georegression.metric

Class Intersection2D_F32

java.lang.Object

georegression.metric.Intersection2D_F32

public class Intersection2D_F32
extends java.lang.Object

Functions relating to finding the points at which two shapes intersect with each other.

Constructor Summary

Constructors

Constructor and Description
Intersection2D_F32()

Method Summary

Modifier and Type	Method and Description
static boolean	containConcave(Polygon2D_F32 polygon, Point2D_F32 pt) Checks to see if the point is contained inside the concave polygon.
static boolean	containConvex(Polygon2D_F32 polygon, Point2D_F32 pt) Checks to see if the point is contained inside the convex polygon.
static boolean	contains(Quadrilateral_F32 quad, Point2D_F32 pt) True if the point is contained inside the quadrilateral.
static boolean	contains(Rectangle2D_F32 a, float x, float y) Checks to see if the specified point is inside the rectangle.
static boolean	contains(RectangleLength2D_F32 a, float x, float y) Checks to see if the specified point is inside the rectangle.
static boolean	contains2(Rectangle2D_F32 a, float x, float y) Checks to see if the specified point is inside the rectangle.
static boolean	contains2(RectangleLength2D_F32 a, float x, float y) Checks to see if the specified point is inside the rectangle.
static boolean	containTriangle(Point2D_F32 a, Point2D_F32 b, Point2D_F32 c, Point2D_F32 pt) Returns true of the the point is inside the triangle.
static Point2D_F32	intersection(LineGeneral2D_F32 a, LineGeneral2D_F32 b, Point2D_F32 ret) Finds the intersection of two lines as a 2D point in coordinates.
static Point3D_F32	intersection(LineGeneral2D_F32 a, LineGeneral2D_F32 b, Point3D_F32 ret) Finds the intersection of two lines as a 2D point in homogeneous coordinates.
static float	intersection(LineParametric2D_F32 a, LineParametric2D_F32 b) Finds the point of intersection between two lines.
static Point2D_F32	intersection(LineParametric2D_F32 a, LineParametric2D_F32 b, Point2D_F32 ret) Finds the point of intersection between two lines and returns the point.
static float	intersection(LineParametric2D_F32 target, LineSegment2D_F32 l) Finds the point of intersection between a line and a line segment.
static Point2D_F32	intersection(LineSegment2D_F32 l_0, LineSegment2D_F32 l_1, Point2D_F32 ret) Finds the point of intersection between two lines segments.
static boolean	intersection(Rectangle2D_F32 a, Rectangle2D_F32 b, Rectangle2D_F32 result) Finds the intersection between two rectangles.
static RectangleLength2D_F32	intersection(RectangleLength2D_F32 a, RectangleLength2D_F32 b)
static float	intersectionArea(Rectangle2D_F32 a, Rectangle2D_F32 b) Returns the area of the intersection of two rectangles.
static boolean	intersects(Rectangle2D_F32 a, Rectangle2D_F32 b) Checks to see if the two rectangles intersect each other

Methods inherited from class java.lang.Object

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

Constructor Detail

Intersection2D_F32

public Intersection2D_F32()

Method Detail

containConvex

public static boolean containConvex(Polygon2D_F32 polygon,
                                    Point2D_F32 pt)

Checks to see if the point is contained inside the convex polygon. If the point is an the polygon's perimeter it is considered to NOT be inside.

Clockwise or counter-clockwise order of the polygon does not matter.

Parameters:

polygon - Convex polygon. Not modified.

pt - Point. Not modified.

Returns:

True if the point is contained inside the polygon.

containConcave

public static boolean containConcave(Polygon2D_F32 polygon,
                                     Point2D_F32 pt)

Checks to see if the point is contained inside the concave polygon. NOTE: Points which lie along the perimeter may or may not be considered as inside

Parameters:

polygon - Convex polygon. Not modified.

pt - Point. Not modified.

Returns:

True if the point is contained inside the polygon.

contains

public static boolean contains(Quadrilateral_F32 quad,
                               Point2D_F32 pt)

True if the point is contained inside the quadrilateral.

Parameters:

quad - quadrilateral

pt - point

Returns:

true if the point is inside and false if it is not.

containTriangle

public static boolean containTriangle(Point2D_F32 a,
                                      Point2D_F32 b,
                                      Point2D_F32 c,
                                      Point2D_F32 pt)

Returns true of the the point is inside the triangle. This function is simply an unrolled version of containConcave(Polygon2D_F32, Point2D_F32).

Parameters:

a - vertex in triangle

b - vertex in triangle

c - vertex in triangle

pt - Point which is being tested for containment inside of triangle

Returns:

true if the point is inside of triangle

intersection

public static Point2D_F32 intersection(LineParametric2D_F32 a,
                                       LineParametric2D_F32 b,
                                       Point2D_F32 ret)

Finds the point of intersection between two lines and returns the point.

Parameters:

a - Line.

b - Line.

ret - storage for the point of intersection. If null a new point will be declared.

Returns:

If the two lines intersect it returns the point of intersection. null if they don't intersect or have infinite intersections.

intersection

public static float intersection(LineParametric2D_F32 a,
                                 LineParametric2D_F32 b)

Finds the point of intersection between two lines. The point of intersection is specified as a point along the parametric line 'a'. (x,y) = (x_0,y_0) + t*(slope_x,slope_y), where 't' is the location returned.

Parameters:

a - Line.

b - Line.

Returns:

The location along 'target'. If the lines do not intersect or have infinite intersections Float.NaN is returned.

intersection

public static Point2D_F32 intersection(LineSegment2D_F32 l_0,
                                       LineSegment2D_F32 l_1,
                                       Point2D_F32 ret)

Finds the point of intersection between two lines segments.

Parameters:

l_0 - Line segment.

l_1 - line segment.

ret - storage for the point of intersection. If null a new point will be declared.

Returns:

If the two lines intersect it returns the point of intersection. null if they don't intersect or have infinite intersections.

intersection

public static Point3D_F32 intersection(LineGeneral2D_F32 a,
                                       LineGeneral2D_F32 b,
                                       Point3D_F32 ret)

Finds the intersection of two lines as a 2D point in homogeneous coordinates. Because the solution is found in homogeneous coordinates it can even handle parallel lines which "intersect at infinity".

A 2D point in homogeneous coordinates is expressed as the triple (x,y,z), which can be converted into the standard notation as x' = x/z and y'= y/z. If the lines are parallel and intersect at infinity then z=0 and the above conversion will fail.

Parameters:

a - Line

b - Line

ret - Storage for point of intersection.

Returns:

Point of intersection represented in homogeneous coordinates.

intersection

public static Point2D_F32 intersection(LineGeneral2D_F32 a,
                                       LineGeneral2D_F32 b,
                                       Point2D_F32 ret)

Finds the intersection of two lines as a 2D point in coordinates. If the lines are parallel then null is returned.

Parameters:

a - Line

b - Line

ret - Storage for point of intersection.

Returns:

Point of intersection in 2D coordinates. null if intersection at infinity

intersection

public static float intersection(LineParametric2D_F32 target,
                                 LineSegment2D_F32 l)

Finds the point of intersection between a line and a line segment. The point of intersection is specified as the distance along the parametric line. If no intersection is found then Float.NaN is returned.

Parameters:

target - A line whose location along which the point of intersection is being found. Not modified.

l - Line segment which is being tested for intersection. Not modified.

Returns:

The location along 'target'. If the lines do not intersect or have infinite intersections Float.NaN is returned.

contains

public static boolean contains(RectangleLength2D_F32 a,
                               float x,
                               float y)

Checks to see if the specified point is inside the rectangle. A point is inside if it is ≥ the lower extend and < the upper extent.

inside = x ≥ x0 AND x < x0+width AND y ≥ y0 AND y < y0+height

Parameters:

a - Rectangle.

x - x-coordinate of point being tested for containment

y - y-coordinate of point being tested for containment

Returns:

true if inside and false if output

contains2

public static boolean contains2(RectangleLength2D_F32 a,
                                float x,
                                float y)

Checks to see if the specified point is inside the rectangle. A point is inside if it is ≥ the lower extend and ≤ the upper extent.

inside = x ≥ x0 AND x ≤ x0+width and y ≥ y0 AND y ≤ y0+height

Parameters:

a - Rectangle.

x - x-coordinate of point being tested for containment

y - y-coordinate of point being tested for containment

Returns:

true if inside and false if output

contains

public static boolean contains(Rectangle2D_F32 a,
                               float x,
                               float y)

Checks to see if the specified point is inside the rectangle. A point is inside if it is ≥ the lower extend and < the upper extent.

inside = x ≥ x0 AND x ≤ x1 AND y ≥ y0 AND y ≤ y1

Parameters:

a - Rectangle.

x - x-coordinate of point being tested for containment

y - y-coordinate of point being tested for containment

Returns:

true if inside and false if output

contains2

public static boolean contains2(Rectangle2D_F32 a,
                                float x,
                                float y)

Checks to see if the specified point is inside the rectangle. A point is inside if it is ≥ the lower extend and ≤ the upper extent.

inside = x ≥ x0 AND x ≤ x1 AND y ≥ y0 AND y ≤ y1

Parameters:

a - Rectangle.

x - x-coordinate of point being tested for containment

y - y-coordinate of point being tested for containment

Returns:

true if inside and false if output

intersection

public static RectangleLength2D_F32 intersection(RectangleLength2D_F32 a,
                                                 RectangleLength2D_F32 b)

intersects

public static boolean intersects(Rectangle2D_F32 a,
                                 Rectangle2D_F32 b)

Checks to see if the two rectangles intersect each other

Parameters:

a - Rectangle

b - Rectangle

Returns:

true if intersection

intersection

public static boolean intersection(Rectangle2D_F32 a,
                                   Rectangle2D_F32 b,
                                   Rectangle2D_F32 result)

Finds the intersection between two rectangles. If the rectangles don't intersect then false is returned.

Parameters:

a - Rectangle

b - Rectangle

result - Storage for the found intersection

Returns:

true if intersection

intersectionArea

public static float intersectionArea(Rectangle2D_F32 a,
                                     Rectangle2D_F32 b)

Returns the area of the intersection of two rectangles.

Parameters:

a - Rectangle

b - Rectangle

Returns:

area of intersection