summaryrefslogtreecommitdiff
path: root/Master/texmf-dist/tex/context/base/m-chart.lua
blob: c4da2eb6378ef2b85cb6ec56022877b095748f28 (plain)
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
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
737
738
739
740
741
742
743
744
745
746
747
748
749
750
751
752
753
754
755
756
757
758
759
760
761
762
763
764
765
766
767
768
769
770
771
772
773
774
775
776
777
778
779
780
781
782
783
784
785
786
787
788
789
790
791
792
793
794
795
796
797
798
799
800
801
802
803
804
805
806
807
808
809
810
811
812
813
814
815
816
817
818
819
820
821
822
823
824
825
826
827
828
829
830
831
832
833
834
835
836
837
838
839
840
841
842
843
844
845
846
847
848
849
850
851
852
853
854
855
856
857
858
859
860
861
862
863
864
865
866
867
868
869
870
871
872
873
874
875
876
877
878
879
880
881
882
883
884
885
886
887
888
889
890
891
892
893
894
895
896
897
898
899
900
901
902
903
904
905
906
907
908
909
910
911
912
913
914
915
916
if not modules then modules = { } end modules ['x-flow'] = {
    version   = 1.001,
    comment   = "companion to m-flow.mkvi",
    author    = "Hans Hagen, PRAGMA-ADE, Hasselt NL",
    copyright = "PRAGMA ADE / ConTeXt Development Team",
    license   = "see context related readme files"
}

-- when we can resolve mpcolor at the lua end we will
-- use metapost.graphic(....) directly

-- todo: labels

moduledata.charts = moduledata.charts or { }

local gsub, match, find, format, lower = string.gsub, string.match, string.find, string.format, string.lower
local setmetatableindex = table.setmetatableindex
local P, S, C, Cc, lpegmatch = lpeg.P, lpeg.S, lpeg.C, lpeg.Cc, lpeg.match

local report_chart = logs.reporter("chart")

local points     = number.points

local variables  = interfaces.variables

local v_yes      = variables.yes
local v_no       = variables.no
local v_none     = variables.none
local v_standard = variables.standard
local v_overlay  = variables.overlay
local v_round    = variables.round
local v_test     = variables.test

local defaults = {
    chart = {
        name            = "",
        option          = "",
        backgroundcolor = "",
        width           = 100*65536,
        height          = 50*65536,
        dx              = 30*65536,
        dy              = 30*65536,
        offset          = 0,
        bodyfont        = "",
        dot             = "",
        hcompact        = variables_no,
        vcompact        = variables_no,
        autofocus       = "",
        focus           = "",
        labeloffset     = 5*65536,
        commentoffset   = 5*65536,
        exitoffset      = 0,

    },
    shape = { -- FLOS
        rulethickness   = 65536,
        default         = "",
        framecolor      = "darkblue",
        backgroundcolor = "lightgray",
    },
    focus = { -- FLOF
        rulethickness   = 65536,
        framecolor      = "darkred",
        backgroundcolor = "gray",
    },
    line = { -- FLOL
        rulethickness   = 65536,
        radius          = 10*65536,
        color           = "darkgreen",
        corner          = "",
        dash            = "",
        arrow           = "",
        offset          = "",
    },
    set = { -- FLOX
    },
    split = {
        nx      = 3,
        ny      = 3,
        command = "",
        marking = "",
        before  = "",
        after   = "",
    }
}

local validshapes = {
    ["node"]            = { kind = "shape", number =  0 },
    ["action"]          = { kind = "shape", number = 24 },
    ["procedure"]       = { kind = "shape", number =  5 },
    ["product"]         = { kind = "shape", number = 12 },
    ["decision"]        = { kind = "shape", number = 14 },
    ["archive"]         = { kind = "shape", number = 19 },
    ["loop"]            = { kind = "shape", number = 35 },
    ["wait"]            = { kind = "shape", number =  6 },
    ["subprocedure"]    = { kind = "shape", number = 20 },
    ["singledocument"]  = { kind = "shape", number = 32 },
    ["multidocument"]   = { kind = "shape", number = 33 },

    ["right"]           = { kind = "line",  number = 66 },
    ["left"]            = { kind = "line",  number = 67 },
    ["up"]              = { kind = "line",  number = 68 },
    ["down"]            = { kind = "line",  number = 69 },
}

local validlabellocations = {
    l  = "l",  left   = "l",
    r  = "r",  right  = "r",
    t  = "t",  top    = "t",
    b  = "b",  bottom = "b",
    lt = "lt",
    rt = "rt",
    lb = "lb",
    rb = "rb",
    tl = "tl",
    tr = "tr",
    bl = "bl",
    br = "br",
}

local validcommentlocations = {
    l  = "l",  left   = "l",
    r  = "r",  right  = "r",
    t  = "t",  top    = "t",
    b  = "b",  bottom = "b",
    lt = "lt",
    rt = "rt",
    lb = "lb",
    rb = "rb",
    tl = "tl",
    tr = "tr",
    bl = "bl",
    br = "br",
}

local validtextlocations = {
    l  = "l",  left   = "l",
    r  = "r",  right  = "r",
    t  = "t",  top    = "t",
    b  = "b",  bottom = "b",
    c  = "c",  center = "c",
    m  = "c",  middle = "m",
    lt = "lt",
    rt = "rt",
    lb = "lb",
    rb = "rb",
    tl = "lt",
    tr = "rt",
    bl = "lb",
    br = "rb",
}

setmetatableindex(validshapes,function(t,k)
    local l = gsub(lower(k)," ","")
    local v = rawget(t,l)
    if not v then
        local n = tonumber(k)
        if n then
            v = { kind = "shape", number = n }
        else
            v = rawget(t,"action")
        end
    end
    t[k] = v
    return v
end)

local charts = { }

local data, hash, temp, last_x, last_y, name

function commands.flow_start_chart(chartname)
    data = { }
    hash = { }
    last_x, last_y = 0, 0
    name = chartname
end

function commands.flow_stop_chart()
    charts[name] = {
        data = data,
        hash = hash,
        last_x = last_x,
        last_y = last_y,
    }
    data, hash, temp = nil, nil, nil
end

-- function commands.flow_set(chartname,chartdata)
--     local hash = { }
--     local data = { }
--     charts[name] = {
--         data = data,
--         hash = hash,
--     }
--     for i=1,#chartdata do
--         local di = data[i]
--         local name = di.name or ""
--         if name then
--             data[#data+1] = {
--                 name        = name,
--                 labels      = di.labels      or { },
--                 comments    = di.comments    or { },
--                 exits       = di.exits       or { },
--                 connections = di.connections or { },
--                 settings    = di.settings    or { },
--                 x           = di.x           or 1,
--                 y           = di.y           or 1,
--             }
--             hash[name] = i
--         end
--      end
-- end

function commands.flow_reset(chartname)
    charts[name] = nil
end

function commands.flow_set_current_cell(n)
    temp = data[tonumber(n)] or { }
end

function commands.flow_start_cell(settings)
    temp = {
        texts       = { },
        labels      = { },
        exits       = { },
        connections = { },
        settings    = settings,
        x           = 1,
        y           = 1,
        name        = "",
    }
end

function commands.flow_stop_cell()
    data[#data+1] = temp
    hash[temp.name or #data] = temp
end

function commands.flow_set_name(str)
    temp.name = str
end

function commands.flow_set_shape(str)
    temp.shape = str
end

function commands.flow_set_destination(str)
    temp.destination = str
end

function commands.flow_set_text(align,str)
    temp.texts[#temp.texts+1] = {
        location = align,
        text = str,
    }
end

function commands.flow_set_overlay(str)
    temp.overlay = str
end

function commands.flow_set_focus(str)
    temp.focus = str
end

function commands.flow_set_figure(str)
    temp.figure = str
end

function commands.flow_set_label(location,text)
    temp.labels[#temp.labels+1] = {
        location = location,
        text = text,
    }
end

function commands.flow_set_comment(location,text)
    local connections = temp.connections
    if connections then
        local connection = connections[#connections]
        if connection then
            local comments = connection.comments
            if comments then
                comments[#comments+1] = {
                    location = location,
                    text = text,
                }
            end
        end
    end
end

function commands.flow_set_exit(location,text)
    temp.exits[#temp.exits+1] = {
        location = location,
        text = text,
    }
end

function commands.flow_set_include(name,x,y,settings)
    data[#data+1] = {
        include  = name,
        x        = x,
        y        = y,
     -- settings = settings,
    }
end

local function inject(includedata,data,hash)
    local subchart = charts[includedata.include]
    if not subchart then
        return
    end
    local subdata = subchart.data
    if not subdata then
        return
    end
    local xoffset  = (includedata.x or 1) - 1
    local yoffset  = (includedata.y or 1) - 1
    local settings = includedata.settings
    for i=1,#subdata do
        local si = subdata[i]
        if si.include then
            inject(si,data,hash)
        else
            local t = {
                x        = si.x + xoffset,
                y        = si.y + yoffset,
                settings = settings,
            }
            setmetatableindex(t,si)
            data[#data+1] = t
            hash[si.name or #data] = t
        end
    end
end

local function pack(data,field)
    local list, max = { }, 0
    for e=1,#data do
        local d = data[e]
        local f = d[field]
        list[f] = true
        if f > max then
            max = f
        end
    end
    for i=1,max do
        if not list[i] then
            for e=1,#data do
                local d = data[e]
                local f = d[field]
                if f > i then
                    d[field] = f - 1
                end
            end
        end
    end
end

local function expanded(chart,chartsettings)
    local expandeddata = { }
    local expandedhash = { }
    local expandedchart = {
        data = expandeddata,
        hash = expandedhash,
    }
    setmetatableindex(expandedchart,chart)
    local data = chart.data
    local hash = chart.hash
    for i=1,#data do
        local di = data[i]
        if di.include then
            inject(di,expandeddata,expandedhash)
        else
            expandeddata[#expandeddata+1]  = di
            expandedhash[di.name or #expandeddata] = di
        end
    end
    --
    expandedchart.settings = chartsettings or { }
    -- make locals
    chartsettings.shape = chartsettings.shape or { }
    chartsettings.focus = chartsettings.focus or { }
    chartsettings.line  = chartsettings.line  or { }
    chartsettings.set   = chartsettings.set   or { }
    chartsettings.split = chartsettings.split or { }
    chartsettings.chart = chartsettings.chart or { }
    setmetatableindex(chartsettings.shape,defaults.shape)
    setmetatableindex(chartsettings.focus,defaults.focus)
    setmetatableindex(chartsettings.line ,defaults.line )
    setmetatableindex(chartsettings.set  ,defaults.set  )
    setmetatableindex(chartsettings.split,defaults.split)
    setmetatableindex(chartsettings.chart,defaults.chart)
    --
    if chartsettings.chart.vcompact == v_yes then
        pack(expandeddata,"y")
    end
    if chartsettings.chart.hcompact == v_yes then
        pack(expandeddata,"x")
    end
    --
    for i=1,#expandeddata do
        local cell = expandeddata[i]
        local settings = cell.settings
        if not settings then
            cell.settings = chartsettings
        else
            settings.shape = settings.shape or { }
            settings.focus = settings.focus or { }
            settings.line  = settings.line  or { }
            setmetatableindex(settings.shape,chartsettings.shape)
            setmetatableindex(settings.focus,chartsettings.focus)
            setmetatableindex(settings.line ,chartsettings.line)
        end
    end
    return expandedchart
end

local splitter = lpeg.splitat(",")

function commands.flow_set_location(x,y)
    if type(x) == "string" and not y then
        x, y = lpegmatch(splitter,x)
    end
    if not x or x == "" then
        x = last_x
    elseif type(x) == "number" then
        -- ok
    elseif x == "+" then
        x = last_x + 1
    elseif x == "-" then
        x = last_x - 1
    elseif find(x,"^[%+%-]") then
        x = last_x + (tonumber(x) or 0)
    else
        x = tonumber(x)
    end
    if not y or y == "" then
        y = last_y
    elseif type(y) == "number" then
        -- ok
    elseif y == "+" then
        y = last_y + 1
    elseif x == "-" then
        y = last_y - 1
    elseif find(y,"^[%+%-]") then
        y = last_y + (tonumber(y) or 0)
    else
        y = tonumber(y)
    end
    temp.x = x or 1
    temp.y = y or 1
    last_x = x or last_x
    last_y = y or last_y
end

function commands.flow_set_connection(location,displacement,name)
    local dx, dy = lpegmatch(splitter,displacement)
    dx = tonumber(dx)
    dy = tonumber(dy)
    temp.connections[#temp.connections+1] = {
        location = location,
        dx       = dx or 0,
        dy       = dy or 0,
        name     = name,
        comments = { },
    }
end

local function visible(chart,cell)
    local x, y = cell.x, cell.y
    return
        x >= chart.from_x and x <= chart.to_x and
        y >= chart.from_y and y <= chart.to_y and cell
end

local function process_cells(chart,xoffset,yoffset)
    local data = chart.data
    if not data then
        return
    end
    local focus = utilities.parsers.settings_to_hash(chart.settings.chart.focus or "")
    for i=1,#data do
        local cell = visible(chart,data[i])
        if cell then
            local settings = cell.settings
            local shapesettings = settings.shape
            local shape = cell.shape
            if not shape or shape == "" then
                shape = shapesettings.default or "none"
            end
            if shape ~= v_none then
                local shapedata = validshapes[shape]
                context("flow_begin_sub_chart ;") -- when is this needed
                if shapedata.kind == "line" then
                    local linesettings = settings.line
                    context("flow_shape_line_color := \\MPcolor{%s} ;", linesettings.color)
                    context("flow_shape_fill_color := \\MPcolor{%s} ;", linesettings.backgroundcolor)
                    context("flow_shape_line_width := %s ; ",           points(linesettingsrulethickness))
                elseif focus[cell.focus] or focus[cell.name] then
                    local focussettings = settings.focus
                    context("flow_shape_line_color := \\MPcolor{%s} ;", focussettings.framecolor)
                    context("flow_shape_fill_color := \\MPcolor{%s} ;", focussettings.backgroundcolor)
                    context("flow_shape_line_width := %s ; ",           points(focussettings.rulethickness))
                else
                    local shapesettings = settings.shape
                    context("flow_shape_line_color := \\MPcolor{%s} ;", shapesettings.framecolor)
                    context("flow_shape_fill_color := \\MPcolor{%s} ;", shapesettings.backgroundcolor)
                    context("flow_shape_line_width := %s ; " ,          points(shapesettings.rulethickness))
                end
                context("flow_peepshape := false ;")   -- todo
                context("flow_new_shape(%s,%s,%s) ;",cell.x+xoffset,cell.y+yoffset,shapedata.number)
                context("flow_end_sub_chart ;")
            end
        end
    end
end

-- todo : make lpeg for splitter

local sign  = S("+p") /  "1"
            + S("-m") / "-1"

local full  = C(P("left"))
            + C(P("right"))
            + C(P("top"))
            + C(P("bottom"))

local char  = P("l") / "left"
            + P("r") / "right"
            + P("t") / "top"
            + P("b") / "bottom"

local space = P(" ")^0

local what  = space
            * (sign + Cc("0"))
            * space
            * (full + char)
            * space
            * (sign + Cc("0"))
            * space
            * (full + char)
            * space
            * P(-1)

-- print(lpegmatch(what,"lr"))
-- print(lpegmatch(what,"+l+r"))
-- print(lpegmatch(what,"+l"))
-- print(lpegmatch(what,"+ left+r     "))

local function process_connections(chart,xoffset,yoffset)
    local data = chart.data
    local hash = chart.hash
    if not data then
        return
    end
    local settings = chart.settings
    for i=1,#data do
        local cell = visible(chart,data[i])
        if cell then
            local connections = cell.connections
            for j=1,#connections do
                local connection = connections[j]
                local othername = connection.name
                local othercell = hash[othername]
                if othercell then -- and visible(chart,data[i]) then
                    local cellx, celly = cell.x, cell.y
                    local otherx, othery, location = othercell.x, othercell.y, connection.location
                    if otherx > 0 and othery > 0 and cellx > 0 and celly > 0 and connection.location then
                        local what_cell, where_cell, what_other, where_other = lpegmatch(what,location)
                        if what_cell and where_cell and what_other and where_other then
                            local linesettings = settings.line
                            context("flow_smooth := %s ;", linesettings.corner == v_round and "true" or "false")
                            context("flow_dashline := %s ;", linesettings.dash == v_yes and "true" or "false")
                            context("flow_arrowtip := %s ;", linesettings.arrow == v_yes and "true" or "false")
                            context("flow_touchshape := %s ;", linesettings.offset == v_none and "true" or "false")
                            context("flow_dsp_x := %s ; flow_dsp_y := %s ;",connection.dx or 0, connection.dy or 0)
                            context("flow_connection_line_color := \\MPcolor{%s} ;",linesettings.color)
                            context("flow_connection_line_width := 2pt ;",points(linesettings.rulethickness))
                            context("flow_connect_%s_%s (%s) (%s,%s,%s) (%s,%s,%s) ;",where_cell,where_other,j,cellx,celly,what_cell,otherx,othery,what_other)
                            context("flow_dsp_x := 0 ; flow_dsp_y := 0 ;")
                        end
                    end
                end
            end
        end
    end
end

local texttemplate = "\\setvariables[flowcell:text][x=%s,y=%s,text={%s},align={%s},figure={%s},destination={%s}]"

local splitter = lpeg.splitat(":")

local function process_texts(chart,xoffset,yoffset)
    local data = chart.data
    local hash = chart.hash
    if not data then
        return
    end
    for i=1,#data do
        local cell = visible(chart,data[i])
        if cell then
            local x = cell.x or 1
            local y = cell.y or 1
            local texts = cell.texts
            for i=1,#texts do
                local text = texts[i]
                local data = text.text
                local align = validlabellocations[text.align or ""] or text.align or ""
                local figure = i == 1 and cell.figure or ""
                local destination = i == 1 and cell.destination or ""
                context('flow_chart_draw_text(%s,%s,textext("%s")) ;',x,y,format(texttemplate,x,y,data,align,figure,destination))
            end
            local labels = cell.labels
            for i=1,#labels do
                local label = labels[i]
                local text = label.text
                local location = validlabellocations[label.location or ""] or label.location or ""
                if text and location then
                    context('flow_chart_draw_label(%s,%s,"%s",textext("\\strut %s")) ;',x,y,location,text)
                end
            end
            local exits = cell.exits
            for i=1,#exits do
                local exit = exits[i]
                local text = exit.text
                local location = validlabellocations[exit.location or ""]
                if text and location then
                    -- maybe make autoexit an option
                    if location == "l" and x == chart.from_x + 1 or
                       location == "r" and x == chart.to_x   - 1 or
                       location == "t" and y == chart.to_y   - 1 or
                       location == "b" and y == chart.from_y + 1 then
                        context('flow_chart_draw_exit(%s,%s,"%s",textext("\\strut %s")) ;',x,y,location,text)
                    end
                end
            end
            local connections = cell.connections
            for i=1,#connections do
                local comments = connections[i].comments
                for j=1,#comments do
                    local comment = comments[j]
                    local text = comment.text
                    local location = comment.location or ""
                    local length = 0
                    -- "tl" "tl:*" "tl:0.5"
                    local loc, len = lpegmatch(splitter,location) -- do the following in lpeg
                    if len == "*" then
                        location = validcommentlocations[loc] or ""
                        if location == "" then
                            location = "*"
                        else
                            location = location .. ":*"
                        end
                    elseif loc then
                        location = validcommentlocations[loc] or "*"
                        length = tonumber(len) or 0
                    else
                        location = validcommentlocations[location] or ""
                    end
                    if text and location then
                        context('flow_chart_draw_comment(%s,%s,%s,"%s",%s,textext("\\strut %s")) ;',x,y,i,location,length,text)
                    end
                end
            end
        end
    end
end

local function getchart(settings,forced_x,forced_y,forced_nx,forced_ny)
    if not settings then
        print("no settings given")
        return
    end
    local chartname = settings.chart.name
    if not chartname then
        print("no name given")
        return
    end
    local chart = charts[chartname]
    if not chart then
        print("no such chart",chartname)
        return
    end
    chart = expanded(chart,settings)
    local chartsettings = chart.settings.chart
    local autofocus = chart.settings.chart.autofocus
    if autofocus then
        autofocus = utilities.parsers.settings_to_hash(autofocus)
        if not next(autofocus) then
            autofocus = false
        end
    end
    -- check natural window
    local x  = forced_x  or tonumber(chartsettings.x)
    local y  = forced_y  or tonumber(chartsettings.y)
    local nx = forced_nx or tonumber(chartsettings.nx)
    local ny = forced_ny or tonumber(chartsettings.ny)
    --
    local minx, miny, maxx, maxy = 0, 0, 0, 0
    local data = chart.data
    for i=1,#data do
        local cell = data[i]
        if not autofocus or autofocus[cell.name] then -- offsets probably interfere with autofocus
            local x = cell.x
            local y = cell.y
            if minx == 0 or x < minx then minx = x end
            if miny == 0 or y < miny then miny = y end
            if minx == 0 or x > maxx then maxx = x end
            if miny == 0 or y > maxy then maxy = y end
        end
    end
 -- print("1>",x,y,nx,ny)
 -- print("2>",minx, miny, maxx, maxy)
    -- check of window should be larger (maybe autofocus + nx/ny?)
    if autofocus then
        -- x and y are ignored
        if nx and nx > 0 then
            maxx = minx + nx - 1
        end
        if ny and ny > 0 then
            maxy = miny + ny - 1
        end
    else
        if x and x > 0 then
            minx = x
        end
        if y and y > 0 then
            miny = y
        end
        if nx and nx > 0 then
            maxx = minx + nx - 1
        end
        if ny and ny > 0 then
            maxy = miny + ny - 1
        end
    end
-- print("3>",minx, miny, maxx, maxy)
    --
    local nx = maxx - minx + 1
    local ny = maxy - miny + 1
    -- relocate cells
    for i=1,#data do
        local cell = data[i]
        cell.x = cell.x - minx + 1
        cell.y = cell.y - miny + 1
    end
    chart.from_x = 1
    chart.from_y = 1
    chart.to_x   = nx
    chart.to_y   = ny
    chart.nx     = nx
    chart.ny     = ny
    --
 -- inspect(chart)
    return chart
end

local function makechart(chart)
    local settings      = chart.settings
    local chartsettings = settings.chart
    --
    context.begingroup()
    context.forgetall()
    --
    context.startMPcode()
    context("if unknown context_flow : input mp-char.mpiv ; fi ;")
    context("flow_begin_chart(0,%s,%s);",chart.nx,chart.ny)
    --
    if chartsettings.option == v_test or chartsettings.dot == v_yes then
        context("flow_show_con_points := true ;")
        context("flow_show_mid_points := true ;")
        context("flow_show_all_points := true ;")
    elseif chartsettings.dot ~= "" then -- no checking done, private option
        context("flow_show_%s_points := true ;",chartsettings.dot)
    end
    --
    local backgroundcolor = chartsettings.backgroundcolor
    if backgroundcolor and backgroundcolor ~= "" then
        context("flow_chart_background_color := \\MPcolor{%s} ;",backgroundcolor)
    end
    --
    local shapewidth    = chartsettings.width
    local gridwidth     = shapewidth + 2*chartsettings.dx
    local shapeheight   = chartsettings.height
    local gridheight    = shapeheight + 2*chartsettings.dy
    local chartoffset   = chartsettings.offset
    local labeloffset   = chartsettings.labeloffset
    local exitoffset    = chartsettings.exitoffset
    local commentoffset = chartsettings.commentoffset
    context("flow_grid_width     := %s ;", points(gridwidth))
    context("flow_grid_height    := %s ;", points(gridheight))
    context("flow_shape_width    := %s ;", points(shapewidth))
    context("flow_shape_height   := %s ;", points(shapeheight))
    context("flow_chart_offset   := %s ;", points(chartoffset))
    context("flow_label_offset   := %s ;", points(labeloffset))
    context("flow_exit_offset    := %s ;", points(exitoffset))
    context("flow_comment_offset := %s ;", points(commentoffset))
    --
    local radius = settings.line.radius
    local rulethickness = settings.line.rulethickness
    local dx = chartsettings.dx
    local dy = chartsettings.dy
    if radius < rulethickness then
        radius = 2.5*rulethickness
        if radius > dx then
            radius = dx
        end
        if radius > dy then
            radius = dy
        end
    end
    context("flow_connection_line_width := %s ;", points(rulethickness))
    context("flow_connection_smooth_size := %s ;", points(radius))
    context("flow_connection_arrow_size := %s ;", points(radius))
    context("flow_connection_dash_size := %s ;", points(radius))
    --
    local offset = chartsettings.offset -- todo: pass string
    if offset == v_none or offset == v_overlay or offset == "" then
        offset = -2.5 * radius -- or rulethickness?
    elseif offset == v_standard then
        offset = radius -- or rulethickness?
    end
    context("flow_chart_offset := %s ;",points(offset))
    --
    context("flow_reverse_y := true ;")
    process_cells(chart,0,0)
    process_connections(chart,0,0)
    process_texts(chart,0,0)
 -- context("clip_chart(%s,%s,%s,%s) ;",x,y,nx,ny) -- todo: draw lines but not shapes
    context("flow_end_chart ;")
    context.stopMPcode()
    context.endgroup()
end

local function splitchart(chart)
    local settings      = chart.settings
    local splitsettings = settings.split
    local chartsettings = settings.chart
    --
    local name = chartsettings.name
    --
    local from_x = chart.from_x
    local from_y = chart.from_y
    local to_x   = chart.to_x
    local to_y   = chart.to_y
    --
    local step_x  = splitsettings.nx or to_x
    local step_y  = splitsettings.ny or to_y
    local delta_x = splitsettings.dx or 0
    local delta_y = splitsettings.dy or 0
    --
    report_chart("spliting %a from (%s,%s) upto (%s,%s) into (%s,%s) with overlap (%s,%s)",
        name,from_x,from_y,to_x,to_y,step_x,step_y,delta_x,delta_y)
    --
    local part_x = 0
    local first_x = from_x
    while true do
        part_x = part_x + 1
        local last_x = first_x + step_x - 1
        local done = last_x >= to_x
        if done then
            last_x = to_x
        end
        local part_y = 0
        local first_y = from_y
        while true do
            part_y = part_y + 1
            local last_y = first_y + step_y - 1
            local done = last_y >= to_y
            if done then
                last_y = to_y
            end
            --
            report_chart("part (%s,%s) of %a is split from (%s,%s) -> (%s,%s)",part_x,part_y,name,first_x,first_y,last_x,last_y)
            local x, y, nx, ny = first_x, first_y, last_x - first_x + 1,last_y - first_y + 1
            context.beforeFLOWsplit()
            context.handleFLOWsplit(function()
                makechart(getchart(settings,x,y,nx,ny)) -- we need to pass frozen settings !
            end)
            context.afterFLOWsplit()
            --
            if done then
                break
            else
                first_y = last_y + 1 - delta_y
            end
        end
        if done then
            break
        else
            first_x = last_x + 1 - delta_x
        end
    end
end

function commands.flow_make_chart(settings)
    local chart = getchart(settings)
    if chart then
        local settings = chart.settings
        if settings then
            local chartsettings = settings.chart
            if chartsettings and chartsettings.split == v_yes then
                splitchart(chart)
            else
                makechart(chart)
            end
        else
            makechart(chart)
        end
    end
end