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