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QuickDraw is the 2D graphics library and associated Application Programming Interface (API) which is a core part of the classic Apple Macintosh operating system. It was initially written by Bill Atkinson and Andy Hertzfeld. QuickDraw still existed as part of the libraries of Mac OS X, but had been largely superseded by the more modern Quartz graphics system. In Mac OS X v10.4, QuickDraw has been officially deprecated. In Mac OS X v10.5 applications using QuickDraw cannot make use of the added 64-bit support. In Mac OS X v10.8, QuickDraw support was removed from the operating system. Applications using QuickDraw will still run under OS X 10.8; however, the current versions of Xcode and the OS X SDK do not contain the header files to compile such programs.〔http://bugs.python.org/issue18098〕 ==Principles of QuickDraw== QuickDraw was grounded in the Apple Lisa's LisaGraf of the early 1980s and was designed to fit well with the Pascal-based interfaces and development environments of the early Apple systems. In addition, QuickDraw was a raster graphics system, which defines the pixel as its basic unit of graphical information. This is in contrast to vector graphics systems, where graphics primitives are defined in mathematical terms and rasterized as required to the display resolution. A raster system requires much less processing power however, and was the prevailing paradigm at the time that QuickDraw was developed. QuickDraw defined a key data structure, the graphics ''port'', or GrafPort. This was a logical drawing area where graphics could be drawn. The most obvious on-screen "object" corresponding to a GrafPort was a window, but the entire desktop view could be a GrafPort, and off-screen ports could also exist. The GrafPort defined a coordinate system. In QuickDraw, this had a resolution of 16 bits, giving 65,536 unique vertical and horizontal locations. These are numbered from -32,767 on the extreme left (or top), to +32,768 on the extreme right (or bottom). A window was usually set up so that the top, left corner of its content area was located at 0,0 in the associated GrafPort. A window's content area did not include the window's frame, drop shadow or title bar (if any). QuickDraw coordinates referred to the infinitely thin lines ''between'' pixel locations. An actual pixel was drawn in the space to the immediate right and below the coordinate. This made it easier for programmers to avoid graphical glitches caused by off-by-one errors. On the Macintosh, pixels were square, and a GrafPort had a default resolution of 72 pixels per inch, chosen to match conventions established by the printing industry of having 72 points per inch. QuickDraw also contained a number of scaling and mapping functions. QuickDraw maintained a number of global variables per process, chief among these being the current port. This originally simplified the API, since all operations pertaind to "the current port", but as the OS developed, this use of global state has also made QuickDraw much harder to integrate with modern design approaches such as multi-threading and pre-emptive multitasking. To address these problems, the Carbon API (a bridge between Mac OS 9 and OS X) added additional parameters to some of the routines, allowing for the (opaque) storage of thread information and a new (non-polled) event structure. 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「QuickDraw」の詳細全文を読む スポンサード リンク
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