1 |
#ifndef lint |
2 |
static const char RCSid[] = "$Id: cone.c,v 2.10 2016/04/21 00:40:35 greg Exp $"; |
3 |
#endif |
4 |
/* |
5 |
* cone.c - routines for making cones |
6 |
*/ |
7 |
|
8 |
#include "copyright.h" |
9 |
|
10 |
#include "standard.h" |
11 |
|
12 |
#include "object.h" |
13 |
|
14 |
#include "otypes.h" |
15 |
|
16 |
#include "cone.h" |
17 |
|
18 |
/* |
19 |
* In general, a cone may be any one of a cone, a cylinder, a ring, |
20 |
* a cup (inverted cone), or a tube (inverted cylinder). |
21 |
* Most cones are specified with a starting point and radius and |
22 |
* an ending point and radius. In the cases of a cylinder or tube, |
23 |
* only one radius is needed. In the case of a ring, a normal direction |
24 |
* is specified instead of a second endpoint. |
25 |
* |
26 |
* mtype (cone|cup) name |
27 |
* 0 |
28 |
* 0 |
29 |
* 8 P0x P0y P0z P1x P1y P1z R0 R1 |
30 |
* |
31 |
* mtype (cylinder|tube) name |
32 |
* 0 |
33 |
* 0 |
34 |
* 7 P0x P0y P0z P1x P1y P1z R |
35 |
* |
36 |
* mtype ring name |
37 |
* 0 |
38 |
* 0 |
39 |
* 8 Px Py Pz Nx Ny Nz R0 R1 |
40 |
*/ |
41 |
|
42 |
|
43 |
CONE * |
44 |
getcone( /* get cone structure */ |
45 |
OBJREC *o, |
46 |
int getxf |
47 |
) |
48 |
{ |
49 |
int sgn0, sgn1; |
50 |
CONE *co; |
51 |
|
52 |
if ((co = (CONE *)o->os) == NULL) { |
53 |
|
54 |
co = (CONE *)malloc(sizeof(CONE)); |
55 |
if (co == NULL) |
56 |
error(SYSTEM, "out of memory in makecone"); |
57 |
|
58 |
co->ca = o->oargs.farg; |
59 |
/* get radii */ |
60 |
if ((o->otype == OBJ_CYLINDER) | (o->otype == OBJ_TUBE)) { |
61 |
if (o->oargs.nfargs != 7) |
62 |
goto argcerr; |
63 |
if (co->ca[6] < -FTINY) { |
64 |
objerror(o, WARNING, "negative radius"); |
65 |
o->otype = o->otype == OBJ_CYLINDER ? |
66 |
OBJ_TUBE : OBJ_CYLINDER; |
67 |
co->ca[6] = -co->ca[6]; |
68 |
} else if (co->ca[6] <= FTINY) |
69 |
goto raderr; |
70 |
co->p0 = 0; co->p1 = 3; |
71 |
co->r0 = co->r1 = 6; |
72 |
} else { |
73 |
if (o->oargs.nfargs != 8) |
74 |
goto argcerr; |
75 |
if (co->ca[6] < -FTINY) sgn0 = -1; |
76 |
else if (co->ca[6] > FTINY) sgn0 = 1; |
77 |
else sgn0 = 0; |
78 |
if (co->ca[7] < -FTINY) sgn1 = -1; |
79 |
else if (co->ca[7] > FTINY) sgn1 = 1; |
80 |
else sgn1 = 0; |
81 |
if (sgn0+sgn1 == 0) |
82 |
goto raderr; |
83 |
if ((sgn0 < 0) | (sgn1 < 0)) { |
84 |
if (o->otype == OBJ_RING) |
85 |
goto raderr; |
86 |
objerror(o, WARNING, "negative radii"); |
87 |
o->otype = o->otype == OBJ_CONE ? |
88 |
OBJ_CUP : OBJ_CONE; |
89 |
} |
90 |
co->ca[6] = co->ca[6]*sgn0; |
91 |
co->ca[7] = co->ca[7]*sgn1; |
92 |
if (co->ca[7] - co->ca[6] > FTINY) { |
93 |
if (o->otype == OBJ_RING) |
94 |
co->p0 = co->p1 = 0; |
95 |
else { |
96 |
co->p0 = 0; co->p1 = 3; |
97 |
} |
98 |
co->r0 = 6; co->r1 = 7; |
99 |
} else if (co->ca[6] - co->ca[7] > FTINY) { |
100 |
if (o->otype == OBJ_RING) |
101 |
co->p0 = co->p1 = 0; |
102 |
else { |
103 |
co->p0 = 3; co->p1 = 0; |
104 |
} |
105 |
co->r0 = 7; co->r1 = 6; |
106 |
} else { |
107 |
if (o->otype == OBJ_RING) |
108 |
goto raderr; |
109 |
o->otype = o->otype == OBJ_CONE ? |
110 |
OBJ_CYLINDER : OBJ_TUBE; |
111 |
o->oargs.nfargs = 7; |
112 |
co->p0 = 0; co->p1 = 3; |
113 |
co->r0 = co->r1 = 6; |
114 |
} |
115 |
} |
116 |
/* get axis orientation */ |
117 |
if (o->otype == OBJ_RING) |
118 |
VCOPY(co->ad, o->oargs.farg+3); |
119 |
else { |
120 |
co->ad[0] = CO_P1(co)[0] - CO_P0(co)[0]; |
121 |
co->ad[1] = CO_P1(co)[1] - CO_P0(co)[1]; |
122 |
co->ad[2] = CO_P1(co)[2] - CO_P0(co)[2]; |
123 |
} |
124 |
co->al = normalize(co->ad); |
125 |
if (co->al == 0.0) { |
126 |
objerror(o, WARNING, "unknown orientation"); |
127 |
free(co); |
128 |
return(NULL); |
129 |
} |
130 |
/* compute axis and side lengths */ |
131 |
if (o->otype == OBJ_RING) { |
132 |
co->al = 0.0; |
133 |
co->sl = CO_R1(co) - CO_R0(co); |
134 |
} else if ((o->otype == OBJ_CONE) | (o->otype == OBJ_CUP)) { |
135 |
co->sl = co->ca[7] - co->ca[6]; |
136 |
co->sl = sqrt(co->sl*co->sl + co->al*co->al); |
137 |
} else { /* OBJ_CYLINDER or OBJ_TUBE */ |
138 |
co->sl = co->al; |
139 |
} |
140 |
co->tm = NULL; |
141 |
o->os = (char *)co; |
142 |
} |
143 |
if (getxf && co->tm == NULL) |
144 |
conexform(co); |
145 |
return(co); |
146 |
|
147 |
argcerr: |
148 |
objerror(o, USER, "bad # arguments"); |
149 |
raderr: |
150 |
objerror(o, WARNING, "illegal radii"); |
151 |
free(co); |
152 |
return(NULL); |
153 |
} |
154 |
|
155 |
|
156 |
void |
157 |
freecone(OBJREC *o) /* free memory associated with cone */ |
158 |
{ |
159 |
CONE *co = (CONE *)o->os; |
160 |
|
161 |
if (co == NULL) |
162 |
return; |
163 |
if (co->tm != NULL) |
164 |
free((void *)co->tm); |
165 |
free((void *)co); |
166 |
o->os = NULL; |
167 |
} |
168 |
|
169 |
|
170 |
void |
171 |
conexform(CONE *co) /* get cone transformation matrix */ |
172 |
{ |
173 |
MAT4 m4; |
174 |
double d; |
175 |
int i; |
176 |
|
177 |
co->tm = (RREAL (*)[4])malloc(sizeof(MAT4)); |
178 |
if (co->tm == NULL) |
179 |
error(SYSTEM, "out of memory in conexform"); |
180 |
|
181 |
/* translate to origin */ |
182 |
setident4(co->tm); |
183 |
if (co->r0 == co->r1) |
184 |
d = 0.0; |
185 |
else |
186 |
d = CO_R0(co) / (CO_R1(co) - CO_R0(co)); |
187 |
for (i = 0; i < 3; i++) |
188 |
co->tm[3][i] = d*(CO_P1(co)[i] - CO_P0(co)[i]) |
189 |
- CO_P0(co)[i]; |
190 |
|
191 |
/* rotate to positive z-axis */ |
192 |
setident4(m4); |
193 |
d = co->ad[1]*co->ad[1] + co->ad[2]*co->ad[2]; |
194 |
if (d <= FTINY*FTINY) { |
195 |
m4[0][0] = 0.0; |
196 |
m4[0][2] = co->ad[0]; |
197 |
m4[2][0] = -co->ad[0]; |
198 |
m4[2][2] = 0.0; |
199 |
} else { |
200 |
d = sqrt(d); |
201 |
m4[0][0] = d; |
202 |
m4[1][0] = -co->ad[0]*co->ad[1]/d; |
203 |
m4[2][0] = -co->ad[0]*co->ad[2]/d; |
204 |
m4[1][1] = co->ad[2]/d; |
205 |
m4[2][1] = -co->ad[1]/d; |
206 |
m4[0][2] = co->ad[0]; |
207 |
m4[1][2] = co->ad[1]; |
208 |
m4[2][2] = co->ad[2]; |
209 |
} |
210 |
multmat4(co->tm, co->tm, m4); |
211 |
|
212 |
/* scale z-axis */ |
213 |
if ((co->p0 != co->p1) & (co->r0 != co->r1)) { |
214 |
setident4(m4); |
215 |
m4[2][2] = (CO_R1(co) - CO_R0(co)) / co->al; |
216 |
multmat4(co->tm, co->tm, m4); |
217 |
} |
218 |
} |