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
|
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%
% Macros to support feyn.mf
% Release 0.4.3, 2022 July 20
def looselink = ..tension 0.75.. enddef;
def pen = pickup diagram_pen enddef;
numeric nn;
def dirlooselink(expr point,rtn) =
looselink{(-point) rotated (90-rtn)}point enddef;
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%
% Draw three related characters, one plain, one with an right-pointing
% arrow, and one with a left-pointing one, at basechar, basechar-0x20 and
% basechar-0x60.
def threechars(expr basechar, name, cp, apoint, wsharp, hsharp, dsharp, anudge, apos) =
% basechar : the charcode of the character in the lowercase range
% name : the name of the character
% cp : the path to be drawn
% apoint : the point along the path where arrow and annotation are to go
% wsharp, hsharp, dsharp : the sharped dimensions of the character
% anudge : if a pair, the offset from (point apoint of cp) where
% the annotation is to go (usually numeric 0, indicating
% no offset)
% apos : one of the apos arguments to annotate_at
beginchar (basechar, wsharp, hsharp, dsharp);
name;
pen;
draw cp;
annotate_at(point apoint of cp if (pair anudge): shifted anudge fi,
apos);
endchar;
beginchar (byte basechar-hex"20", wsharp, hsharp, dsharp);
"r-arrowed " & name;
pen;
draw cp;
drawarrow (littlearrow,
point apoint of cp,
angle(direction apoint of cp));
annotate_at(point apoint of cp if (pair anudge): shifted anudge fi,
apos);
endchar;
beginchar (byte basechar-hex"60", wsharp, hsharp, dsharp);
"l-arrowed " & name;
pen;
draw cp;
drawarrow (littlearrow,
point apoint of cp,
angle(direction apoint of cp) + 180);
annotate_at(point apoint of cp if (pair anudge): shifted anudge fi,
apos);
endchar;
enddef;
% Writes on the log file a string consisting of
% annotate charcode xofs yofs apos
% where charcode is the current character code, and xofs and yofs are the
% positions of the given point, relative to the reference point, in units
% of the font module. The string apos is one of top, bot, urt, ulft, lrt,
% llft, to indicate where the annotation is to sit, relative to the
% indicated position.
%
% Must be called within beginchar()...endchar;
def annotate_at (expr p, apos) =
message "annotate " & decimal charcode & " " &
decimal (xpart p/module) & " " & decimal (ypart p/module) & " "
& apos & " ";
enddef;
% Draw an arrow.
def drawarrow (expr size, pos, ang) =
% size : the scale of the arrow
% pos : the position of the arrow, relative to the reference point
% ang : the direction in which the arrow points
begingroup
pair t[];
y0 = y1 = y4 = 0;
x1 = -4x4 = -2x2 = size;
x2 = x3 = x0;
y2 - y0 = y0 - y3 = size/2;
forsuffixes s = 1,2,3,4 :
t[s] := z[s] rotated ang shifted pos;
endfor;
fill t4--t2--t1--t3--cycle;
endgroup
enddef;
def garrow (expr code, ang, onaxis) =
numeric localarrowsize;
% if onaxis = 1 :
% localarrowsize := bigarrow;
% else :
localarrowsize := littlearrow;
% fi
beginchar (code, 0, 0, 0); "garrow";
drawarrow (localarrowsize, (0, onaxis*a), ang);
endchar;
enddef;
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%
% Error character.
%
% The parameter ht is the nominal height of the character.
def errorchar (expr ht) =
begingroup
numeric rad,npetals,ilowest;
pair cent;
cent=(0,2ht/3); % centre of the flower
rad=ht/6; % radius of the inner points
npetals=5; % number of petals
pickup pencircle scaled (thinlinewidth); % thin line
z0 = cent shifted (rad,0);
for i=1 upto npetals-1:
z[i] = z0 rotatedabout (cent, i*360/npetals);
endfor
draw z0{dir 0}
for i=1 upto npetals-1:
.. tension 0.75 ..{dir (i*360/npetals+180)}z[i]{dir (i*360/npetals)}
endfor
..{dir 180}z0;
ilowest := 0;
for i=1 upto npetals-1:
if y[i] <= y[ilowest]: ilowest := i; fi
endfor
draw z[ilowest]{dir (ilowest*360/npetals)}..origin;
pair leafend;
xpart(leafend) = 3rad; % want something like currentpicture.rt;
ypart(leafend) = 2y[ilowest]/3;
draw origin{dir 60} .. leafend;
draw leafend .. {dir 180}origin;
endgroup
enddef;
|
