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Diffstat (limited to 'Build/source/texk/dvipsk/dvips.texi')
-rw-r--r-- | Build/source/texk/dvipsk/dvips.texi | 54 |
1 files changed, 29 insertions, 25 deletions
diff --git a/Build/source/texk/dvipsk/dvips.texi b/Build/source/texk/dvipsk/dvips.texi index 4e25a69aaec..f66f0334925 100644 --- a/Build/source/texk/dvipsk/dvips.texi +++ b/Build/source/texk/dvipsk/dvips.texi @@ -2,7 +2,7 @@ @setfilename dvips.info @settitle Dvips: A DVI-to-PostScript translator -@set version 5.999 +@set version 2020.1 @set month-year January 2020 @copying @@ -3386,19 +3386,22 @@ italics, and @file{texmsym.enc} for math symbols. @node Bitmap font encodings @subsection Bitmap font encodings +@cindex bitmap font encodings +@cindex font encodings, bitmap +@cindex encodings, for bitmap fonts + To dvips, bitmapped fonts do not have any notion of linguistics; they are simply a vector of glyphs. By comparison, PostScript fonts are required to contain an encoding vector that at the least provides glyph names; these names can permit PostScript and PDF viewers to extract legible text from Postscript and PDF output. -Unlike previous versions, -dvips versions 2019 and later add glyph naming information to Type 3 -bitmapped fonts (if they can locate such information) as an Encoding -vector. This provides some support for search, for copy and paste, -and even some limited support for accessibility. The -J command line -option and J configuration option enables and disables this -functionality; by default it is enabled. +Unlike previous versions, dvips versions 2019 and later add glyph +naming information to Type 3 bitmapped fonts (if they can locate such +information) as an Encoding vector. This provides some support for +search, for copy and paste, and even some limited support for +accessibility. The -J command line option and J configuration option +enables and disables this functionality; by default it is enabled. To do this, dvips must find encoding information for the bitmapped fonts. It does this by first searching for a font-specific encoding @@ -3407,23 +3410,24 @@ in the standard encoding path. If it does not find such a file, it will search for a @file{dvips-all.enc} file which contains a base set of encodings for many fonts. -The specific syntax of an encoding file is unspecified, except that -it must be a PostScript fragment that leaves exactly one object on -the operand stack. (This is different from the encoding files used -to define encodings for PostScript fonts, described earlier). -Normally that object is just an array of 256 -names; in this case, that array is used as the encoding vector for -the font. Alternatively, the object can be a procedure that, when -executed, leaves a legal encoding vector on the stack. This second -option is made available to support future enhancements that may -add additional constructs to the font dictionary to enhance the -interpretation of font characters. - -The @file{dvips-all.enc} file contains encodings for many fonts, and it -is loaded by dvips at most once. The format is just a sequence of -font names, one per line, each terminated by a colon, followed by -the encoding to use for those files. - +The specific syntax of an encoding file is unspecified, except that it +must be a PostScript fragment that leaves exactly one object on the +operand stack. (This is different from the encoding files used to +define encodings for PostScript fonts, described earlier). Normally +that object is just an array of 256 names; in this case, that array is +used as the encoding vector for the font. Alternatively, the object +can be a procedure that, when executed, leaves a legal encoding vector +on the stack. This second option is made available to support future +enhancements that may add additional constructs to the font dictionary +to enhance the interpretation of font characters. + +The @file{dvips-all.enc} file contains encodings for many fonts, and +it is loaded by dvips at most once. The format is just a sequence of +font names, one per line, each terminated by a colon, followed by the +encoding to use for those files. + +@cindex bounding box, for bitmap fonts +@cindex coordinate system, for bitmap fonts As part of its operation, to enable heuristics in PostScript and PDF viewers to properly identify word breaks and column gutters, dvips also generates a modified font bounding box and a modified |