--Copyright The Numerical Algorithms Group Limited 1994.
-- relative size of the arrow head compared to the length of the arrow
arrowScale := 0.2@DFLOAT
 
-- angle of the arrow head
arrowAngle := %pi-%pi/10.0@DFLOAT
 
-- Add an arrow head to a line segment, which starts at 'p1', ends at 'p2',
-- has length 'len', and and angle 'arg'.  We pass 'len' and 'arg' as
-- arguments since they were already computed by the calling program
makeArrow(p1, p2) ==
  delta := p2 - p1
  len := arrowScale * length delta
  theta := atan(delta.1, delta.2)
  c1 := len * cos(theta + arrowAngle) 
  s1 := len * sin(theta + arrowAngle)
  c2 := len * cos(theta - arrowAngle) 
  s2 := len * sin(theta - arrowAngle)
  z  := p2.3*(1 - arrowScale)
  p3 := point [p2.1 + c1, p2.2 + s1, z, p2.4]
  p4 := point [p2.1 + c2, p2.2 + s2, z, p2.4]
  [[p1, p2, p3], [p2, p4]]
 
drawBouquet(n,title) ==
  angle := 0.0@DFLOAT
  sp := create3Space()$ThreeSpace(DFLOAT)
  for i in 0..n-1 repeat
    start := point [0.0@DFLOAT,0.0@DFLOAT,0.0@DFLOAT,angle] 
    end   := point [cos angle, sin angle, 1.0@DFLOAT, angle]
    arrow := makeArrow(start, end)
    for a in arrow repeat curve(sp,a)
    angle := angle + 2*%pi/n
  makeViewport3D(sp,title)$VIEW3D





