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Diffstat (limited to 'contrib/Opcode/OPC_SphereTriOverlap.h')
| -rw-r--r-- | contrib/Opcode/OPC_SphereTriOverlap.h | 187 |
1 files changed, 187 insertions, 0 deletions
diff --git a/contrib/Opcode/OPC_SphereTriOverlap.h b/contrib/Opcode/OPC_SphereTriOverlap.h new file mode 100644 index 0000000..012d9ea --- /dev/null +++ b/contrib/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 IcePoint& vert0, const IcePoint& vert1, const IcePoint& vert2) +{ + // Stats + mNbVolumePrimTests++; + + // Early exit if one of the vertices is inside the sphere + IcePoint 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 + IcePoint TriEdge0 = vert1 - vert0; + IcePoint TriEdge1 = vert2 - vert0; + +//IcePoint 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 IcePoint + 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; +} |