Package georegression.geometry

Class UtilPolygons2D_I32

java.lang.Object

georegression.geometry.UtilPolygons2D_I32

public class UtilPolygons2D_I32
extends Object

Various functions related to polygons.

Constructor Summary

Constructors

Constructor	Description
UtilPolygons2D_I32()

Method Summary

Modifier and Type	Method	Description
static void	bounding(Polygon2D_I32 quad, Rectangle2D_I32 rectangle)	Finds the minimum area bounding rectangle which is aligned to the x and y axis around the polygon.
static void	bounding(List<Point2D_I32> points, Rectangle2D_I32 rectangle)	Finds the minimum area bounding rectangle which is aligned to the x and y axis around the list of points.
static void	flip(Polygon2D_I32 a)	Flips the order of points inside the polygon.
static boolean	isCCW(List<Point2D_I32> polygon)	Returns true if the polygon is ordered in a counter-clockwise order.
static boolean	isConvex(Polygon2D_I32 poly)	Determines if the polugon is convex or concave.
static boolean	isEquivalent(Polygon2D_I32 a, Polygon2D_I32 b)	Checks to see if the vertexes of the two polygon's are the same up to the specified tolerance and allows for a shift in their order
static boolean	isIdentical(Polygon2D_I32 a, Polygon2D_I32 b)	Checks to see if the vertexes of the two polygon's are the same up to the specified tolerance
static boolean	isPositiveZ(Point2D_I32 a, Point2D_I32 b, Point2D_I32 c)	Returns true if the cross product would result in a strictly positive z (e.g.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Details

UtilPolygons2D_I32

public UtilPolygons2D_I32()

Method Details

bounding

public static void bounding(List<Point2D_I32> points,
 Rectangle2D_I32 rectangle)

Finds the minimum area bounding rectangle which is aligned to the x and y axis around the list of points. Note (x0,y0) is inclusive and (x1,y1) is exclusive.

Parameters:

points - (Input) Quadrilateral

rectangle - (Output) Minimum area rectangle

bounding

public static void bounding(Polygon2D_I32 quad,
 Rectangle2D_I32 rectangle)

Finds the minimum area bounding rectangle which is aligned to the x and y axis around the polygon. Note (x0,y0) is inclusive and (x1,y1) is exclusive.

Parameters:

quad - (Input) Quadrilateral

rectangle - (Output) Minimum area rectangle

isCCW

public static boolean isCCW(List<Point2D_I32> polygon)

Returns true if the polygon is ordered in a counter-clockwise order. This is done by summing up the interior angles.

Parameters:

polygon - List of ordered points which define a polygon

Returns:

true if CCW and false if CW

flip

public static void flip(Polygon2D_I32 a)

Flips the order of points inside the polygon. The first index will remain the same will otherwise be reversed

Parameters:

a - Polygon of order 3 or more.

isConvex

public static boolean isConvex(Polygon2D_I32 poly)

Determines if the polugon is convex or concave.

Parameters:

poly - Polygon

Returns:

true if convex and false if concave

isPositiveZ

public static boolean isPositiveZ(Point2D_I32 a,
 Point2D_I32 b,
 Point2D_I32 c)

Returns true if the cross product would result in a strictly positive z (e.g. z > 0 ). If true then the order is clockwise. v0 = a-b v1 = c-b

Parameters:

a - first point in sequence

b - second point in sequence

c - third point in sequence

Returns:

true if positive z

isIdentical

public static boolean isIdentical(Polygon2D_I32 a,
 Polygon2D_I32 b)

Checks to see if the vertexes of the two polygon's are the same up to the specified tolerance

Parameters:

a - Polygon

b - Polygon

Returns:

true if identical up to tolerance or false if not

isEquivalent

public static boolean isEquivalent(Polygon2D_I32 a,
 Polygon2D_I32 b)

Checks to see if the vertexes of the two polygon's are the same up to the specified tolerance and allows for a shift in their order

Parameters:

a - Polygon

b - Polygon

Returns:

true if identical up to tolerance or false if not