gov.nasa.worldwind.geom

Class Frustum

java.lang.Object

gov.nasa.worldwind.geom.Frustum

public class Frustum
extends java.lang.Object

Represents a six-sided view frustum in Cartesian coordinates with a corresponding viewport in screen coordinates.

Constructor Summary

Constructors

Constructor and Description
Frustum() Constructs a new unit frustum with each of its planes 1 meter from the center and a viewport with width and height both 1.
Frustum(Plane left, Plane right, Plane bottom, Plane top, Plane near, Plane far, Viewport viewport) Constructs a frustum.

Method Summary

Modifier and Type	Method and Description
boolean	containsPoint(Vec3 point)
boolean	intersectsSegment(Vec3 pointA, Vec3 pointB) Determines whether a line segment intersects this frustum.
boolean	intersectsViewport(Viewport viewport) Determines whether a screen coordinate viewport intersects this frustum.
Frustum	setToModelviewProjection(Matrix4 projection, Matrix4 modelview, Viewport viewport) Sets this frustum to one appropriate for a modelview-projection matrix.
Frustum	setToModelviewProjection(Matrix4 projection, Matrix4 modelview, Viewport viewport, Viewport subViewport) Sets this frustum to one appropriate for a subset of a modelview-projection matrix.
Frustum	setToUnitFrustum() Sets this frustum to a unit frustum with each of its planes 1 meter from the center a viewport with width and height both 1.

Methods inherited from class java.lang.Object

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

Constructor Detail

Frustum

public Frustum()

Constructs a new unit frustum with each of its planes 1 meter from the center and a viewport with width and height both 1.

Frustum

public Frustum(Plane left,
               Plane right,
               Plane bottom,
               Plane top,
               Plane near,
               Plane far,
               Viewport viewport)

Constructs a frustum.

Parameters:

left - the frustum's left plane

right - the frustum's right plane

bottom - the frustum's bottom plane

top - the frustum's top plane

near - the frustum's near plane

far - the frustum's far plane

viewport - the frustum's viewport

Throws:

java.lang.IllegalArgumentException - If any argument is null

Method Detail

setToUnitFrustum

public Frustum setToUnitFrustum()

Sets this frustum to a unit frustum with each of its planes 1 meter from the center a viewport with width and height both 1.

Returns:

this frustum, set to a unit frustum

setToModelviewProjection

public Frustum setToModelviewProjection(Matrix4 projection,
                                        Matrix4 modelview,
                                        Viewport viewport)

Sets this frustum to one appropriate for a modelview-projection matrix. A modelview-projection matrix's view frustum is a Cartesian volume that contains everything visible in a scene displayed using that modelview-projection matrix.

This method assumes that the specified matrices represents a projection matrix and a modelview matrix respectively. If this is not the case the results are undefined.

Parameters:

projection - the projection matrix to extract the frustum from

modelview - the modelview matrix defining the frustum's position and orientation in Cartesian coordinates

viewport - the screen coordinate viewport corresponding to the projection matrix

Returns:

this frustum, with its planes set to the modelview-projection matrix's view frustum, in Cartesian coordinates

Throws:

java.lang.IllegalArgumentException - If any argument is null

setToModelviewProjection

public Frustum setToModelviewProjection(Matrix4 projection,
                                        Matrix4 modelview,
                                        Viewport viewport,
                                        Viewport subViewport)

Sets this frustum to one appropriate for a subset of a modelview-projection matrix. A modelview-projection matrix's view frustum is a Cartesian volume that contains everything visible in a scene displayed using that modelview-projection matrix. The subset is defined by the region within the original viewport that the frustum contains.

This method assumes that the specified matrices represents a projection matrix and a modelview matrix respectively. If this is not the case the results are undefined.

Parameters:

projection - the projection matrix to extract the frustum from

modelview - the modelview matrix defining the frustum's position and orientation in Cartesian coordinates

viewport - the screen coordinate viewport corresponding to the projection matrix

subViewport - the screen coordinate region the frustum should contain

Returns:

this frustum, with its planes set to the modelview-projection matrix's view frustum, in Cartesian coordinates

Throws:

java.lang.IllegalArgumentException - If any argument is null

containsPoint

public boolean containsPoint(Vec3 point)

intersectsSegment

public boolean intersectsSegment(Vec3 pointA,
                                 Vec3 pointB)

Determines whether a line segment intersects this frustum.

Parameters:

pointA - the first line segment endpoint

pointB - the second line segment endpoint

Returns:

true if the segment intersects or is contained in this frustum, otherwise false

Throws:

java.lang.IllegalArgumentException - If either point is null

intersectsViewport

public boolean intersectsViewport(Viewport viewport)

Determines whether a screen coordinate viewport intersects this frustum.

Parameters:

viewport - the viewport to test

Returns:

true if the viewport intersects or is contained in this frustum, otherwise false

Throws:

java.lang.IllegalArgumentException - If the viewport is null