CHAPTER 1
Overview of Quartz 2D
Table 1-1
Parameters that are associated with the graphics state
Parameters
Discussed in this chapter
Current transformation matrix (CTM)
“Transforms” (page 75)
Clipping area
“Paths” (page 43)
Line: width, join, cap, dash, miter limit
“Paths” (page 43)
Accuracy of curve estimation (flatness)
“Paths” (page 43)
Anti-‐aliasing setting
“Graphics Contexts” (page 29)
Color: fill and stroke settings
“Color and Color Spaces” (page 67)
Alpha value (transparency)
“Color and Color Spaces” (page 67)
Rendering intent
“Color and Color Spaces” (page 67)
Color space: fill and stroke settings
“Color and Color Spaces” (page 67)
Text: font, font size, character spacing, text drawing “Text” (page 193) mode Blend mode
“Paths” (page 43) and “Bitmap Images and Image Masks” (page 135)
Quartz 2D Coordinate Systems A coordinate system, shown in Figure 1-‐4, defines the range of locations used to express the location and sizes of objects to be drawn on the page. You specify the location and size of graphics in the user-‐space coordinate system, or, more simply, the user space. Coordinates are defined as floating-‐point values. Figure 1-4
The Quartz coordinate system
y-axis
(0,0)
x-axis
Because different devices have different underlying imaging capabilities, the locations and sizes of graphics must be defined in a device-‐independent manner. For example, a screen display device might be capable of displaying no more than 96 pixels per inch, while a printer might be capable of displaying 300 pixels per
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Quartz 2D Coordinate Systems 2010-11-19 | © 2001, 2010 Apple Inc. All Rights Reserved.