CHAPTER 4
220
Graphics
name of a
graphics state parameter dictionary
whose contents specify the values of
one or more graphics state parameters. This name is looked up in the
ExtGState
subdictionary of the current resource dictionary. (The name
ExtGState
, for
extended graphics state,
is a vestige of earlier versions of PDF.)
Note:
The graphics state parameter dictionary is also used by type 2 patterns, which
do not have a content stream in which the graphics state operators could be invoked
(see Section 4.6.3, “Shading Patterns”).
Each entry in the parameter dictionary specifies the value of an individual graph-
ics state parameter, as shown in Table 4.8. All entries need not be present for ev-
ery invocation of the
gs
operator; the supplied parameter dictionary may include
any combination of parameter entries. The results of
gs
are cumulative; parame-
ter values established in previous invocations persist until explicitly overridden.
Note that some parameters appear in both Tables 4.7 and 4.8; these parameters
can be set either with individual graphics state operators or with
gs
. It is expected
that any future extensions to the graphics state will be implemented by adding
new entries to the graphics state parameter dictionary rather than by introducing
new graphics state operators.
TABLE 4.8 Entries in a graphics state parameter dictionary
KEY
TYPE
DESCRIPTION
Type
name
number
integer
integer
number
array
(Optional)
The type of PDF object that this dictionary describes; must be
ExtGState
for a graphics state parameter dictionary.
(Optional; PDF 1.3)
The line width (see “Line Width” on page 215).
(Optional; PDF 1.3)
The line cap style (see “Line Cap Style” on page 216).
(Optional; PDF 1.3)
The line join style (see “Line Join Style” on page 216).
(Optional; PDF 1.3)
The miter limit (see “Miter Limit” on page 217).
(Optional; PDF 1.3)
The line dash pattern, expressed as an array of the form
[
dashArray dashPhase
]
, where
dashArray
is itself an array and
dashPhase
is an
integer (see “Line Dash Pattern” on page 217).
(Optional; PDF 1.3)
The name of the rendering intent (see “Rendering
LW
LC
LJ
ML
D
RI
name