Quartz (graphics layer)
Encyclopedia
Quartz specifically refers to a pair of Mac OS X
technologies, each part of the Core Graphics framework: Quartz 2D
and Quartz Compositor
. It includes both a 2D renderer in Core Graphics and the composition engine that sends instructions to the graphics card. Because of this vertical nature, Quartz is often interchanged synonymously with Core Graphics.
In a more general sense, the term Quartz or Quartz technologies can refer to almost every part of the Mac OS X graphics model from the rendering layer down to the compositor. In this use, the term covers Core Image and Core Video as well.
is the primary two-dimensional (2D) text and graphics rendering library: It directly supports Aqua
by displaying two-dimensional graphics
to create the user interface, including on-the-fly rendering
and anti-aliasing
. Quartz can render text with sub-pixel precision
; graphics are limited to more traditional anti-aliasing, which is the default mode of operation but can be turned off. In Mac OS X v10.4
, Apple introduced Quartz 2D Extreme, which allows Quartz 2D to use supported GPUs for rendering. In Mac OS X 10.4, Quartz 2D Extreme is not enabled by default, because it may lead to video redraw issues or kernel panics
.
As of Mac OS X v10.5
Quartz 2D Extreme has been renamed to QuartzGL - however it still remains disabled by default, as there are some situations where it can degrade performance, or experience visual glitches; it is a per-application setting which can be turned on if the developer wishes.
Quartz Compositor
is the compositing
engine used by Quartz 2D and other renderers, such as OpenGL
, Core Image
, and QuickTime
. In Mac OS X 10.2 and later, Quartz Compositor uses the processors (GPUs) on supported graphics cards to vastly improve composition performance. This technology is known as Quartz Extreme, and is enabled automatically on systems with supported graphics cards.
technology used in NeXTSTEP
(of which Mac OS X
is a descendant) and OPENSTEP
. Quartz's internal imaging model correlates well with the PDF
object graph, making it easy to output PDF to multiple devices.
Mac OS X
Mac OS X is a series of Unix-based operating systems and graphical user interfaces developed, marketed, and sold by Apple Inc. Since 2002, has been included with all new Macintosh computer systems...
technologies, each part of the Core Graphics framework: Quartz 2D
Quartz 2D
Quartz 2D is the primary two-dimensional graphics rendering API for Mac OS X, part of the Core Graphics framework.-Overview:Quartz 2D is available to all Mac OS X application environments, and provides resolution-independent and device-independent rendering of bitmap graphics, text, and vectors...
and Quartz Compositor
Quartz Compositor
Quartz Compositor is the windowing system in Mac OS X. It is responsible for presenting and maintaining rasterized, rendered graphics from the rest of the Core Graphics framework and other renderers in the Quartz technologies family...
. It includes both a 2D renderer in Core Graphics and the composition engine that sends instructions to the graphics card. Because of this vertical nature, Quartz is often interchanged synonymously with Core Graphics.
In a more general sense, the term Quartz or Quartz technologies can refer to almost every part of the Mac OS X graphics model from the rendering layer down to the compositor. In this use, the term covers Core Image and Core Video as well.
Quartz 2D & Quartz Compositor
Quartz 2DQuartz 2D
Quartz 2D is the primary two-dimensional graphics rendering API for Mac OS X, part of the Core Graphics framework.-Overview:Quartz 2D is available to all Mac OS X application environments, and provides resolution-independent and device-independent rendering of bitmap graphics, text, and vectors...
is the primary two-dimensional (2D) text and graphics rendering library: It directly supports Aqua
Aqua (user interface)
Aqua is the GUI and primary visual theme of Apple Inc.'s Mac OS X operating system. It is based around the theme of water, as its name suggests, with droplet-like elements and liberal use of translucency and reflection effects...
by displaying two-dimensional graphics
2D computer graphics
2D computer graphics is the computer-based generation of digital images—mostly from two-dimensional models and by techniques specific to them...
to create the user interface, including on-the-fly rendering
Rendering (computer graphics)
Rendering is the process of generating an image from a model , by means of computer programs. A scene file contains objects in a strictly defined language or data structure; it would contain geometry, viewpoint, texture, lighting, and shading information as a description of the virtual scene...
and anti-aliasing
Anti-aliasing
In digital signal processing, spatial anti-aliasing is the technique of minimizing the distortion artifacts known as aliasing when representing a high-resolution image at a lower resolution...
. Quartz can render text with sub-pixel precision
Subpixel rendering
Subpixel rendering is a way to increase the apparent resolution of a computer's liquid crystal display or Organic Light Emitting Diode display by rendering pixels to take into account the screen type's physical properties...
; graphics are limited to more traditional anti-aliasing, which is the default mode of operation but can be turned off. In Mac OS X v10.4
Mac OS X v10.4
Mac OS X v10.4 Tiger is the fifth major release of Mac OS X, Apple's desktop and server operating system for Macintosh computers. Tiger was released to the public on 29 April 2005 for US$129.95 as the successor to Mac OS X Panther , which had been released 18 months earlier...
, Apple introduced Quartz 2D Extreme, which allows Quartz 2D to use supported GPUs for rendering. In Mac OS X 10.4, Quartz 2D Extreme is not enabled by default, because it may lead to video redraw issues or kernel panics
Kernel panic
A kernel panic is an action taken by an operating system upon detecting an internal fatal error from which it cannot safely recover. The term is largely specific to Unix and Unix-like systems; for Microsoft Windows operating systems the equivalent term is "Bug check" .The kernel routines that...
.
As of Mac OS X v10.5
Mac OS X v10.5
Mac OS X Leopard is the sixth major release of Mac OS X, Apple's desktop and server operating system for Macintosh computers. Leopard was released on 26 October 2007 as the successor of Tiger , and is available in two variants: a desktop version suitable for personal computers, and a...
Quartz 2D Extreme has been renamed to QuartzGL - however it still remains disabled by default, as there are some situations where it can degrade performance, or experience visual glitches; it is a per-application setting which can be turned on if the developer wishes.
Quartz Compositor
Quartz Compositor
Quartz Compositor is the windowing system in Mac OS X. It is responsible for presenting and maintaining rasterized, rendered graphics from the rest of the Core Graphics framework and other renderers in the Quartz technologies family...
is the compositing
Compositing
Compositing is the combining of visual elements from separate sources into single images, often to create the illusion that all those elements are parts of the same scene. Live-action shooting for compositing is variously called "chroma key", "blue screen", "green screen" and other names. Today,...
engine used by Quartz 2D and other renderers, such as OpenGL
OpenGL
OpenGL is a standard specification defining a cross-language, cross-platform API for writing applications that produce 2D and 3D computer graphics. The interface consists of over 250 different function calls which can be used to draw complex three-dimensional scenes from simple primitives. OpenGL...
, Core Image
Core Image
Core Image is a pixel-accurate, near-realtime, non-destructive image processing technology in Mac OS X. Implemented as part of the QuartzCore framework of Mac OS X 10.4 and later, Core Image provides a plugin-based architecture for applying filters and effects within the Quartz graphics rendering...
, and QuickTime
QuickTime
QuickTime is an extensible proprietary multimedia framework developed by Apple Inc., capable of handling various formats of digital video, picture, sound, panoramic images, and interactivity. The classic version of QuickTime is available for Windows XP and later, as well as Mac OS X Leopard and...
. In Mac OS X 10.2 and later, Quartz Compositor uses the processors (GPUs) on supported graphics cards to vastly improve composition performance. This technology is known as Quartz Extreme, and is enabled automatically on systems with supported graphics cards.
Use of PDF
It is widely stated that Quartz "uses PDF" internally (notably by Apple in Quartz's early developer documentation), often by people making comparisons with the Display PostScriptDisplay PostScript
Display PostScript is an on-screen display system. As the name implies, DPS uses the PostScript imaging model and language to generate on-screen graphics...
technology used in NeXTSTEP
NEXTSTEP
NeXTSTEP was the object-oriented, multitasking operating system developed by NeXT Computer to run on its range of proprietary workstation computers, such as the NeXTcube...
(of which Mac OS X
Mac OS X
Mac OS X is a series of Unix-based operating systems and graphical user interfaces developed, marketed, and sold by Apple Inc. Since 2002, has been included with all new Macintosh computer systems...
is a descendant) and OPENSTEP
OpenStep
OpenStep was an object-oriented application programming interface specification for an object-oriented operating system that used a non-NeXTSTEP operating system as its core, principally developed by NeXT with Sun Microsystems. OPENSTEP was a specific implementation of the OpenStep API developed...
. Quartz's internal imaging model correlates well with the PDF
Portable Document Format
Portable Document Format is an open standard for document exchange. This file format, created by Adobe Systems in 1993, is used for representing documents in a manner independent of application software, hardware, and operating systems....
object graph, making it easy to output PDF to multiple devices.
External links
- Quartz in Tiger (from a review of Mac OS X 10.4 in Ars Technica)
- Apple's Quartz page for developers
- Introduction to OS X graphics APIs
- Cocoa Graphics with Quartz: Part 1
- Cocoa Graphics with Quartz: Part 2