WorldWind Source Analysis Series: Outer bounding box, outer surround Ball

The outer bounding box and the outer bounding ball in the pluginsdk are described in class BoundingBox and Boundingsphere respectively, and the class diagram is as follows.

The corners field of the outer bounding box BoundingBox class is used to store the 8 vertex vectors of the outer bounding box. There are two forms of its constructor. The first constructor uses 8 vertex vectors to instantiate an outer bounding box. The second constructor uses the given east, south, west, and North four range values, and the top and bottom two values to instantiate a bounding box by calculating the values of 8 vertex vectors.

The Calculatecenter method is used to calculate the center coordinate vector of the outer bounding box.

The Calcrelativescreenarea method is used to calculate the area of pixels covered by the bottom of an outer bounding box. The camera parent class camerabase is used.

The contents of the outer bounding ball boundingsphere are roughly similar. The main purpose is to calculate the sphere and radius of the outer bounding sphere.

WorldWind Source Analysis Series: Outer bounding box, outer surround Ball