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source: code/branches/ode/ode-0.9/OPCODE/OPC_SphereTriOverlap.h @ 216

Last change on this file since 216 was 216, checked in by mathiask, 16 years ago
[Physik] add ode-0.9
File size: 4.3 KB

Line
1
2	// This is collision detection. If you do another distance test for collision response,
3	// if might be useful to simply skip the test below completely, and report a collision.
4	// - if sphere-triangle overlap, result is ok
5	// - if they don't, we'll discard them during collision response with a similar test anyway
6	// Overall this approach should run faster.
7
8	// Original code by David Eberly in Magic.
9	BOOL SphereCollider::SphereTriOverlap(const Point& vert0, const Point& vert1, const Point& vert2)
10	{
11	// Stats
12	mNbVolumePrimTests++;
13
14	// Early exit if one of the vertices is inside the sphere
15	Point kDiff = vert2 - mCenter;
16	float fC = kDiff.SquareMagnitude();
17	if(fC <= mRadius2) return TRUE;
18
19	kDiff = vert1 - mCenter;
20	fC = kDiff.SquareMagnitude();
21	if(fC <= mRadius2) return TRUE;
22
23	kDiff = vert0 - mCenter;
24	fC = kDiff.SquareMagnitude();
25	if(fC <= mRadius2) return TRUE;
26
27	// Else do the full distance test
28	Point TriEdge0 = vert1 - vert0;
29	Point TriEdge1 = vert2 - vert0;
30
31	//Point kDiff = vert0 - mCenter;
32	float fA00 = TriEdge0.SquareMagnitude();
33	float fA01 = TriEdge0 \| TriEdge1;
34	float fA11 = TriEdge1.SquareMagnitude();
35	float fB0 = kDiff \| TriEdge0;
36	float fB1 = kDiff \| TriEdge1;
37	//float fC = kDiff.SquareMagnitude();
38	float fDet = fabsf(fA00fA11 - fA01fA01);
39	float u = fA01fB1-fA11fB0;
40	float v = fA01fB0-fA00fB1;
41	float SqrDist;
42
43	if(u + v <= fDet)
44	{
45	if(u < 0.0f)
46	{
47	if(v < 0.0f) // region 4
48	{
49	if(fB0 < 0.0f)
50	{
51	// v = 0.0f;
52	if(-fB0>=fA00) { /u = 1.0f;/ SqrDist = fA00+2.0f*fB0+fC; }
53	else { u = -fB0/fA00; SqrDist = fB0*u+fC; }
54	}
55	else
56	{
57	// u = 0.0f;
58	if(fB1>=0.0f) { /v = 0.0f;/ SqrDist = fC; }
59	else if(-fB1>=fA11) { /v = 1.0f;/ SqrDist = fA11+2.0f*fB1+fC; }
60	else { v = -fB1/fA11; SqrDist = fB1*v+fC; }
61	}
62	}
63	else // region 3
64	{
65	// u = 0.0f;
66	if(fB1>=0.0f) { /v = 0.0f;/ SqrDist = fC; }
67	else if(-fB1>=fA11) { /v = 1.0f;/ SqrDist = fA11+2.0f*fB1+fC; }
68	else { v = -fB1/fA11; SqrDist = fB1*v+fC; }
69	}
70	}
71	else if(v < 0.0f) // region 5
72	{
73	// v = 0.0f;
74	if(fB0>=0.0f) { /u = 0.0f;/ SqrDist = fC; }
75	else if(-fB0>=fA00) { /u = 1.0f;/ SqrDist = fA00+2.0f*fB0+fC; }
76	else { u = -fB0/fA00; SqrDist = fB0*u+fC; }
77	}
78	else // region 0
79	{
80	// minimum at interior point
81	if(fDet==0.0f)
82	{
83	// u = 0.0f;
84	// v = 0.0f;
85	SqrDist = MAX_FLOAT;
86	}
87	else
88	{
89	float fInvDet = 1.0f/fDet;
90	u *= fInvDet;
91	v *= fInvDet;
92	SqrDist = u(fA00u+fA01v+2.0ffB0) + v(fA01u+fA11v+2.0ffB1)+fC;
93	}
94	}
95	}
96	else
97	{
98	float fTmp0, fTmp1, fNumer, fDenom;
99
100	if(u < 0.0f) // region 2
101	{
102	fTmp0 = fA01 + fB0;
103	fTmp1 = fA11 + fB1;
104	if(fTmp1 > fTmp0)
105	{
106	fNumer = fTmp1 - fTmp0;
107	fDenom = fA00-2.0f*fA01+fA11;
108	if(fNumer >= fDenom)
109	{
110	// u = 1.0f;
111	// v = 0.0f;
112	SqrDist = fA00+2.0f*fB0+fC;
113	}
114	else
115	{
116	u = fNumer/fDenom;
117	v = 1.0f - u;
118	SqrDist = u(fA00u+fA01v+2.0ffB0) + v(fA01u+fA11v+2.0ffB1)+fC;
119	}
120	}
121	else
122	{
123	// u = 0.0f;
124	if(fTmp1 <= 0.0f) { /v = 1.0f;/ SqrDist = fA11+2.0f*fB1+fC; }
125	else if(fB1 >= 0.0f) { /v = 0.0f;/ SqrDist = fC; }
126	else { v = -fB1/fA11; SqrDist = fB1*v+fC; }
127	}
128	}
129	else if(v < 0.0f) // region 6
130	{
131	fTmp0 = fA01 + fB1;
132	fTmp1 = fA00 + fB0;
133	if(fTmp1 > fTmp0)
134	{
135	fNumer = fTmp1 - fTmp0;
136	fDenom = fA00-2.0f*fA01+fA11;
137	if(fNumer >= fDenom)
138	{
139	// v = 1.0f;
140	// u = 0.0f;
141	SqrDist = fA11+2.0f*fB1+fC;
142	}
143	else
144	{
145	v = fNumer/fDenom;
146	u = 1.0f - v;
147	SqrDist = u(fA00u+fA01v+2.0ffB0) + v(fA01u+fA11v+2.0ffB1)+fC;
148	}
149	}
150	else
151	{
152	// v = 0.0f;
153	if(fTmp1 <= 0.0f) { /u = 1.0f;/ SqrDist = fA00+2.0f*fB0+fC; }
154	else if(fB0 >= 0.0f) { /u = 0.0f;/ SqrDist = fC; }
155	else { u = -fB0/fA00; SqrDist = fB0*u+fC; }
156	}
157	}
158	else // region 1
159	{
160	fNumer = fA11 + fB1 - fA01 - fB0;
161	if(fNumer <= 0.0f)
162	{
163	// u = 0.0f;
164	// v = 1.0f;
165	SqrDist = fA11+2.0f*fB1+fC;
166	}
167	else
168	{
169	fDenom = fA00-2.0f*fA01+fA11;
170	if(fNumer >= fDenom)
171	{
172	// u = 1.0f;
173	// v = 0.0f;
174	SqrDist = fA00+2.0f*fB0+fC;
175	}
176	else
177	{
178	u = fNumer/fDenom;
179	v = 1.0f - u;
180	SqrDist = u(fA00u+fA01v+2.0ffB0) + v(fA01u+fA11v+2.0ffB1)+fC;
181	}
182	}
183	}
184	}
185
186	return fabsf(SqrDist) < mRadius2;
187	}

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