5 % * `stemslant' gives the direction of the stem's left boundary
6 % (needed for brushed stems, equals "up" for straight stems)
7 % * `extend' is used to make the stem longer or shorter (if negative);
8 % different kinds of accidentals need different values here
10 def draw_arrow (expr attach, stemwidth, stemslant, extend, pointingdown) =
12 save htip; % tip height
13 save wwing; % wing `radius'
14 save angle_wing_bot, angle_wing_top, angle_tip;
18 wwing := 0.26 stemwidth;
19 htip := staff_space * 0.85 + stafflinethickness - wwing;
21 % `flip' is used to reflect the arrow vertically
22 % if arrow points downward
25 flip = identity reflectedabout (origin, right);
30 z1 = attach shifted (-stemwidth / 2, 0);
31 upshift := max (0, wwing + 0.1 staff_space + extend);
32 z2 = z1 shifted (((unitvector stemslant)
33 scaled upshift) transformed flip);
35 z7 = attach shifted ((stemwidth/2),0);
36 z6 = z7 shifted (((unitvector (-xpart stemslant, ypart stemslant))
37 scaled upshift) transformed flip);
38 z2 - z3 = ( 0.38 staff_space, 0.05 htip) transformed flip;
39 z6 - z5 = (-0.38 staff_space, 0.05 htip) transformed flip;
41 z4 = attach shifted ((-0.2 stemwidth, upshift + htip)
43 z4'= attach shifted (( 0.2 stemwidth, upshift + htip)
46 % `angle_wing_bot' is the angle at which the arc
47 % from z2 to z3a enters z3a
48 % `angle_wing_top' is the angle at which the arc
49 % from z3b to z4 leaves z3b
50 % `angle_tip' is the angle at which the arc
51 % from z4 to z4' leaves z4
56 z3a = z3 shifted ((((dir angle_wing_bot) rotated -90)
57 scaled wwing) transformed flip);
58 z3b = z3 shifted ((((dir angle_wing_top) rotated 90)
59 scaled wwing) transformed flip);
61 z5a = z5 shifted ((((dir (180 - angle_wing_bot)) rotated 90)
62 scaled wwing) transformed flip);
63 z5b = z5 shifted ((((dir (180 - angle_wing_top)) rotated -90)
64 scaled wwing) transformed flip);
67 pickup pencircle scaled 1;
69 -- z2{stemslant transformed flip}
70 .. {(-dir angle_wing_bot) transformed flip}z3a
71 .. z3b{(dir angle_wing_top) transformed flip}
72 .. z4{(dir angle_tip) transformed flip}
73 .. z4'{(dir (-angle_tip)) transformed flip}
74 .. {(dir (-angle_wing_top)) transformed flip}z5b
75 .. z5a{(-dir (-angle_wing_bot)) transformed flip}
76 .. z6{((-stemslant) reflectedabout (origin, up)) transformed flip}
80 labels (range 0 thru 7, 4', 3a, 3b, 5a, 5b);