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/* Copyright (c) 1998 Silicon Graphics, Inc. */ |
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|
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#ifndef lint |
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static char SCCSid[] = "$SunId$ SGI"; |
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#endif |
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|
7 |
/* |
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* sm_geom.c |
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*/ |
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|
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#include "standard.h" |
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#include "sm_geom.h" |
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|
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tri_centroid(v0,v1,v2,c) |
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FVECT v0,v1,v2,c; |
16 |
{ |
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/* Average three triangle vertices to give centroid: return in c */ |
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c[0] = (v0[0] + v1[0] + v2[0])/3.0; |
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c[1] = (v0[1] + v1[1] + v2[1])/3.0; |
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c[2] = (v0[2] + v1[2] + v2[2])/3.0; |
21 |
} |
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|
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|
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int |
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vec3_equal(v1,v2) |
26 |
FVECT v1,v2; |
27 |
{ |
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return(EQUAL(v1[0],v2[0]) && EQUAL(v1[1],v2[1])&& EQUAL(v1[2],v2[2])); |
29 |
} |
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#if 0 |
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extern FVECT Norm[500]; |
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extern int Ncnt; |
33 |
#endif |
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|
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int |
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convex_angle(v0,v1,v2) |
37 |
FVECT v0,v1,v2; |
38 |
{ |
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double dp,dp1; |
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int test,test1; |
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FVECT nv0,nv1,nv2; |
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FVECT cp01,cp12,cp; |
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|
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/* test sign of (v0Xv1)X(v1Xv2). v1 */ |
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/* un-Simplified: */ |
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VCOPY(nv0,v0); |
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normalize(nv0); |
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VCOPY(nv1,v1); |
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normalize(nv1); |
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VCOPY(nv2,v2); |
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normalize(nv2); |
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|
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VCROSS(cp01,nv0,nv1); |
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VCROSS(cp12,nv1,nv2); |
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VCROSS(cp,cp01,cp12); |
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normalize(cp); |
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dp1 = DOT(cp,nv1); |
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if(dp1 <= 1e-8 || dp1 >= (1-1e-8)) /* Test if on other side,or colinear*/ |
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test1 = FALSE; |
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else |
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test1 = TRUE; |
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|
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dp = nv0[2]*nv1[0]*nv2[1] - nv0[2]*nv1[1]*nv2[0] - nv0[0]*nv1[2]*nv2[1] |
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+ nv0[0]*nv1[1]*nv2[2] + nv0[1]*nv1[2]*nv2[0] - nv0[1]*nv1[0]*nv2[2]; |
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|
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if(dp <= 1e-8 || dp1 >= (1-1e-8)) |
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test = FALSE; |
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else |
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test = TRUE; |
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|
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if(test != test1) |
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fprintf(stderr,"test %f simplified %f\n",dp1,dp); |
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return(test1); |
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} |
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|
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/* calculates the normal of a face contour using Newell's formula. e |
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|
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a = SUMi (yi - yi+1)(zi + zi+1); |
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b = SUMi (zi - zi+1)(xi + xi+1) |
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c = SUMi (xi - xi+1)(yi + yi+1) |
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*/ |
82 |
double |
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tri_normal(v0,v1,v2,n,norm) |
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FVECT v0,v1,v2,n; |
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int norm; |
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{ |
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double mag; |
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|
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n[0] = (v0[2] + v1[2]) * (v0[1] - v1[1]) + |
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(v1[2] + v2[2]) * (v1[1] - v2[1]) + |
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(v2[2] + v0[2]) * (v2[1] - v0[1]); |
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|
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n[1] = (v0[2] - v1[2]) * (v0[0] + v1[0]) + |
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(v1[2] - v2[2]) * (v1[0] + v2[0]) + |
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(v2[2] - v0[2]) * (v2[0] + v0[0]); |
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|
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n[2] = (v0[1] + v1[1]) * (v0[0] - v1[0]) + |
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(v1[1] + v2[1]) * (v1[0] - v2[0]) + |
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(v2[1] + v0[1]) * (v2[0] - v0[0]); |
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|
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if(!norm) |
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return(0); |
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|
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mag = normalize(n); |
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|
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return(mag); |
107 |
} |
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|
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|
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tri_plane_equation(v0,v1,v2,peqptr,norm) |
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FVECT v0,v1,v2; |
112 |
FPEQ *peqptr; |
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int norm; |
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{ |
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tri_normal(v0,v1,v2,FP_N(*peqptr),norm); |
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|
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FP_D(*peqptr) = -(DOT(FP_N(*peqptr),v0)); |
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} |
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|
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|
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/* returns TRUE if ray from origin in direction v intersects plane defined |
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* by normal plane_n, and plane_d. If plane is not parallel- returns |
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* intersection point if r != NULL. If tptr!= NULL returns value of |
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* t, if parallel, returns t=FHUGE |
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*/ |
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int |
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intersect_vector_plane(v,peq,tptr,r) |
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FVECT v; |
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FPEQ peq; |
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double *tptr; |
131 |
FVECT r; |
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{ |
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double t,d; |
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int hit; |
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/* |
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Plane is Ax + By + Cz +D = 0: |
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plane[0] = A,plane[1] = B,plane[2] = C,plane[3] = D |
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*/ |
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|
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/* line is l = p1 + (p2-p1)t, p1=origin */ |
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|
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/* Solve for t: */ |
143 |
d = -(DOT(FP_N(peq),v)); |
144 |
if(ZERO(d)) |
145 |
{ |
146 |
t = FHUGE; |
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hit = 0; |
148 |
} |
149 |
else |
150 |
{ |
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t = FP_D(peq)/d; |
152 |
if(t < 0 ) |
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hit = 0; |
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else |
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hit = 1; |
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if(r) |
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{ |
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r[0] = v[0]*t; |
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r[1] = v[1]*t; |
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r[2] = v[2]*t; |
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} |
162 |
} |
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if(tptr) |
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*tptr = t; |
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return(hit); |
166 |
} |
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|
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int |
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intersect_ray_plane(orig,dir,peq,pd,r) |
170 |
FVECT orig,dir; |
171 |
FPEQ peq; |
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double *pd; |
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FVECT r; |
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{ |
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double t,d; |
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int hit; |
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/* |
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Plane is Ax + By + Cz +D = 0: |
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plane[0] = A,plane[1] = B,plane[2] = C,plane[3] = D |
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*/ |
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/* A(orig[0] + dxt) + B(orig[1] + dyt) + C(orig[2] + dzt) + pd = 0 |
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t = -(DOT(plane_n,orig)+ plane_d)/(DOT(plane_n,d)) |
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line is l = p1 + (p2-p1)t |
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*/ |
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/* Solve for t: */ |
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d = DOT(FP_N(peq),dir); |
187 |
if(ZERO(d)) |
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return(0); |
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t = -(DOT(FP_N(peq),orig) + FP_D(peq))/d; |
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|
191 |
if(t < 0) |
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hit = 0; |
193 |
else |
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hit = 1; |
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|
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if(r) |
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VSUM(r,orig,dir,t); |
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|
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if(pd) |
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*pd = t; |
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return(hit); |
202 |
} |
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|
204 |
|
205 |
int |
206 |
intersect_ray_oplane(orig,dir,n,pd,r) |
207 |
FVECT orig,dir; |
208 |
FVECT n; |
209 |
double *pd; |
210 |
FVECT r; |
211 |
{ |
212 |
double t,d; |
213 |
int hit; |
214 |
/* |
215 |
Plane is Ax + By + Cz +D = 0: |
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plane[0] = A,plane[1] = B,plane[2] = C,plane[3] = D |
217 |
*/ |
218 |
/* A(orig[0] + dxt) + B(orig[1] + dyt) + C(orig[2] + dzt) + pd = 0 |
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t = -(DOT(plane_n,orig)+ plane_d)/(DOT(plane_n,d)) |
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line is l = p1 + (p2-p1)t |
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*/ |
222 |
/* Solve for t: */ |
223 |
d= DOT(n,dir); |
224 |
if(ZERO(d)) |
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return(0); |
226 |
t = -(DOT(n,orig))/d; |
227 |
if(t < 0) |
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hit = 0; |
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else |
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hit = 1; |
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|
232 |
if(r) |
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VSUM(r,orig,dir,t); |
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|
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if(pd) |
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*pd = t; |
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return(hit); |
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} |
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|
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/* Assumption: know crosses plane:dont need to check for 'on' case */ |
241 |
intersect_edge_coord_plane(v0,v1,w,r) |
242 |
FVECT v0,v1; |
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int w; |
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FVECT r; |
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{ |
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FVECT dv; |
247 |
int wnext; |
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double t; |
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|
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VSUB(dv,v1,v0); |
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t = -v0[w]/dv[w]; |
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r[w] = 0.0; |
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wnext = (w+1)%3; |
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r[wnext] = v0[wnext] + dv[wnext]*t; |
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wnext = (w+2)%3; |
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r[wnext] = v0[wnext] + dv[wnext]*t; |
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} |
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|
259 |
int |
260 |
intersect_edge_plane(e0,e1,peq,pd,r) |
261 |
FVECT e0,e1; |
262 |
FPEQ peq; |
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double *pd; |
264 |
FVECT r; |
265 |
{ |
266 |
double t; |
267 |
int hit; |
268 |
FVECT d; |
269 |
/* |
270 |
Plane is Ax + By + Cz +D = 0: |
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plane[0] = A,plane[1] = B,plane[2] = C,plane[3] = D |
272 |
*/ |
273 |
/* A(orig[0] + dxt) + B(orig[1] + dyt) + C(orig[2] + dzt) + pd = 0 |
274 |
t = -(DOT(plane_n,orig)+ plane_d)/(DOT(plane_n,d)) |
275 |
line is l = p1 + (p2-p1)t |
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*/ |
277 |
/* Solve for t: */ |
278 |
VSUB(d,e1,e0); |
279 |
t = -(DOT(FP_N(peq),e0) + FP_D(peq))/(DOT(FP_N(peq),d)); |
280 |
if(t < 0) |
281 |
hit = 0; |
282 |
else |
283 |
hit = 1; |
284 |
|
285 |
VSUM(r,e0,d,t); |
286 |
|
287 |
if(pd) |
288 |
*pd = t; |
289 |
return(hit); |
290 |
} |
291 |
|
292 |
int |
293 |
point_set_in_stri(v0,v1,v2,p,n,nset,sides) |
294 |
FVECT v0,v1,v2,p; |
295 |
FVECT n[3]; |
296 |
int *nset; |
297 |
int sides[3]; |
298 |
|
299 |
{ |
300 |
double d; |
301 |
/* Find the normal to the triangle ORIGIN:v0:v1 */ |
302 |
if(!NTH_BIT(*nset,0)) |
303 |
{ |
304 |
VCROSS(n[0],v0,v1); |
305 |
SET_NTH_BIT(*nset,0); |
306 |
} |
307 |
/* Test the point for sidedness */ |
308 |
d = DOT(n[0],p); |
309 |
|
310 |
if(d > 0.0) |
311 |
{ |
312 |
sides[0] = GT_OUT; |
313 |
sides[1] = sides[2] = GT_INVALID; |
314 |
return(FALSE); |
315 |
} |
316 |
else |
317 |
sides[0] = GT_INTERIOR; |
318 |
|
319 |
/* Test next edge */ |
320 |
if(!NTH_BIT(*nset,1)) |
321 |
{ |
322 |
VCROSS(n[1],v1,v2); |
323 |
SET_NTH_BIT(*nset,1); |
324 |
} |
325 |
/* Test the point for sidedness */ |
326 |
d = DOT(n[1],p); |
327 |
if(d > 0.0) |
328 |
{ |
329 |
sides[1] = GT_OUT; |
330 |
sides[2] = GT_INVALID; |
331 |
return(FALSE); |
332 |
} |
333 |
else |
334 |
sides[1] = GT_INTERIOR; |
335 |
/* Test next edge */ |
336 |
if(!NTH_BIT(*nset,2)) |
337 |
{ |
338 |
VCROSS(n[2],v2,v0); |
339 |
SET_NTH_BIT(*nset,2); |
340 |
} |
341 |
/* Test the point for sidedness */ |
342 |
d = DOT(n[2],p); |
343 |
if(d > 0.0) |
344 |
{ |
345 |
sides[2] = GT_OUT; |
346 |
return(FALSE); |
347 |
} |
348 |
else |
349 |
sides[2] = GT_INTERIOR; |
350 |
/* Must be interior to the pyramid */ |
351 |
return(GT_INTERIOR); |
352 |
} |
353 |
|
354 |
|
355 |
|
356 |
set_sidedness_tests(t0,t1,t2,p0,p1,p2,test,sides,nset,n) |
357 |
FVECT t0,t1,t2,p0,p1,p2; |
358 |
int test[3]; |
359 |
int sides[3][3]; |
360 |
int nset; |
361 |
FVECT n[3]; |
362 |
{ |
363 |
int t; |
364 |
double d; |
365 |
|
366 |
|
367 |
/* p=0 */ |
368 |
test[0] = 0; |
369 |
if(sides[0][0] == GT_INVALID) |
370 |
{ |
371 |
if(!NTH_BIT(nset,0)) |
372 |
VCROSS(n[0],t0,t1); |
373 |
/* Test the point for sidedness */ |
374 |
d = DOT(n[0],p0); |
375 |
if(d >= 0.0) |
376 |
SET_NTH_BIT(test[0],0); |
377 |
} |
378 |
else |
379 |
if(sides[0][0] != GT_INTERIOR) |
380 |
SET_NTH_BIT(test[0],0); |
381 |
|
382 |
if(sides[0][1] == GT_INVALID) |
383 |
{ |
384 |
if(!NTH_BIT(nset,1)) |
385 |
VCROSS(n[1],t1,t2); |
386 |
/* Test the point for sidedness */ |
387 |
d = DOT(n[1],p0); |
388 |
if(d >= 0.0) |
389 |
SET_NTH_BIT(test[0],1); |
390 |
} |
391 |
else |
392 |
if(sides[0][1] != GT_INTERIOR) |
393 |
SET_NTH_BIT(test[0],1); |
394 |
|
395 |
if(sides[0][2] == GT_INVALID) |
396 |
{ |
397 |
if(!NTH_BIT(nset,2)) |
398 |
VCROSS(n[2],t2,t0); |
399 |
/* Test the point for sidedness */ |
400 |
d = DOT(n[2],p0); |
401 |
if(d >= 0.0) |
402 |
SET_NTH_BIT(test[0],2); |
403 |
} |
404 |
else |
405 |
if(sides[0][2] != GT_INTERIOR) |
406 |
SET_NTH_BIT(test[0],2); |
407 |
|
408 |
/* p=1 */ |
409 |
test[1] = 0; |
410 |
/* t=0*/ |
411 |
if(sides[1][0] == GT_INVALID) |
412 |
{ |
413 |
if(!NTH_BIT(nset,0)) |
414 |
VCROSS(n[0],t0,t1); |
415 |
/* Test the point for sidedness */ |
416 |
d = DOT(n[0],p1); |
417 |
if(d >= 0.0) |
418 |
SET_NTH_BIT(test[1],0); |
419 |
} |
420 |
else |
421 |
if(sides[1][0] != GT_INTERIOR) |
422 |
SET_NTH_BIT(test[1],0); |
423 |
|
424 |
/* t=1 */ |
425 |
if(sides[1][1] == GT_INVALID) |
426 |
{ |
427 |
if(!NTH_BIT(nset,1)) |
428 |
VCROSS(n[1],t1,t2); |
429 |
/* Test the point for sidedness */ |
430 |
d = DOT(n[1],p1); |
431 |
if(d >= 0.0) |
432 |
SET_NTH_BIT(test[1],1); |
433 |
} |
434 |
else |
435 |
if(sides[1][1] != GT_INTERIOR) |
436 |
SET_NTH_BIT(test[1],1); |
437 |
|
438 |
/* t=2 */ |
439 |
if(sides[1][2] == GT_INVALID) |
440 |
{ |
441 |
if(!NTH_BIT(nset,2)) |
442 |
VCROSS(n[2],t2,t0); |
443 |
/* Test the point for sidedness */ |
444 |
d = DOT(n[2],p1); |
445 |
if(d >= 0.0) |
446 |
SET_NTH_BIT(test[1],2); |
447 |
} |
448 |
else |
449 |
if(sides[1][2] != GT_INTERIOR) |
450 |
SET_NTH_BIT(test[1],2); |
451 |
|
452 |
/* p=2 */ |
453 |
test[2] = 0; |
454 |
/* t = 0 */ |
455 |
if(sides[2][0] == GT_INVALID) |
456 |
{ |
457 |
if(!NTH_BIT(nset,0)) |
458 |
VCROSS(n[0],t0,t1); |
459 |
/* Test the point for sidedness */ |
460 |
d = DOT(n[0],p2); |
461 |
if(d >= 0.0) |
462 |
SET_NTH_BIT(test[2],0); |
463 |
} |
464 |
else |
465 |
if(sides[2][0] != GT_INTERIOR) |
466 |
SET_NTH_BIT(test[2],0); |
467 |
/* t=1 */ |
468 |
if(sides[2][1] == GT_INVALID) |
469 |
{ |
470 |
if(!NTH_BIT(nset,1)) |
471 |
VCROSS(n[1],t1,t2); |
472 |
/* Test the point for sidedness */ |
473 |
d = DOT(n[1],p2); |
474 |
if(d >= 0.0) |
475 |
SET_NTH_BIT(test[2],1); |
476 |
} |
477 |
else |
478 |
if(sides[2][1] != GT_INTERIOR) |
479 |
SET_NTH_BIT(test[2],1); |
480 |
/* t=2 */ |
481 |
if(sides[2][2] == GT_INVALID) |
482 |
{ |
483 |
if(!NTH_BIT(nset,2)) |
484 |
VCROSS(n[2],t2,t0); |
485 |
/* Test the point for sidedness */ |
486 |
d = DOT(n[2],p2); |
487 |
if(d >= 0.0) |
488 |
SET_NTH_BIT(test[2],2); |
489 |
} |
490 |
else |
491 |
if(sides[2][2] != GT_INTERIOR) |
492 |
SET_NTH_BIT(test[2],2); |
493 |
} |
494 |
|
495 |
double |
496 |
point_on_sphere(ps,p,c) |
497 |
FVECT ps,p,c; |
498 |
{ |
499 |
double d; |
500 |
VSUB(ps,p,c); |
501 |
d= normalize(ps); |
502 |
return(d); |
503 |
} |
504 |
|
505 |
int |
506 |
point_in_stri(v0,v1,v2,p) |
507 |
FVECT v0,v1,v2,p; |
508 |
{ |
509 |
double d; |
510 |
FVECT n; |
511 |
|
512 |
VCROSS(n,v0,v1); |
513 |
/* Test the point for sidedness */ |
514 |
d = DOT(n,p); |
515 |
if(d > 0.0) |
516 |
return(FALSE); |
517 |
|
518 |
/* Test next edge */ |
519 |
VCROSS(n,v1,v2); |
520 |
/* Test the point for sidedness */ |
521 |
d = DOT(n,p); |
522 |
if(d > 0.0) |
523 |
return(FALSE); |
524 |
|
525 |
/* Test next edge */ |
526 |
VCROSS(n,v2,v0); |
527 |
/* Test the point for sidedness */ |
528 |
d = DOT(n,p); |
529 |
if(d > 0.0) |
530 |
return(FALSE); |
531 |
/* Must be interior to the pyramid */ |
532 |
return(GT_INTERIOR); |
533 |
} |
534 |
|
535 |
|
536 |
int |
537 |
ray_intersect_tri(orig,dir,v0,v1,v2,pt) |
538 |
FVECT orig,dir; |
539 |
FVECT v0,v1,v2; |
540 |
FVECT pt; |
541 |
{ |
542 |
FVECT p0,p1,p2,p; |
543 |
FPEQ peq; |
544 |
int type; |
545 |
|
546 |
VSUB(p0,v0,orig); |
547 |
VSUB(p1,v1,orig); |
548 |
VSUB(p2,v2,orig); |
549 |
|
550 |
if(point_in_stri(p0,p1,p2,dir)) |
551 |
{ |
552 |
/* Intersect the ray with the triangle plane */ |
553 |
tri_plane_equation(v0,v1,v2,&peq,FALSE); |
554 |
return(intersect_ray_plane(orig,dir,peq,NULL,pt)); |
555 |
} |
556 |
return(FALSE); |
557 |
} |
558 |
|
559 |
|
560 |
calculate_view_frustum(vp,hv,vv,horiz,vert,near,far,fnear,ffar) |
561 |
FVECT vp,hv,vv; |
562 |
double horiz,vert,near,far; |
563 |
FVECT fnear[4],ffar[4]; |
564 |
{ |
565 |
double height,width; |
566 |
FVECT t,nhv,nvv,ndv; |
567 |
double w2,h2; |
568 |
/* Calculate the x and y dimensions of the near face */ |
569 |
/* hv and vv are the horizontal and vertical vectors in the |
570 |
view frame-the magnitude is the dimension of the front frustum |
571 |
face at z =1 |
572 |
*/ |
573 |
VCOPY(nhv,hv); |
574 |
VCOPY(nvv,vv); |
575 |
w2 = normalize(nhv); |
576 |
h2 = normalize(nvv); |
577 |
/* Use similar triangles to calculate the dimensions at z=near */ |
578 |
width = near*0.5*w2; |
579 |
height = near*0.5*h2; |
580 |
|
581 |
VCROSS(ndv,nvv,nhv); |
582 |
/* Calculate the world space points corresponding to the 4 corners |
583 |
of the front face of the view frustum |
584 |
*/ |
585 |
fnear[0][0] = width*nhv[0] + height*nvv[0] + near*ndv[0] + vp[0] ; |
586 |
fnear[0][1] = width*nhv[1] + height*nvv[1] + near*ndv[1] + vp[1]; |
587 |
fnear[0][2] = width*nhv[2] + height*nvv[2] + near*ndv[2] + vp[2]; |
588 |
fnear[1][0] = -width*nhv[0] + height*nvv[0] + near*ndv[0] + vp[0]; |
589 |
fnear[1][1] = -width*nhv[1] + height*nvv[1] + near*ndv[1] + vp[1]; |
590 |
fnear[1][2] = -width*nhv[2] + height*nvv[2] + near*ndv[2] + vp[2]; |
591 |
fnear[2][0] = -width*nhv[0] - height*nvv[0] + near*ndv[0] + vp[0]; |
592 |
fnear[2][1] = -width*nhv[1] - height*nvv[1] + near*ndv[1] + vp[1]; |
593 |
fnear[2][2] = -width*nhv[2] - height*nvv[2] + near*ndv[2] + vp[2]; |
594 |
fnear[3][0] = width*nhv[0] - height*nvv[0] + near*ndv[0] + vp[0]; |
595 |
fnear[3][1] = width*nhv[1] - height*nvv[1] + near*ndv[1] + vp[1]; |
596 |
fnear[3][2] = width*nhv[2] - height*nvv[2] + near*ndv[2] + vp[2]; |
597 |
|
598 |
/* Now do the far face */ |
599 |
width = far*0.5*w2; |
600 |
height = far*0.5*h2; |
601 |
ffar[0][0] = width*nhv[0] + height*nvv[0] + far*ndv[0] + vp[0] ; |
602 |
ffar[0][1] = width*nhv[1] + height*nvv[1] + far*ndv[1] + vp[1] ; |
603 |
ffar[0][2] = width*nhv[2] + height*nvv[2] + far*ndv[2] + vp[2] ; |
604 |
ffar[1][0] = -width*nhv[0] + height*nvv[0] + far*ndv[0] + vp[0] ; |
605 |
ffar[1][1] = -width*nhv[1] + height*nvv[1] + far*ndv[1] + vp[1] ; |
606 |
ffar[1][2] = -width*nhv[2] + height*nvv[2] + far*ndv[2] + vp[2] ; |
607 |
ffar[2][0] = -width*nhv[0] - height*nvv[0] + far*ndv[0] + vp[0] ; |
608 |
ffar[2][1] = -width*nhv[1] - height*nvv[1] + far*ndv[1] + vp[1] ; |
609 |
ffar[2][2] = -width*nhv[2] - height*nvv[2] + far*ndv[2] + vp[2] ; |
610 |
ffar[3][0] = width*nhv[0] - height*nvv[0] + far*ndv[0] + vp[0] ; |
611 |
ffar[3][1] = width*nhv[1] - height*nvv[1] + far*ndv[1] + vp[1] ; |
612 |
ffar[3][2] = width*nhv[2] - height*nvv[2] + far*ndv[2] + vp[2] ; |
613 |
} |
614 |
|
615 |
int |
616 |
max_index(v,r) |
617 |
FVECT v; |
618 |
double *r; |
619 |
{ |
620 |
double p[3]; |
621 |
int i; |
622 |
|
623 |
p[0] = fabs(v[0]); |
624 |
p[1] = fabs(v[1]); |
625 |
p[2] = fabs(v[2]); |
626 |
i = (p[0]>=p[1])?((p[0]>=p[2])?0:2):((p[1]>=p[2])?1:2); |
627 |
if(r) |
628 |
*r = p[i]; |
629 |
return(i); |
630 |
} |
631 |
|
632 |
int |
633 |
closest_point_in_tri(p0,p1,p2,p,p0id,p1id,p2id) |
634 |
FVECT p0,p1,p2,p; |
635 |
int p0id,p1id,p2id; |
636 |
{ |
637 |
double d,d1; |
638 |
int i; |
639 |
|
640 |
d = DIST_SQ(p,p0); |
641 |
d1 = DIST_SQ(p,p1); |
642 |
if(d < d1) |
643 |
{ |
644 |
d1 = DIST_SQ(p,p2); |
645 |
i = (d1 < d)?p2id:p0id; |
646 |
} |
647 |
else |
648 |
{ |
649 |
d = DIST_SQ(p,p2); |
650 |
i = (d < d1)? p2id:p1id; |
651 |
} |
652 |
return(i); |
653 |
} |
654 |
|
655 |
/* Find the normalized barycentric coordinates of p relative to |
656 |
* triangle v0,v1,v2. Return result in coord |
657 |
*/ |
658 |
bary2d(x1,y1,x2,y2,x3,y3,px,py,coord) |
659 |
double x1,y1,x2,y2,x3,y3; |
660 |
double px,py; |
661 |
double coord[3]; |
662 |
{ |
663 |
double a; |
664 |
|
665 |
a = (x2 - x1) * (y3 - y1) - (x3 - x1) * (y2 - y1); |
666 |
coord[0] = ((x2 - px) * (y3 - py) - (x3 - px) * (y2 - py)) / a; |
667 |
coord[1] = ((x3 - px) * (y1 - py) - (x1 - px) * (y3 - py)) / a; |
668 |
coord[2] = ((x1 - px) * (y2 - py) - (x2 - px) * (y1 - py)) / a; |
669 |
|
670 |
} |
671 |
|
672 |
|
673 |
|
674 |
|
675 |
bary_parent(coord,i) |
676 |
BCOORD coord[3]; |
677 |
int i; |
678 |
{ |
679 |
switch(i) { |
680 |
case 0: |
681 |
/* update bary for child */ |
682 |
coord[0] = (coord[0] >> 1) + MAXBCOORD4; |
683 |
coord[1] >>= 1; |
684 |
coord[2] >>= 1; |
685 |
break; |
686 |
case 1: |
687 |
coord[0] >>= 1; |
688 |
coord[1] = (coord[1] >> 1) + MAXBCOORD4; |
689 |
coord[2] >>= 1; |
690 |
break; |
691 |
|
692 |
case 2: |
693 |
coord[0] >>= 1; |
694 |
coord[1] >>= 1; |
695 |
coord[2] = (coord[2] >> 1) + MAXBCOORD4; |
696 |
break; |
697 |
|
698 |
case 3: |
699 |
coord[0] = MAXBCOORD4 - (coord[0] >> 1); |
700 |
coord[1] = MAXBCOORD4 - (coord[1] >> 1); |
701 |
coord[2] = MAXBCOORD4 - (coord[2] >> 1); |
702 |
break; |
703 |
#ifdef DEBUG |
704 |
default: |
705 |
eputs("bary_parent():Invalid child\n"); |
706 |
break; |
707 |
#endif |
708 |
} |
709 |
} |
710 |
|
711 |
bary_from_child(coord,child,next) |
712 |
BCOORD coord[3]; |
713 |
int child,next; |
714 |
{ |
715 |
#ifdef DEBUG |
716 |
if(child <0 || child > 3) |
717 |
{ |
718 |
eputs("bary_from_child():Invalid child\n"); |
719 |
return; |
720 |
} |
721 |
if(next <0 || next > 3) |
722 |
{ |
723 |
eputs("bary_from_child():Invalid next\n"); |
724 |
return; |
725 |
} |
726 |
#endif |
727 |
if(next == child) |
728 |
return; |
729 |
|
730 |
switch(child){ |
731 |
case 0: |
732 |
coord[0] = 0; |
733 |
coord[1] = MAXBCOORD2 - coord[1]; |
734 |
coord[2] = MAXBCOORD2 - coord[2]; |
735 |
break; |
736 |
case 1: |
737 |
coord[0] = MAXBCOORD2 - coord[0]; |
738 |
coord[1] = 0; |
739 |
coord[2] = MAXBCOORD2 - coord[2]; |
740 |
break; |
741 |
case 2: |
742 |
coord[0] = MAXBCOORD2 - coord[0]; |
743 |
coord[1] = MAXBCOORD2 - coord[1]; |
744 |
coord[2] = 0; |
745 |
break; |
746 |
case 3: |
747 |
switch(next){ |
748 |
case 0: |
749 |
coord[0] = 0; |
750 |
coord[1] = MAXBCOORD2 - coord[1]; |
751 |
coord[2] = MAXBCOORD2 - coord[2]; |
752 |
break; |
753 |
case 1: |
754 |
coord[0] = MAXBCOORD2 - coord[0]; |
755 |
coord[1] = 0; |
756 |
coord[2] = MAXBCOORD2 - coord[2]; |
757 |
break; |
758 |
case 2: |
759 |
coord[0] = MAXBCOORD2 - coord[0]; |
760 |
coord[1] = MAXBCOORD2 - coord[1]; |
761 |
coord[2] = 0; |
762 |
break; |
763 |
} |
764 |
break; |
765 |
} |
766 |
} |
767 |
|
768 |
int |
769 |
bary_child(coord) |
770 |
BCOORD coord[3]; |
771 |
{ |
772 |
int i; |
773 |
|
774 |
if(coord[0] > MAXBCOORD4) |
775 |
{ |
776 |
/* update bary for child */ |
777 |
coord[0] = (coord[0]<< 1) - MAXBCOORD2; |
778 |
coord[1] <<= 1; |
779 |
coord[2] <<= 1; |
780 |
return(0); |
781 |
} |
782 |
else |
783 |
if(coord[1] > MAXBCOORD4) |
784 |
{ |
785 |
coord[0] <<= 1; |
786 |
coord[1] = (coord[1] << 1) - MAXBCOORD2; |
787 |
coord[2] <<= 1; |
788 |
return(1); |
789 |
} |
790 |
else |
791 |
if(coord[2] > MAXBCOORD4) |
792 |
{ |
793 |
coord[0] <<= 1; |
794 |
coord[1] <<= 1; |
795 |
coord[2] = (coord[2] << 1) - MAXBCOORD2; |
796 |
return(2); |
797 |
} |
798 |
else |
799 |
{ |
800 |
coord[0] = MAXBCOORD2 - (coord[0] << 1); |
801 |
coord[1] = MAXBCOORD2 - (coord[1] << 1); |
802 |
coord[2] = MAXBCOORD2 - (coord[2] << 1); |
803 |
return(3); |
804 |
} |
805 |
} |
806 |
|
807 |
int |
808 |
bary_nth_child(coord,i) |
809 |
BCOORD coord[3]; |
810 |
int i; |
811 |
{ |
812 |
|
813 |
switch(i){ |
814 |
case 0: |
815 |
/* update bary for child */ |
816 |
coord[0] = (coord[0]<< 1) - MAXBCOORD2; |
817 |
coord[1] <<= 1; |
818 |
coord[2] <<= 1; |
819 |
break; |
820 |
case 1: |
821 |
coord[0] <<= 1; |
822 |
coord[1] = (coord[1] << 1) - MAXBCOORD2; |
823 |
coord[2] <<= 1; |
824 |
break; |
825 |
case 2: |
826 |
coord[0] <<= 1; |
827 |
coord[1] <<= 1; |
828 |
coord[2] = (coord[2] << 1) - MAXBCOORD2; |
829 |
break; |
830 |
case 3: |
831 |
coord[0] = MAXBCOORD2 - (coord[0] << 1); |
832 |
coord[1] = MAXBCOORD2 - (coord[1] << 1); |
833 |
coord[2] = MAXBCOORD2 - (coord[2] << 1); |
834 |
break; |
835 |
} |
836 |
} |
837 |
|
838 |
|
839 |
|