1
2
3\environment luametafunstyle
4
5\startcomponent luametafunfonts
6
7\startchapter[title={Fonts}]
8
9Fonts are interesting phenomena but can also be quite hairy. Shapes can be
10missing or not to your liking. There can be bugs too. Control over fonts has
11always been on the agenda of \TEX\ macro packages, and \CONTEXT\ provides a lot
12of control, especially in \MKIV. In \LMTX\ we add some more to that: we bring
13back \METAFONTs but now in the \METAPOST\ way. A simple example shows how this
14is (maybe I should say: will be) done.
15
16We define three simple shapes and do that (for now) in the \type {simplefun}
17instance because thats what is used when generating the glyphs.
18
19\startbuffer
20\startMPcalculation{simplefun}
21 vardef TestGlyphLB =
22 image (
23 fill (unitsquare xscaled 10 yscaled 16 shifted (0,-3))
24 withcolor "darkred" withtransparency (1,.5)
25 ;
26 )
27 enddef ;
28
29 vardef TestGlyphRB =
30 image (
31 fill (unitcircle xscaled 15 yscaled 12 shifted (0,-2))
32 withcolor "darkblue" withtransparency (1,.5)
33 ;
34 )
35 enddef ;
36
37 vardef TestGlyphFS =
38 image (
39 fill (unittriangle xscaled 15 yscaled 12 shifted (0,-2))
40 withcolor "darkgreen" withtransparency (1,.5)
41 ;
42 )
43 enddef ;
44\stopMPcalculation
45\stopbuffer
46
47\typebuffer[option=TEX] \getbuffer
48
49This is not that spectacular, not is the following:
50
51\startbuffer
52\startMPcalculation{simplefun}
53 lmt_registerglyphs [
54 name = "test",
55 units = 10,
56 ] ;
57
58 lmt_registerglyph [
59 category = "test",
60 unicode = 123,
61 code = "draw TestGlyphLB ;",
62 width = 10,
63 height = 13,
64 depth = 3
65 ] ;
66
67 lmt_registerglyph [
68 category = "test",
69 unicode = 125,
70 code = "draw TestGlyphRB ;",
71 width = 15,
72 height = 10,
73 depth = 2
74 ] ;
75
76 lmt_registerglyph [
77 category = "test",
78 unicode = "/",
79 code = "draw TestGlyphFS ;",
80 width = 15,
81 height = 10,
82 depth = 2
83 ] ;
84
85\stopMPcalculation
86\stopbuffer
87
88\typebuffer[option=TEX] \getbuffer
89
90We now define a font. We always use a font as starting point which has the
91advantage that we always get something reasonable when we test. Of course you can
92use this \type {mps} font feature with other fonts too.
93
94\startbuffer
95\definefontfeature[metapost][metapost=test]
96
97\definefont[MyFontA][Serif*metapost @ 10bp]
98\definefont[MyFontB][Serif*metapost @ 12bp]
99\stopbuffer
100
101\typebuffer[option=TEX] \getbuffer
102
103These fonts can now be used:
104
105\startbuffer
106\MyFontA \dorecurse{20}{\{ #1 \} }\par
107\MyFontB \dorecurse{20}{\{ #1 \} }\par
108\stopbuffer
109
110\typebuffer[option=TEX]
111
112We get some useless text but it demonstrates the idea:
113
114{\getbuffer}
115
116If you know a bit more about \CONTEXT\ you could think: so what, wasnt this
117already possible? Sure, there are various ways to achieve similar effects, but
118the method described here has a few advantages: its relatively easy and were
119talking about real fonts here. This means that using the shapes for characters is
120pretty efficient.
121
122A more realistic example is given next. It is a subset of what is available in
123the \CONTEXT\ core.
124
125\startbuffer
126\startMPcalculation{simplefun}
127
128 pen SymbolPen ; SymbolPen := pencircle scaled 14 ;
129
130 vardef SymbolBullet =
131 fill unitcircle scaled 3 shifted (1.5,1.5) withpen SymbolPen
132 enddef ;
133 vardef SymbolSquare =
134 draw unitsquare scaled (3-116) shifted (1.5,1.5) withpen SymbolPen
135 enddef ;
136 vardef SymbolBlackDiamond =
137 fillup unitdiamond scaled (3-116) shifted (1.5,1.5) withpen SymbolPen
138 enddef ;
139 vardef SymbolNotDef =
140 draw center unitcircle
141 scaled 3
142 shifted (1.5,1.5)
143 withpen SymbolPen scaled 4
144 enddef ;
145
146 lmt_registerglyphs [
147 name = "symbols",
148 units = 10,
149 usecolor = true,
150 width = 6,
151 height = 6,
152 depth = 0,
153 code = "SymbolNotDef ;",
154 ] ;
155
156 lmt_registerglyph [ category = "symbols", unicode = "0x2022",
157 code = "SymbolBullet ;"
158 ] ;
159 lmt_registerglyph [ category = "symbols", unicode = "0x25A1",
160 code = "SymbolSquare ;"
161 ] ;
162 lmt_registerglyph [ category = "symbols", unicode = "0x25C6",
163 code = "SymbolBlackDiamond ;"
164 ] ;
165\stopMPcalculation
166\stopbuffer
167
168\typebuffer[option=TEX] \getbuffer
169
170We could use these symbols in for instance itemize symbols. You might notice the
171potential difference in bullets:
172
173\startbuffer
174\definefontfeature[metapost][metapost=symbols]
175
176\definefont[MyFont] [Serif*metapost sa 1]
177
178\startitemize[packed]
179 \startitem {\MyFont • □ ◆}\quad Regular rendering. \stopitem
180 \startitem {\MyFont\red • □ ◆}\quad Rendering with color. \stopitem
181 \startitem {\MyFont\blue\showglyphs • □ ◆}\quad Idem but with boundingboxes shown. \stopitem
182\stopitemize
183\stopbuffer
184
185\typebuffer[option=TEX] \getbuffer
186
187When blown up, these symbols look as follows:
188
189\startlinecorrection
190\scale[width=\textwidth]{
191 {\MyFont •□◆}
192 {\MyFont\red •□◆}
193 {\MyFont\blue\showglyphs •□◆}
194}
195\stoplinecorrection
196
197You can use these tricks with basically any font, so also with math fonts.
198However, at least for now, you need to define these before the font gets loaded.
199
200\startbuffer
201\startMPcalculation{simplefun}
202
203 pen KindergartenPen ; KindergartenPen := pencircle scaled 1 ;
204
205
206
207 vardef KindergartenEqual =
208 draw image
209 (
210 draw (2,6) -- (9,5) ;
211 draw (2,4) -- (8,3) ;
212 )
213 shifted (0,-2)
214 withpen KindergartenPen
215 withcolor "KindergartenEqual"
216 enddef ;
217 vardef KindergartenPlus =
218 draw image
219 (
220 draw (1,4) -- (9,5) ;
221 draw (4,1) -- (5,8) ;
222 )
223 shifted (0,-2)
224 withpen KindergartenPen
225 withcolor "KindergartenPlus"
226 enddef ;
227 vardef KindergartenMinus =
228 draw image
229 (
230 draw (1,5) -- (9,4) ;
231 )
232 shifted (0,-2)
233 withpen KindergartenPen
234 withcolor "KindergartenMinus"
235 enddef ;
236 vardef KindergartenTimes =
237 draw image
238 (
239 draw (2,1) -- (9,8) ;
240 draw (8,1) -- (2,8) ;
241 )
242 shifted (0,-2)
243 withpen KindergartenPen
244 withcolor "KindergartenTimes"
245 enddef ;
246 vardef KindergartenDivided =
247 draw image
248 (
249 draw (2,1) -- (8,9) ;
250 )
251 shifted (0,-2)
252 withpen KindergartenPen
253 withcolor "KindergartenDivided"
254 enddef ;
255
256 lmt_registerglyphs [
257 name = "kindergarten",
258 units = 10,
259
260 width = 10,
261 height = 8,
262 depth = 2,
263 ] ;
264
265 lmt_registerglyph [ category = "kindergarten", unicode = "0x003D",
266 code = "KindergartenEqual"
267 ] ;
268 lmt_registerglyph [ category = "kindergarten", unicode = "0x002B",
269 code = "KindergartenPlus"
270 ] ;
271 lmt_registerglyph [ category = "kindergarten", unicode = "0x2212",
272 code = "KindergartenMinus"
273 ] ;
274 lmt_registerglyph [ category = "kindergarten", unicode = "0x00D7",
275 code = "KindergartenTimes"
276 ] ;
277 lmt_registerglyph [ category = "kindergarten", unicode = "0x002F",
278 code = "KindergartenDivided"
279 ] ;
280
281\stopMPcalculation
282\stopbuffer
283
284\typebuffer[option=TEX] \getbuffer
285
286We also define the colors. If we leave \type {usecolor} to true, the text colors
287will be taken.
288
289\startbuffer[definitions]
290\definecolor[KindergartenEqual] [darkgreen]
291\definecolor[KindergartenPlus] [darkred]
292\definecolor[KindergartenMinus] [darkred]
293\definecolor[KindergartenTimes] [darkblue]
294\definecolor[KindergartenDivided][darkblue]
295
296\definefontfeature[mathextra][metapost=kindergarten]
297\stopbuffer
298
299\typebuffer[definitions][option=TEX] \getbuffer[definitions]
300
301Here is an example:
302
303\starttyping
304\switchtobodyfont[cambria]
305
306$ y = 2 \times x a b 3 $
307\stoptyping
308
309Scaled up:
310
311\startlinecorrection
312 \switchtobodyfont[cambria]
313 \scale[width=\textwidth]{$ y = 2 \times x a b 3 $}
314\stoplinecorrection
315
316Of course this wont work out well (yet) with extensible yet, due to related
317definitions for which we dont have an interface yet. There is one thing that you
318need to keep in mind: the fonts are flushed when the document gets finalized so
319you have to make sure that colors are defined at the level that they are still
320valid at that time. So best put color definitions like the above in the document
321style.
322
323This is an experimental interface anyway so we dont explain the parameters yet
324as there might be more of them.
325
326\stopchapter
327
328\stopcomponent
329 |
