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
142
143
144
145
146
147
148
|
-- $Id: x27a.adb.cmake 9378 2009-01-23 09:13:27Z jbauck $
-- Drawing "spirograph" curves - epitrochoids, cycolids, roulettes
-- Copyright (C) 2008 Jerry Bauck
-- This file is part of PLplot.
-- PLplot is free software; you can redistribute it and/or modify
-- it under the terms of the GNU General Library Public License as published
-- by the Free Software Foundation; either version 2 of the License, or
-- (at your option) any later version.
-- PLplot is distributed in the hope that it will be useful,
-- but WITHOUT ANY WARRANTY; without even the implied warranty of
-- MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
-- GNU Library General Public License for more details.
-- You should have received a copy of the GNU Library General Public License
-- along with PLplot; if not, write to the Free Software
-- Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
with
Ada.Numerics.Long_Elementary_Functions,
PLplot_Auxiliary,
PLplot_Traditional;
use
Ada.Numerics.Long_Elementary_Functions,
PLplot_Auxiliary,
PLplot_Traditional;
@Ada_Is_2007_With_and_Use_Numerics@
------------------------------------------------------------------------------
-- Generates two kinds of plots:
-- - construction of a cycloid (animated)
-- - series of epitrochoids and hypotrochoids
------------------------------------------------------------------------------
procedure x27a is
-- R, r, p, N
params : Real_Matrix(0 .. 8, 0 .. 3) :=
((21.0, 7.0, 7.0, 3.0),
(21.0, 7.0, 10.0, 3.0),
(21.0, -7.0, 10.0, 3.0),
(20.0, 3.0, 7.0, 20.0),
(20.0, 3.0, 10.0, 20.0),
(20.0, -3.0, 10.0, 20.0),
(20.0, 13.0, 7.0, 20.0),
(20.0, 13.0, 20.0, 20.0),
(20.0,-13.0, 20.0, 20.0));
procedure spiro(params : Real_Matrix; row : Integer) is
NPNT : constant Integer := 20000;
xcoord, ycoord : Real_Vector(0 .. 20000);
windings : Integer;
steps : Integer;
phi : Long_Float;
phiw : Long_Float;
dphi : Long_Float;
xmin : Long_Float;
xmax : Long_Float;
ymin : Long_Float;
ymax : Long_Float;
scale : Long_Float;
begin
-- Fill the coordinates
windings := Integer(params(row, 3));
steps := NPNT / windings;
dphi := 8.0 * arccos(-1.0) / Long_Float(steps);
xmin := 0.0; -- This initialisation is safe!
xmax := 0.0;
ymin := 0.0;
ymax := 0.0;
for i in 0 .. windings * steps loop
phi := Long_Float(i) * dphi;
phiw := (params(row, 0) - params(row, 1)) / params(row, 1) * phi;
xcoord(i) := (params(row, 0) - params(row, 1)) * cos(phi) + params(row, 2) * cos(phiw);
ycoord(i) := (params(row, 0) - params(row, 1)) * sin(phi) - params(row, 2) * sin(phiw);
if xmin > xcoord(i) then xmin := xcoord(i); end if;
if xmax < xcoord(i) then xmax := xcoord(i); end if;
if ymin > ycoord(i) then ymin := ycoord(i); end if;
if ymax < ycoord(i) then ymax := ycoord(i); end if;
end loop;
if xmax - xmin > ymax - ymin then
scale := xmax - xmin;
else
scale := ymax - ymin;
end if;
xmin := - 0.65 * scale;
xmax := 0.65 * scale;
ymin := - 0.65 * scale;
ymax := 0.65 * scale;
plwind(xmin, xmax, ymin, ymax);
plcol0(1);
declare
xcoord_local, ycoord_local : Real_Vector(0 .. steps * windings);
begin
xcoord_local := xcoord(0 .. steps * windings);
ycoord_local := ycoord(0 .. steps * windings);
plline(xcoord_local, ycoord_local);
end;
end spiro;
procedure cycloid is
begin
null; -- TODO
end cycloid;
begin
-- Parse and process command line arguments
plparseopts(PL_PARSE_FULL);
-- Initialize plplot
plinit;
-- Illustrate the construction of a cycloid
cycloid;
-- Loop over the various curves.
-- First an overview, then all curves one by one
plssub(3, 3) ; -- Three by three window
for i in params'range(1) loop
pladv(0);
plvpor( 0.0, 1.0, 0.0, 1.0 );
spiro(params, i);
end loop;
pladv(0) ;
plssub(1, 1) ; -- One window per curve
for i in params'range(1) loop
pladv(0) ;
plvpor( 0.0, 1.0, 0.0, 1.0 ) ;
spiro(params, i);
end loop;
-- Don't forget to call plend to finish off!
plend;
end x27a;
|
