Skip site navigation (1)Skip section navigation (2)

FreeBSD Manual Pages

  
 
  

home | help 
M_LINE(3)		    Library Functions Manual		     M_LINE(3)

NAME
       M_Line -- Agar-Math line	segment	/ half-line structure

SYNOPSIS
       #include	<agar/core.h>
       #include	<agar/gui.h>
       #include	<agar/math/m.h>

DESCRIPTION
       The  M_Line2 structure describes	a line segment,	an Euclidean vector or
       a half-line in R^2.  An M_Line is defined by an origin point p, a  nor-
       malized	direction  vector  d  and a real length	t (which can be	set to
       M_INFINITY in order to express a	half-line).  The structure is  defined
       as:

       typedef struct m_line2 {
	       M_Vector2 p;
	       M_Vector2 d;
	       M_Real t;
       } M_Line2;

       Similarly,  M_Line3  describes a	line segment, an Euclidean vector or a
       half-line in R^3:

       typedef struct m_line3 {
	       M_Vector3 p;
	       M_Vector3 d;
	       M_Real t;
       } M_Line3;

INITIALIZATION
       M_Line2 M_LineFromPtDir2(M_Vector2 p, M_Vector2 d, M_Real t)

       M_Line3 M_LineFromPtDir3(M_Vector3 p, M_Vector3 d, M_Real t)

       M_Line2 M_LineFromPts2(M_Vector2	p1, M_Vector2 p2)

       M_Line3 M_LineFromPts3(M_Vector3	p1, M_Vector3 p2)

       M_Line2 M_LineRead2(AG_DataSource *ds)

       M_Line3 M_LineRead3(AG_DataSource *ds)

       void M_LineWrite2(AG_DataSource *ds, M_Line2 *L)

       void M_LineWrite3(AG_DataSource *ds, M_Line3 *L)

       M_Line2 M_LINE2_INITIALIZER(M_Real px, M_Real py, M_Real	nx, M_Real ny,
       M_Real t)

       M_Line3 M_LINE3_INITIALIZER(M_Real px, M_Real py, M_Real	pz, M_Real nx,
       M_Real ny, M_Real nz, M_Real t)

       The  functions  M_LineFromPtDir2()  and	M_LineFromPtDir3()  return  an
       M_Line2	or  M_Line3 describing a line segment a	specified origin point
       p, direction vector d (of unit-length) and length t.  The endpoints  of
       the line	will be	p and (p + d*t).

       M_LineFromPts2()	 and  M_LineFromPts3()	return a line segment from two
       specified endpoints p1 and p2.

       The M_LineRead[23]() and	M_LineWrite[23]() functions read  or  write  a
       line structure from/to an AG_DataSource(3).

       The  macros  M_LINE2_INITIALIZER()  and M_LINE3_INITIALIZER() expand to
       static initializers for M_Line2 and M_Line3, respectively.

OPERATIONS
       M_Vector2 M_LineInitPt2(M_Line2 L)

       M_Vector2 M_LineTermPt2(M_Line2 L)

       M_Vector3 M_LineInitPt3(M_Line3 L)

       M_Vector3 M_LineTermPt3(M_Line3 L)

       void M_LineToPts2(M_Line2 L, M_Vector2 *p1, M_Vector2 *p2)

       void M_LineToPts3(M_Line3 L, M_Vector3 *p1, M_Vector3 *p2)

       void M_LineIsRay2(M_Line2 L)

       void M_LineIsRay3(M_Line3 L)

       M_Real M_LinePointSide2(M_Line2 L, M_Vector2 p)

       M_Real M_LinePointDistance2(M_Line2 L, M_Vector2	p)

       M_Real M_LinePointDistance3(M_Line3 L, M_Vector3	p)

       M_Real M_LineLineAngle2(M_Line2 L1, M_Line2 L2)

       M_Real M_LineLineAngle3(M_Line3 L1, M_Line3 L2)

       M_Line2 M_LineParallel2(M_Line2 L, M_Real offset)

       M_Line3 M_LineParallel3(M_Line3 L, M_Real offset)

       M_Line2 M_LineProject2(M_Line3 L)

       M_Line3 M_LineProject3(M_Line2 L)

       int M_LineLineIntersect2(M_Line2	L1, M_Line2 L2,	M_Vector2 *x)

       int M_LineLineShortest3(M_Line3 L1, M_Line3 L2, M_Line3 *Ls)

       The M_LineInitPt[23]() routines return the initial point	(i.e.,	the  p
       vector).	  M_LineTermPt[23]() routines return the terminal point	(i.e.,
       p + d*t).  The M_LineToPts[23]()	functions return the two endpoints  of
       line L into p1 and p2.

       M_LineIsRay2()  and M_LineIsRay3() evaluate to 1	of the line is defined
       as a half-line (i.e., t is M_INFINITY).

       M_LinePointSide2() tests	whether	point p	lies on	the left (<0), is  co-
       incident	 (==0),	 or is on the right (>0) of the	line L.	 The direction
       is determined by	the handedness of the line.

       The M_LinePointDistance2() and M_LinePointDistance3() routines  compute
       the minimal distance between a line L and a point p.

       M_LineLineAngle2()  and	M_LineLineAngle3() return the counterclockwise
       angle (in radians) between L1 and L2.  The angle	is computed as the arc
       cosine of the dot product of the	direction vectors of the two lines.

       The M_LineParallel[23]()	functions return a line	parallel  to  L,  with
       the specified offset amount.  The direction of the offset is determined
       by the handedness of L.

       M_LineProject2()	computes a line	in R^2 from the	projection onto	the X-
       Y  plane	of a specified line in R^3.  M_LineProject3() returns the pro-
       jection of a line in R^2	onto the X-Y plane in R^3.

       The M_LineLineIntersect2() function computes the	intersection  point  x
       of  two	lines in R^2.  If there	is a solution, the function returns 1,
       otherwise it returns 0.

       The M_LineLineShortest3() function computes the shortest	 line  segment
       Ls connecting two lines in R^3.	Returns	1 if there is a	solution, 0 if
       there is	not.

SEE ALSO
       AG_DataSource(3),  AG_Intro(3), M_Circle(3), M_Geometry(3), M_Plane(3),
       M_Polygon(3), M_Rectangle(3), M_Sphere(3), M_Triangle(3), M_Vector(3)

HISTORY
       The M_Line structure first appeared in Agar 1.3.4.

Agar 1.7		       December	21, 2022		     M_LINE(3)

Want to link to this manual page? Use this URL:
<https://man.freebsd.org/cgi/man.cgi?query=M_Line&sektion=3&manpath=FreeBSD+Ports+14.3.quarterly>

home | help