src/common/cone.c

/* Copyright (c) 1991 Regents of the University of California */

#ifndef lint
static char SCCSid[] = "$SunId$ LBL";
#endif

/*
 *  cone.c - routines for making cones
 *
 *     2/12/86
 */

#include  "standard.h"

#include  "object.h"

#include  "otypes.h"

#include  "cone.h"

/*
 *     In general, a cone may be any one of a cone, a cylinder, a ring,
 *  a cup (inverted cone), or a tube (inverted cylinder).
 *     Most cones are specified with a starting point and radius and
 *  an ending point and radius.  In the cases of a cylinder or tube,
 *  only one radius is needed.  In the case of a ring, a normal direction
 *  is specified instead of a second endpoint.
 *
 *      mtype (cone|cup) name
 *      0
 *      0
 *      8 P0x P0y P0z P1x P1y P1z R0 R1
 *
 *      mtype (cylinder|tube) name
 *      0
 *      0
 *      7 P0x P0y P0z P1x P1y P1z R
 *
 *      mtype ring name
 *      0
 *      0
 *      8 Px Py Pz Nx Ny Nz R0 R1
 */


CONE *
getcone(o, getxf)                       /* get cone structure */
register OBJREC  *o;
int  getxf;
{
        double  fabs(), sqrt();
        int  sgn0, sgn1;
        register CONE  *co;

        if ((co = (CONE *)o->os) == NULL) {

                co = (CONE *)malloc(sizeof(CONE));
                if (co == NULL)
                        error(SYSTEM, "out of memory in makecone");

                co->ca = o->oargs.farg;
                                                /* get radii */
                if (o->otype == OBJ_CYLINDER || o->otype == OBJ_TUBE) {
                        if (o->oargs.nfargs != 7)
                                goto argcerr;
                        if (co->ca[6] < -FTINY) {
                                objerror(o, WARNING, "negative radius");
                                o->otype = o->otype == OBJ_CYLINDER ?
                                                OBJ_TUBE : OBJ_CYLINDER;
                                co->ca[6] = -co->ca[6];
                        } else if (co->ca[6] <= FTINY)
                                goto raderr;
                        co->r0 = co->r1 = 6;
                } else {
                        if (o->oargs.nfargs != 8)
                                goto argcerr;
                        if (co->ca[6] < -FTINY) sgn0 = -1;
                        else if (co->ca[6] > FTINY) sgn0 = 1;
                        else sgn0 = 0;
                        if (co->ca[7] < -FTINY) sgn1 = -1;
                        else if (co->ca[7] > FTINY) sgn1 = 1;
                        else sgn1 = 0;
                        if (sgn0+sgn1 == 0)
                                goto raderr;
                        if (sgn0 < 0 || sgn1 < 0) {
                                objerror(o, o->otype==OBJ_RING?USER:WARNING,
                                        "negative radii");
                                o->otype = o->otype == OBJ_CONE ?
                                                OBJ_CUP : OBJ_CONE;
                        }
                        co->ca[6] = co->ca[6]*sgn0;
                        co->ca[7] = co->ca[7]*sgn1;
                        co->r0 = 6;
                        co->r1 = 7;
                        if (fabs(co->ca[7] - co->ca[6]) <= FTINY) {
                                if (o->otype == OBJ_RING)
                                        goto raderr;
                                o->otype = o->otype == OBJ_CONE ?
                                                OBJ_CYLINDER : OBJ_TUBE;
                                o->oargs.nfargs = 7;
                                co->r1 = 6;
                        }
                }
                                                /* get axis orientation */
                co->p0 = 0;
                if (o->otype == OBJ_RING) {
                        if (co->ca[6] > co->ca[7]) {    /* make r0 smaller */
                                co->r0 = 7;
                                co->r1 = 6;
                        }
                        co->p1 = 0;
                        VCOPY(co->ad, o->oargs.farg+3);
                } else {
                        co->p1 = 3;
                        co->ad[0] = co->ca[3] - co->ca[0];
                        co->ad[1] = co->ca[4] - co->ca[1];
                        co->ad[2] = co->ca[5] - co->ca[2];
                }
                co->al = normalize(co->ad);
                if (co->al == 0.0)
                        objerror(o, USER, "zero orientation");
                                        /* compute axis and side lengths */
                if (o->otype == OBJ_RING) {
                        co->al = 0.0;
                        co->sl = co->ca[co->r1] - co->ca[co->r0];
                } else if (o->otype == OBJ_CONE || o->otype == OBJ_CUP) {
                        co->sl = co->ca[7] - co->ca[6];
                        co->sl = sqrt(co->sl*co->sl + co->al*co->al);
                } else { /* OBJ_CYLINDER || OBJ_TUBE */
                        co->sl = co->al;
                }
                co->tm = NULL;
                o->os = (char *)co;
        }
        if (getxf && co->tm == NULL)
                conexform(co);
        return(co);

argcerr:
        objerror(o, USER, "bad # arguments");
raderr:
        objerror(o, USER, "illegal radii");
}


freecone(o)                     /* free memory associated with cone */
OBJREC  *o;
{
        register CONE  *co = (CONE *)o->os;

        if (co->tm != NULL)
                free((char *)co->tm);
        free(o->os);
        o->os = NULL;
}


conexform(co)                   /* get cone transformation matrix */
register CONE  *co;
{
        double  sqrt(), fabs();
        double  m4[4][4];
        register double  d;
        register int  i;

        co->tm = (double (*)[4])malloc(sizeof(m4));
        if (co->tm == NULL)
                error(SYSTEM, "out of memory in conexform");

                                /* translate to origin */
        setident4(co->tm);
        if (co->r0 == co->r1)
                d = 0.0;
        else
                d = co->ca[co->r0] / (co->ca[co->r1] - co->ca[co->r0]);
        for (i = 0; i < 3; i++)
                co->tm[3][i] = d*(co->ca[co->p1+i] - co->ca[co->p0+i])
                                - co->ca[co->p0+i];
        
                                /* rotate to positive z-axis */
        setident4(m4);
        d = co->ad[1]*co->ad[1] + co->ad[2]*co->ad[2];
        if (d <= FTINY*FTINY) {
                m4[0][0] = 0.0;
                m4[0][2] = co->ad[0];
                m4[2][0] = -co->ad[0];
                m4[2][2] = 0.0;
        } else {
                d = sqrt(d);
                m4[0][0] = d;
                m4[1][0] = -co->ad[0]*co->ad[1]/d;
                m4[2][0] = -co->ad[0]*co->ad[2]/d;
                m4[1][1] = co->ad[2]/d;
                m4[2][1] = -co->ad[1]/d;
                m4[0][2] = co->ad[0];
                m4[1][2] = co->ad[1];
                m4[2][2] = co->ad[2];
        }
        multmat4(co->tm, co->tm, m4);

                                /* scale z-axis */
        setident4(m4);
        if (co->p0 != co->p1 && co->r0 != co->r1) {
                d = fabs(co->ca[co->r1] - co->ca[co->r0]);
                m4[2][2] = d/co->al;
        }
        multmat4(co->tm, co->tm, m4);
}
Revision:	1.4
Committed:	Wed May 22 16:51:12 1991 UTC (32 years, 11 months ago) by greg
Content type:	text/plain
Branch:	MAIN
Changes since 1.3:	+30 -6 lines
Log Message:	made getcone VERY forgiving of improper input -- negative radii now result in warnings and altered types
#	Content
1	/* Copyright (c) 1991 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	int sgn0, sgn1;
53	register CONE *co;
54
55	if ((co = (CONE *)o->os) == NULL) {
56
57	co = (CONE *)malloc(sizeof(CONE));
58	if (co == NULL)
59	error(SYSTEM, "out of memory in makecone");
60
61	co->ca = o->oargs.farg;
62	/* get radii */
63	if (o->otype == OBJ_CYLINDER \|\| o->otype == OBJ_TUBE) {
64	if (o->oargs.nfargs != 7)
65	goto argcerr;
66	if (co->ca[6] < -FTINY) {
67	objerror(o, WARNING, "negative radius");
68	o->otype = o->otype == OBJ_CYLINDER ?
69	OBJ_TUBE : OBJ_CYLINDER;
70	co->ca[6] = -co->ca[6];
71	} else if (co->ca[6] <= FTINY)
72	goto raderr;
73	co->r0 = co->r1 = 6;
74	} else {
75	if (o->oargs.nfargs != 8)
76	goto argcerr;
77	if (co->ca[6] < -FTINY) sgn0 = -1;
78	else if (co->ca[6] > FTINY) sgn0 = 1;
79	else sgn0 = 0;
80	if (co->ca[7] < -FTINY) sgn1 = -1;
81	else if (co->ca[7] > FTINY) sgn1 = 1;
82	else sgn1 = 0;
83	if (sgn0+sgn1 == 0)
84	goto raderr;
85	if (sgn0 < 0 \|\| sgn1 < 0) {
86	objerror(o, o->otype==OBJ_RING?USER:WARNING,
87	"negative radii");
88	o->otype = o->otype == OBJ_CONE ?
89	OBJ_CUP : OBJ_CONE;
90	}
91	co->ca[6] = co->ca[6]*sgn0;
92	co->ca[7] = co->ca[7]*sgn1;
93	co->r0 = 6;
94	co->r1 = 7;
95	if (fabs(co->ca[7] - co->ca[6]) <= FTINY) {
96	if (o->otype == OBJ_RING)
97	goto raderr;
98	o->otype = o->otype == OBJ_CONE ?
99	OBJ_CYLINDER : OBJ_TUBE;
100	o->oargs.nfargs = 7;
101	co->r1 = 6;
102	}
103	}
104	/* get axis orientation */
105	co->p0 = 0;
106	if (o->otype == OBJ_RING) {
107	if (co->ca[6] > co->ca[7]) { /* make r0 smaller */
108	co->r0 = 7;
109	co->r1 = 6;
110	}
111	co->p1 = 0;
112	VCOPY(co->ad, o->oargs.farg+3);
113	} else {
114	co->p1 = 3;
115	co->ad[0] = co->ca[3] - co->ca[0];
116	co->ad[1] = co->ca[4] - co->ca[1];
117	co->ad[2] = co->ca[5] - co->ca[2];
118	}
119	co->al = normalize(co->ad);
120	if (co->al == 0.0)
121	objerror(o, USER, "zero orientation");
122	/* compute axis and side lengths */
123	if (o->otype == OBJ_RING) {
124	co->al = 0.0;
125	co->sl = co->ca[co->r1] - co->ca[co->r0];
126	} else if (o->otype == OBJ_CONE \|\| o->otype == OBJ_CUP) {
127	co->sl = co->ca[7] - co->ca[6];
128	co->sl = sqrt(co->slco->sl + co->alco->al);
129	} else { /* OBJ_CYLINDER \|\| OBJ_TUBE */
130	co->sl = co->al;
131	}
132	co->tm = NULL;
133	o->os = (char *)co;
134	}
135	if (getxf && co->tm == NULL)
136	conexform(co);
137	return(co);
138
139	argcerr:
140	objerror(o, USER, "bad # arguments");
141	raderr:
142	objerror(o, USER, "illegal radii");
143	}
144
145
146	freecone(o) /* free memory associated with cone */
147	OBJREC *o;
148	{
149	register CONE co = (CONE )o->os;
150
151	if (co->tm != NULL)
152	free((char *)co->tm);
153	free(o->os);
154	o->os = NULL;
155	}
156
157
158	conexform(co) /* get cone transformation matrix */
159	register CONE *co;
160	{
161	double sqrt(), fabs();
162	double m4[4][4];
163	register double d;
164	register int i;
165
166	co->tm = (double (*)[4])malloc(sizeof(m4));
167	if (co->tm == NULL)
168	error(SYSTEM, "out of memory in conexform");
169
170	/* translate to origin */
171	setident4(co->tm);
172	if (co->r0 == co->r1)
173	d = 0.0;
174	else
175	d = co->ca[co->r0] / (co->ca[co->r1] - co->ca[co->r0]);
176	for (i = 0; i < 3; i++)
177	co->tm[3][i] = d*(co->ca[co->p1+i] - co->ca[co->p0+i])
178	- co->ca[co->p0+i];
179
180	/* rotate to positive z-axis */
181	setident4(m4);
182	d = co->ad[1]co->ad[1] + co->ad[2]co->ad[2];
183	if (d <= FTINY*FTINY) {
184	m4[0][0] = 0.0;
185	m4[0][2] = co->ad[0];
186	m4[2][0] = -co->ad[0];
187	m4[2][2] = 0.0;
188	} else {
189	d = sqrt(d);
190	m4[0][0] = d;
191	m4[1][0] = -co->ad[0]*co->ad[1]/d;
192	m4[2][0] = -co->ad[0]*co->ad[2]/d;
193	m4[1][1] = co->ad[2]/d;
194	m4[2][1] = -co->ad[1]/d;
195	m4[0][2] = co->ad[0];
196	m4[1][2] = co->ad[1];
197	m4[2][2] = co->ad[2];
198	}
199	multmat4(co->tm, co->tm, m4);
200
201	/* scale z-axis */
202	setident4(m4);
203	if (co->p0 != co->p1 && co->r0 != co->r1) {
204	d = fabs(co->ca[co->r1] - co->ca[co->r0]);
205	m4[2][2] = d/co->al;
206	}
207	multmat4(co->tm, co->tm, m4);
208	}