Previous Next

                                           392
CHAPTER 5                                                                     Text



Other graphical effects can be achieved by treating the glyph outline as a path in-
stead of filling it. The text rendering mode parameter in the graphics state speci-
fies whether glyph outlines are to be filled, stroked, used as a clipping boundary,
or some combination of these effects. (This parameter does not apply to Type 3
fonts.)

Example 5.4 treats glyph outlines as a path to be stroked. The Tr operator sets the
text rendering mode to 1 (stroke). The w operator sets the line width to 2 units in
user space. Given those graphics state parameters, the Tj operator strokes the
glyph outlines with a line 2 points thick (see Figure 5.2).

Example 5.4

  BT
       /F13 48 Tf
       20 38 Td
       1 Tr
       2 w
       ( ABC ) Tj
  ET




                               ABC
                    FIGURE 5.2 Glyph outlines treated as a stroked path


Example 5.5 treats the glyphs’ outlines as a clipping boundary. The Tr operator
sets the text rendering mode to 7 (clip), causing the subsequent Tj operator to
impose the glyph outlines as the current clipping path. All subsequent painting
operations mark the page only within this path, as illustrated in Figure 5.3. This
state persists until some earlier clipping path is reinstated by the Q operator.

Previous Next