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source: code/branches/ode/ode-0.9/OPCODE/OPC_SphereTriOverlap.h @ 274

Last change on this file since 274 was 216, checked in by mathiask, 18 years ago
[Physik] add ode-0.9
File size: 4.3 KB

Rev	Line
[216]	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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