of file geometry.h.

Here is the call graph for this function:

Here is the caller graph for this function:

◆ det2_error()

static void det2_error	(	double	a,
		double	b,
		double	c,
		double	d,
		double *restrict	det,
		double *restrict	det_error )

inlinestatic

computes the determinant of a 2x2 matrix with error tracking using error-free transformation (EFT)

Computes det = a*d - b*c with accumulated rounding error

Parameters

[in]	a	element (0,0) of the matrix
[in]	b	element (0,1) of the matrix
[in]	c	element (1,0) of the matrix
[in]	d	element (1,1) of the matrix
[out]	det	determinant result (ad - bc)
[out]	det_error	accumulated rounding error of the computation

Definition at line 382 of file geometry.h.

Here is the call graph for this function:

Here is the caller graph for this function:

◆ det2_kahan()

static double det2_kahan	(	double	a,
		double	b,
		double	c,
		double	d )

inlinestatic

Definition at line 398 of file geometry.h.

Here is the caller graph for this function:

◆ dotproduct_eft()

static double dotproduct_eft	(	double const	a[],
		double const	b[] )

inlinestatic

Computes the dot product of two vectors with error compensation using error-free transformation (EFT)

Definition at line 434 of file geometry.h.

Here is the call graph for this function:

Here is the caller graph for this function:

◆ get_angle()

static double get_angle	(	double	a_lon,
		double	b_lon )

inlinestatic

computes the angle between two longitude coordinates (in rad)
takes into account that longitude have a period of 2 pi

Parameters

[in]	a_lon
[in]	b_lon

Returns: angle between both coordinates (in rad)

Definition at line 110 of file geometry.h.

Here is the caller graph for this function:

◆ get_angle_deg()

static double get_angle_deg	(	double	a_lon,
		double	b_lon )

inlinestatic

computes the angle between two longitude coordinates (in deg)
takes into account that longitude have a period of 360

Parameters

[in]	a_lon
[in]	b_lon

Returns: angle between both coordinates (in rad)

Definition at line 126 of file geometry.h.

Here is the caller graph for this function:

◆ get_vector_angle()

static double get_vector_angle	(	double const	a[3],
		double const	b[3] )

inlinestatic

computes the great circle distance in rad for two points given in xyz coordinates

uses the following formula: angle = 2 * atan(|a-b|/|a+b|) (taken from “How Futile are Mindless Assessments of Roundoff in Floating-Point Computation?” by W. Kahan. https://people.eecs.berkeley.edu/~wkahan/Mindless.pdf)

In contrast to other formulas, this one provided the very good accuracy across all angles. An due to its simiple nature (no branching) also good performance.

Parameters

[in]	a	point coordinates of point a
[in]	b	point coordinates of point b

Returns: great circle distance in rad between both points

Definition at line 463 of file geometry.h.

Here is the caller graph for this function:

◆ get_vector_angle_2()

static struct sin_cos_angle get_vector_angle_2	(	double const	a[3],
		double const	b[3] )

inlinestatic

Definition at line 484 of file geometry.h.

Here is the call graph for this function:

Here is the caller graph for this function:

◆ half_angle()

static struct sin_cos_angle half_angle ( struct sin_cos_angle angle )

inlinestatic

computes angle / 2 The basic idea is to imagin angle being a vector v with (cos(x); sin(x)) and w being a vector with (1.0; 0.0). The normalised sum of v and w gives us v_h with (cos(x/2); sin(x/2)). For quadrants 2, 3, and 4 we have to apply some little tricks for higher accuracy.

Definition at line 669 of file geometry.h.

Here is the call graph for this function:

Here is the caller graph for this function:

◆ LLtoXYZ()

static void LLtoXYZ	(	double	lon,
		double	lat,
		double	p_out[] )

inlinestatic

converts lon-lat coordinates into xyz ones

Further information: http://en.wikipedia.org/wiki/List_of_common_coordinate_transformations

Parameters

[in]	lon	longitude coordinates in radian
[in]	lat	latitude coordinates in radian
[out]	p_out	xyz coordinates

Definition at line 249 of file geometry.h.

Here is the call graph for this function:

Here is the caller graph for this function:

◆ LLtoXYZ_deg()

static void LLtoXYZ_deg	(	double	lon,
		double	lat,
		double	p_out[] )

inlinestatic

converts lon-lat coordinates into xyz ones

Parameters

[in]	lon	longitude coordinates in deg
[in]	lat	latitude coordinates in deg
[out]	p_out	xyz coordinates

Definition at line 269 of file geometry.h.

Here is the call graph for this function:

Here is the caller graph for this function:

◆ normalise_vector()

static void normalise_vector ( double v[] )

inlinestatic

normalises a vector

Definition at line 743 of file geometry.h.

Here is the caller graph for this function:

◆ points_are_identically()

static int points_are_identically	(	double const *	a,
		double const *	b )

inlinestatic

determines whether two given points are (nearly) identically

Parameters

[in]	a	point coordinates of point a
[in]	b	point coordinates of point b

Returns: true if both points are (nearly) identically

Definition at line 717 of file geometry.h.

Here is the call graph for this function:

Here is the caller graph for this function:

◆ product_eft()

static void product_eft	(	double	a,
		double	b,
		double *restrict	product,
		double *restrict	error )

inlinestatic

computes the product of two floating-point numbers with error tracking using error-free transformation (EFT)

based on code by Hongyu Chen (https://github.com/hongyuchen1030/regridding-geom-benchmark)

Parameters

[in]	a	first factor
[in]	b	second factor
[out]	product	result of a * b
[out]	error	rounding error of the multiplication

Definition at line 300 of file geometry.h.

Here is the caller graph for this function:

◆ quarter_angle()

static struct sin_cos_angle quarter_angle ( struct sin_cos_angle angle )

inlinestatic

computes angle / 4 I derived it based on half_angle

Definition at line 686 of file geometry.h.

Here is the call graph for this function:

◆ rotate_vector()

static void rotate_vector	(	double	axis[],
		double	angle,
		double	v_in[],
		double	v_out[] )

inlinestatic

rotate vector v_in around the given axis by a given angle

Parameters

[in]	axis	axis around which v_in is to rotated
[in]	angle	rotation angle
[in]	v_in	vector to be rotated
[out]	v_out	rotated vector

Definition at line 786 of file geometry.h.

Here is the call graph for this function:

Here is the caller graph for this function:

◆ rotate_vector2()

static void rotate_vector2	(	double	axis[],
		struct sin_cos_angle	angle,
		double	v_in[],
		double	v_out[] )

inlinestatic

rotate vector v_in around the given axis by a given angle

Parameters

[in]	axis	axis around which v_in is to rotated
[in]	angle	rotation angle
[in]	v_in	vector to be rotated
[out]	v_out	rotated vector

Definition at line 758 of file geometry.h.

Here is the call graph for this function:

Here is the caller graph for this function:

◆ sin_cos_angle_new()

static struct sin_cos_angle sin_cos_angle_new	(	double	sin,
		double	cos )

inlinestatic

Definition at line 474 of file geometry.h.

Here is the call graph for this function:

Here is the caller graph for this function:

◆ sin_cos_angle_to_dble()

static double sin_cos_angle_to_dble ( struct sin_cos_angle angle )

inlinestatic

this routine converts a struct sin_cos_angle into a double, which allows to easily compare angles 0: 0 <= angle < PI/4 => ret = 0 * M_SQRT1_2 + sin(angle) 1: PI/4 <= angle < 3*PI/4 => ret = 2 * M_SQRT1_2 - cos(angle) 2: 3*PI/4 <= angle < 5*PI/4 => ret = 4 * M_SQRT1_2 - sin(angle) 3: 5*PI/4 <= angle < 7*PI/4 => ret = 6 * M_SQRT1_2 + cos(angle) 4: 7*PI/4 <= angle < 2*PI => ret = 8 * M_SQRT1_2 + sin(angle)

Definition at line 574 of file geometry.h.

◆ sq_len_diff_vec()

static double sq_len_diff_vec	(	double const	a[3],
		double const	b[3] )

inlinestatic

computes square of the lenght of the vector ab

Definition at line 180 of file geometry.h.

Here is the caller graph for this function:

◆ sub_angles()

static int sub_angles	(	struct sin_cos_angle	a,
		struct sin_cos_angle	b,
		struct sin_cos_angle *restrict	sub )

inlinestatic

computes (a-b), if (a-b) <= 0, the result is (a-b+2*PI) a and be have to be in the range [0;2*PI[

Returns: 1 if (a-b) < 0

Definition at line 627 of file geometry.h.

Here is the call graph for this function:

Here is the caller graph for this function:

◆ sub_angles_no_check()

static struct sin_cos_angle sub_angles_no_check	(	struct sin_cos_angle	a,
		struct sin_cos_angle	b )

inlinestatic

computes (a-b), if (a-b) < 0, the result is (a-b+2*PI) a and be have to be in the range [0;2*PI[

Definition at line 617 of file geometry.h.

Here is the call graph for this function:

Here is the caller graph for this function:

◆ sum_angles()

static int sum_angles	(	struct sin_cos_angle	a,
		struct sin_cos_angle	b,
		struct sin_cos_angle *restrict	sum )

inlinestatic

computes (a+b), if (a+b) >= 2*PI, the result is (a+b-2*PI) a and be have to be in the range [0;2*PI[

Returns: 1 if (a+b) is >= 2*PI

Definition at line 603 of file geometry.h.

Here is the call graph for this function:

Here is the caller graph for this function:

◆ sum_angles_no_check()

static struct sin_cos_angle sum_angles_no_check	(	struct sin_cos_angle	a,
		struct sin_cos_angle	b )

inlinestatic

computes (a+b), if (a+b) >= 2*PI, the result is (a+b-2*PI) a and be have to be in the range [0;2*PI[

Definition at line 593 of file geometry.h.

Here is the call graph for this function:

Here is the caller graph for this function:

◆ sum_eft()

static void sum_eft	(	double	a,
		double	b,
		double *restrict	sum,
		double *restrict	error )

inlinestatic

computes the sum of two floating-point numbers with error tracking using error-free transformation (EFT)

based on code by Hongyu Chen (https://github.com/hongyuchen1030/regridding-geom-benchmark)

Parameters

[in]	a	first summand
[in]	b	second summand
[out]	sum	result of a + b
[out]	error	rounding error of the addition

Definition at line 317 of file geometry.h.

Here is the caller graph for this function:

◆ XYZtoLL()

static void XYZtoLL	(	double const	p_in[],
		double *	lon,
		double *	lat )

inlinestatic

converts lon-lat coordinates into xyz ones

Further information: http://en.wikipedia.org/wiki/List_of_common_coordinate_transformations

Parameters

[in]	p_in	xyz coordinates
[out]	lon	longitude coordinate in radian
[out]	lat	latitude coordinate in radian

Definition at line 283 of file geometry.h.

◆ yac_circle_intersect()

int yac_circle_intersect	(	struct yac_circle	a,
		struct yac_circle	b,
		double	p[3],
		double	q[3] )

Definition at line 266 of file intersection.c.

Here is the call graph for this function:

Here is the caller graph for this function:

◆ yac_compute_bnd_triangle()

void yac_compute_bnd_triangle	(	double *	vertices,
		size_t	num_vertices,
		double	triangle[][3],
		size_t	num_tests )

computes a spherical triangle that contains all given vertices, the algorithm tries to minimise the size of the triangle

Parameters

[in]	vertices	vertices that are supposed to be within the triangle
[in]	num_vertices	number of vertices in vertices
[out]	triangle	bounding triangle
[in]	num_tests	with increasing number of tests computation time and chance of smaller bounding triangle increases

Remarks: num_tests has to be > 0

Definition at line 99 of file bnd_triangle.c.

Here is the call graph for this function:

Here is the caller graph for this function:

◆ yac_extents_overlap()

int yac_extents_overlap	(	struct bounding_circle *	extent_a,
		struct bounding_circle *	extent_b )

checks whether two extents overlap

Parameters

[in]	extent_a	bounding circle
[in]	extent_b	bounding circle

Returns: 0 if the bounding circles do not overlap

Definition at line 533 of file bnd_circle.c.

Here is the call graph for this function:

Here is the caller graph for this function:

◆ yac_get_cell_bounding_circle()

void yac_get_cell_bounding_circle	(	struct yac_grid_cell	cell,
		struct bounding_circle *	bnd_circle )

gets the bounding circle for a grid cell

Parameters

[in]	cell	grid cell (coordinates have to be in radian)
[out]	bnd_circle	bounding circle of the grid cell

Definition at line 422 of file bnd_circle.c.

Here is the call graph for this function:

Here is the caller graph for this function:

◆ yac_intersect_vec()

int yac_intersect_vec	(	enum yac_edge_type	edge_type_a,
		double const	a[3],
		double const	b[3],
		enum yac_edge_type	edge_type_b,
		double const	c[3],
		double const	d[3],
		double	p[3],
		double	q[3] )

computes the intersection points of two edges

Parameters

[in]	edge_type_a	type of edge a
[in]	a	first point of edge a
[in]	b	second point of edge a
[in]	edge_type_b	type of edge b
[in]	c	first point of edge b
[in]	d	second point of edge b
[out]	p	first intersection point
[out]	q	second intersection point

Returns: 0 if the intersection points are neither on edge a or b
-1 if the two circles do not intersect
1st bit will be set if p is on edge a
2nd bit will be set if q is on edge a
3rd bit will be set if p is on edge b
4th bit will be set if q is on edge b
5th bit will be set if both circles are identically

Remarks: if -1 is returned neither p or q is set; if the two circles only have one intersection point, p and q will be identically, but only the p bits will be set

Definition at line 763 of file intersection.c.

Here is the call graph for this function:

Here is the caller graph for this function:

◆ yac_point_in_bounding_circle_vec()

static int yac_point_in_bounding_circle_vec	(	double	point_vector[3],
		struct bounding_circle *	bnd_circle )

inlinestatic

checks whether a point is within a bounding circle

Parameters

[in]	point_vector	point to be checked
[in]	bnd_circle	bounding circle

Returns: 0 if point is not within the bounding circle

Definition at line 197 of file geometry.h.

Here is the call graph for this function:

Here is the caller graph for this function:

◆ yac_point_in_cell()

int yac_point_in_cell	(	double	point_coords[3],
		struct yac_grid_cell	cell )

checks whether a given point is within a given cell

Parameters

[in]	point_coords
[in]	cell

Returns: 0 if the point is not in the cell

Definition at line 465 of file check_overlap.c.

Here is the call graph for this function:

Here is the caller graph for this function:

◆ yac_point_in_cell2()

int yac_point_in_cell2	(	double	point_coords[3],
		struct yac_grid_cell	cell,
		struct bounding_circle	bnd_circle )

checks whether a given point is within a given cell

Parameters

[in]	point_coords
[in]	cell
[in]	bnd_circle

Returns: 0 if the point is not in the cell

Definition at line 474 of file check_overlap.c.

Here is the call graph for this function:

Here is the caller graph for this function:

◆ yac_point_on_edge()

int yac_point_on_edge	(	double	p[3],
		double const	a[3],
		double const	b[3],
		enum yac_circle_type	circle_type )

Definition at line 860 of file intersection.c.

Here is the call graph for this function:

Here is the caller graph for this function:

◆ yac_triangulate_cell()

void yac_triangulate_cell	(	struct yac_grid_cell	cell,
		size_t	start_corner,
		struct yac_grid_cell *	triangles )

splits given cell into triangles

Parameters

[in]	cell	cell to be triangulated
[in]	start_corner	start algorithm at corner with this index (0 <= start_corner < n; with n being number of cell corners)
[out]	triangles	triangles that are the result of the triangulation

Remarks: the user needs to provide (n-2) initialised grid_cells for the argument triangles (n being the number of cell corners of the cell); this routine currently only works for convex grid cells; the algorithm ignores that actual edge types for cells with more than 3 corners and assumes them to be great circle edges

Definition at line 66 of file grid_cell.c.

Here is the call graph for this function:

◆ yac_triangulate_cell_indices()

void yac_triangulate_cell_indices	(	size_t const *	corner_indices,
		size_t	num_corners,
		size_t	start_corner,
		size_t(*)	triangle_indices[3] )

splits given indices of a cell into triangles

Parameters

[in]	corner_indices	cell corner indices to be triangulated
[in]	num_corners	number of corners of the cell
[in]	start_corner	start algorithm at corner with this index (0 <= start_corner < n; with n being number of cell corners)
[out]	triangle_indices	triangle indices that are the result of the triangulation

Remarks: the user needs to provide provide an array of size 3*(num_corners-2) for the argument triangle_indices

Definition at line 144 of file grid_cell.c.

Here is the caller graph for this function:

Variable Documentation

◆ SIN_COS_7_M_PI_4

const struct sin_cos_angle SIN_COS_7_M_PI_4 = {-0.707106781186547524401, +0.707106781186547524401}

static

Definition at line 42 of file geometry.h.

◆ SIN_COS_LOW_TOL

const struct sin_cos_angle SIN_COS_LOW_TOL = {yac_angle_low_tol, yac_cos_angle_low_tol}

static

Definition at line 38 of file geometry.h.

◆ SIN_COS_M_PI

const struct sin_cos_angle SIN_COS_M_PI = {0.0, -1.0}

static

Definition at line 41 of file geometry.h.

◆ SIN_COS_M_PI_2

const struct sin_cos_angle SIN_COS_M_PI_2 = {1.0, 0.0}

static

Definition at line 40 of file geometry.h.

◆ SIN_COS_TOL

const struct sin_cos_angle SIN_COS_TOL = {yac_angle_tol, yac_cos_angle_tol}

static

Definition at line 37 of file geometry.h.

◆ SIN_COS_ZERO

const struct sin_cos_angle SIN_COS_ZERO = {0.0, 1.0}

static

Definition at line 36 of file geometry.h.

Data Structures

Macros

Enumerations

Functions

Variables

Macro Definition Documentation

◆ yac_angle_low_tol

◆ yac_angle_tol

◆ yac_cos_angle_low_tol

◆ yac_cos_angle_tol

◆ YAC_RAD

◆ yac_sq_angle_tol

Enumeration Type Documentation

◆ yac_circle_type

Function Documentation

◆ accu_eft()

◆ accu_product_eft()

◆ clamp_abs_one()

◆ compare_angles()

◆ compare_coords()

◆ compute_angle()

◆ compute_sin_cos()

◆ compute_sq_crd()

◆ crossproduct_d()

◆ crossproduct_kahan()

◆ det2_error()

◆ det2_kahan()

◆ dotproduct_eft()

◆ get_angle()

◆ get_angle_deg()

◆ get_vector_angle()

◆ get_vector_angle_2()

◆ half_angle()

◆ LLtoXYZ()

◆ LLtoXYZ_deg()

◆ normalise_vector()

◆ points_are_identically()

◆ product_eft()

◆ quarter_angle()

◆ rotate_vector()

◆ rotate_vector2()

◆ sin_cos_angle_new()

◆ sin_cos_angle_to_dble()

◆ sq_len_diff_vec()

◆ sub_angles()

◆ sub_angles_no_check()

◆ sum_angles()

◆ sum_angles_no_check()

◆ sum_eft()

◆ XYZtoLL()

◆ yac_circle_intersect()

◆ yac_compute_bnd_triangle()

◆ yac_extents_overlap()

◆ yac_get_cell_bounding_circle()

◆ yac_intersect_vec()

◆ yac_point_in_bounding_circle_vec()

◆ yac_point_in_cell()

◆ yac_point_in_cell2()

◆ yac_point_on_edge()

◆ yac_triangulate_cell()

◆ yac_triangulate_cell_indices()

Variable Documentation

◆ SIN_COS_7_M_PI_4

◆ SIN_COS_LOW_TOL

◆ SIN_COS_M_PI

◆ SIN_COS_M_PI_2

◆ SIN_COS_TOL

◆ SIN_COS_ZERO