Mac OS X Leopard - ARCAism

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CHAPTER 24 MAC OS X DEVELOPMENT: THE APPLICATION FRAMEWORKS
Because the underlying Quartz compositing engine is based on PDF, Core Graphics is also
able to deal with PDF directly, including simple file operations like parsing and creation, as well
as transforms, metadata access, and conversion from PostScript.
Figure 24-17. Photo Booth uses Core Image filters, including everyone’s favorite: Hologram.
Core Graphics is blazing fast thanks to hardware acceleration, offloading as much processing
as possible to the video card. It provides an abstraction layer, so you can deal with graphics
directly, without worrying about how the actual processing will be done. Yesterday’s machines
will automatically ramp to CPU processing, and tomorrow’s machines will take advantage of
whatever heavy silicon they’ve got.
Even if you never use Core Graphics directly, you’ll see its influence (and its prefix, CG)
everywhere. For example, its width-agnostic floating-point scalar, CGFloat, replaces standard
float and double types in many applications.
NOTE In lieu of separate namespaces, frameworks use informal prefixes to give their members
unique names. For example, consider three different classes for representing an image:
CGImage, CIImage, and NSImage, from Core Graphics, Core Image, and Cocoa (formerly known
as NeXTSTEP).
Core Video
When you think about it, video is more of a concept than a thing. When you say you have “a
video,” you really mean you have a VHS tape, or a DVD, or an MP4 file, or some of that newfangled
H.264 the kids are talking about. Video, while one simple term, actually encompasses a
lot of complexity that the operating system protects us from.