summaryrefslogtreecommitdiff
path: root/Build/source/utils/asymptote/drawpath.cc
blob: c1d2c85efc0861491b3155e93af8bfe645427c80 (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
/*****
 * drawpath.cc
 * Andy Hammerlindl 2002/06/06
 *
 * Stores a path that has been added to a picture.
 *****/

#include <sstream>
#include <vector>
#include <cfloat>

#include "drawpath.h"
#include "psfile.h"
#include "util.h"

namespace camp {


double PatternLength(double arclength, const std::vector<double>& pat,
                     bool cyclic, double penwidth)
{
  double sum=0.0;
      
  size_t n=pat.size();
  for(unsigned i=0; i < n; i ++)
    sum += pat[i]*penwidth;
  
  if(sum == 0.0) return 0.0;
  
  if(n % 2 == 1) sum *= 2.0; // On/off pattern repeats after 2 cycles.
      
  // Fix bounding box resolution problem. Example:
  // asy -f pdf testlinetype; gv -scale -2 testlinetype.pdf
  if(!cyclic && pat[0] == 0) sum += 1.0e-3*penwidth;
      
  double terminator=(cyclic && arclength >= 0.5*sum) ? 0.0 : pat[0]*penwidth;
  int ncycle=(int)((arclength-terminator)/sum+0.5);

  return (ncycle >= 1 || terminator >= 0.75*arclength) ? 
    ncycle*sum+terminator : 0.0;
}

pen adjustdash(pen& p, double arclength, bool cyclic)
{
  pen q=p;
  // Adjust dash sizes to fit arclength; also compensate for linewidth.
  string stroke=q.stroke();
  
  if(!stroke.empty()) {
    double penwidth=q.linetype().scale ? q.width() : 1.0;
    double factor=penwidth;
    
    std::vector<double> pat;
    
    istringstream ibuf(stroke);
    double l;
    while(ibuf >> l) {
      if(l < 0) l=0;
      pat.push_back(l);
    }
      
    size_t n=pat.size();
    
    if(q.linetype().adjust) {
      if(arclength) {
        if(n == 0) return q;
      
        double denom=PatternLength(arclength,pat,cyclic,penwidth);
        if(denom != 0.0) factor *= arclength/denom;
      }
    }
    
    factor=max(factor,0.1);
    
    ostringstream buf;
    buf.setf(std::ios::fixed);
    if(n > 0) {
      for(size_t i=0; i < n-1; i++)
        buf << pat[i]*factor << " ";
      buf << pat[n-1]*factor;
    }
    q.setstroke(buf.str());
    q.setoffset(q.linetype().offset*factor);
  }
  return q;
}
 
// Account for square or extended pen cap contributions to bounding box.
void cap(bbox& b, double t, path p, pen pentype) {
  transform T=pentype.getTransform();  
  
  double h=0.5*pentype.width();
  pair v=p.dir(t);
  transform S=rotate(conj(v))*shiftless(T);
  double xx=S.getxx(), xy=S.getxy();
  double yx=S.getyx(), yy=S.getyy();
  double y=hypot(yx,yy);
  if(y == 0) return;
  double numer=xx*yx+xy*yy;
  double x=numer/y;
  pair z=shift(T)*p.point(t);
  
  switch(pentype.cap()) {
    case 0:
    {
      pair d=rotate(v)*pair(x,y)*h;
      b += z+d;
      b += z-d;
      break;
    }
    case 2:
    {
      transform R=rotate(v);
      double w=(xx*yy-xy*yx)/y;
      pair dp=R*pair(x+w,y)*h;
      pair dm=R*pair(x-w,y)*h;
      b += z+dp;
      b += z+dm;
      b += z-dp;
      b += z-dm;
      break;
    }
  }
}

void drawPathPenBase::strokebounds(bbox& b, const path& p)
{
  Int l=p.length();
  if(l < 0) return;
  
  bbox penbounds=pentype.bounds();
  
  if(cyclic() || pentype.cap() == 1) {
    b += pad(p.bounds(),penbounds);
    return;
  }
  
  b += p.internalbounds(penbounds);
  
  cap(b,0,p,pentype);
  cap(b,l,p,pentype);
}

bool drawPath::draw(psfile *out)
{
  Int n = p.size();
  if (n == 0 || pentype.invisible())
    return true;

  pen pen0=adjustdash(pentype,p.arclength(),p.cyclic());

  penSave(out);
  penTranslate(out);

  out->write(p);

  penConcat(out);

  out->setpen(pen0);
  
  out->stroke();

  penRestore(out);

  return true;
}

drawElement *drawPath::transformed(const transform& t)
{
  return new drawPath(transpath(t), transpen(t));
}

} //namespace camp