2 //! if OPC_TRITRI_EPSILON_TEST is true then we do a check (if |dv|<EPSILON then dv=0.0;) else no check is done (which is less robust, but faster)
3 #define LOCAL_EPSILON 0.000001f
14 //! Edge to edge test based on Franlin Antonio's gem: "Faster Line Segment Intersection", in Graphics Gems III, pp. 199-202
15 #define EDGE_EDGE_TEST(V0, U0, U1) \
16 Bx = U0[i0] - U1[i0]; \
17 By = U0[i1] - U1[i1]; \
18 Cx = V0[i0] - U0[i0]; \
19 Cy = V0[i1] - U0[i1]; \
22 if((f>0.0f && d>=0.0f && d<=f) || (f<0.0f && d<=0.0f && d>=f)) \
24 const float e=Ax*Cy - Ay*Cx; \
27 if(e>=0.0f && e<=f) return TRUE; \
31 if(e<=0.0f && e>=f) return TRUE; \
36 #define EDGE_AGAINST_TRI_EDGES(V0, V1, U0, U1, U2) \
38 float Bx,By,Cx,Cy,d,f; \
39 const float Ax = V1[i0] - V0[i0]; \
40 const float Ay = V1[i1] - V0[i1]; \
41 /* test edge U0,U1 against V0,V1 */ \
42 EDGE_EDGE_TEST(V0, U0, U1); \
43 /* test edge U1,U2 against V0,V1 */ \
44 EDGE_EDGE_TEST(V0, U1, U2); \
45 /* test edge U2,U1 against V0,V1 */ \
46 EDGE_EDGE_TEST(V0, U2, U0); \
50 #define POINT_IN_TRI(V0, U0, U1, U2) \
52 /* is T1 completly inside T2? */ \
53 /* check if V0 is inside tri(U0,U1,U2) */ \
54 float a = U1[i1] - U0[i1]; \
55 float b = -(U1[i0] - U0[i0]); \
56 float c = -a*U0[i0] - b*U0[i1]; \
57 float d0 = a*V0[i0] + b*V0[i1] + c; \
59 a = U2[i1] - U1[i1]; \
60 b = -(U2[i0] - U1[i0]); \
61 c = -a*U1[i0] - b*U1[i1]; \
62 const float d1 = a*V0[i0] + b*V0[i1] + c; \
64 a = U0[i1] - U2[i1]; \
65 b = -(U0[i0] - U2[i0]); \
66 c = -a*U2[i0] - b*U2[i1]; \
67 const float d2 = a*V0[i0] + b*V0[i1] + c; \
70 if(d0*d2>0.0f) return TRUE; \
75 BOOL
CoplanarTriTri(const Point
& n
, const Point
& v0
, const Point
& v1
, const Point
& v2
, const Point
& u0
, const Point
& u1
, const Point
& u2
)
79 /* first project onto an axis-aligned plane, that maximizes the area */
80 /* of the triangles, compute indices: i0,i1. */
88 i0
=1; /* A[0] is greatest */
93 i0
=0; /* A[2] is greatest */
101 i0
=0; /* A[2] is greatest */
106 i0
=0; /* A[1] is greatest */
111 /* test all edges of triangle 1 against the edges of triangle 2 */
112 EDGE_AGAINST_TRI_EDGES(v0
, v1
, u0
, u1
, u2
);
113 EDGE_AGAINST_TRI_EDGES(v1
, v2
, u0
, u1
, u2
);
114 EDGE_AGAINST_TRI_EDGES(v2
, v0
, u0
, u1
, u2
);
116 /* finally, test if tri1 is totally contained in tri2 or vice versa */
117 POINT_IN_TRI(v0
, u0
, u1
, u2
);
118 POINT_IN_TRI(u0
, v0
, v1
, v2
);
124 #define NEWCOMPUTE_INTERVALS(VV0, VV1, VV2, D0, D1, D2, D0D1, D0D2, A, B, C, X0, X1) \
128 /* here we know that D0D2<=0.0 */ \
129 /* that is D0, D1 are on the same side, D2 on the other or on the plane */ \
130 A=VV2; B=(VV0 - VV2)*D2; C=(VV1 - VV2)*D2; X0=D2 - D0; X1=D2 - D1; \
134 /* here we know that d0d1<=0.0 */ \
135 A=VV1; B=(VV0 - VV1)*D1; C=(VV2 - VV1)*D1; X0=D1 - D0; X1=D1 - D2; \
137 else if(D1*D2>0.0f || D0!=0.0f) \
139 /* here we know that d0d1<=0.0 or that D0!=0.0 */ \
140 A=VV0; B=(VV1 - VV0)*D0; C=(VV2 - VV0)*D0; X0=D0 - D1; X1=D0 - D2; \
144 A=VV1; B=(VV0 - VV1)*D1; C=(VV2 - VV1)*D1; X0=D1 - D0; X1=D1 - D2; \
148 A=VV2; B=(VV0 - VV2)*D2; C=(VV1 - VV2)*D2; X0=D2 - D0; X1=D2 - D1; \
152 /* triangles are coplanar */ \
153 return CoplanarTriTri(N1, V0, V1, V2, U0, U1, U2); \
157 ///////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////
159 * Triangle/triangle intersection test routine,
160 * by Tomas Moller, 1997.
161 * See article "A Fast Triangle-Triangle Intersection Test",
162 * Journal of Graphics Tools, 2(2), 1997
164 * Updated June 1999: removed the divisions -- a little faster now!
165 * Updated October 1999: added {} to CROSS and SUB macros
167 * int NoDivTriTriIsect(float V0[3],float V1[3],float V2[3],
168 * float U0[3],float U1[3],float U2[3])
170 * \param V0 [in] triangle 0, vertex 0
171 * \param V1 [in] triangle 0, vertex 1
172 * \param V2 [in] triangle 0, vertex 2
173 * \param U0 [in] triangle 1, vertex 0
174 * \param U1 [in] triangle 1, vertex 1
175 * \param U2 [in] triangle 1, vertex 2
176 * \return true if triangles overlap
178 ///////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////
179 inline_ BOOL
AABBTreeCollider::TriTriOverlap(const Point
& V0
, const Point
& V1
, const Point
& V2
, const Point
& U0
, const Point
& U1
, const Point
& U2
)
184 // Compute plane equation of triangle(V0,V1,V2)
187 const Point N1
= E1
^ E2
;
188 const float d1
=-N1
| V0
;
189 // Plane equation 1: N1.X+d1=0
191 // Put U0,U1,U2 into plane equation 1 to compute signed distances to the plane
192 float du0
= (N1
|U0
) + d1
;
193 float du1
= (N1
|U1
) + d1
;
194 float du2
= (N1
|U2
) + d1
;
196 // Coplanarity robustness check
197 #ifdef OPC_TRITRI_EPSILON_TEST
198 if(fabsf(du0
)<LOCAL_EPSILON
) du0
= 0.0f
;
199 if(fabsf(du1
)<LOCAL_EPSILON
) du1
= 0.0f
;
200 if(fabsf(du2
)<LOCAL_EPSILON
) du2
= 0.0f
;
202 const float du0du1
= du0
* du1
;
203 const float du0du2
= du0
* du2
;
205 if(du0du1
>0.0f
&& du0du2
>0.0f
) // same sign on all of them + not equal 0 ?
206 return FALSE
; // no intersection occurs
208 // Compute plane of triangle (U0,U1,U2)
211 const Point N2
= E1
^ E2
;
212 const float d2
=-N2
| U0
;
213 // plane equation 2: N2.X+d2=0
215 // put V0,V1,V2 into plane equation 2
216 float dv0
= (N2
|V0
) + d2
;
217 float dv1
= (N2
|V1
) + d2
;
218 float dv2
= (N2
|V2
) + d2
;
220 #ifdef OPC_TRITRI_EPSILON_TEST
221 if(fabsf(dv0
)<LOCAL_EPSILON
) dv0
= 0.0f
;
222 if(fabsf(dv1
)<LOCAL_EPSILON
) dv1
= 0.0f
;
223 if(fabsf(dv2
)<LOCAL_EPSILON
) dv2
= 0.0f
;
226 const float dv0dv1
= dv0
* dv1
;
227 const float dv0dv2
= dv0
* dv2
;
229 if(dv0dv1
>0.0f
&& dv0dv2
>0.0f
) // same sign on all of them + not equal 0 ?
230 return FALSE
; // no intersection occurs
232 // Compute direction of intersection line
233 const Point D
= N1
^N2
;
235 // Compute and index to the largest component of D
236 float max
=fabsf(D
[0]);
238 float bb
=fabsf(D
[1]);
239 float cc
=fabsf(D
[2]);
240 if(bb
>max
) max
=bb
,index
=1;
241 if(cc
>max
) max
=cc
,index
=2;
243 // This is the simplified projection onto L
244 const float vp0
= V0
[index
];
245 const float vp1
= V1
[index
];
246 const float vp2
= V2
[index
];
248 const float up0
= U0
[index
];
249 const float up1
= U1
[index
];
250 const float up2
= U2
[index
];
252 // Compute interval for triangle 1
254 NEWCOMPUTE_INTERVALS(vp0
,vp1
,vp2
,dv0
,dv1
,dv2
,dv0dv1
,dv0dv2
,a
,b
,c
,x0
,x1
);
256 // Compute interval for triangle 2
258 NEWCOMPUTE_INTERVALS(up0
,up1
,up2
,du0
,du1
,du2
,du0du1
,du0du2
,d
,e
,f
,y0
,y1
);
260 const float xx
=x0
*x1
;
261 const float yy
=y0
*y1
;
262 const float xxyy
=xx
*yy
;
264 float isect1
[2], isect2
[2];
267 isect1
[0]=tmp
+b
*x1
*yy
;
268 isect1
[1]=tmp
+c
*x0
*yy
;
271 isect2
[0]=tmp
+e
*xx
*y1
;
272 isect2
[1]=tmp
+f
*xx
*y0
;
274 SORT(isect1
[0],isect1
[1]);
275 SORT(isect2
[0],isect2
[1]);
277 if(isect1
[1]<isect2
[0] || isect2
[1]<isect1
[0]) return FALSE
;