PS
# diamond.m4
gen_init
NeedDpicTools
# See LaTeX Graphics Companion pp 57-58 and
#
https://tex.stackexchange.com/questions/730392/rotating-triangle
ifdpic(`
dimen = 1.3
ratio = 0.9
n = 30
North: (0,dimen)
East: (dimen,0)
South: (0,-dimen)
West: (-dimen,0)
define(`diamond',`[
for i = 2 to n do {
ifelse(`$1',,
`hsvtorgb(hue,1,1,r0,g0,b0)
line from North to East then to South then to West then to North \
shaded rgbstring(r0,g0,b0)
hue = hue+360/(n-1)',
`shade(`$1',
line from North to East then to South then to West then to North)')
Tmp: North
North: ratio between East and North
East: ratio between South and East
South: ratio between West and South
West: ratio between Tmp and West
}]')
define(`triangle',`[
for i = 2 to n do {
hue = 180+(i-2)/(n-1)*360
hsvtorgb(hue,1,1,r0,g0,b0)
line from North to East then to West then to North shaded rgbstring(r0,g0,b0)
Tmp: North
North: ratio between East and North
East: ratio between West and East
West: ratio between Tmp and West
}]')
linethick = 0.4
diamond( (n-i)/(n-2) )
hue = 0
diamond with .w at last [].e+(0.125,0)
North: (0,dimen*sqrt(3)/2)
East: (dimen,-dimen*sqrt(3)/2)
West: (-dimen,-dimen*sqrt(3)/2)
hue = 180
triangle with .w at last [].e-(0.2,0)
',
`box "diamond.m4" "requires" "dpic"')
PE
