toxi.geom
Class Circle

java.lang.Object
  toxi.geom.Vec2D
      toxi.geom.Ellipse
          toxi.geom.Circle

All Implemented Interfaces:

java.lang.Comparable<ReadonlyVec2D>, ReadonlyVec2D, Shape2D

public class Circle
extends Ellipse

This class overrides Ellipse to define a 2D circle and provides several utility methods for it, including factory methods to construct circles from points.

Nested Class Summary

Nested classes/interfaces inherited from class toxi.geom.Vec2D

Vec2D.Axis

Field Summary

Fields inherited from class toxi.geom.Vec2D

MAX_VALUE, MIN_VALUE, x, X_AXIS, y, Y_AXIS, ZERO

Constructor Summary

Circle()

Circle(Circle c)

Circle(float radius)

Circle(float x, float y, float radius)

Circle(ReadonlyVec2D origin, float radius)

Method Summary

boolean	containsPoint(ReadonlyVec2D p) Checks if the point is within the given shape.
static Circle	from2Points(Vec2D p1, Vec2D p2) Factory method to construct a circle which has the two given points lying on its perimeter.
static Circle	from3Points(Vec2D p1, Vec2D p2, Vec2D p3) Factory method to construct a circle which has the three given points lying on its perimeter.
float	getCircumference() Computes the approximate circumference of the ellipse, using this equation: 2 * PI * sqrt(1/2 * (rx*rx+ry*ry)).
float	getRadius()
Vec2D[]	getTangentPoints(ReadonlyVec2D p)
Vec2D[]	intersectsCircle(Circle c)
Circle	setRadius(float r)

Methods inherited from class toxi.geom.Ellipse

getArea, getFoci, getRadii, setRadii, setRadii, toPolygon2D

Methods inherited from class toxi.geom.Vec2D

abs, add, add, add, addSelf, addSelf, angleBetween, angleBetween, bisect, clear, compareTo, constrain, constrain, copy, cross, distanceTo, distanceToSquared, dot, equals, equalsWithTolerance, floor, frac, fromTheta, getAbs, getComponent, getComponent, getConstrained, getFloored, getFrac, getInverted, getLimited, getNormalized, getNormalizedTo, getPerpendicular, getReciprocal, getReflected, getRotated, getSignum, hashCode, heading, interpolateTo, interpolateTo, interpolateTo, interpolateTo, interpolateToSelf, interpolateToSelf, invert, isInCircle, isInRectangle, isInTriangle, isMajorAxis, isZeroVector, jitter, jitter, jitter, jitter, jitter, jitter, limit, magnitude, magSquared, max, max, maxSelf, min, min, minSelf, normalize, normalizeTo, perpendicular, randomVector, randomVector, reciprocal, reflect, rotate, roundToAxis, scale, scale, scale, scale, scaleSelf, scaleSelf, scaleSelf, set, set, set, setComponent, setComponent, signum, sub, sub, sub, subSelf, subSelf, tangentNormalOfEllipse, to3DXY, to3DXZ, to3DYZ, toArray, toCartesian, toPolar, toString, x, y

Methods inherited from class java.lang.Object

getClass, notify, notifyAll, wait, wait, wait

Constructor Detail

Circle

public Circle()

Circle

public Circle(Circle c)

Circle

public Circle(float radius)

Circle

public Circle(float x,
              float y,
              float radius)

Circle

public Circle(ReadonlyVec2D origin,
              float radius)

Method Detail

from2Points

public static Circle from2Points(Vec2D p1,
                                 Vec2D p2)

Factory method to construct a circle which has the two given points lying on its perimeter. If the points are coincident, the circle will have a radius of zero.

Parameters:

p1 -

p2 -

Returns:

new circle instance

from3Points

public static Circle from3Points(Vec2D p1,
                                 Vec2D p2,
                                 Vec2D p3)

Factory method to construct a circle which has the three given points lying on its perimeter. The function returns null, if the 3 points are co-linear (in which case it's impossible to find a circle). Based on CPP code by Paul Bourke: http://local.wasp.uwa.edu.au/~pbourke/geometry/circlefrom3/

Parameters:

p1 -

p2 -

p3 -

Returns:

new circle instance or null

containsPoint

public boolean containsPoint(ReadonlyVec2D p)

Description copied from interface: Shape2D

Checks if the point is within the given shape.

Specified by:

containsPoint in interface Shape2D

Overrides:

containsPoint in class Ellipse

Returns:

true, if inside

getCircumference

public float getCircumference()

Description copied from class: Ellipse

Computes the approximate circumference of the ellipse, using this equation: 2 * PI * sqrt(1/2 * (rx*rx+ry*ry)). The precise value is an infinite series elliptical integral, but the approximation comes sufficiently close. See Wikipedia for more details: http://en.wikipedia.org/wiki/Ellipse

Specified by:

getCircumference in interface Shape2D

Overrides:

getCircumference in class Ellipse

Returns:

circumference

getRadius

public float getRadius()

getTangentPoints

public Vec2D[] getTangentPoints(ReadonlyVec2D p)

intersectsCircle

public Vec2D[] intersectsCircle(Circle c)

setRadius

public Circle setRadius(float r)