This repository has been archived by the owner on Sep 27, 2019. It is now read-only.
forked from phi-gamma/lualibs
-
Notifications
You must be signed in to change notification settings - Fork 3
/
lualibs-util-dim.lua
452 lines (382 loc) · 13.2 KB
/
lualibs-util-dim.lua
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
if not modules then modules = { } end modules ['util-dim'] = {
version = 1.001,
comment = "support for dimensions",
author = "Hans Hagen, PRAGMA-ADE, Hasselt NL",
copyright = "PRAGMA ADE / ConTeXt Development Team",
license = "see context related readme files"
}
--[[ldx--
<p>Internally <l n='luatex'/> work with scaled point, which are
represented by integers. However, in practice, at east at the
<l n='tex'/> end we work with more generic units like points (pt). Going
from scaled points (numbers) to one of those units can be
done by using the conversion factors collected in the following
table.</p>
--ldx]]--
local format, match, gsub, type, setmetatable = string.format, string.match, string.gsub, type, setmetatable
local P, S, R, Cc, C, lpegmatch = lpeg.P, lpeg.S, lpeg.R, lpeg.Cc, lpeg.C, lpeg.match
local allocate = utilities.storage.allocate
local setmetatableindex = table.setmetatableindex
local formatters = string.formatters
local texget = tex and tex.get or function() return 65536*10*100 end
local p_stripzeros = lpeg.patterns.stripzeros
--this might become another namespace
number = number or { }
local number = number
number.tonumberf = function(n) return lpegmatch(p_stripzeros,format("%.20f",n)) end
number.tonumberg = function(n) return format("%.20g",n) end
local dimenfactors = allocate {
["pt"] = 1/65536,
["in"] = ( 100/ 7227)/65536,
["cm"] = ( 254/ 7227)/65536,
["mm"] = ( 2540/ 7227)/65536,
["sp"] = 1, -- 65536 sp in 1pt
["bp"] = ( 7200/ 7227)/65536,
["pc"] = ( 1/ 12)/65536,
["dd"] = ( 1157/ 1238)/65536,
["cc"] = ( 1157/14856)/65536,
["nd"] = (20320/21681)/65536,
["nc"] = ( 5080/65043)/65536
}
-- print(table.serialize(dimenfactors))
--
-- %.99g:
--
-- t={
-- ["bp"]=1.5201782378580324e-005,
-- ["cc"]=1.1883696112892098e-006,
-- ["cm"]=5.3628510057769479e-007,
-- ["dd"]=1.4260435335470516e-005,
-- ["em"]=0.000152587890625,
-- ["ex"]=6.103515625e-005,
-- ["in"]=2.1113586636917117e-007,
-- ["mm"]=5.3628510057769473e-008,
-- ["nc"]=1.1917446679504327e-006,
-- ["nd"]=1.4300936015405194e-005,
-- ["pc"]=1.2715657552083333e-006,
-- ["pt"]=1.52587890625e-005,
-- ["sp"]=1,
-- }
--
-- patched %s and tonumber
--
-- t={
-- ["bp"]=0.00001520178238,
-- ["cc"]=0.00000118836961,
-- ["cm"]=0.0000005362851,
-- ["dd"]=0.00001426043534,
-- ["em"]=0.00015258789063,
-- ["ex"]=0.00006103515625,
-- ["in"]=0.00000021113587,
-- ["mm"]=0.00000005362851,
-- ["nc"]=0.00000119174467,
-- ["nd"]=0.00001430093602,
-- ["pc"]=0.00000127156576,
-- ["pt"]=0.00001525878906,
-- ["sp"]=1,
-- }
--[[ldx--
<p>A conversion function that takes a number, unit (string) and optional
format (string) is implemented using this table.</p>
--ldx]]--
local f_none = formatters["%s%s"]
local f_true = formatters["%0.5F%s"]
local function numbertodimen(n,unit,fmt) -- will be redefined later !
if type(n) == 'string' then
return n
else
unit = unit or 'pt'
n = n * dimenfactors[unit]
if not fmt then
fmt = f_none(n,unit)
elseif fmt == true then
fmt = f_true(n,unit)
else
return formatters[fmt](n,unit)
end
end
end
--[[ldx--
<p>We collect a bunch of converters in the <type>number</type> namespace.</p>
--ldx]]--
number.maxdimen = 1073741823
number.todimen = numbertodimen
number.dimenfactors = dimenfactors
function number.topoints (n,fmt) return numbertodimen(n,"pt",fmt) end
function number.toinches (n,fmt) return numbertodimen(n,"in",fmt) end
function number.tocentimeters (n,fmt) return numbertodimen(n,"cm",fmt) end
function number.tomillimeters (n,fmt) return numbertodimen(n,"mm",fmt) end
function number.toscaledpoints(n,fmt) return numbertodimen(n,"sp",fmt) end
function number.toscaledpoints(n) return n .. "sp" end
function number.tobasepoints (n,fmt) return numbertodimen(n,"bp",fmt) end
function number.topicas (n,fmt) return numbertodimen(n "pc",fmt) end
function number.todidots (n,fmt) return numbertodimen(n,"dd",fmt) end
function number.tociceros (n,fmt) return numbertodimen(n,"cc",fmt) end
function number.tonewdidots (n,fmt) return numbertodimen(n,"nd",fmt) end
function number.tonewciceros (n,fmt) return numbertodimen(n,"nc",fmt) end
--[[ldx--
<p>More interesting it to implement a (sort of) dimen datatype, one
that permits calculations too. First we define a function that
converts a string to scaledpoints. We use <l n='lpeg'/>. We capture
a number and optionally a unit. When no unit is given a constant
capture takes place.</p>
--ldx]]--
local amount = (S("+-")^0 * R("09")^0 * P(".")^0 * R("09")^0) + Cc("0")
local unit = R("az")^1 + P("%")
local dimenpair = amount/tonumber * (unit^1/dimenfactors + Cc(1)) -- tonumber is new
lpeg.patterns.dimenpair = dimenpair
local splitter = amount/tonumber * C(unit^1)
function number.splitdimen(str)
return lpegmatch(splitter,str)
end
--[[ldx--
<p>We use a metatable to intercept errors. When no key is found in
the table with factors, the metatable will be consulted for an
alternative index function.</p>
--ldx]]--
setmetatableindex(dimenfactors, function(t,s)
-- error("wrong dimension: " .. (s or "?")) -- better a message
return false
end)
--[[ldx--
<p>We redefine the following function later on, so we comment it
here (which saves us bytecodes.</p>
--ldx]]--
-- function string.todimen(str)
-- if type(str) == "number" then
-- return str
-- else
-- local value, unit = lpegmatch(dimenpair,str)
-- return value/unit
-- end
-- end
--
-- local stringtodimen = string.todimen
local stringtodimen -- assigned later (commenting saves bytecode)
local amount = S("+-")^0 * R("09")^0 * S(".,")^0 * R("09")^0
local unit = P("pt") + P("cm") + P("mm") + P("sp") + P("bp") + P("in") +
P("pc") + P("dd") + P("cc") + P("nd") + P("nc")
local validdimen = amount * unit
lpeg.patterns.validdimen = validdimen
--[[ldx--
<p>This converter accepts calls like:</p>
<typing>
string.todimen("10")
string.todimen(".10")
string.todimen("10.0")
string.todimen("10.0pt")
string.todimen("10pt")
string.todimen("10.0pt")
</typing>
<p>With this in place, we can now implement a proper datatype for dimensions, one
that permits us to do this:</p>
<typing>
s = dimen "10pt" + dimen "20pt" + dimen "200pt"
- dimen "100sp" / 10 + "20pt" + "0pt"
</typing>
<p>We create a local metatable for this new type:</p>
--ldx]]--
local dimensions = { }
--[[ldx--
<p>The main (and globally) visible representation of a dimen is defined next: it is
a one-element table. The unit that is returned from the match is normally a number
(one of the previously defined factors) but we also accept functions. Later we will
see why. This function is redefined later.</p>
--ldx]]--
-- function dimen(a)
-- if a then
-- local ta= type(a)
-- if ta == "string" then
-- local value, unit = lpegmatch(pattern,a)
-- if type(unit) == "function" then
-- k = value/unit()
-- else
-- k = value/unit
-- end
-- a = k
-- elseif ta == "table" then
-- a = a[1]
-- end
-- return setmetatable({ a }, dimensions)
-- else
-- return setmetatable({ 0 }, dimensions)
-- end
-- end
--[[ldx--
<p>This function return a small hash with a metatable attached. It is
through this metatable that we can do the calculations. We could have
shared some of the code but for reasons of speed we don't.</p>
--ldx]]--
function dimensions.__add(a, b)
local ta, tb = type(a), type(b)
if ta == "string" then a = stringtodimen(a) elseif ta == "table" then a = a[1] end
if tb == "string" then b = stringtodimen(b) elseif tb == "table" then b = b[1] end
return setmetatable({ a + b }, dimensions)
end
function dimensions.__sub(a, b)
local ta, tb = type(a), type(b)
if ta == "string" then a = stringtodimen(a) elseif ta == "table" then a = a[1] end
if tb == "string" then b = stringtodimen(b) elseif tb == "table" then b = b[1] end
return setmetatable({ a - b }, dimensions)
end
function dimensions.__mul(a, b)
local ta, tb = type(a), type(b)
if ta == "string" then a = stringtodimen(a) elseif ta == "table" then a = a[1] end
if tb == "string" then b = stringtodimen(b) elseif tb == "table" then b = b[1] end
return setmetatable({ a * b }, dimensions)
end
function dimensions.__div(a, b)
local ta, tb = type(a), type(b)
if ta == "string" then a = stringtodimen(a) elseif ta == "table" then a = a[1] end
if tb == "string" then b = stringtodimen(b) elseif tb == "table" then b = b[1] end
return setmetatable({ a / b }, dimensions)
end
function dimensions.__unm(a)
local ta = type(a)
if ta == "string" then a = stringtodimen(a) elseif ta == "table" then a = a[1] end
return setmetatable({ - a }, dimensions)
end
--[[ldx--
<p>It makes no sense to implement the power and modulo function but
the next two do make sense because they permits is code like:</p>
<typing>
local a, b = dimen "10pt", dimen "11pt"
...
if a > b then
...
end
</typing>
--ldx]]--
-- makes no sense: dimensions.__pow and dimensions.__mod
function dimensions.__lt(a, b)
return a[1] < b[1]
end
function dimensions.__eq(a, b)
return a[1] == b[1]
end
--[[ldx--
<p>We also need to provide a function for conversion to string (so that
we can print dimensions). We print them as points, just like <l n='tex'/>.</p>
--ldx]]--
function dimensions.__tostring(a)
return a[1]/65536 .. "pt" -- instead of todimen(a[1])
end
--[[ldx--
<p>Since it does not take much code, we also provide a way to access
a few accessors</p>
<typing>
print(dimen().pt)
print(dimen().sp)
</typing>
--ldx]]--
function dimensions.__index(tab,key)
local d = dimenfactors[key]
if not d then
error("illegal property of dimen: " .. key)
d = 1
end
return 1/d
end
--[[ldx--
<p>In the converter from string to dimension we support functions as
factors. This is because in <l n='tex'/> we have a few more units:
<type>ex</type> and <type>em</type>. These are not constant factors but
depend on the current font. They are not defined by default, but need
an explicit function call. This is because at the moment that this code
is loaded, the relevant tables that hold the functions needed may not
yet be available.</p>
--ldx]]--
dimenfactors["ex"] = 4 * 1/65536 -- 4pt
dimenfactors["em"] = 10 * 1/65536 -- 10pt
-- dimenfactors["%"] = 4 * 1/65536 -- 400pt/100
--[[ldx--
<p>The previous code is rather efficient (also thanks to <l n='lpeg'/>) but we
can speed it up by caching converted dimensions. On my machine (2008) the following
loop takes about 25.5 seconds.</p>
<typing>
for i=1,1000000 do
local s = dimen "10pt" + dimen "20pt" + dimen "200pt"
- dimen "100sp" / 10 + "20pt" + "0pt"
end
</typing>
<p>When we cache converted strings this becomes 16.3 seconds. In order not
to waste too much memory on it, we tag the values of the cache as being
week which mean that the garbage collector will collect them in a next
sweep. This means that in most cases the speed up is mostly affecting the
current couple of calculations and as such the speed penalty is small.</p>
<p>We redefine two previous defined functions that can benefit from
this:</p>
--ldx]]--
local known = { } setmetatable(known, { __mode = "v" })
function dimen(a)
if a then
local ta= type(a)
if ta == "string" then
local k = known[a]
if k then
a = k
else
local value, unit = lpegmatch(dimenpair,a)
if value and unit then
k = value/unit -- to be considered: round
else
k = 0
end
known[a] = k
a = k
end
elseif ta == "table" then
a = a[1]
end
return setmetatable({ a }, dimensions)
else
return setmetatable({ 0 }, dimensions)
end
end
function string.todimen(str) -- maybe use tex.sp when available
if type(str) == "number" then
return str
else
local k = known[str]
if not k then
local value, unit = lpegmatch(dimenpair,str)
if value and unit then
k = value/unit -- to be considered: round
else
k = 0
end
-- print(str,value,unit)
known[str] = k
end
return k
end
end
-- local known = { }
--
-- function string.todimen(str) -- maybe use tex.sp
-- local k = known[str]
-- if not k then
-- k = tex.sp(str)
-- known[str] = k
-- end
-- return k
-- end
stringtodimen = string.todimen -- local variable defined earlier
function number.toscaled(d)
return format("%0.5f",d/2^16)
end
--[[ldx--
<p>In a similar fashion we can define a glue datatype. In that case we
probably use a hash instead of a one-element table.</p>
--ldx]]--
--[[ldx--
<p>Goodie:s</p>
--ldx]]--
function number.percent(n,d) -- will be cleaned up once luatex 0.30 is out
d = d or texget("hsize")
if type(d) == "string" then
d = stringtodimen(d)
end
return (n/100) * d
end
number["%"] = number.percent