| /*************************************************************************/ |
| /* */ |
| /* Copyright (c) 1994 Stanford University */ |
| /* */ |
| /* All rights reserved. */ |
| /* */ |
| /* Permission is given to use, copy, and modify this software for any */ |
| /* non-commercial purpose as long as this copyright notice is not */ |
| /* removed. All other uses, including redistribution in whole or in */ |
| /* part, are forbidden without prior written permission. */ |
| /* */ |
| /* This software is provided with absolutely no warranty and no */ |
| /* support. */ |
| /* */ |
| /*************************************************************************/ |
| |
| |
| /* |
| * NAME |
| * poly.c |
| * |
| * DESCRIPTION |
| * This file contains all routines that operate on polygon objects. |
| * |
| */ |
| |
| |
| #include <stdio.h> |
| #include <math.h> |
| #include "rt.h" |
| |
| |
| /* |
| * Define polygon data structure. |
| */ |
| |
| typedef struct poly |
| { |
| INT nverts; /* Number of vertices in polygon. */ |
| VEC3 norm; /* Face normal. */ |
| REAL d; /* Plane eqn D. */ |
| VEC3 *vptr; /* Global vertex list pointer. */ |
| INT *vindex; /* Index of vertices. */ |
| INT axis_proj; /* Best axis for projection. */ |
| } |
| POLY; |
| |
| |
| |
| /* |
| * NAME |
| * PolyName - return the object name |
| * |
| * SYNOPSIS |
| * CHAR *PolyName() |
| * |
| * RETURNS |
| * A pointer to the name string. |
| */ |
| |
| CHAR *PolyName() |
| { |
| return ("poly"); |
| } |
| |
| |
| |
| /* |
| * NAME |
| * PolyPrint - print the polygon object data to stdout |
| * |
| * SYNOPSIS |
| * VOID PolyPrint(po) |
| * OBJECT *po; // Ptr to polygon object. |
| * |
| * RETURNS |
| * Nothing. |
| */ |
| |
| VOID PolyPrint(po) |
| OBJECT *po; |
| { |
| INT i, j; |
| INT *vindex; /* Ptr to vertex index. */ |
| VEC3 *vlist, *vptr; /* Ptr to vertex list. */ |
| POLY *pp; /* Ptr to polygon data. */ |
| ELEMENT *pe; /* Ptr to polygon element. */ |
| |
| pe = po->pelem; |
| fprintf(stderr, "\tpolygon: %ld polygons.\n", po->numelements); |
| |
| for (i = 0; i < po->numelements; i++) |
| { |
| pp = (POLY *)pe->data; |
| |
| fprintf(stderr, "\t\tVertices: %ld Plane eq: %f %f %f %f\n", pp->nverts, pp->norm[0], pp->norm[1], pp->norm[2], pp->d); |
| |
| vlist = pp->vptr; |
| vindex = pp->vindex; |
| |
| for (j = 0; j < pp->nverts; j++) |
| { |
| vptr = vlist + (*vindex); |
| fprintf(stderr, "\t\t%f %f %f \n", (*vptr)[0], (*vptr)[1], (*vptr)[2]); |
| vindex++; |
| } |
| |
| pe++; |
| } |
| } |
| |
| |
| |
| /* |
| * NAME |
| * PolyElementBoundBox - compute polygon element bounding box |
| * |
| * SYNOPSIS |
| * VOID PolyElementBoundBox(pe, pp) |
| * ELEMENT *pe; // Ptr to polygon element. |
| * POLY *pp; // Ptr to polygon data. |
| * |
| * RETURNS |
| * Nothing. |
| */ |
| |
| VOID PolyElementBoundBox(pe, pp) |
| ELEMENT *pe; |
| POLY *pp; |
| { |
| INT i; /* Index. */ |
| INT *vindex; /* Vertex index pointer. */ |
| BBOX *pbb; /* Ptr to bounding box. */ |
| VEC3 *vlist, *vptr; /* Vertex list pointer. */ |
| REAL minx, maxx; |
| REAL miny, maxy; |
| REAL minz, maxz; |
| |
| pbb = &(pe->bv); |
| |
| minx = miny = minz = HUGE_REAL; |
| maxx = maxy = maxz = -HUGE_REAL; |
| |
| vlist = pp->vptr; |
| vindex = pp->vindex; |
| |
| for (i = 0; i < pp->nverts; i++) |
| { |
| vptr = vlist + (*vindex); |
| |
| minx = Min(minx, (*vptr)[0]); |
| miny = Min(miny, (*vptr)[1]); |
| minz = Min(minz, (*vptr)[2]); |
| |
| maxx = Max(maxx, (*vptr)[0]); |
| maxy = Max(maxy, (*vptr)[1]); |
| maxz = Max(maxz, (*vptr)[2]); |
| |
| vindex++; |
| } |
| |
| pbb->dnear[0] = minx; |
| pbb->dnear[1] = miny; |
| pbb->dnear[2] = minz; |
| |
| pbb->dfar[0] = maxx; |
| pbb->dfar[1] = maxy; |
| pbb->dfar[2] = maxz; |
| } |
| |
| |
| |
| /* |
| * NAME |
| * PolyBoundBox - compute polygon object bounding box |
| * |
| * SYNOPSIS |
| * VOID PolyBoundBox(po) |
| * OBJECT *po; // Ptr to polygon object. |
| * |
| * RETURNS |
| * Nothing. |
| */ |
| |
| VOID PolyBoundBox(po) |
| OBJECT *po; |
| { |
| INT i; |
| POLY *pp; /* Ptr to polygon data. */ |
| ELEMENT *pe; /* Ptr to polygon element. */ |
| BBOX *pbb; /* Ptr to bounding box. */ |
| REAL minx, maxx; |
| REAL miny, maxy; |
| REAL minz, maxz; |
| |
| pe = po->pelem; |
| pbb = &(po->bv); |
| |
| minx = miny = minz = HUGE_REAL; |
| maxx = maxy = maxz = -HUGE_REAL; |
| |
| for (i = 0; i < po->numelements; i++) |
| { |
| pp = (POLY *)pe->data; |
| PolyElementBoundBox(pe, pp); |
| |
| minx = Min(minx, pe->bv.dnear[0]); |
| miny = Min(miny, pe->bv.dnear[1]); |
| minz = Min(minz, pe->bv.dnear[2]); |
| |
| maxx = Max(maxx, pe->bv.dfar[0]); |
| maxy = Max(maxy, pe->bv.dfar[1]); |
| maxz = Max(maxz, pe->bv.dfar[2]); |
| |
| pe++; |
| } |
| |
| pbb->dnear[0] = minx; |
| pbb->dnear[1] = miny; |
| pbb->dnear[2] = minz; |
| |
| pbb->dfar[0] = maxx; |
| pbb->dfar[1] = maxy; |
| pbb->dfar[2] = maxz; |
| } |
| |
| |
| |
| /* |
| * NAME |
| * PolyNormal - compute polygon unit normal at given point on the surface |
| * |
| * SYNOPSIS |
| * VOID PolyNormal(hit, Pi, Ni) |
| * IRECORD *hit; // Ptr to intersection record. |
| * POINT Pi; // Ipoint. |
| * POINT Ni; // Normal. |
| * |
| * NOTES |
| * If no normal interpolation, the normal is the face normal. Otherwise, |
| * interpolate with the normal plane equation. |
| * |
| * RETURNS |
| * Nothing. |
| */ |
| |
| VOID PolyNormal(hit, Pi, Ni) |
| IRECORD *hit; |
| POINT Pi; |
| POINT Ni; |
| { |
| ELEMENT *pe; |
| POLY *pp; |
| |
| /* Retrieve normal from hit polygon. */ |
| |
| pe = hit->pelem; |
| pp = (POLY *)pe->data; |
| VecCopy(Ni, pp->norm); |
| } |
| |
| |
| |
| /* |
| * NAME |
| * PolyDataNormalize - normalize polygon data and bounding box |
| * |
| * SYNOPSIS |
| * VOID PolyDataNormalize(po, normMat) |
| * OBJECT *po; // Ptr to polygon object. |
| * MATRIX normMat; // Normalization matrix. |
| * |
| * RETURNS |
| * Nothing. |
| */ |
| |
| VOID PolyDataNormalize(po, normMat) |
| OBJECT *po; |
| MATRIX normMat; |
| { |
| INT i; |
| POINT coord; |
| VEC3 *pv; /* Ptr to vertex list. */ |
| POLY *pp; /* Ptr to polygon data. */ |
| ELEMENT *pe; /* Ptr to polygon element. */ |
| |
| |
| /* Normalize bounding box. */ |
| |
| pe = po->pelem; |
| NormalizeBoundBox(&po->bv, normMat); |
| |
| |
| /* Normalize vertex list. */ |
| |
| pp = (POLY *)pe->data; |
| pv = pp->vptr; |
| |
| coord[0] = (*pv)[0]; |
| coord[1] = (*pv)[1]; |
| coord[2] = (*pv)[2]; |
| coord[3] = 1.0; |
| |
| |
| /* Transform coordinate by xform matrix. */ |
| |
| while (coord[0] != HUGE_REAL && coord[1] != HUGE_REAL && coord[2] != HUGE_REAL) |
| { |
| VecMatMult(coord, normMat, coord); |
| |
| (*pv)[0] = coord[0]; |
| (*pv)[1] = coord[1]; |
| (*pv)[2] = coord[2]; |
| |
| pv++; |
| |
| coord[0] = (*pv)[0]; |
| coord[1] = (*pv)[1]; |
| coord[2] = (*pv)[2]; |
| coord[3] = 1.0; |
| } |
| |
| |
| /* Normalize bounding boxes of object elements. */ |
| |
| for (i = 0; i < po->numelements; i++) |
| { |
| pp = (POLY *)pe->data; |
| NormalizeBoundBox(&pe->bv, normMat); |
| |
| /* Find new d of plane equation. */ |
| |
| pv = pp->vptr + (*(pp->vindex)); |
| pp->d = -(pp->norm[0]*(*pv)[0] + pp->norm[1]*(*pv)[1] + pp->norm[2]*(*pv)[2]); |
| |
| pe++; |
| } |
| } |
| |
| |
| |
| /* |
| * NAME |
| * PolyPeIntersect - calculate intersection of ray with polygon |
| * |
| * SYNOPSIS |
| * INT PolyPeIntersect(pr, pe, hit) |
| * RAY *pr; // Ptr to incident ray. |
| * ELEMENT *pe; // Polyangle object |
| * IRECORD *hit; // Intersection record. |
| * |
| * NOTES |
| * Check first to see if ray is parallel to plane or if the intersection |
| * point with the plane is behind the eye. |
| * |
| * If neither of these cases applies, determine if the intersection point |
| * is contained in the polygon. First, project onto a plane. Translate |
| * the intersection point to the origin. If a ray starting from the |
| * origin along the 2 - d X axis of the plane crosses an odd number of |
| * polygon edges, the point is in the polygon. |
| * |
| * RETURNS |
| * The number of intersection points. |
| */ |
| |
| INT PolyPeIntersect(pr, pe, hit) |
| RAY *pr; |
| ELEMENT *pe; |
| IRECORD *hit; |
| { |
| INT i; |
| INT *vindex; /* Vertex index pointer. */ |
| INT toright; /* Counter. */ |
| INT sh, nsh; /* Sign holders. */ |
| REAL tmp; |
| REAL Rd_dot_Pn; /* Polygon normal dot ray direction. */ |
| REAL Ro_dot_Pn; /* Polygon normal dot ray origin. */ |
| REAL q1, q2; |
| REAL tval; /* Intersection t distance value. */ |
| REAL x[MAX_VERTS + 1]; /* Projection list. */ |
| REAL y[MAX_VERTS + 1]; /* Projection list. */ |
| REAL ix, iy; /* Intersection projection point. */ |
| REAL dx, dy; /* Deltas between 2 vertices. */ |
| REAL xint; /* Intersection value. */ |
| VEC3 I; /* Intersection point. */ |
| VEC3 *vlist, *vpos; /* Vertex list pointer. */ |
| VEC3 *v1, *v2, *v3; /* Vertex list pointers. */ |
| POLY *pp; /* Ptr to polygon data. */ |
| |
| pp = (POLY *)pe->data; |
| |
| Rd_dot_Pn = VecDot(pp->norm, pr->D); |
| |
| if (ABS(Rd_dot_Pn) < RAYEPS) /* Ray is parallel. */ |
| return (0); |
| |
| Ro_dot_Pn = VecDot(pp->norm, pr->P); |
| |
| tval = -(pp->d + Ro_dot_Pn)/Rd_dot_Pn; /* Intersection distance. */ |
| if (tval < RAYEPS) /* Intersects behind ray. */ |
| return (0); |
| |
| RayPoint(I, pr, tval); |
| |
| |
| /* Polygon containment. */ |
| |
| /* Project onto plane with greatest normal component. */ |
| |
| vlist = pp->vptr; |
| vindex = pp->vindex; |
| |
| switch (pp->axis_proj) |
| { |
| case X_AXIS: |
| for (i = 0; i < pp->nverts; i++) |
| { |
| vpos = vlist + (*vindex); |
| x[i] = (*vpos)[1]; |
| y[i] = (*vpos)[2]; |
| vindex++; |
| } |
| |
| ix = I[1]; |
| iy = I[2]; |
| break; |
| |
| case Y_AXIS: |
| for (i = 0; i < pp->nverts; i++) |
| { |
| vpos = vlist + (*vindex); |
| x[i] = (*vpos)[0]; |
| y[i] = (*vpos)[2]; |
| vindex++; |
| } |
| |
| ix = I[0]; |
| iy = I[2]; |
| break; |
| |
| case Z_AXIS: |
| for (i = 0; i < pp->nverts; i++) |
| { |
| vpos = vlist + (*vindex); |
| x[i] = (*vpos)[0]; |
| y[i] = (*vpos)[1]; |
| vindex++; |
| } |
| |
| ix = I[0]; |
| iy = I[1]; |
| break; |
| } |
| |
| |
| /* Translate to origin. */ |
| |
| for (i = 0; i < pp->nverts; i++) |
| { |
| x[i] -= ix; |
| y[i] -= iy; |
| |
| if (ABS(y[i]) < RAYEPS) |
| y[i] = 0.0; |
| } |
| |
| x[pp->nverts] = x[0]; |
| y[pp->nverts] = y[0]; |
| |
| |
| /* |
| * If intersection point crosses an odd number of line segments, |
| * the point is inside the polygon |
| */ |
| |
| |
| if (y[0] < 0.0) |
| sh = 0; |
| else |
| sh = 1; |
| |
| toright = 0; |
| |
| for (i = 0; i < pp->nverts; i++) |
| { |
| /* Check if segment crosses in y. */ |
| |
| if (y[i + 1] < 0.0) |
| nsh = 0; |
| else |
| nsh = 1; |
| |
| if (nsh ^ sh) |
| { |
| dy = y[i + 1] - y[i]; |
| |
| if (ABS(dy) >= RAYEPS) |
| { |
| dx = x[i + 1] - x[i]; |
| xint = x[i] - y[i]*dx / dy; |
| |
| if (xint > 0.0) |
| toright++; |
| } |
| } |
| |
| sh = nsh; |
| } |
| |
| if (toright%2 == 1) |
| { |
| IsectAdd(hit, tval, pe); |
| return (1); |
| } |
| else |
| return (0); |
| } |
| |
| |
| |
| /* |
| * NAME |
| * PolyIntersect - call polygon object intersection routine |
| * |
| * SYNOPSIS |
| * INT PolyIntersect(pr, po, hit) |
| * RAY *pr; // Ptr to incident ray. |
| * OBJECT *po; // Ptr to polygon object. |
| * IRECORD *hit; // Intersection record. |
| * |
| * RETURNS |
| * The number of intersections found. |
| */ |
| |
| INT PolyIntersect(pr, po, hit) |
| RAY *pr; |
| OBJECT *po; |
| IRECORD *hit; |
| { |
| INT i; |
| INT nhits; /* # hits in polyhedra. */ |
| ELEMENT *pe; /* Ptr to polygon element. */ |
| IRECORD newhit; /* Hit list. */ |
| |
| /* Traverse polygon list to find intersections. */ |
| |
| nhits = 0; |
| pe = po->pelem; |
| hit[0].t = HUGE_REAL; |
| |
| for (i = 0; i < po->numelements; i++) |
| { |
| if (PolyPeIntersect(pr, pe, &newhit)) |
| { |
| nhits++; |
| if (newhit.t < hit[0].t) |
| { |
| hit[0].t = newhit.t; |
| hit[0].pelem = newhit.pelem; |
| } |
| } |
| |
| pe++; |
| } |
| |
| return (nhits); |
| } |
| |
| |
| |
| /* |
| * NAME |
| * PolyTransform - transform polygon object by a transformation matrix |
| * |
| * SYNOPSIS |
| * VOID PolyTransform(po, xtrans, xinvT) |
| * OBJECT *po; // Ptr to polygon object. |
| * MATRIX xtrans; // Transformation matrix. |
| * MATRIX xinvT; // Transpose of inverse matrix. |
| * |
| * NOTES |
| * Routine must: |
| * - transform face normals |
| * - transform vertices |
| * - calculate plane equation d variables |
| * |
| * RETURNS |
| * Nothing. |
| */ |
| |
| VOID PolyTransform(po, xtrans, xinvT) |
| OBJECT *po; |
| MATRIX xtrans; |
| MATRIX xinvT; |
| { |
| INT i, j; /* Indices. */ |
| INT numelems; /* # of elements. */ |
| INT *vindex; /* Vertex index pointer. */ |
| VEC3 *vptr, *vp; /* Vertex list pointers. */ |
| VEC4 norm, coord; /* Transform 4 vectors. */ |
| POLY *pp; /* Ptr to polygon data. */ |
| ELEMENT *pe; /* Ptr to polygon element. */ |
| |
| |
| pe = po->pelem; |
| numelems = po->numelements; |
| |
| /* Get vertex list address and transform vertices. */ |
| |
| pp = (POLY *)pe->data; |
| vptr = pp->vptr; |
| |
| coord[0] = (*vptr)[0]; |
| coord[1] = (*vptr)[1]; |
| coord[2] = (*vptr)[2]; |
| coord[3] = 1.0; |
| |
| while (coord[0] != HUGE_REAL && coord[1] != HUGE_REAL && coord[2] != HUGE_REAL) |
| { |
| /* Transform coordinate by xform matrix. */ |
| |
| VecMatMult(coord, xtrans, coord); |
| |
| (*vptr)[0] = coord[0]; |
| (*vptr)[1] = coord[1]; |
| (*vptr)[2] = coord[2]; |
| |
| vptr++; |
| |
| coord[0] = (*vptr)[0]; |
| coord[1] = (*vptr)[1]; |
| coord[2] = (*vptr)[2]; |
| coord[3] = 1.0; |
| } |
| |
| |
| /* Transform polygon list. */ |
| |
| for (i = 0; i < numelems; i++) |
| { |
| pp = (POLY *)pe->data; |
| |
| /* Transform face normal by view matrix inverse. */ |
| |
| norm[0] = pp->norm[0]; |
| norm[1] = pp->norm[1]; |
| norm[2] = pp->norm[2]; |
| norm[3] = 0.0; |
| |
| VecMatMult(norm, xinvT, norm); |
| VecNorm(norm); |
| |
| pp->norm[0] = norm[0]; |
| pp->norm[1] = norm[1]; |
| pp->norm[2] = norm[2]; |
| |
| |
| /* Calculate plane equation variable d. */ |
| |
| vp = pp->vptr + *(pp->vindex); |
| pp->d = -(pp->norm[0]*(*vp)[0] + pp->norm[1]*(*vp)[1] + pp->norm[2]*(*vp)[2]); |
| |
| |
| /* Set best axis projection. */ |
| |
| norm[0] = ABS(pp->norm[0]); |
| norm[1] = ABS(pp->norm[1]); |
| norm[2] = ABS(pp->norm[2]); |
| |
| if (norm[0] >= norm[1] && norm[0] >= norm[2]) |
| pp->axis_proj = X_AXIS; |
| else |
| if (norm[1] >= norm[0] && norm[1] >= norm[2]) |
| pp->axis_proj = Y_AXIS; |
| else |
| pp->axis_proj = Z_AXIS; |
| |
| pe++; |
| } |
| } |
| |
| |
| |
| /* |
| * NAME |
| * PolyRead - read polygon object data from file |
| * |
| * SYNOPSIS |
| * VOID PolyRead(po, pf) |
| * OBJECT *po; // Ptr to polygon object. |
| * FILE *pf; // Ptr to file. |
| * |
| * RETURNS |
| * Nothing. |
| */ |
| |
| VOID PolyRead(po, pf) |
| OBJECT *po; |
| FILE *pf; |
| { |
| INT i, j; /* Indices. */ |
| INT instat; /* Read status. */ |
| INT *vindex; |
| INT totalverts; /* Total # of vertices in poly mesh. */ |
| CHAR normstr[5]; /* Face/vertex normal flag string. */ |
| BOOL pnormals; /* Face normals present? */ |
| BOOL vnormals; /* Vertex normals present? */ |
| VEC3 pnorm; /* Polygon normal accumulator. */ |
| VEC3 *vlist, *vptr, *vp; /* Ptr to vertex list. */ |
| VEC3 *vptmp, *vptmp2; /* Ptr to vertex list. */ |
| VEC3 tmppnt, tmppnt2, cross; |
| POLY *pp; /* Ptr to polygon data. */ |
| ELEMENT *pe; /* Ptr to polygon element. */ |
| |
| |
| pe = po->pelem; |
| |
| /* Allocate space for object data. */ |
| |
| instat = fscanf(pf, "%ld", &totalverts); |
| |
| if (instat != 1) |
| { |
| printf("Error in PolyRead: totalverts.\n"); |
| exit(-1); |
| } |
| |
| pp = GlobalMalloc(sizeof(POLY)*po->numelements, "poly.c"); |
| vlist = GlobalMalloc(sizeof(VEC3)*(totalverts + 1), "poly.c"); |
| vptr = vlist; |
| |
| |
| /* Are polygon face normals supplied? */ |
| |
| instat = fscanf(pf, "%s\n", normstr); |
| |
| if (instat != 1) |
| { |
| printf("Error in PolyRead: face normal indicator.\n"); |
| exit(-1); |
| } |
| |
| pnormals = (normstr[2] == 'y' ? TRUE : FALSE); |
| |
| |
| /* Read vertex list. */ |
| |
| for (i = 0; i < totalverts; i++) |
| { |
| instat = fscanf(pf, "%lf %lf %lf", &(*vptr)[0], &(*vptr)[1], &(*vptr)[2]); |
| |
| if (instat != 3) |
| { |
| printf("Error in PolyRead: vertex %ld.\n", i); |
| exit(-1); |
| } |
| |
| vptr++; |
| } |
| |
| |
| (*vptr)[0] = HUGE_REAL; |
| (*vptr)[1] = HUGE_REAL; |
| (*vptr)[2] = HUGE_REAL; |
| |
| |
| /* Read polygon list. */ |
| |
| for (i = 0; i < po->numelements; i++) |
| { |
| instat = fscanf(pf, "%ld", &(pp->nverts)); |
| |
| if (instat != 1) |
| { |
| printf("Error in PolyRead: vertex count.\n"); |
| exit(-1); |
| } |
| |
| if (pp->nverts > MAX_VERTS) |
| { |
| printf("Polygon vertex count, %ld, exceeds maximum.\n", pp->nverts); |
| exit(-1); |
| } |
| |
| if (pnormals) |
| { |
| instat = fscanf(pf, " %lf %lf %lf", &(pp->norm[0]), &(pp->norm[1]), &(pp->norm[2])); |
| |
| if (instat != 3) |
| { |
| printf("Error in PolyRead: face normal %ld.\n", i); |
| exit(-1); |
| } |
| } |
| |
| pp->vptr = vlist; |
| pp->vindex = GlobalMalloc(sizeof(INT)*pp->nverts, "poly.c"); |
| vindex = pp->vindex; |
| |
| for (j = 0; j < pp->nverts; j++) |
| { |
| instat = fscanf(pf, "%ld", vindex++); |
| |
| if (instat != 1) |
| { |
| printf("Error in PolyRead: vertex index %ld.\n", i); |
| exit(-1); |
| } |
| } |
| |
| /* If not supplied, calculate plane normal. */ |
| |
| vindex = pp->vindex; |
| vptr = vlist; |
| |
| if (!pnormals) |
| { |
| vp = vptr + (*vindex); |
| VecZero(pnorm); |
| |
| for (j = 0; j < pp->nverts - 2; j++) |
| { |
| vptmp = vptr + (*(vindex + 1)); |
| vptmp2 = vptr + (*(vindex + 2)); |
| |
| VecSub(tmppnt, (*vptmp), (*vp)); |
| VecSub(tmppnt2, (*vptmp2), (*vptmp)); |
| |
| VecCross(cross, tmppnt, tmppnt2); |
| VecAdd(pnorm, pnorm, cross); |
| |
| vp = vptmp; |
| vindex += 1; |
| } |
| |
| VecSub(tmppnt, (*vptmp2), (*vp)); |
| vindex = pp->vindex; |
| vp = vptr + (*vindex); |
| |
| VecSub(tmppnt2, (*vp), (*vptmp2)); |
| VecCross(cross, tmppnt, tmppnt2); |
| VecAdd(pnorm, pnorm, cross); |
| |
| vp = vptr + (*vindex); |
| VecSub(tmppnt, (*vp), (*vptmp2)); |
| vptmp = vptr + (*(vindex + 1)); |
| |
| VecSub(tmppnt2, (*vptmp), (*vp)); |
| VecCross(cross, tmppnt, tmppnt2); |
| VecAdd(pnorm, pnorm, cross); |
| VecScale(pp->norm, 1.0/VecLen(pnorm), pnorm); |
| } |
| |
| |
| /* Calculate plane equation d. */ |
| |
| vp = pp->vptr + *(pp->vindex); |
| pp->d = -(pp->norm[0]*(*vp)[0] + pp->norm[1]*(*vp)[1] + pp->norm[2]*(*vp)[2]); |
| |
| pe->data = (CHAR *)pp; |
| pe->parent = po; |
| |
| PolyElementBoundBox(pe, pp); |
| |
| pp++; |
| pe++; |
| } |
| } |
| |