Calculating Black-and-White Fills (IM: Im)

Inside Macintosh: Imaging With QuickDraw /

Chapter 3 - QuickDraw Drawing / QuickDraw Drawing Reference

Calculating Black-and-White Fills
QuickDraw provides the SeedFill and CalcMask procedures to help you determine the results of filling operations on portions of bitmaps. (Procedures for determining filling operations on pixel maps--namely, SeedCFill and CalcCMask--are described in the chapter "Color QuickDraw.")
The SeedFill procedure produces a mask showing where bits would be filled from a starting point, like the paint pouring from the MacPaintŹ paint-bucket tool. The CalcMask procedure produces a mask showing where paint could not flow from any of the outer edges of a rectangle. You can use the resulting masks to transfer portions of bit images from one graphics port to another with the CopyBits or CopyMask procedure, both of which are described in "Copying Images" beginning on page 3-107.

Subtopics

SeedFill

CalcMask