| 1 |
#ifndef lint |
| 2 |
static const char RCSid[] = "$Id: xf.c,v 1.15 2011/01/14 05:46:12 greg Exp $"; |
| 3 |
#endif |
| 4 |
/* |
| 5 |
* Routines for 4x4 homogeneous, rigid-body transformations |
| 6 |
*/ |
| 7 |
|
| 8 |
#include <stdio.h> |
| 9 |
#include <stdlib.h> |
| 10 |
#include "mgf_parser.h" |
| 11 |
|
| 12 |
#define d2r(a) ((PI/180.)*(a)) |
| 13 |
|
| 14 |
#define checkarg(a,l) if (av[i][a] || badarg(ac-i-1,av+i+1,l)) goto done |
| 15 |
|
| 16 |
XF_SPEC *xf_context = NULL; /* current context */ |
| 17 |
char **xf_argend; /* end of transform argument list */ |
| 18 |
static char **xf_argbeg; /* beginning of transform argument list */ |
| 19 |
|
| 20 |
|
| 21 |
int |
| 22 |
xf_handler(int ac, char **av) /* handle xf entity */ |
| 23 |
{ |
| 24 |
register XF_SPEC *spec; |
| 25 |
register int n; |
| 26 |
int rv; |
| 27 |
|
| 28 |
if (ac == 1) { /* something with existing transform */ |
| 29 |
if ((spec = xf_context) == NULL) |
| 30 |
return(MG_ECNTXT); |
| 31 |
n = -1; |
| 32 |
if (spec->xarr != NULL) { /* check for iteration */ |
| 33 |
register struct xf_array *ap = spec->xarr; |
| 34 |
|
| 35 |
(void)xf_aname((struct xf_array *)NULL); |
| 36 |
n = ap->ndim; |
| 37 |
while (n--) { |
| 38 |
if (++ap->aarg[n].i < ap->aarg[n].n) |
| 39 |
break; |
| 40 |
(void)strcpy(ap->aarg[n].arg, "0"); |
| 41 |
ap->aarg[n].i = 0; |
| 42 |
} |
| 43 |
if (n >= 0) { |
| 44 |
if ((rv = mg_fgoto(&ap->spos)) != MG_OK) |
| 45 |
return(rv); |
| 46 |
sprintf(ap->aarg[n].arg, "%d", ap->aarg[n].i); |
| 47 |
(void)xf_aname(ap); |
| 48 |
} |
| 49 |
} |
| 50 |
if (n < 0) { /* pop transform */ |
| 51 |
xf_context = spec->prev; |
| 52 |
free_xf(spec); |
| 53 |
return(MG_OK); |
| 54 |
} |
| 55 |
} else { /* else allocate transform */ |
| 56 |
if ((spec = new_xf(ac-1, av+1)) == NULL) |
| 57 |
return(MG_EMEM); |
| 58 |
if (spec->xarr != NULL) |
| 59 |
(void)xf_aname(spec->xarr); |
| 60 |
spec->prev = xf_context; /* push onto stack */ |
| 61 |
xf_context = spec; |
| 62 |
} |
| 63 |
/* translate new specification */ |
| 64 |
n = xf_ac(spec); |
| 65 |
n -= xf_ac(spec->prev); /* incremental comp. is more eff. */ |
| 66 |
if (xf(&spec->xf, n, xf_av(spec)) != n) |
| 67 |
return(MG_ETYPE); |
| 68 |
/* check for vertex reversal */ |
| 69 |
if ((spec->rev = (spec->xf.sca < 0.))) |
| 70 |
spec->xf.sca = -spec->xf.sca; |
| 71 |
/* compute total transformation */ |
| 72 |
if (spec->prev != NULL) { |
| 73 |
multmat4(spec->xf.xfm, spec->xf.xfm, spec->prev->xf.xfm); |
| 74 |
spec->xf.sca *= spec->prev->xf.sca; |
| 75 |
spec->rev ^= spec->prev->rev; |
| 76 |
} |
| 77 |
spec->xid = comp_xfid(spec->xf.xfm); /* compute unique ID */ |
| 78 |
return(MG_OK); |
| 79 |
} |
| 80 |
|
| 81 |
|
| 82 |
XF_SPEC * |
| 83 |
new_xf(int ac, char **av) /* allocate new transform structure */ |
| 84 |
{ |
| 85 |
register XF_SPEC *spec; |
| 86 |
register int i; |
| 87 |
char *cp; |
| 88 |
int n, ndim; |
| 89 |
|
| 90 |
ndim = 0; |
| 91 |
n = 0; /* compute space req'd by arguments */ |
| 92 |
for (i = 0; i < ac; i++) |
| 93 |
if (!strcmp(av[i], "-a")) { |
| 94 |
ndim++; |
| 95 |
i++; |
| 96 |
} else |
| 97 |
n += strlen(av[i]) + 1; |
| 98 |
if (ndim > XF_MAXDIM) |
| 99 |
return(NULL); |
| 100 |
spec = (XF_SPEC *)malloc(sizeof(XF_SPEC) + n); |
| 101 |
if (spec == NULL) |
| 102 |
return(NULL); |
| 103 |
if (ndim) { |
| 104 |
spec->xarr = (struct xf_array *)malloc(sizeof(struct xf_array)); |
| 105 |
if (spec->xarr == NULL) |
| 106 |
return(NULL); |
| 107 |
mg_fgetpos(&spec->xarr->spos); |
| 108 |
spec->xarr->ndim = 0; /* incremented below */ |
| 109 |
} else |
| 110 |
spec->xarr = NULL; |
| 111 |
spec->xac = ac + xf_argc; |
| 112 |
/* and store new xf arguments */ |
| 113 |
if (xf_argbeg == NULL || xf_av(spec) < xf_argbeg) { |
| 114 |
register char **newav = |
| 115 |
(char **)malloc((spec->xac+1)*sizeof(char *)); |
| 116 |
if (newav == NULL) |
| 117 |
return(NULL); |
| 118 |
for (i = xf_argc; i-- > 0; ) |
| 119 |
newav[ac+i] = xf_argend[i-xf_context->xac]; |
| 120 |
*(xf_argend = newav + spec->xac) = NULL; |
| 121 |
if (xf_argbeg != NULL) |
| 122 |
free(xf_argbeg); |
| 123 |
xf_argbeg = newav; |
| 124 |
} |
| 125 |
cp = (char *)(spec + 1); /* use memory allocated above */ |
| 126 |
for (i = 0; i < ac; i++) |
| 127 |
if (!strcmp(av[i], "-a")) { |
| 128 |
xf_av(spec)[i++] = "-i"; |
| 129 |
xf_av(spec)[i] = strcpy( |
| 130 |
spec->xarr->aarg[spec->xarr->ndim].arg, |
| 131 |
"0"); |
| 132 |
spec->xarr->aarg[spec->xarr->ndim].i = 0; |
| 133 |
spec->xarr->aarg[spec->xarr->ndim++].n = atoi(av[i]); |
| 134 |
} else { |
| 135 |
xf_av(spec)[i] = strcpy(cp, av[i]); |
| 136 |
cp += strlen(av[i]) + 1; |
| 137 |
} |
| 138 |
return(spec); |
| 139 |
} |
| 140 |
|
| 141 |
|
| 142 |
void |
| 143 |
free_xf(XF_SPEC *spec) /* free a transform */ |
| 144 |
{ |
| 145 |
if (spec->xarr != NULL) |
| 146 |
free(spec->xarr); |
| 147 |
free(spec); |
| 148 |
} |
| 149 |
|
| 150 |
|
| 151 |
int |
| 152 |
xf_aname(struct xf_array *ap) /* put out name for this instance */ |
| 153 |
{ |
| 154 |
static char oname[10*XF_MAXDIM]; |
| 155 |
static char *oav[3] = {mg_ename[MG_E_OBJECT], oname}; |
| 156 |
register int i; |
| 157 |
register char *cp1, *cp2; |
| 158 |
|
| 159 |
if (ap == NULL) |
| 160 |
return(mg_handle(MG_E_OBJECT, 1, oav)); |
| 161 |
cp1 = oname; |
| 162 |
*cp1 = 'a'; |
| 163 |
for (i = 0; i < ap->ndim; i++) { |
| 164 |
for (cp2 = ap->aarg[i].arg; *cp2; ) |
| 165 |
*++cp1 = *cp2++; |
| 166 |
*++cp1 = '.'; |
| 167 |
} |
| 168 |
*cp1 = '\0'; |
| 169 |
return(mg_handle(MG_E_OBJECT, 2, oav)); |
| 170 |
} |
| 171 |
|
| 172 |
|
| 173 |
long |
| 174 |
comp_xfid(MAT4 xfm) /* compute unique ID from matrix */ |
| 175 |
{ |
| 176 |
static char shifttab[64] = { 15, 5, 11, 5, 6, 3, |
| 177 |
9, 15, 13, 2, 13, 5, 2, 12, 14, 11, |
| 178 |
11, 12, 12, 3, 2, 11, 8, 12, 1, 12, |
| 179 |
5, 4, 15, 9, 14, 5, 13, 14, 2, 10, |
| 180 |
10, 14, 12, 3, 5, 5, 14, 6, 12, 11, |
| 181 |
13, 9, 12, 8, 1, 6, 5, 12, 7, 13, |
| 182 |
15, 8, 9, 2, 6, 11, 9, 11 }; |
| 183 |
register int i; |
| 184 |
register long xid; |
| 185 |
|
| 186 |
xid = 0; /* compute unique transform id */ |
| 187 |
for (i = 0; i < sizeof(MAT4)/sizeof(unsigned short); i++) |
| 188 |
xid ^= (long)(((unsigned short *)xfm)[i]) << shifttab[i&63]; |
| 189 |
return(xid); |
| 190 |
} |
| 191 |
|
| 192 |
|
| 193 |
void |
| 194 |
xf_clear(void) /* clear transform stack */ |
| 195 |
{ |
| 196 |
register XF_SPEC *spec; |
| 197 |
|
| 198 |
if (xf_argbeg != NULL) { |
| 199 |
free(xf_argbeg); |
| 200 |
xf_argbeg = xf_argend = NULL; |
| 201 |
} |
| 202 |
while ((spec = xf_context) != NULL) { |
| 203 |
xf_context = spec->prev; |
| 204 |
free_xf(spec); |
| 205 |
} |
| 206 |
} |
| 207 |
|
| 208 |
|
| 209 |
void |
| 210 |
xf_xfmpoint(FVECT v1, FVECT v2) /* transform a point by the current matrix */ |
| 211 |
{ |
| 212 |
if (xf_context == NULL) { |
| 213 |
VCOPY(v1, v2); |
| 214 |
return; |
| 215 |
} |
| 216 |
multp3(v1, v2, xf_context->xf.xfm); |
| 217 |
} |
| 218 |
|
| 219 |
|
| 220 |
void |
| 221 |
xf_xfmvect(FVECT v1, FVECT v2) /* transform a vector using current matrix */ |
| 222 |
{ |
| 223 |
if (xf_context == NULL) { |
| 224 |
VCOPY(v1, v2); |
| 225 |
return; |
| 226 |
} |
| 227 |
multv3(v1, v2, xf_context->xf.xfm); |
| 228 |
} |
| 229 |
|
| 230 |
|
| 231 |
void |
| 232 |
xf_rotvect(FVECT v1, FVECT v2) /* rotate a vector using current matrix */ |
| 233 |
{ |
| 234 |
xf_xfmvect(v1, v2); |
| 235 |
if (xf_context == NULL) |
| 236 |
return; |
| 237 |
v1[0] /= xf_context->xf.sca; |
| 238 |
v1[1] /= xf_context->xf.sca; |
| 239 |
v1[2] /= xf_context->xf.sca; |
| 240 |
} |
| 241 |
|
| 242 |
|
| 243 |
double |
| 244 |
xf_scale(double d) /* scale a number by the current transform */ |
| 245 |
{ |
| 246 |
if (xf_context == NULL) |
| 247 |
return(d); |
| 248 |
return(d*xf_context->xf.sca); |
| 249 |
} |
