Quartz 2D

Quartz 2D is the primary graphics library in Mac OS X, it supersedes QuickDraw which was used in earlier versions of the Mac OS, now known as "Classic".

Quartz 2D is based on version 1.4 of the Adobe Portable Document Format (PDF &mdash; a universal file format that preserves all of the fonts, formatting, colors and graphics of any source document, regardless of the platform used to create it.) It is descended from NeXT's Display PostScript.

Quartz 2D differs from QuickDraw in a number of key areas. QuickDraw is inherently based on raster graphics, where the fundamental graphical entity is the pixel. Everything is defined in terms of pixels laid out on a 2-dimensional integer grid. Quartz 2D instead takes a more mathematical approach, where the coordinate space is an abstract concept defined by real values in 2 dimensions. Points in this space can be connected to form paths, such as straight lines, bezier curves, and so on. To create actual graphics on the display, the paths are rasterised as needed to generate the pixels at the display device's resolution. This permits the same graphics commands to yield the same output on any device using the best resolution available. As in PostScript, paths can be "stroked" to give outlines, lines and so forth, and closed paths can be filled to create solid shapes. Text is generated simply by paths formed into the shapes of the text glyphs.