SYNOPSIS
#include <agar/core.h> #include <agar/gui.h> #include <agar/math/m.h>
DESCRIPTION
The
M_Polygon structure describes a simple polygon.
The polygon may be convex or concave.
Self-intersections and holes are not allowed.
typedef struct m_polygon {
M_Vector2 *v; /* Vertices */
Uint n; /* Vertex count */
} M_Polygon;
INITIALIZATION
void M_PolygonInit (M_Polygon *P)
M_Polygon M_POLYGON_INITIALIZER (void)
void M_PolygonFree (M_Polygon *P)
M_Polygon M_PolygonFromPts (Uint n, const M_Vector2 *v)
M_Polygon M_PolygonFromPointSet2 (const M_PointSet2 *ps)
M_Polygon M_PolygonFromPointSet2i (const M_PointSet2i *ps)
M_Polygon M_PolygonFromLines (Uint n, const M_Line2 *L)
M_PointSet2 M_PolygonToPointSet2 (const M_Polygon *P)
M_PointSet2i M_PolygonToPointSet2i (const M_Polygon *P, M_Real w, M_Real h)
M_Polygon M_PolygonRead (AG_DataSource *ds)
void M_PolygonWrite (AG_DataSource *ds, const M_Polygon *P)
The M_PolygonInit() function initializes a M_Polygon structure. The M_POLYGON_INITIALIZER() macro may also be used as a static initializer.
The M_PolygonFree() function releases the memory allocated for vertices.
The M_PolygonFromPts() function returns a polygon structure given an array of points. The M_PolygonFromPointSet() variant accepts a M_PointSet2(3) argument. M_PolygonFromLines() returns a polygon from an array of lines L. n is the number of elements in the array.
The M_PolygonToPointSet2() and M_PolygonToPointSet2i() routines convert a M_Polygon to a M_PointSet2 or M_PointSet2i structure.
The M_PolygonRead() and M_PolygonWrite() functions read or write a polygon structure from/to an AG_DataSource(3).
OPERATIONS
int M_PolygonAddVertex (M_Polygon *P, M_Vector2 v)
int M_PolygonAddLine (M_Polygon *P, M_Line2 L)
int M_PolygonDelVertex (M_Polygon *P, int v)
int M_PolygonCopy (M_Polygon *Pdst, const M_Polygon *Psrc)
void M_PolygonScale (M_Polygon *P, M_Real xScale, M_Real yScale)
void M_PolygonOffset (M_Polygon *P, M_Real xOffs, M_Real yOffs)
int M_PointInPolygon (const M_Polygon *P, M_Vector2 p)
int M_PolygonIsConvex (const M_Polygon *P)
The M_PolygonAddVertex() function adds a new vertex to a polygon. Returns index of new vertex on success, -1 on failure. The M_PolygonAddLine() variant accepts a M_Line(3) argument instead of a vector.
M_PolygonDelVertex() removes the vertex at given index v.
The M_PolygonCopy() function copies the vertices of a source polygon Psrc to a destination polygon Pdst. The destination structure does not need to be initialized. Any existing vertices in Pdst will be overwritten. The function returns 0 on success or -1 if insufficient memory is available.
M_PolygonScale() multiplies all vertices of a polygon with the given scaling factors xScale, yScale. M_PolygonOffset() translates all vertices against xOffs, yOffs.
The M_PointInPolygon() function returns 1 if the point p lies inside the polygon.
M_PolygonIsConvex() returns 1 if the polygon is convex.
SEE ALSO
AG_DataSource(3), AG_Intro(3), M_Circle(3), M_Geometry(3), M_Plane(3), M_PointSet(3), M_Polygon(3), M_Rectangle(3), M_Sphere(3), M_Triangle(3), M_Vector(3)
HISTORY
The
M_Polygon structure first appeared in
Agar 1.3.4.
