two-dimensional line defined by an origin, a direction vector, and a length

Collaboration diagram for two-dimensional line defined by an origin, a direction vector, and a length:

Data Structures
struct	a_line2
	instance structure for two-dimensional line defined by an origin, a direction vector, and a length More...

Macros
#define	a_line2_c(x)
#define	a_line2_(_, x)

Typedefs
typedef struct a_line2	a_line2

Functions
a_real	a_line2_max (a_line2 const *ctx)
	get the maximum length of the line segment.
a_point2 const *	a_line2_org (a_line2 const *ctx)
	get the address of the origin point of the line.
a_vector2 const *	a_line2_dir (a_line2 const *ctx)
	get the address of the direction vector of the line.
void	a_line2_tgt (a_line2 const *ctx, a_point2 *res)
	compute the target endpoint of the line segment.
void	a_line2_set_org (a_line2 *ctx, a_real x, a_real y)
	set the origin coordinates of the line.
void	a_line2_set_max (a_line2 *ctx, a_real max)
	set the maximum length of the line segment.
int	a_line2_set_dir (a_line2 *ctx, a_real x, a_real y)
	set the direction vector and length of the line using raw components.
int	a_line2_set_tgt (a_line2 *ctx, a_real x, a_real y)
	Set the line direction and length based on a target point relative to the current origin.
int	a_line2_setv (a_line2 *ctx, a_point2 const *p, a_vector2 const *v)
	initialize the line segment from a start point and a direction vector.
int	a_line2_set (a_line2 *ctx, a_point2 const *p, a_point2 const *q)
	initialize the line segment from two points (start point p, end point q).
void	a_line2_eval (a_line2 const *ctx, a_real w, a_point2 *res)
	evaluate a point on the line at a given parameter.
a_real	a_line2_parm (a_line2 const *ctx, a_point2 const *rhs)
	compute the scalar projection parameter of a point onto the infinite line.
a_real	a_line2_proj (a_line2 const *ctx, a_point2 const *rhs, a_point2 *res)
	project a point onto the infinite line.
a_real	a_line2_limparm (a_line2 const *ctx, a_real min, a_real max, a_point2 const *rhs)
	compute the scalar projection parameter of a point onto the line segment.
a_real	a_line2_limproj (a_line2 const *ctx, a_real min, a_real max, a_point2 const *rhs, a_point2 *res)
	project a point onto a line segment.
a_real	a_line2_sdist (a_line2 const *ctx, a_point2 const *rhs)
	compute the signed distance from a point to the infinite line.
a_real	a_line2_dist (a_line2 const *ctx, a_point2 const *rhs)
	compute the absolute distance from a point to the infinite line.
a_real	a_line2_limdist (a_line2 const *ctx, a_real min, a_real max, a_point2 const *rhs, a_real *w, a_point2 *p)
	compute the distance from a point to the closest point on a line segment.
a_real	a_line2_limdist2 (a_line2 const *ctx, a_real min, a_real max, a_point2 const *rhs, a_real *w, a_point2 *p)
	compute the squared distance from a point to the closest point on a line segment.
a_real	a_line2_segdist (a_line2 const *ctx, a_real min1, a_real max1, a_line2 const *rhs, a_real min2, a_real max2, a_real *w1, a_point2 *p1, a_real *w2, a_point2 *p2)
	compute the distance between two line segments.
a_real	a_line2_segdist2 (a_line2 const *ctx, a_real min1, a_real max1, a_line2 const *rhs, a_real min2, a_real max2, a_real *w1, a_point2 *p1, a_real *w2, a_point2 *p2)
	compute the squared distance between two line segments.
int	a_line2_int0 (a_line2 const *ctx, a_real min, a_real max, a_point2 const *rhs, a_real *w)
	compute the intersection between a point and a line segment.
int	a_line2_int1 (a_line2 const *ctx, a_real min1, a_real max1, a_line2 const *rhs, a_real min2, a_real max2, a_real *w1, a_real *w2)
	compute the intersection between two line segments.
void	a_line2_rot_ (a_line2 const *ctx, a_point2 const *rhs, a_real sin, a_real cos, a_line2 *res)
	rotate a line segment around a pivot point using pre-calculated sine and cosine values.
void	a_line2_rot (a_line2 const *ctx, a_point2 const *rhs, a_real angle, a_line2 *res)
	rotate a line segment around a specified pivot point.

Detailed Description

Macro Definition Documentation

a_line2_

#define a_line2_	(		_,
			x )

Value:

a_cast_s(a_line2 _, x)

a_line2_c

#define a_line2_c

(

x

)

Value:

a_cast_s(a_line2, x)

static cast to two-dimensional line defined by an origin, a direction vector, and a length

Function Documentation

a_line2_dir()

a_vector2 const * a_line2_dir

(

a_line2 const *

ctx

)

get the address of the direction vector of the line.

Parameters

[in]

ctx

points to an instance of the two-dimensional line

Returns

the address of the direction vector

a_line2_dist()

a_real a_line2_dist	(	a_line2 const *	ctx,
		a_point2 const *	rhs )

compute the absolute distance from a point to the infinite line.

Parameters

[in]	ctx	points to an instance of the two-dimensional line
[in]	rhs	points to the point

Returns

the absolute distance

a_line2_eval()

void a_line2_eval	(	a_line2 const *	ctx,
		a_real	w,
		a_point2 *	res )

evaluate a point on the line at a given parameter.

Parameters

[in]	ctx	points to an instance of the two-dimensional line
[in]	w	is the scalar parameter
[out]	res	stores the result

a_line2_int0()

int a_line2_int0	(	a_line2 const *	ctx,
		a_real	min,
		a_real	max,
		a_point2 const *	rhs,
		a_real *	w )

compute the intersection between a point and a line segment.

Parameters

[in]	ctx	points to an instance of the line segment
[in]	min	is the lower bound of the line segment
[in]	max	is the upper bound of the line segment
[in]	rhs	points to the point to intersect
[out]	w	stores the parameter on the segment

Returns

the intersection type

Return values

1	intersection found
0	no intersection

a_line2_int1()

int a_line2_int1	(	a_line2 const *	ctx,
		a_real	min1,
		a_real	max1,
		a_line2 const *	rhs,
		a_real	min2,
		a_real	max2,
		a_real *	w1,
		a_real *	w2 )

compute the intersection between two line segments.

Parameters

[in]	ctx	points to an instance of the first line segment
[in]	min1	is the lower bound of the first line segment
[in]	max1	is the upper bound of the first line segment
[in]	rhs	points to an instance of the second line segment
[in]	min2	is the lower bound of the second line segment
[in]	max2	is the upper bound of the second line segment
[out]	w1	stores parameter of the point on the first segment or the start point on the first segment
[out]	w2	stores parameter of the point on the second segment or the end point on the first segment

Returns

the intersection type

Return values

2	intersection is a segment, the start point and the end point on the first segment
1	intersection is a point, the point on the first segment and the second segment
0	no intersection

a_line2_limdist()

a_real a_line2_limdist	(	a_line2 const *	ctx,
		a_real	min,
		a_real	max,
		a_point2 const *	rhs,
		a_real *	w,
		a_point2 *	p )

compute the distance from a point to the closest point on a line segment.

Parameters

[in]	ctx	points to an instance of the line segment
[in]	min	is the lower bound of the line segment
[in]	max	is the upper bound of the line segment
[in]	rhs	points to the point
[out]	w	stores the parameter of the closest point
[out]	p	stores the coordinates of the closest point

Returns

the distance

a_line2_limdist2()

a_real a_line2_limdist2	(	a_line2 const *	ctx,
		a_real	min,
		a_real	max,
		a_point2 const *	rhs,
		a_real *	w,
		a_point2 *	p )

compute the squared distance from a point to the closest point on a line segment.

Parameters

[in]	ctx	points to an instance of the line segment
[in]	min	is the lower bound of the line segment
[in]	max	is the upper bound of the line segment
[in]	rhs	points to the point
[out]	w	stores the parameter of the closest point
[out]	p	stores the coordinates of the closest point

Returns

the squared distance

a_line2_limparm()

a_real a_line2_limparm	(	a_line2 const *	ctx,
		a_real	min,
		a_real	max,
		a_point2 const *	rhs )

compute the scalar projection parameter of a point onto the line segment.

Parameters

[in]	ctx	points to an instance of the line segment
[in]	min	is the lower bound of the line segment
[in]	max	is the upper bound of the line segment
[in]	rhs	points to the point to project

Returns

the clamped scalar parameter

a_line2_limproj()

a_real a_line2_limproj	(	a_line2 const *	ctx,
		a_real	min,
		a_real	max,
		a_point2 const *	rhs,
		a_point2 *	res )

project a point onto a line segment.

Parameters

[in]	ctx	points to an instance of the line segment
[in]	min	is the lower bound of the line segment
[in]	max	is the upper bound of the line segment
[in]	rhs	points to the point to project
[in]	res	stores the projection result

Returns

the clamped projection parameter

a_line2_max()

a_real a_line2_max

(

a_line2 const *

ctx

)

get the maximum length of the line segment.

Parameters

[in]

ctx

points to an instance of the two-dimensional line

Returns

the maximum length value

a_line2_org()

a_point2 const * a_line2_org

(

a_line2 const *

ctx

)

get the address of the origin point of the line.

Parameters

[in]

ctx

points to an instance of the two-dimensional line

Returns

the address of the origin point

a_line2_parm()

a_real a_line2_parm	(	a_line2 const *	ctx,
		a_point2 const *	rhs )

compute the scalar projection parameter of a point onto the infinite line.

Parameters

[in]	ctx	points to an instance of the two-dimensional line
[in]	rhs	points to the point to project

Returns

the scalar parameter

a_line2_proj()

a_real a_line2_proj	(	a_line2 const *	ctx,
		a_point2 const *	rhs,
		a_point2 *	res )

project a point onto the infinite line.

Parameters

[in]	ctx	points to an instance of the two-dimensional line
[in]	rhs	points to the point to project
[in]	res	stores the projection result

Returns

the projection parameter

a_line2_rot()

void a_line2_rot	(	a_line2 const *	ctx,
		a_point2 const *	rhs,
		a_real	angle,
		a_line2 *	res )

rotate a line segment around a specified pivot point.

Parameters

[in]	ctx	points to an instance of the line segment
[in]	rhs	points to the pivot point
[in]	angle	is rotation angle in radians
[out]	res	stores the result line segment

a_line2_rot_()

void a_line2_rot_	(	a_line2 const *	ctx,
		a_point2 const *	rhs,
		a_real	sin,
		a_real	cos,
		a_line2 *	res )

rotate a line segment around a pivot point using pre-calculated sine and cosine values.

Parameters

[in]	ctx	points to an instance of the line segment
[in]	rhs	points to the pivot point
[in]	sin	is precomputed \(\sin(\theta)\)
[in]	cos	is precomputed \(\cos(\theta)\)
[out]	res	stores the result line segment

a_line2_sdist()

a_real a_line2_sdist	(	a_line2 const *	ctx,
		a_point2 const *	rhs )

compute the signed distance from a point to the infinite line.

Parameters

[in]	ctx	points to an instance of the two-dimensional line
[in]	rhs	points to the point

Returns

the signed distance

a_line2_segdist()

a_real a_line2_segdist	(	a_line2 const *	ctx,
		a_real	min1,
		a_real	max1,
		a_line2 const *	rhs,
		a_real	min2,
		a_real	max2,
		a_real *	w1,
		a_point2 *	p1,
		a_real *	w2,
		a_point2 *	p2 )

compute the distance between two line segments.

Parameters

[in]	ctx	points to an instance of the first line segment
[in]	min1	is the lower bound of the first line segment
[in]	max1	is the upper bound of the first line segment
[in]	rhs	points to an instance of the second line segment
[in]	min2	is the lower bound of the second line segment
[in]	max2	is the upper bound of the second line segment
[out]	w1	stores parameter of the closest point on the first segment
[out]	p1	stores coordinates of the closest point on the first segment
[out]	w2	stores parameter of the closest point on the second segment
[out]	p2	stores coordinates of the closest point on the second segment

Returns

the distance between the two segments

a_line2_segdist2()

a_real a_line2_segdist2	(	a_line2 const *	ctx,
		a_real	min1,
		a_real	max1,
		a_line2 const *	rhs,
		a_real	min2,
		a_real	max2,
		a_real *	w1,
		a_point2 *	p1,
		a_real *	w2,
		a_point2 *	p2 )

compute the squared distance between two line segments.

Parameters

[in]	ctx	points to an instance of the first line segment
[in]	min1	is the lower bound of the first line segment
[in]	max1	is the upper bound of the first line segment
[in]	rhs	points to an instance of the second line segment
[in]	min2	is the lower bound of the second line segment
[in]	max2	is the upper bound of the second line segment
[out]	w1	stores parameter of the closest point on the first segment
[out]	p1	stores coordinates of the closest point on the first segment
[out]	w2	stores parameter of the closest point on the second segment
[out]	p2	stores coordinates of the closest point on the second segment

Returns

the squared distance between the two segments

a_line2_set()

int a_line2_set	(	a_line2 *	ctx,
		a_point2 const *	p,
		a_point2 const *	q )

initialize the line segment from two points (start point p, end point q).

Parameters

[in,out]	ctx	points to an instance of the two-dimensional line
[in]	p	points to the start point (origin)
[in]	q	points to the end point (target)

Returns

error code value

Return values

<0	failure
0	success

a_line2_set_dir()

int a_line2_set_dir	(	a_line2 *	ctx,
		a_real	x,
		a_real	y )

set the direction vector and length of the line using raw components.

Parameters

[in,out]	ctx	points to an instance of the two-dimensional line
[in]	x	is X component of the direction vector
[in]	y	is Y component of the direction vector

Returns

error code value

Return values

<0	failure
0	success

a_line2_set_max()

void a_line2_set_max	(	a_line2 *	ctx,
		a_real	max )

set the maximum length of the line segment.

Parameters

[in,out]	ctx	points to an instance of the two-dimensional line
[in]	max	is the maximum length

a_line2_set_org()

void a_line2_set_org	(	a_line2 *	ctx,
		a_real	x,
		a_real	y )

set the origin coordinates of the line.

Parameters

[in,out]	ctx	points to an instance of the two-dimensional line
[in]	x	is the x-coordinate of the origin
[in]	y	is the y-coordinate of the origin

a_line2_set_tgt()

int a_line2_set_tgt	(	a_line2 *	ctx,
		a_real	x,
		a_real	y )

Set the line direction and length based on a target point relative to the current origin.

Parameters

[in,out]	ctx	points to an instance of the two-dimensional line
[in]	x	is X coordinate of the target point
[in]	y	is Y coordinate of the target point

Returns

error code value

Return values

<0	failure
0	success

a_line2_setv()

int a_line2_setv	(	a_line2 *	ctx,
		a_point2 const *	p,
		a_vector2 const *	v )

initialize the line segment from a start point and a direction vector.

Parameters

[in,out]	ctx	points to an instance of the two-dimensional line
[in]	p	points to the start point (origin)
[in]	v	points to the direction vector (defines direction and length)

Returns

error code value

Return values

<0	failure
0	success

a_line2_tgt()

void a_line2_tgt	(	a_line2 const *	ctx,
		a_point2 *	res )

compute the target endpoint of the line segment.

Parameters

[in]	ctx	points to an instance of the two-dimensional line
[out]	res	stores the target endpoint of the line segment