About Bitmap Shapes
Like all shapes, a bitmap shape is represented in memory by a shape object, a style object, an ink object, and a transform object. A shape object representing a bitmap shape contains the same properties as a shape object representing a geometric or typographic shape: owner count, tag list, shape type, shape fill, geometry, and so on.Figure 5-1 shows a graphic representation of a bitmap shape and a bitmap geometry.
Bitmap shapes make extensive use of their geometry property. In fact, most of the information useful to bitmap shapes is stored in their geometry--the values of the bitmap's pixels, the dimensions of the bitmap, and the color information used by the bitmap.
Bitmap shapes don't make much use of their shape fill property, and they use very little of their associated style object. In fact, the only information in a style object used by bitmap shapes are the style attributes that determine whether the upper-left corner of the bitmap should be constrained to an integer grid position.
Bitmap shapes don't use the color property of their ink objects because they store their own color information in their geometries. However, they do use the transfer mode property of their ink objects.
Bitmap shapes do make full use of their transform objects. For example, you can scale, skew, rotate, and clip bitmap shapes. You can also hit-test bitmap shapes, but you cannot hit-test parts of a bitmap shape, as you can for other types of shapes. For more information about transform objects and hit-testing, see the chapter "Transform Objects" of Inside Macintosh: QuickDraw GX Objects.
The next few sections discuss bitmap geometries, bitmap styles, bitmap inks, and bitmap transforms.
Subtopics
- Bitmap Geometries
- Bitmap Styles and Inks
- Bitmap Transforms
- Bitmaps and View Devices
