Agar

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SYNOPSIS

#include <agar/math.h>

DESCRIPTION

The M_Circle2 structure describes a circle in R2 in terms of an origin point p and radius r:
typedef struct m_circle2 {
	M_Vector2 p;
	M_Real r;
} M_Circle2;

Similarly, M_Circle3 describes a circle in R3:
typedef struct m_circle3 {
	M_Vector3 p;
	M_Real r;
} M_Circle3;

INITIALIZATION


M_Circle2 M_CircleFromPt (M_Vector2 p, M_Real r)

M_Circle2 M_CircleRead2 (AG_DataSource *ds)

M_Circle3 M_CircleRead3 (AG_DataSource *ds)

void M_CircleWrite2 (AG_DataSource *ds, M_Circle2 *C)

void M_CircleWrite3 (AG_DataSource *ds, M_Circle3 *C)

M_Circle2 M_CIRCLE2_INITIALIZER (M_Real x, M_Real y, M_Real r)

M_Circle3 M_CIRCLE3_INITIALIZER (M_Real x, M_Real y, M_Real z, M_Real r)


The M_CircleFromPt() function returns a M_Circle2 describing a circle of radius r centered at point p.

The M_CircleRead[23]() and M_CircleWrite[23]() functions read or write a circle structure from/to an AG_DataSource(3).

The macros M_CIRCLE2_INITIALIZER() and M_CIRCLE3_INITIALIZER() expand to static initializers for M_Circle2 and M_Circle3, respectively.

COMPUTATIONS


M_Real M_CirclePointDistance2 (M_Circle2 C, M_Vector2 p)

M_GeomSet2 M_IntersectCircleCircle2 (M_Circle2 C1, M_Circle2 C2)

M_GeomSet2 M_IntersectCircleLine2 (M_Circle2 C, M_Line2 L)


The M_CirclePointDistance2() routine computes the minimal distance between a circle C and a point p.

M_IntersectCircleCircle2() computes the intersection of two circles in R2 and returns an M_GeomSet2(3) describing the intersection. The returned set may be:
  • Two points.
  • One point (circles are tangent up to machine precision).
  • A circle (circles are equivalent).
  • The empty set.

The M_IntersectCircleCircle2() function computes the intersection of a circle and a line in R2. The returned set may be:
  • Two points.
  • One point (line is tangent up to machine precision).
  • The empty set.

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_Circle structure first appeared in Agar 1.3.4.

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