QuickDraw is the 2D graphics library and associated Application Programming Interface (API) which is a core part of the classic Mac OS operating system. It was initially written by Bill Atkinson and Andy Hertzfeld. QuickDraw is the part of the Macintosh Toolbox that performs graphics operations on the user's screen. All Macintosh applications use QuickDraw indirectly whenever they call other Toolbox managers to create and manage the basic user interface elements (such as windows, controls, and menus, as described in Inside Macintosh: Macintosh Toolbox Essentials).
As the Macintosh has evolved toward greater graphics capabilities, QuickDraw has grown along with it. Each new generation of QuickDraw has maintained compatibility with those that preceded it, while adding new capabilities and expanding the range of possible display devices. This evolutionary approach has helped to ensure that existing applications, written for earlier Macintosh models, continue to work as more powerful computers are developed.
The development of QuickDraw has progressed along these three main evolutionary stages:
- Basic QuickDraw, which was designed for the earliest Macintosh models with their built-in black-and-white screens. System 7 added new capabilities to basic QuickDraw, including support for offscreen graphics worlds and the extended version 2 picture format. Basic QuickDraw is still used in more recent black-and-white Macintosh systems such as the Macintosh Classic and PowerBook 100 computers.
- The original version of Color QuickDraw, which was introduced with the first Macintosh II systems. This first generation of Color QuickDraw could support up to 256 colors.
- The current version of Color QuickDraw, which was originally introduced as 32-Bit Color QuickDraw and is now part of System 7. This version has been expanded to support up to millions of colors.
Applications that use only basic QuickDraw routines are compatible with all Macintosh systems. However, applications that use routines specific to Color QuickDraw cannot run on computers supporting only basic QuickDraw.