Calculating Screen Coverage
May 1996
When drawing a 3D object, it is sometimes useful to find a rectangle on the screen that completely encloses the object. This can be used to minimize screen-update and z buffer–clear regions. If the entire object is visible within the screen boundaries, this calculation is easy. You just find the minimum and maximum x and y screen coordinates. If the object extends outside the screen boundaries in one or more coordinates, this calculation is a little trickier. Simply extending the enclosing boundaries to the entire screen dimensions is overly conservative. This chapter describes a way to determine a ...
Get Jim Blinn's Corner: Notation, Notation, Notation now with the O’Reilly learning platform.
O’Reilly members experience books, live events, courses curated by job role, and more from O’Reilly and nearly 200 top publishers.
