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
|
############################################################################
#
# File: flake.icn
#
# Subject: Program to draw a fractal snowflake
#
# Author: Stephen B. Wampler
#
# Date: August 14, 1996
#
############################################################################
#
# This file is in the public domain.
#
############################################################################
#
# Version: 1.0
#
############################################################################
#
#
# Comments: This program display a fractal snowflake of specified
# order. Options exist to do colors, etc.
# See the procedure 'helpmsg' for command line options
#
# An order 4 snowflake is particularly nice.
#
# Waits for a window event before closing window
#
############################################################################
#
# Links: glib, wopen
#
############################################################################
#
# Requires: Version 9 graphics and co-expressions (for glib.icn)
#
############################################################################
link glib
link wopen
global win, mono, h, w
global Window, XMAX, YMAX
global nextcolor
procedure main (args)
local nextarg, arg, n, doclip, docolor, Cpoly
XMAX := YMAX := 700 # physical screen size
w := h := 1.0
nextarg := create !args
while arg := @nextarg do {
if arg == ("-help"|"-h") then stop(helpmsg())
else if arg == "-n" then n := integer(@nextarg)
else if arg == "-clip" then doclip := "yes"
else if arg == "-color" then docolor := "yes"
}
/n := 3 # default order
if \doclip then {
Cpoly := [ # a simple convext polygon to clip against
[0.3,0.4],[0.5,0.8],[0.7,0.4]
]
}
win := WOpen("label=Fractal Snowflake", "width="||XMAX, "height="||YMAX)
mono := WAttrib (win, "depth") == "1"
Window := set_window(win, point(0,0), point(w,h),
viewport(point(0,0), point(XMAX, YMAX), win))
if \docolor then
nextcolor := create vpara([0,0,65535], [65535,0,0], |((0 to 12)/12.0))
EraseArea(win)
Fg(win, "black")
fract_flake(Window, point(0.20,0.33), point(0.80,0.33), n, 1, Cpoly)
Event(win)
close(win)
end
procedure helpmsg()
write("Usage: Flake [-n order] [-clip] [-color]")
write(" where")
write(" -n order -- Depth of recursion {3}")
write(" -clip -- Clip to a convex polygon")
write(" -color -- Color cycle while drawing")
return
end
|
