'''Glyphs''' is a pure-tcl library for digging into TrueType font-files. '''Glyphs''' is able to extract the vectorial paths of each glyph - points, lines, curves. [Image glyphBeta] '''Download''' * '''glyphs 1.1''' [https://googledrive.com/host/0B74bNhLEGm4ZX2R6V0RCX1o3U2s/Glyphs-1.1.zip] ** added methods for getting glyph's advancewidth, leftsidebearing, chars ** added methods for kerning ** updated test-suite * '''glyphs 1.0.1''' [https://googledrive.com/host/0B74bNhLEGm4ZX2R6V0RCX1o3U2s/Glyphs-1.0.1.zip] ** FIX for TclTk 8.6.1 BUG (Itcl incompatibility). Changes now works with TclTk 8.6.1 as well with previous versions. * '''glyphs 1.0''' [http://irrational-numbers.googlecode.com/files/Glyphs-1.0.zip] (BUG) * '''glyphs 0.9''' [http://irrational-numbers.googlecode.com/files/glyphs-0.9.zip] (OLD) See also [glyphs-demo] ** Opening and closing ** This is a first quick trip; just open a .ttf, look inside and close ====== > package require Glyphs > set fObj [Glyphs::new "arial.ttf"] > set ng [$fObj get numGlyphs] > puts "found $ng glyphs" > $fObj destroy ====== ** Inspecting font file's properties ** Reopen the .ttf file ====== > set fObj [Glyphs::new "arial.ttf"] ====== we already know how to get the number-of-glyphs ====== > set res1 [$fObj get numGlyphs] 1674 ====== and we can also get the overall-bounding box, or where the descender-line is placed ====== > set res2 [$fObj get bbox] -1361 -665 4096 2060 >set res3 [$fObj get Descender] -434 ====== but there're a lot of properties and the better way to know which properties are set is: ====== > set props [$fObj get] fontPath numGlyphs bbox unitsPerEm fontRevision Ascender Descender ..... ====== Other font properties can be retrieved from the internal 'name' table: ====== > foreach {id name} [$fObj nameinfo] { > lassign [$fObj nameinfo $id] id name value > puts "$id - $name\n$value\n" > } 1 - Font Family name Arial 2 - Font Subfamily name Regular 3 - Unique font identifier Monotype:Arial Regular:Version 3.00 (Microsoft) 4 - Full font name Arial .... ====== ** Locating a single glyph ** The quickest way to locate a single glyph is through its glyph-index. We know that "arial.ttf" has 1674 glyphs, therefore we can get all glyphs from 0 to 1674. Now let' take the 144th glyph ====== >set g144 [$fObj glyph 144] ====== As with fObj's properties, we can get some specific glyph's property: ====== >$g144 get index 144 >$g144 get bbox 1 0 1936 1466 ====== In order to list all the available properties ====== > $g144 get index bbox points instructions pathlengths paths ... ====== Forget about the "instructions" property it' a binary string "Glyphs" is not currently able to decode. (Probably it will removed in the next revision) The most important properties are '''points '''and '''paths''' Let's take a glyph simpler than 144 ====== >set g103 [$fObj glyph 103] >set L [$g103 get points] {99 714 1 99 1079 0 ...} {299 711 1 299 446 0 ...} {516 1556 1 516 1761 1 ...} {889 1556 1 ...} ====== Result looks like a list of 4 lists (4 contours). Each contour is made of a sequence of triples: x y flag. Flag "1" means that point (x,y) is on-curve, Flag "0" means point (x,y) is the control point of a Quadratic Bezier curve. But, how to translate these "points" in a parametric curve ? ====== >set L [$g103 get paths] {{M 99 714} {Q 99 1079 295.0 1285.5} ...} {{M 299 711} {Q 299 446 441.5 293.5} ... } {{M 516 1556} {L 516 1761} ... } {{M 889 1556} {L 889 1761} ...} ====== Result is a list of (4) contours. Each contour is made of a sequence of simple abstract commands: * M x y -- set (x,y) as the current point * L x y -- draw a line from current point to (x,y). (x,y) then becomes the current point * Q x1 y1 x2 xy -- draw a quadratic bezier from current point, to (x1,y1) (control point) and to (x2,y2) (end-point). (x,y) then becomes the current point. It's your app's responsability to translate these 'abstract commands' in real drawing commands. A very simple implementation for the standard canvas-widget could be the following: ====== proc Paths2Canvas { cvs paths } { foreach path $paths { # first command should be M (MOVETO) foreach pCmd $path { set points [lassign $pCmd cmd] switch -- $cmd { M { ; } L { $cvs create line $lastX $lastY {*}$points } Q { $cvs create line $lastX $lastY {*}$points -smooth true } default { error "unrecognized path command \"$cmd\"" } } set lastX [lindex $points end-1] set lastY [lindex $points end] } } } ====== A better implementation should take care to join consecutive segments in a single polyline .... Look at [glyphs-demo] code for a more complete example. ** Converting a glyph in a polyline, tangents, normals and more .. ** The "onUniformDistance" method is the last, more powerful method acting on a glyph. We can 'split' the whole glyphs in a series of 2D points equally spaced.. ====== > $g103 onUniformDistance 100.0 "at" ====== returns N (long) lists (one list for each glyph's countour) made of x y pairs; each (x,y) is a point on the glyph, and all these points are equally spaced (with some arrangements for dealing with the curves extremities ...) We can also get the tangent or normal *versors* for these points ====== > $g103 onUniformDistance 100.0 "tangent_at" > $g103 onUniformDistance 100.0 "normal_at" ====== and finally we can get the tangent or normal *vectors* (i.e. a segment starting from point "at" having the tangent/normal direction) ====== > $g103 onUniformDistance 100.0 "vtangent_at" > $g103 onUniformDistance 100.0 "vnormal_at" ====== We suggest to do some experiment with the [glyphs-demo] app. ** Getting more glyph metrics ** Getting the AdvanceWidth, LeftSideBearing, chars (list of all characters (unicode) sharing a glyph) ====== > $g103 get advancewidth 1593 > $g103 get leftsidebearing 99 > $g103 get chars 214 ====== the above commands are equivalent to: ====== > $fObj gget 103 advancewidth > $fObj gget 103 leftsidebearing > $fObj gget 103 chars ====== Getting the horizontal kerning value for the "A" "V" letters ====== > $fObj getKerning [$fObj unicode2glyphIndex "A"] [$fObj unicode2glyphIndex "V"] "H" -152 ====== ---- There's no much more to do with a single-glyph. Since it's a dynamic object, you can free space when it's no more useful ====== >$g103 destroy ====== but, you are not required to do it. In fact, when the 'font-file' is destroyed ====== >$fObj destroy ====== all space used for its allocated glyphs is freed. ** More on accessing glyphs ** We've seen the standard way to access a glyph by-index. The major part of TrueType Fonts holds a table for converting a "character" (unicode) to index. ====== >$fObj unicode2glyphIndex "A" >$fObj unicode2glyphIndex "ß" ; # unicode char \u03B2 (greek letter "Beta") >$fObj unicode2glyphIndex \u03B2 ; # unicode char \u03B2 (greek letter "Beta") >$fObj numcode2glyphIndex 946 ; # it's always the greek letter "Beta" ! ====== For your convenience, you can access a glyph, with two new methods ====== >$fObj glyphByUnicode "ß" ; # glyph by Unicode >$fObj glyphByCharCode 946 ; # glyph by CharCode ====== ** Comments and Suggestions ** [ABU] '''Glyphs ''' is a fresh new library and it still requires more documentation. <> Package