--- ray/src/hd/rhdisp3.c 1997/11/21 18:17:37 3.4 +++ ray/src/hd/rhdisp3.c 1998/01/06 15:08:50 3.9 @@ -20,50 +20,63 @@ struct cellist { int npixels(vp, hr, vr, hp, bi) /* compute appropriate number to evaluate */ -VIEW *vp; +register VIEW *vp; int hr, vr; HOLO *hp; int bi; { - static VIEW vdo, vlast; - static HOLO *hplast; + VIEW vrev; GCOORD gc[2]; - FVECT cp[4]; - FVECT ip[4]; - double d; + FVECT cp[4], ip[4]; + double af, ab; register int i; /* compute cell corners in image */ if (!hdbcoord(gc, hp, bi)) error(CONSISTENCY, "bad beam index in npixels"); - /* has holodeck or view changed? */ - if (hp != hplast || bcmp((char *)vp, (char *)&vlast, sizeof(VIEW))) { - copystruct(&vdo, vp); - if (sect_behind(hp, &vdo)) { /* reverse view sense */ - vdo.vdir[0] = -vdo.vdir[0]; - vdo.vdir[1] = -vdo.vdir[1]; - vdo.vdir[2] = -vdo.vdir[2]; - setview(&vdo); + hdcell(cp, hp, gc+1); /* find cell on front image */ + for (i = 0; i < 4; i++) { + viewloc(ip[i], vp, cp[i]); + if (ip[i][2] < 0.) { + af = 0; + goto getback; } - hplast = hp; - copystruct(&vlast, vp); + ip[i][0] *= (double)hr; /* scale by resolution */ + ip[i][1] *= (double)vr; } - hdcell(cp, hp, gc+1); /* find cell on image */ + /* compute front area */ + af = (ip[1][0]-ip[0][0])*(ip[2][1]-ip[0][1]) - + (ip[2][0]-ip[0][0])*(ip[1][1]-ip[0][1]); + af += (ip[2][0]-ip[3][0])*(ip[1][1]-ip[3][1]) - + (ip[1][0]-ip[3][0])*(ip[2][1]-ip[3][1]); + if (af >= 0) af *= 0.5; + else af *= -0.5; +getback: + copystruct(&vrev, vp); /* compute reverse view */ + for (i = 0; i < 3; i++) { + vrev.vdir[i] = -vp->vdir[i]; + vrev.vup[i] = -vp->vup[i]; + vrev.hvec[i] = -vp->hvec[i]; + vrev.vvec[i] = -vp->vvec[i]; + } + hdcell(cp, hp, gc); /* find cell on back image */ for (i = 0; i < 4; i++) { - viewloc(ip[i], &vdo, cp[i]); + viewloc(ip[i], &vrev, cp[i]); if (ip[i][2] < 0.) - return(0); + return((int)(af + 0.5)); ip[i][0] *= (double)hr; /* scale by resolution */ ip[i][1] *= (double)vr; } - /* compute quad area */ - d = (ip[1][0]-ip[0][0])*(ip[2][1]-ip[0][1]) - + /* compute back area */ + ab = (ip[1][0]-ip[0][0])*(ip[2][1]-ip[0][1]) - (ip[2][0]-ip[0][0])*(ip[1][1]-ip[0][1]); - d += (ip[2][0]-ip[3][0])*(ip[1][1]-ip[3][1]) - + ab += (ip[2][0]-ip[3][0])*(ip[1][1]-ip[3][1]) - (ip[1][0]-ip[3][0])*(ip[2][1]-ip[3][1]); - if (d < 0) - d = -d; - /* round off result */ - return((int)(.5*d+.5)); + if (ab >= 0) ab *= 0.5; + else ab *= -0.5; + /* round off smaller area */ + if (af <= ab) + return((int)(af + 0.5)); + return((int)(ab + 0.5)); } @@ -71,19 +84,20 @@ int bi; * The ray directions that define the pyramid in visit_cells() needn't * be normalized, but they must be given in clockwise order as seen * from the pyramid's apex (origin). + * If no cell centers fall within the domain, the closest cell is visited. */ int visit_cells(orig, pyrd, hp, vf, dp) /* visit cells within a pyramid */ FVECT orig, pyrd[4]; /* pyramid ray directions in clockwise order */ -HOLO *hp; +register HOLO *hp; int (*vf)(); char *dp; { - int n = 0; + int ncalls = 0, n = 0; int inflags = 0; FVECT gp, pn[4], lo, ld; double po[4], lbeg, lend, d, t; - GCOORD gc; + GCOORD gc, gc2[2]; register int i; /* figure out whose side we're on */ hdgrid(gp, hp, orig); @@ -101,17 +115,17 @@ char *dp; if (!(inflags & 1<grid[((gc.w>>1)+2)%3]; gc.i[1]--; ) { + for (gc.i[1] = hp->grid[hdwg1[gc.w]]; gc.i[1]--; ) { /* compute scanline */ gp[gc.w>>1] = gc.w&1 ? hp->grid[gc.w>>1] : 0; - gp[((gc.w>>1)+1)%3] = 0; - gp[((gc.w>>1)+2)%3] = gc.i[1] + 0.5; + gp[hdwg0[gc.w]] = 0; + gp[hdwg1[gc.w]] = gc.i[1] + 0.5; hdworld(lo, hp, gp); - gp[((gc.w>>1)+1)%3] = 1; + gp[hdwg0[gc.w]] = 1; hdworld(ld, hp, gp); ld[0] -= lo[0]; ld[1] -= lo[1]; ld[2] -= lo[2]; /* find scanline limits */ - lbeg = 0; lend = hp->grid[((gc.w>>1)+1)%3]; + lbeg = 0; lend = hp->grid[hdwg0[gc.w]]; for (i = 0; i < 4; i++) { t = DOT(pn[i], lo) - po[i]; d = -DOT(pn[i], ld); @@ -129,11 +143,26 @@ char *dp; if (lbeg >= lend) continue; i = lend + .5; /* visit cells on this scan */ - for (gc.i[0] = lbeg + .5; gc.i[0] < i; gc.i[0]++) + for (gc.i[0] = lbeg + .5; gc.i[0] < i; gc.i[0]++) { n += (*vf)(&gc, dp); + ncalls++; + } } } - return(n); + if (ncalls) /* got one at least */ + return(n); + /* else find closest cell */ + VSUM(ld, pyrd[0], pyrd[1], 1.); + VSUM(ld, ld, pyrd[2], 1.); + VSUM(ld, ld, pyrd[3], 1.); +#if 0 + if (normalize(ld) == 0.0) /* technically not necessary */ + return(0); +#endif + d = hdinter(gc2, NULL, &t, hp, orig, ld); + if (d >= FHUGE || t <= 0.) + return(0); + return((*vf)(gc2+1, dp)); /* visit it */ } @@ -257,4 +286,55 @@ VIEW *vp; return(cl.cl); memerr: error(SYSTEM, "out of memory in getviewcells"); +} + + +gridlines(f) /* run through holodeck section grid lines */ +int (*f)(); +{ + register int hd, w, i; + int g0, g1; + FVECT wp[2], mov; + double d; + /* do each wall on each section */ + for (hd = 0; hdlist[hd] != NULL; hd++) + for (w = 0; w < 6; w++) { + g0 = hdwg0[w]; + g1 = hdwg1[w]; + d = 1.0/hdlist[hd]->grid[g0]; + mov[0] = d * hdlist[hd]->xv[g0][0]; + mov[1] = d * hdlist[hd]->xv[g0][1]; + mov[2] = d * hdlist[hd]->xv[g0][2]; + if (w & 1) { + VSUM(wp[0], hdlist[hd]->orig, + hdlist[hd]->xv[w>>1], 1.); + VSUM(wp[0], wp[0], mov, 1.); + } else + VCOPY(wp[0], hdlist[hd]->orig); + VSUM(wp[1], wp[0], hdlist[hd]->xv[g1], 1.); + for (i = hdlist[hd]->grid[g0]; ; ) { /* g0 lines */ + (*f)(wp); + if (!--i) break; + wp[0][0] += mov[0]; wp[0][1] += mov[1]; + wp[0][2] += mov[2]; wp[1][0] += mov[0]; + wp[1][1] += mov[1]; wp[1][2] += mov[2]; + } + d = 1.0/hdlist[hd]->grid[g1]; + mov[0] = d * hdlist[hd]->xv[g1][0]; + mov[1] = d * hdlist[hd]->xv[g1][1]; + mov[2] = d * hdlist[hd]->xv[g1][2]; + if (w & 1) + VSUM(wp[0], hdlist[hd]->orig, + hdlist[hd]->xv[w>>1], 1.); + else + VSUM(wp[0], hdlist[hd]->orig, mov, 1.); + VSUM(wp[1], wp[0], hdlist[hd]->xv[g0], 1.); + for (i = hdlist[hd]->grid[g1]; ; ) { /* g1 lines */ + (*f)(wp); + if (!--i) break; + wp[0][0] += mov[0]; wp[0][1] += mov[1]; + wp[0][2] += mov[2]; wp[1][0] += mov[0]; + wp[1][1] += mov[1]; wp[1][2] += mov[2]; + } + } }