src/texbeam.cc

   1 /*
   2
   3   Code to generate beams for TeX
   4
   5   */
   6
   7 #include <math.h>
   8 #include "symbol.hh"
   9 #include "molecule.hh"
  10 #include "tex.hh"
  11 #include "symtable.hh"
  12 #include "dimen.hh"
  13 #include "debug.hh"
  14 #include "lookup.hh"
  15
  16 Symbol
  17 Lookup::beam_element(int sidx, int widx, Real slope)
  18 {
  19     Symbol bs=(*symtables_)("beamslopes")->lookup("slope");
  20
  21     Array<String> args;
  22     args.push(sidx);
  23     args.push(widx);
  24     bs.tex = substitute_args(bs.tex,args);
  25     int w = 2 << widx;
  26     Real width = w PT;
  27     bs.dim.x = Interval(0,width);
  28     bs.dim.y = Interval(0,width*slope);
  29     return bs;
  30 }
  31
  32 // ugh.. hard wired tex-code.
  33 static int
  34 slope_index(Real &s)
  35 {
  36     if (abs(s) > 0.5) {
  37         WARN << "beam steeper than 0.5 (" << s << ")\n";
  38         s = sign(s) * 0.5;
  39     }
  40
  41     int i = int(rint(s *  20.0));
  42
  43     s = i/20.0;
  44     if (s>0)
  45         return 6*i +122;
  46     else
  47         return -6 * i+ 186;
  48 }
  49
  50 Symbol
  51 Lookup::rule_symbol(Real height, Real width)
  52 {
  53     Symbol bs=(*symtables_)("beamslopes")->lookup("horizontal");
  54     Array<String> args;
  55     args.push(print_dimen(height));
  56     args.push(print_dimen(width));
  57     bs.tex = substitute_args(bs.tex,args);
  58     bs.dim.x = Interval(0,width);
  59     bs.dim.y = Interval(0,height);
  60     return bs;
  61 }
  62
  63 Symbol
  64 Lookup::beam(Real &slope, Real width)
  65 {
  66     int sidx = slope_index(slope);
  67     if (!slope)
  68         return rule_symbol(2 PT, width);
  69     if (width < 2 PT) {
  70         WARN<<"Beam too narrow. (" << print_dimen(width) <<")\n";
  71         width = 2 PT;
  72     }
  73     Real elemwidth = 64 PT;
  74     int widx = 5;
  75
  76     Molecule m;
  77
  78     while (elemwidth > width) {
  79         widx --;
  80         elemwidth /= 2.0;
  81     }
  82     Real overlap = elemwidth/4;
  83     Real last_x = width - elemwidth;
  84     Real x = overlap;
  85     Atom elem(beam_element(sidx, widx, slope));
  86     Atom a(elem);
  87     m.add(a);
  88     while (x < last_x) {
  89         a=elem;
  90         a.translate(Offset(x-overlap, (x-overlap)*slope));
  91         m.add(a);
  92         x += elemwidth - overlap;
  93     }
  94     a=elem;
  95     a.translate(Offset(last_x, (last_x) * slope));
  96     m.add(a);
  97
  98     Symbol ret;
  99     ret.tex = m.TeXstring();
 100     ret.dim.y = Interval(0,width*slope);
 101     ret.dim.x = Interval(0,width);
 102
 103     return ret;
 104 }
 105
 106