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root/radiance/ray/src/common/cone.c
Revision: 1.2
Committed: Tue Feb 21 14:39:51 1989 UTC (35 years, 2 months ago) by greg
Content type: text/plain
Branch: MAIN
Changes since 1.1: +1 -1 lines
Log Message:
portability fixes for SGI

File Contents

# User Rev Content
1 greg 1.1 /* Copyright (c) 1986 Regents of the University of California */
2    
3     #ifndef lint
4     static char SCCSid[] = "$SunId$ LBL";
5     #endif
6    
7     /*
8     * cone.c - routines for making cones
9     *
10     * 2/12/86
11     */
12    
13     #include "standard.h"
14    
15     #include "object.h"
16    
17     #include "otypes.h"
18    
19     #include "cone.h"
20    
21     /*
22     * In general, a cone may be any one of a cone, a cylinder, a ring,
23     * a cup (inverted cone), or a tube (inverted cylinder).
24     * Most cones are specified with a starting point and radius and
25     * an ending point and radius. In the cases of a cylinder or tube,
26     * only one radius is needed. In the case of a ring, a normal direction
27     * is specified instead of a second endpoint.
28     *
29     * mtype (cone|cup) name
30     * 0
31     * 0
32     * 8 P0x P0y P0z P1x P1y P1z R0 R1
33     *
34     * mtype (cylinder|tube) name
35     * 0
36     * 0
37     * 7 P0x P0y P0z P1x P1y P1z R
38     *
39     * mtype ring name
40     * 0
41     * 0
42     * 8 Px Py Pz Nx Ny Nz R0 R1
43     */
44    
45    
46     CONE *
47     getcone(o, getxf) /* get cone structure */
48     register OBJREC *o;
49     int getxf;
50     {
51     double fabs(), sqrt();
52     register CONE *co;
53    
54     if ((co = (CONE *)o->os) == NULL) {
55    
56     co = (CONE *)malloc(sizeof(CONE));
57     if (co == NULL)
58     error(SYSTEM, "out of memory in makecone");
59    
60     co->ca = o->oargs.farg;
61     /* get radii */
62     if (o->otype == OBJ_CYLINDER || o->otype == OBJ_TUBE) {
63     if (o->oargs.nfargs != 7)
64     goto argcerr;
65     if (co->ca[6] <= FTINY)
66     goto raderr;
67     co->r0 = co->r1 = 6;
68     } else {
69     if (o->oargs.nfargs != 8)
70     goto argcerr;
71     if (co->ca[6] < 0.0 || co->ca[7] < 0.0)
72     goto raderr;
73     if (fabs(co->ca[7] - co->ca[6]) <= FTINY)
74     goto raderr;
75     co->r0 = 6;
76     co->r1 = 7;
77     }
78     /* get axis orientation */
79     co->p0 = 0;
80     if (o->otype == OBJ_RING) {
81     if (co->ca[6] > co->ca[7]) { /* make r0 smaller */
82     co->r0 = 7;
83     co->r1 = 6;
84     }
85     co->p1 = 0;
86     VCOPY(co->ad, o->oargs.farg+3);
87     } else {
88     co->p1 = 3;
89     co->ad[0] = co->ca[3] - co->ca[0];
90     co->ad[1] = co->ca[4] - co->ca[1];
91     co->ad[2] = co->ca[5] - co->ca[2];
92     }
93     co->al = normalize(co->ad);
94     if (co->al == 0.0)
95     objerror(o, USER, "zero orientation");
96     /* compute axis and side lengths */
97     if (o->otype == OBJ_RING) {
98     co->al = 0.0;
99     co->sl = co->ca[co->r1] - co->ca[co->r0];
100     } else if (o->otype == OBJ_CONE || o->otype == OBJ_CUP) {
101     co->sl = co->ca[7] - co->ca[6];
102     co->sl = sqrt(co->sl*co->sl + co->al*co->al);
103     } else { /* OBJ_CYLINDER || OBJ_TUBE */
104     co->sl = co->al;
105     }
106     co->tm = NULL;
107 greg 1.2 o->os = (char *)co;
108 greg 1.1 }
109     if (getxf && co->tm == NULL)
110     conexform(co);
111     return(co);
112    
113     argcerr:
114     objerror(o, USER, "bad # arguments");
115     raderr:
116     objerror(o, USER, "illegal radii");
117     }
118    
119    
120     freecone(o) /* free memory associated with cone */
121     OBJREC *o;
122     {
123     register CONE *co = (CONE *)o->os;
124    
125     if (co->tm != NULL)
126     free((char *)co->tm);
127     free(o->os);
128     o->os = NULL;
129     }
130    
131    
132     conexform(co) /* get cone transformation matrix */
133     register CONE *co;
134     {
135     double sqrt(), fabs();
136     double m4[4][4];
137     register double d;
138     register int i;
139    
140     co->tm = (double (*)[4])malloc(sizeof(m4));
141     if (co->tm == NULL)
142     error(SYSTEM, "out of memory in conexform");
143    
144     /* translate to origin */
145     setident4(co->tm);
146     if (co->r0 == co->r1)
147     d = 0.0;
148     else
149     d = co->ca[co->r0] / (co->ca[co->r1] - co->ca[co->r0]);
150     for (i = 0; i < 3; i++)
151     co->tm[3][i] = d*(co->ca[co->p1+i] - co->ca[co->p0+i])
152     - co->ca[co->p0+i];
153    
154     /* rotate to positive z-axis */
155     setident4(m4);
156     d = co->ad[1]*co->ad[1] + co->ad[2]*co->ad[2];
157     if (d <= FTINY*FTINY) {
158     m4[0][0] = 0.0;
159     m4[0][2] = co->ad[0];
160     m4[2][0] = -co->ad[0];
161     m4[2][2] = 0.0;
162     } else {
163     d = sqrt(d);
164     m4[0][0] = d;
165     m4[1][0] = -co->ad[0]*co->ad[1]/d;
166     m4[2][0] = -co->ad[0]*co->ad[2]/d;
167     m4[1][1] = co->ad[2]/d;
168     m4[2][1] = -co->ad[1]/d;
169     m4[0][2] = co->ad[0];
170     m4[1][2] = co->ad[1];
171     m4[2][2] = co->ad[2];
172     }
173     multmat4(co->tm, co->tm, m4);
174    
175     /* scale z-axis */
176     setident4(m4);
177     if (co->p0 != co->p1 && co->r0 != co->r1) {
178     d = fabs(co->ca[co->r1] - co->ca[co->r0]);
179     m4[2][2] = d/co->al;
180     }
181     multmat4(co->tm, co->tm, m4);
182     }