# FreeBSD Manual Pages

```M_POINT_SET(3)	       FreeBSD Library Functions Manual		M_POINT_SET(3)

NAME
M_PointSet	-- Agar-Math point set structures

SYNOPSIS
#include <agar/math.h>

DESCRIPTION
The M_PointSet family of structures describe arbitrary sets of points in
space.  They are defined as follows:

/*	Points in R^2 */
typedef struct m_point_set2 {
M_Vector2 *p;
Uint n, nMax;
} M_PointSet2;

/*	Points in Z^2 */
typedef struct m_point_set2i {
M_Real w, h;
int *x, *y;
Uint n, nMax;
} M_PointSet2i;

/*	Points in R^3 */
typedef struct m_point_set3 {
M_Vector3 *p;
Uint n, nMax;
} M_PointSet3;

/*	Points in Z^3 */
typedef struct m_point_set3i {
M_Real w, h, d;		     /*	Scaling	factor */
int *x, *y, *z;
Uint n, nMax;
} M_PointSet3i;

The points	in a M_PointSet[23] are	stored under the p array of vectors
(see M_Vector(3)).

The points	in M_PointSet[23]i are stored as separate arrays of integers
x,	y, z.  The w, h	and d members specify scaling factors to use when con-
verting from an integer set to a real set.

INITIALIZATION
void M_PointSetInit2(M_PointSet2 *S)

void M_PointSetInit3(M_PointSet3 *S)

void M_PointSetInit2i(M_PointSet2i	*S, M_Real w, M_Real h)

void M_PointSetInit3i(M_PointSet3i	*S, M_Real w, M_Real h,	M_Real d)

int M_PointSetAlloc2(M_PointSet2 *S, Uint n)

int M_PointSetAlloc3(M_PointSet3 *S, Uint n)

int M_PointSetAlloc2i(M_PointSet2i	*S, Uint n)

int M_PointSetAlloc3i(M_PointSet3i	*S, Uint n)

void M_PointSetFree2(M_PointSet2 *S)

void M_PointSetFree3(M_PointSet3 *S)

void M_PointSetFree2i(M_PointSet2i	*S)

void M_PointSetFree3i(M_PointSet2i	*S)

void M_PointSetWrite2(AG_DataSource *ds, const M_PointSet2	*S)

void M_PointSetWrite3(AG_DataSource *ds, const M_PointSet3	*S)

void M_PointSetWrite2i(AG_DataSource *ds, const M_PointSet2i *S)

void M_PointSetWrite3i(AG_DataSource *ds, const M_PointSet3i *S)

M_PointSet2 M_POINT_SET2_EMPTY(void)

M_PointSet3 M_POINT_SET3_EMPTY(void)

M_PointSet2i M_POINT_SET2I_EMPTY(void)

M_PointSet3i M_POINT_SET3I_EMPTY(void)

The M_PointSetInit[23]() functions	initialize a point set in R^2 or R^3
to	the null set.

The M_PointSetInit[23]i() functions initialize a point set	in Z^3 or Z^3
to	the null set.  The w, h, d arguments specify the scaling factor	to use
when converting from an integer to	a real point set.

The M_PointSetAlloc*() functions allocates	memory for the specified num-
ber of points, returning 0	on success or -1 if insufficient memory	is
available.

The M_PointSetFree*() functions free the point sets, clearing the arrays
and reinitializing	the point count	to 0.

triangle structure	from/to	an AG_DataSource(3).

The macros	M_POINT_SET*_EMPTY() expand to static initializers for any of
the M_PointSet structures.

OPERATIONS

int M_PointSetAdd2i(M_PointSet2 *S, int x,	int y)

int M_PointSetAdd3i(M_PointSet3i *S, int x, int y,	int z)

int M_PointSetCopy2(M_PointSet2 *D, const M_PointSet2 *S)

int M_PointSetCopy3(M_PointSet3 *D, const M_PointSet3 *S)

int M_PointSetCopy2i(M_PointSet2i *D, const M_PointSet2i *S)

int M_PointSetCopy3i(M_PointSet3i *D, const M_PointSet3i *S)

void M_PointSetSort2(M_PointSet2 *S, enum m_point_set_sort_mode2)

void M_PointSetSort3(M_PointSet3 *S, enum m_point_set_sort_mode3)

The M_PointSetAdd*() functions insert a new point at the end of the set
S.	 On success, the index of the new point	is returned.  If insufficient
memory is available, -1 is	returned.

The M_PointSetCopy*() functions copy the contents of source set S into
destination set D,	returning 0 on success or -1 if	insufficient memory is
available.

The M_PointSetSort[23]() functions	sort the point sets by point coordi-
nate.  The	mode arguments specify the sorting mode:

enum m_point_set_sort_mode2 {
M_POINT_SET_SORT_XY,
M_POINT_SET_SORT_YX,
};
enum m_point_set_sort_mode3 {
M_POINT_SET_SORT_XYZ,
M_POINT_SET_SORT_XZY,
M_POINT_SET_SORT_YXZ,
M_POINT_SET_SORT_YZX,
M_POINT_SET_SORT_ZXY,
M_POINT_SET_SORT_ZYX,
};