APPENDIX F
1036
Linearized PDF
7.
FontFile
streams, which contain the actual definitions of embedded fonts.
These are assumed to be large and slow to transfer; therefore, the viewer appli-
cation uses substitute fonts until the real ones have arrived. Only those fonts
for which substitution is possible can be deferred in this way. (Currently, this
includes any Type 1 or TrueType font that has a font descriptor with the
Nonsymbolic flag set, indicating the Adobe standard Latin character set).
See Section F.4, “Access Strategies,” for additional discussion about object order
and incremental drawing strategies.
F.2.7 Remaining Pages (Part 7)
for all remaining pages of the file, with the objects for each page grouped togeth-
er. The pages are contiguous and are ordered by page number. If the first page of
the file is not page 0, this section starts with page 0 and skips over the first page
when its position in the sequence is reached.
For each page, the objects required to display that page are grouped together,
except for resources and other objects that are shared with other pages. Shared
objects are located in the shared objects section (part 8). The starting file offset
and length of any page can be determined from the hint tables.
The recommended order of objects within a page is essentially the same as in the
first page. In particular, the page object must be the first object in each section.
In most cases, unlike for the first page, little benefit is gained from interleaving
contents with resources because most resources other than images—fonts in par-
ticular—are shared among multiple pages and therefore reside in the shared ob-
jects section. Image XObjects usually are not shared, but they should appear at
the end of the page’s section of the file, since rendering of images is deferred.
F.2.8 Shared Objects (Part 8)
from more than one page but that are not referenced (directly or indirectly) from
the first page. The hint tables contain an index of these objects. For more infor-
mation on named resources, see Section 3.7.2, “Resource Dictionaries.”