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#ifndef lint |
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static const char RCSid[] = "$Id: xf.c,v 1.15 2011/01/14 05:46:12 greg Exp $"; |
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#endif |
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/* |
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* Routines for 4x4 homogeneous, rigid-body transformations |
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*/ |
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|
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#include <stdio.h> |
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#include <stdlib.h> |
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#include "mgf_parser.h" |
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|
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#define d2r(a) ((PI/180.)*(a)) |
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|
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#define checkarg(a,l) if (av[i][a] || badarg(ac-i-1,av+i+1,l)) goto done |
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|
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XF_SPEC *xf_context = NULL; /* current context */ |
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char **xf_argend; /* end of transform argument list */ |
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static char **xf_argbeg; /* beginning of transform argument list */ |
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|
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|
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int |
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xf_handler(int ac, char **av) /* handle xf entity */ |
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{ |
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register XF_SPEC *spec; |
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register int n; |
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int rv; |
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|
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if (ac == 1) { /* something with existing transform */ |
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if ((spec = xf_context) == NULL) |
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return(MG_ECNTXT); |
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n = -1; |
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if (spec->xarr != NULL) { /* check for iteration */ |
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register struct xf_array *ap = spec->xarr; |
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|
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(void)xf_aname((struct xf_array *)NULL); |
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n = ap->ndim; |
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while (n--) { |
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if (++ap->aarg[n].i < ap->aarg[n].n) |
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break; |
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(void)strcpy(ap->aarg[n].arg, "0"); |
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ap->aarg[n].i = 0; |
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} |
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if (n >= 0) { |
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if ((rv = mg_fgoto(&ap->spos)) != MG_OK) |
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return(rv); |
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sprintf(ap->aarg[n].arg, "%d", ap->aarg[n].i); |
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(void)xf_aname(ap); |
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} |
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} |
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if (n < 0) { /* pop transform */ |
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xf_context = spec->prev; |
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free_xf(spec); |
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return(MG_OK); |
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} |
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} else { /* else allocate transform */ |
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if ((spec = new_xf(ac-1, av+1)) == NULL) |
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return(MG_EMEM); |
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if (spec->xarr != NULL) |
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(void)xf_aname(spec->xarr); |
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spec->prev = xf_context; /* push onto stack */ |
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xf_context = spec; |
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} |
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/* translate new specification */ |
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n = xf_ac(spec); |
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n -= xf_ac(spec->prev); /* incremental comp. is more eff. */ |
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if (xf(&spec->xf, n, xf_av(spec)) != n) |
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return(MG_ETYPE); |
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/* check for vertex reversal */ |
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if ((spec->rev = (spec->xf.sca < 0.))) |
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spec->xf.sca = -spec->xf.sca; |
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/* compute total transformation */ |
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if (spec->prev != NULL) { |
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multmat4(spec->xf.xfm, spec->xf.xfm, spec->prev->xf.xfm); |
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spec->xf.sca *= spec->prev->xf.sca; |
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spec->rev ^= spec->prev->rev; |
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} |
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spec->xid = comp_xfid(spec->xf.xfm); /* compute unique ID */ |
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return(MG_OK); |
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} |
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|
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|
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XF_SPEC * |
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new_xf(int ac, char **av) /* allocate new transform structure */ |
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{ |
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register XF_SPEC *spec; |
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register int i; |
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char *cp; |
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int n, ndim; |
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|
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ndim = 0; |
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n = 0; /* compute space req'd by arguments */ |
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for (i = 0; i < ac; i++) |
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if (!strcmp(av[i], "-a")) { |
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ndim++; |
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i++; |
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} else |
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n += strlen(av[i]) + 1; |
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if (ndim > XF_MAXDIM) |
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return(NULL); |
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spec = (XF_SPEC *)malloc(sizeof(XF_SPEC) + n); |
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if (spec == NULL) |
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return(NULL); |
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if (ndim) { |
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spec->xarr = (struct xf_array *)malloc(sizeof(struct xf_array)); |
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if (spec->xarr == NULL) |
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return(NULL); |
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mg_fgetpos(&spec->xarr->spos); |
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spec->xarr->ndim = 0; /* incremented below */ |
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} else |
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spec->xarr = NULL; |
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spec->xac = ac + xf_argc; |
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/* and store new xf arguments */ |
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if (xf_argbeg == NULL || xf_av(spec) < xf_argbeg) { |
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register char **newav = |
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(char **)malloc((spec->xac+1)*sizeof(char *)); |
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if (newav == NULL) |
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return(NULL); |
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for (i = xf_argc; i-- > 0; ) |
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newav[ac+i] = xf_argend[i-xf_context->xac]; |
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*(xf_argend = newav + spec->xac) = NULL; |
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if (xf_argbeg != NULL) |
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free(xf_argbeg); |
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xf_argbeg = newav; |
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} |
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cp = (char *)(spec + 1); /* use memory allocated above */ |
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for (i = 0; i < ac; i++) |
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if (!strcmp(av[i], "-a")) { |
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xf_av(spec)[i++] = "-i"; |
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xf_av(spec)[i] = strcpy( |
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spec->xarr->aarg[spec->xarr->ndim].arg, |
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"0"); |
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spec->xarr->aarg[spec->xarr->ndim].i = 0; |
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spec->xarr->aarg[spec->xarr->ndim++].n = atoi(av[i]); |
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} else { |
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xf_av(spec)[i] = strcpy(cp, av[i]); |
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cp += strlen(av[i]) + 1; |
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} |
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return(spec); |
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} |
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|
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|
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void |
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free_xf(XF_SPEC *spec) /* free a transform */ |
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{ |
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if (spec->xarr != NULL) |
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free(spec->xarr); |
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free(spec); |
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} |
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|
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|
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int |
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xf_aname(struct xf_array *ap) /* put out name for this instance */ |
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{ |
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static char oname[10*XF_MAXDIM]; |
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static char *oav[3] = {mg_ename[MG_E_OBJECT], oname}; |
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register int i; |
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register char *cp1, *cp2; |
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|
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if (ap == NULL) |
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return(mg_handle(MG_E_OBJECT, 1, oav)); |
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cp1 = oname; |
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*cp1 = 'a'; |
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for (i = 0; i < ap->ndim; i++) { |
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for (cp2 = ap->aarg[i].arg; *cp2; ) |
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*++cp1 = *cp2++; |
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*++cp1 = '.'; |
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} |
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*cp1 = '\0'; |
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return(mg_handle(MG_E_OBJECT, 2, oav)); |
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} |
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|
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|
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long |
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comp_xfid(MAT4 xfm) /* compute unique ID from matrix */ |
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{ |
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static char shifttab[64] = { 15, 5, 11, 5, 6, 3, |
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9, 15, 13, 2, 13, 5, 2, 12, 14, 11, |
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11, 12, 12, 3, 2, 11, 8, 12, 1, 12, |
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5, 4, 15, 9, 14, 5, 13, 14, 2, 10, |
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10, 14, 12, 3, 5, 5, 14, 6, 12, 11, |
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13, 9, 12, 8, 1, 6, 5, 12, 7, 13, |
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15, 8, 9, 2, 6, 11, 9, 11 }; |
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register int i; |
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register long xid; |
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|
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xid = 0; /* compute unique transform id */ |
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for (i = 0; i < sizeof(MAT4)/sizeof(unsigned short); i++) |
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xid ^= (long)(((unsigned short *)xfm)[i]) << shifttab[i&63]; |
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return(xid); |
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} |
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|
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|
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void |
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xf_clear(void) /* clear transform stack */ |
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{ |
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register XF_SPEC *spec; |
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|
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if (xf_argbeg != NULL) { |
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free(xf_argbeg); |
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xf_argbeg = xf_argend = NULL; |
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} |
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while ((spec = xf_context) != NULL) { |
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xf_context = spec->prev; |
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free_xf(spec); |
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} |
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} |
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|
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|
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void |
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xf_xfmpoint(FVECT v1, FVECT v2) /* transform a point by the current matrix */ |
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{ |
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if (xf_context == NULL) { |
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VCOPY(v1, v2); |
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return; |
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} |
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multp3(v1, v2, xf_context->xf.xfm); |
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} |
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|
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|
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void |
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xf_xfmvect(FVECT v1, FVECT v2) /* transform a vector using current matrix */ |
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{ |
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if (xf_context == NULL) { |
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VCOPY(v1, v2); |
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return; |
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} |
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multv3(v1, v2, xf_context->xf.xfm); |
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} |
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|
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|
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void |
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xf_rotvect(FVECT v1, FVECT v2) /* rotate a vector using current matrix */ |
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{ |
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xf_xfmvect(v1, v2); |
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if (xf_context == NULL) |
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return; |
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v1[0] /= xf_context->xf.sca; |
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v1[1] /= xf_context->xf.sca; |
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v1[2] /= xf_context->xf.sca; |
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} |
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|
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|
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double |
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xf_scale(double d) /* scale a number by the current transform */ |
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{ |
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if (xf_context == NULL) |
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return(d); |
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return(d*xf_context->xf.sca); |
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} |