Newton Developer Technical Information: Newton Programmer's Guide: 2.1 OS Addendum /

Chapter 6 - Drawing and Graphics 2.1 / About Drawing and Graphics in the Newton 2.1 OS

About Gray Bitmaps (Pix Families)

A new data structure called a pix family has been introduced in the Newton 2.1 OS. A pix family is a group of one or more bitmaps at various bit depths. The system picks the most appropriate image to display on the current hardware. A pix family can be backwards compatible if 1-bit data is included.

Note

Currently support exists for creating a pix family only
from the Mac OS version of NTK. Future versions of WinNTK will make pix families.

The term "bitmap" is still used however to refer to the graphic shape produced from a pix family with *MakeShape. Bitmaps of a 1, 2, an 4-bit depths can also be created with the *MakeBitmap function.

Pix families and bitmap shapes can include a mask. The mask is used when the bitmap is rendered in the modeMask transfer mode. The mask is a 1-bit image used to "punch a hole" in the background before the regular image is rendered. Figure 6-1 illustrates the how a mask is used to punch a hole in the background.

Figure 6-1 The effect of a mask for a pix family

WARNING

You must not use the MungeBitmap function with the 'rotateLeft, 'rotateRight, or 'flipHorizontal options, the source bitmap is destructively replaced with garbage. You can still use the 'rotate180 and 'flipVertical, however.