From f205de7847da7ae1c10212d82e7042d0100b4ce0 Mon Sep 17 00:00:00 2001
From: dan miller
Date: Fri, 19 Oct 2007 05:24:38 +0000
Subject: from the start... checking in ode-0.9

---
 libraries/ode-0.9/OPCODE/OPC_SphereTriOverlap.h | 187 ++++++++++++++++++++++++
 1 file changed, 187 insertions(+)
 create mode 100644 libraries/ode-0.9/OPCODE/OPC_SphereTriOverlap.h

(limited to 'libraries/ode-0.9/OPCODE/OPC_SphereTriOverlap.h')

diff --git a/libraries/ode-0.9/OPCODE/OPC_SphereTriOverlap.h b/libraries/ode-0.9/OPCODE/OPC_SphereTriOverlap.h
new file mode 100644
index 0000000..77e59f3
--- /dev/null
+++ b/libraries/ode-0.9/OPCODE/OPC_SphereTriOverlap.h
@@ -0,0 +1,187 @@
+
+// This is collision detection. If you do another distance test for collision *response*,
+// if might be useful to simply *skip* the test below completely, and report a collision.
+// - if sphere-triangle overlap, result is ok
+// - if they don't, we'll discard them during collision response with a similar test anyway
+// Overall this approach should run faster.
+
+// Original code by David Eberly in Magic.
+BOOL SphereCollider::SphereTriOverlap(const Point& vert0, const Point& vert1, const Point& vert2)
+{
+	// Stats
+	mNbVolumePrimTests++;
+
+	// Early exit if one of the vertices is inside the sphere
+	Point kDiff = vert2 - mCenter;
+	float fC = kDiff.SquareMagnitude();
+	if(fC <= mRadius2)	return TRUE;
+
+	kDiff = vert1 - mCenter;
+	fC = kDiff.SquareMagnitude();
+	if(fC <= mRadius2)	return TRUE;
+
+	kDiff = vert0 - mCenter;
+	fC = kDiff.SquareMagnitude();
+	if(fC <= mRadius2)	return TRUE;
+
+	// Else do the full distance test
+	Point TriEdge0	= vert1 - vert0;
+	Point TriEdge1	= vert2 - vert0;
+
+//Point kDiff	= vert0 - mCenter;
+	float fA00	= TriEdge0.SquareMagnitude();
+	float fA01	= TriEdge0 | TriEdge1;
+	float fA11	= TriEdge1.SquareMagnitude();
+	float fB0	= kDiff | TriEdge0;
+	float fB1	= kDiff | TriEdge1;
+//float fC	= kDiff.SquareMagnitude();
+	float fDet	= fabsf(fA00*fA11 - fA01*fA01);
+	float u		= fA01*fB1-fA11*fB0;
+	float v		= fA01*fB0-fA00*fB1;
+	float SqrDist;
+
+	if(u + v <= fDet)
+	{
+		if(u < 0.0f)
+		{
+			if(v < 0.0f)  // region 4
+			{
+				if(fB0 < 0.0f)
+				{
+//					v = 0.0f;
+					if(-fB0>=fA00)			{ /*u = 1.0f;*/		SqrDist = fA00+2.0f*fB0+fC;	}
+					else					{ u = -fB0/fA00;	SqrDist = fB0*u+fC;			}
+				}
+				else
+				{
+//					u = 0.0f;
+					if(fB1>=0.0f)			{ /*v = 0.0f;*/		SqrDist = fC;				}
+					else if(-fB1>=fA11)		{ /*v = 1.0f;*/		SqrDist = fA11+2.0f*fB1+fC;	}
+					else					{ v = -fB1/fA11;	SqrDist = fB1*v+fC;			}
+				}
+			}
+			else  // region 3
+			{
+//				u = 0.0f;
+				if(fB1>=0.0f)				{ /*v = 0.0f;*/		SqrDist = fC;				}
+				else if(-fB1>=fA11)			{ /*v = 1.0f;*/		SqrDist = fA11+2.0f*fB1+fC;	}
+				else						{ v = -fB1/fA11;	SqrDist = fB1*v+fC;			}
+			}
+		}
+		else if(v < 0.0f)  // region 5
+		{
+//			v = 0.0f;
+			if(fB0>=0.0f)					{ /*u = 0.0f;*/		SqrDist = fC;				}
+			else if(-fB0>=fA00)				{ /*u = 1.0f;*/		SqrDist = fA00+2.0f*fB0+fC;	}
+			else							{ u = -fB0/fA00;	SqrDist = fB0*u+fC;			}
+		}
+		else  // region 0
+		{
+			// minimum at interior point
+			if(fDet==0.0f)
+			{
+//				u = 0.0f;
+//				v = 0.0f;
+				SqrDist = MAX_FLOAT;
+			}
+			else
+			{
+				float fInvDet = 1.0f/fDet;
+				u *= fInvDet;
+				v *= fInvDet;
+				SqrDist = u*(fA00*u+fA01*v+2.0f*fB0) + v*(fA01*u+fA11*v+2.0f*fB1)+fC;
+			}
+		}
+	}
+	else
+	{
+		float fTmp0, fTmp1, fNumer, fDenom;
+
+		if(u < 0.0f)  // region 2
+		{
+			fTmp0 = fA01 + fB0;
+			fTmp1 = fA11 + fB1;
+			if(fTmp1 > fTmp0)
+			{
+				fNumer = fTmp1 - fTmp0;
+				fDenom = fA00-2.0f*fA01+fA11;
+				if(fNumer >= fDenom)
+				{
+//					u = 1.0f;
+//					v = 0.0f;
+					SqrDist = fA00+2.0f*fB0+fC;
+				}
+				else
+				{
+					u = fNumer/fDenom;
+					v = 1.0f - u;
+					SqrDist = u*(fA00*u+fA01*v+2.0f*fB0) + v*(fA01*u+fA11*v+2.0f*fB1)+fC;
+				}
+			}
+			else
+			{
+//				u = 0.0f;
+				if(fTmp1 <= 0.0f)		{ /*v = 1.0f;*/		SqrDist = fA11+2.0f*fB1+fC;	}
+				else if(fB1 >= 0.0f)	{ /*v = 0.0f;*/		SqrDist = fC;				}
+				else					{ v = -fB1/fA11;	SqrDist = fB1*v+fC;			}
+			}
+		}
+		else if(v < 0.0f)  // region 6
+		{
+			fTmp0 = fA01 + fB1;
+			fTmp1 = fA00 + fB0;
+			if(fTmp1 > fTmp0)
+			{
+				fNumer = fTmp1 - fTmp0;
+				fDenom = fA00-2.0f*fA01+fA11;
+				if(fNumer >= fDenom)
+				{
+//					v = 1.0f;
+//					u = 0.0f;
+					SqrDist = fA11+2.0f*fB1+fC;
+				}
+				else
+				{
+					v = fNumer/fDenom;
+					u = 1.0f - v;
+					SqrDist = u*(fA00*u+fA01*v+2.0f*fB0) + v*(fA01*u+fA11*v+2.0f*fB1)+fC;
+				}
+			}
+			else
+			{
+//				v = 0.0f;
+				if(fTmp1 <= 0.0f)		{ /*u = 1.0f;*/		SqrDist = fA00+2.0f*fB0+fC;	}
+				else if(fB0 >= 0.0f)	{ /*u = 0.0f;*/		SqrDist = fC;				}
+				else					{ u = -fB0/fA00;	SqrDist = fB0*u+fC;			}
+			}
+		}
+		else  // region 1
+		{
+			fNumer = fA11 + fB1 - fA01 - fB0;
+			if(fNumer <= 0.0f)
+			{
+//				u = 0.0f;
+//				v = 1.0f;
+				SqrDist = fA11+2.0f*fB1+fC;
+			}
+			else
+			{
+				fDenom = fA00-2.0f*fA01+fA11;
+				if(fNumer >= fDenom)
+				{
+//					u = 1.0f;
+//					v = 0.0f;
+					SqrDist = fA00+2.0f*fB0+fC;
+				}
+				else
+				{
+					u = fNumer/fDenom;
+					v = 1.0f - u;
+					SqrDist = u*(fA00*u+fA01*v+2.0f*fB0) + v*(fA01*u+fA11*v+2.0f*fB1)+fC;
+				}
+			}
+		}
+	}
+
+	return fabsf(SqrDist) < mRadius2;
+}
-- 
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