NAME

M_Geometry — Agar-Math geometrical structures

SYNOPSIS

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

DESCRIPTION

The Agar-Math library implements a number of algorithms and operations on related to geometrical structures. The following basic structures are defined, see their respective manual pages for more details:

M_Line(3): Line segment or ray in R^2 (M_Line2) or R^3 (M_Line3).
M_Circle(3): Circle in R^2 (M_Circle2) or R^3 (M_Circle3).
M_Sphere(3): Sphere in R^3.
M_Plane(3): Plane in R^3 (M_Plane).
M_Triangle(3): Triangle in R^2 (M_Triangle2) or R^3 (M_Triangle3).
M_Rectangle(3): Rectangle in R^2 (M_Rectangle2) or R^3 (M_Rectangle3).
M_Polygon(3): Polygon in R^2.
M_Polyhedron(3): Polyhedron in R^3.

GENERIC GEOMETRIC ENTITIES

A number of routines (e.g., computation of intersections) return sets of zero or more geometrical structures of different types, depending on the

The M_Geom2 structure defines a geometrical entity in R^2:

typedef struct m_geom2 {
	M_GeomType type;
	union {
		M_Vector2    point;
		M_Line2      line;
		M_Circle2    circle;
		M_Triangle2  triangle;
		M_Rectangle2 rectangle;
		M_Polygon    polygon;
	} g;
} M_Geom2;

Similarly, M_Geom3 defines an entity in R^3:

typedef struct m_geom3 {
	M_GeomType type;
	union {
		M_Vector3    point;
		M_Line3      line;
		M_Circle3    circle;
		M_Triangle3  triangle;
		M_Rectangle3 rectangle;
		M_Polygon    polygon;
		M_Sphere     sphere;
		M_Plane      plane;
		M_Polyhedron polyhedron;
	} g;
} M_Geom3;

The type field can take on the following values:

M_NONE: Undefined type
M_POINT: An M_Vector2(3) or M_Vector3(3).
M_LINE: An M_Line2(3) or M_Line3(3).
M_CIRCLE: An M_Circle2(3) or M_Circle3(3).
M_POLYGON: An M_Polygon(3).
M_TRIANGLE: An M_Triangle2(3) or M_Triangle3(3).
M_RECTANGLE: An M_Rectangle2(3) or M_Rectnagle3(3).
M_SPHERE: An M_Sphere(3).
M_PLANE: An M_Plane3(3).

GENERIC GEOMETRIC ENTITIES: SETS

Sets of generic geometric entities in R^2 are described by the structure:

typedef struct m_geom_set2 {
	M_Geom2 *g;
	Uint n;
} M_GeomSet2;

Similarly for R^3:

typedef struct m_geom_set3 {
	M_Geom3 *g;
	Uint n;
} M_GeomSet3;

The following routines allow the manipulation of these sets.

M_GeomSet2
M_GEOM_SET_EMPTY(void);

M_GeomSet3
M_GEOM_SET_EMPTY(void);

void
M_GeomSetAdd2(M_GeomSet2 *S, const M_Geom2 *g);

void
M_GeomSetAdd3(M_GeomSet3 *S, const M_Geom3 *g);

void
M_GeomSetFree2(M_GeomSet2 *S);

void
M_GeomSetFree3(M_GeomSet3 *S);

The M_GEOM_SET_EMPTY() macro is provided as a static initializer for M_GeomSet2 and M_GeomSet3.

The M_GeomSetAdd2() and M_GeomSetAdd3() functions insert a copy of the entity g into the geometric set S.

M_GeomSetFree2() and M_GeomSetFree3() release the resources allocated by a geometric set.

HISTORY

The M_Geometry structure first appeared in Agar 1.3.4.