Previous Next


                                                196
CHAPTER 4                                                                       Graphics



Although the painting behavior described above is often attributed to individual
operators making up an object, it is always the object as a whole that is painted.
Figure 4.1 shows the ordering rules for the operations that define graphics
objects. Some operations are permitted only in certain types of graphics objects
or in the intervals between graphics objects (called the page description level in
the figure). Every content stream begins at the page description level, where
changes can be made to the graphics state, such as colors and text attributes, as
discussed in the following sections.

In the figure, arrows indicate the operators that mark the beginning or end of
each type of graphics object. Some operators are identified individually, others by
general category. Table 4.1 summarizes these categories for all PDF operators.

                           TABLE 4.1 Operator categories
CATEGORY                 OPERATORS                                      TABLE   PAGE

General graphics state   w, J, j, M, d, ri, i, gs                       4.7     219
Special graphics state   q, Q, cm                                       4.7     219
Path construction        m, l, c, v, y, h, re                           4.9     226
Path painting            S, s, f, F, f*, B, B*, b, b*, n                4.10    230
Clipping paths           W, W*                                          4.11    235
Text objects             BT, ET                                         5.4     405
Text state               Tc, Tw, Tz, TL, Tf, Tr, Ts                     5.2     398
Text positioning         Td, TD, Tm, T*                                 5.5     406
Text showing             Tj, TJ, ', "                                   5.6     407
Type 3 fonts             d0, d1                                         5.10    423
Color                    CS, cs, SC, SCN, sc, scn, G, g, RG, rg, K, k   4.24    287
Shading patterns         sh                                             4.27    303
Inline images            BI, ID, EI                                     4.42    352
XObjects                 Do                                             4.37    332
Marked content           MP, DP, BMC, BDC, EMC                          10.7    851
Compatibility            BX, EX                                         3.29    152

Previous Next