Inside Macintosh: QuickDraw GX Graphics /

Chapter 5 - Bitmap Shapes

Using Bitmap Shapes

This section shows you how to create, edit, and draw bitmap shapes. In particular, this section shows you how to

• create and draw black-and-white bitmaps
• create and draw color bitmaps
• dither and halftone bitmaps
• apply transfer modes to bitmaps
• convert other types of shapes to bitmap shapes
• apply transformations to bitmaps
• create offscreen bitmaps
• edit sections of bitmaps

Bitmap shape geometries use a gxPoint structure to indicate the initial position of the bitmap. Since a gxPoint structure contains two fixed-point values (type Fixed), the sample functions in this section must convert integer constants to fixed-point constants when specifying bitmap positions. QuickDraw GX provides the GXIntToFixed macro to perform this conversion:

#define GXIntToFixed(a) ((Fixed)(a) << 16)

QuickDraw GX also provides the ff macro as a convenient alias:

#define ff(a) GXIntToFixed(a)

---

Subtopics

Creating and Drawing Bitmaps

Dithering and Halftoning Bitmaps

Applying Transfer Modes to Bitmaps

Converting Other Types of Shapes to Bitmaps

Applying Transformations to Bitmaps

Creating Bitmaps With Disk-Based Pixel Images

Creating Bitmaps Offscreen

Editing Part of a Bitmap

Main | Page One | What's New | Apple Computer, Inc. | Find It | Contact Us | Help