| 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 |
} |
