1PDF::Builder::Resource:U:sFeorntC(o3n)tributed Perl DocuPmDeFn:t:aBtuiiolnder::Resource::Font(3)
2
6 PDF::Builder::Resource::Font - some common support routines for font
7 files. Inherits from PDF::Builder::Resource::BaseFont
8
10 $font->automap()
11 This applies to core fonts ("$pdf->corefont()") and PostScript
12 fonts ("$pdf->psfont()"). These cannot use UTF-8 (or other
13 multibyte character) encoded text; only single byte characters.
14 This limits a font to a maximum of 256 glyphs (the "standard"
15 single-byte encoding being used). Any other glyphs supplied with
16 the font are inaccessible.
17 "automap" splits a font containing more than 256 glyphs into
19 "planes" of single byte fonts of up to 256 glyphs, so that all
20 glyphs may be accessed in separate "fonts". An array of new fonts
21 will be returned, with [0] being the standard code page (of the
22 selected encoding). If there are any glyphs beyond xFF on the
23 standard encoding page, they will be returned in one or more
24 additional fonts of 223 glyphs each. Why 223? The first 32 are
25 reserved as control characters (although they have no glyphs), and
26 number x20 is a space. This, plus 223, gives 256 in total (the last
27 plane may have fewer than 223 glyphs). These "fonts" are temporary
28 (dynamic), though as usable as any other font.
29 Note that a plane may be empty (only space at x20 and possibly an
31 unusable character at x21) if the previous plane was full. You
32 might want to check if any character in the plane has a Unicode
33 value (if not, it's empty).
34 The ordering of these 223 glyphs in each following plane does not
36 appear to follow any particular official scheme, so be sure to
37 reference something like "examples/020_corefonts" to see what is
38 available, and what code point a glyph is at (e.g., an 'A' in the
39 text stream will print something different if you're not on plane
40 0). For a given font file, they should be consistent. For instance,
41 in Times-Roman core font, an \x21 or ! in plane[1] should always
42 give an A+macron. Further note that new editions of font files
43 released in the future may have changes to the glyph list and the
44 ordering (affecting which plane a glyph appears on), so use
45 automap() with caution. It appears that glyphs are sorted by
46 Unicode number, but if a new glyph is inserted, it would bump other
47 glyphs to new positions, and even to the next plane.
48 An example:
50 $fnt = $pdf->corefont('Times-Roman', -encode => 'latin1');
52 @planes = ($fnt, $fnt->automap()); # two planes
53 $text->font($planes[0], 15); # or just $fnt will work
54 $text->text('!'); # prints !
55 $text->font($planes[1], 15);
56 $text->text('!'); # prints A+macron
57 If you had used 'latin2' encoding, an \x21 on plane 1 will give an
59 inverted ! (¡ HTML entity).
60 Note that "$planes[$n]->fontname()" should always be the desired
62 base font (e.g., Times-Roman), while "$planes[$n]->name()" will be
63 the font ID (e.g., TiRoCBC) for plane 0, while for other planes
64 there will be a unique suffix added (e.g., TiRoCBCam0).
65 If you have just an occasional non-plane 0 character (or run of
67 characters), it may be tolerable to switch back and forth between
68 planes like this, just as typing an HTML entity once in a while
69 when you need a Greek letter on a web page is acceptable to most
70 people. However, if you're typing a lot of Greek text, a dedicated
71 keyboard may be better for you. Like that, switching to a TTF font
72 in order to be able to use UTF-8 may be easier.
73perl v5.34.0 2022-01-21 PDF::Builder::Resource::Font(3)