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
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
|
%%%% cones01.ldf
%%%% Created by Laurence D. Finston (LDF) Thu Nov 9 21:35:51 CET 2006
%%%% Modified LDF 2006.11.11.
%% * (1) Copyright and License.
%%%% This file is part of GNU 3DLDF, a package for three-dimensional drawing.
%%%% Copyright (C) 2003, 2004, 2005, 2006, 2007, 2008, 2009, 2010, 2011, 2012, 2013 The Free Software Foundation
%%%% GNU 3DLDF is free software; you can redistribute it and/or modify
%%%% it under the terms of the GNU General Public License as published by
%%%% the Free Software Foundation; either version 3 of the License, or
%%%% (at your option) any later version.
%%%% GNU 3DLDF 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 General Public License for more details.
%%%% You should have received a copy of the GNU General Public License
%%%% along with GNU 3DLDF; if not, write to the Free Software
%%%% Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
%%%% GNU 3DLDF is a GNU package.
%%%% It is part of the GNU Project of the
%%%% Free Software Foundation
%%%% and is published under the GNU General Public License.
%%%% See the website http://www.gnu.org
%%%% for more information.
%%%% GNU 3DLDF is available for downloading from
%%%% http://www.gnu.org/software/3dldf/LDF.html.
%%%% Please send bug reports to Laurence.Finston@gmx.de
%%%% The mailing list help-3dldf@gnu.org is available for people to
%%%% ask other users for help.
%%%% The mailing list info-3dldf@gnu.org is for the maintainer of
%%%% GNU 3DLDF to send announcements to users.
%%%% To subscribe to these mailing lists, send an
%%%% email with ``subscribe <email-address>'' as the subject.
%%%% The author can be contacted at:
%%%% Laurence D. Finston
%%%% c/o The Free Software Foundation, Inc.
%%%% 51 Franklin St, Fifth Floor
%%%% Boston, MA 02110-1301
%%%% USA
%%%% Laurence.Finston@gmx.de
%% *** (3) Cones.
%% The shadow of a double-napped cone.
%% LDF 2006.11.09.
verbatim_metapost "verbatimtex \magnification=\magstep3 etex";
focus f;
set f with_position (-3, 15, -30)
with_direction (-3, 15, 100) with_distance 15;
picture save_picture;
pickup pencircle scaled (.75mm, .75mm);
%% **** (4)
beginfig(1);
%% ***** (5)
cone c;
y_value := 12;
set c with_type circular with_type double_napped with_radius 10 with_axis_y y_value
with_point_count 32 with_divisions 6;
shift c(10, 0, 20);
rectangle r;
r := unit_rectangle scaled (100, 0, 100);
shift r (0, 0, 20);
%% ***** (5)
point p;
p := (1, 0, 0);
rotate p(0, 0, 32);
rotate p(0, 25);
p *= -1;
%% ***** (5)
point q[];
path s[];
path proj[];
bool_point_vector bpv;
point apex[];
apex0 := get_apex c;
q0 := apex0;
q0 += p * 10;
s0 := apex0 -- q0;
bpv := s0 intersection_points r;
q2 := bpv0;
q3 := bpv1;
if not is_invalid q2:
apex1 := q2;
else:
if not is_invalid q3:
apex1 := q3;
fi;
fi;
path cap;
path base;
cap := get_cap c;
base := get_base c;
for i = 0 upto 31:
q0 := get_point (i) cap;
q4 := get_point (i) base;
q1 := q0 + (p * 10);
s0 := q0 -- q1;
bpv := s0 intersection_points r;
q2 := bpv0;
q3 := bpv1;
if not is_invalid q2:
proj0 += q2;
draw q4 -- apex1 -- q2;
fi;
if not is_invalid q3:
proj0 += q3;
draw q4 -- apex1 -- q3;
fi;
endfor;
proj0 += ..;
proj0 += cycle;
draw proj0;
draw c;
%draw r;
%label("point light source: angle $25^\circ$, elevation $32^\circ$", (5, 0, 0));
save_picture := current_picture;
endfig with_focus f no_sort;
beginfig(2);
output save_picture with_projection parallel_x_z;
endfig;
verbatim_metapost "end";
end;
|
