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Diffstat (limited to 'third-party/Opcode/OPC_RayTriOverlap.h')
-rw-r--r-- | third-party/Opcode/OPC_RayTriOverlap.h | 89 |
1 files changed, 89 insertions, 0 deletions
diff --git a/third-party/Opcode/OPC_RayTriOverlap.h b/third-party/Opcode/OPC_RayTriOverlap.h new file mode 100644 index 0000000..405c7e1 --- /dev/null +++ b/third-party/Opcode/OPC_RayTriOverlap.h @@ -0,0 +1,89 @@ +#define LOCAL_EPSILON 0.000001f + +/////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////// +/** + * Computes a ray-triangle intersection test. + * Original code from Tomas Möller's "Fast Minimum Storage Ray-Triangle Intersection". + * It's been optimized a bit with integer code, and modified to return a non-intersection if distance from + * ray origin to triangle is negative. + * + * \param vert0 [in] triangle vertex + * \param vert1 [in] triangle vertex + * \param vert2 [in] triangle vertex + * \return true on overlap. mStabbedFace is filled with relevant info. + */ +/////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////// +inline_ BOOL RayCollider::RayTriOverlap(const IcePoint& vert0, const IcePoint& vert1, const IcePoint& vert2) +{ + // Stats + mNbRayPrimTests++; + + // Find vectors for two edges sharing vert0 + IcePoint edge1 = vert1 - vert0; + IcePoint edge2 = vert2 - vert0; + + // Begin calculating determinant - also used to calculate U parameter + IcePoint pvec = mDir^edge2; + + // If determinant is near zero, ray lies in plane of triangle + float det = edge1|pvec; + + if(mCulling) + { + if(det<LOCAL_EPSILON) return FALSE; + // From here, det is > 0. So we can use integer cmp. + + // Calculate distance from vert0 to ray origin + IcePoint tvec = mOrigin - vert0; + + // Calculate U parameter and test bounds + mStabbedFace.mU = tvec|pvec; +// if(IR(u)&0x80000000 || u>det) return FALSE; + if(IS_NEGATIVE_FLOAT(mStabbedFace.mU) || IR(mStabbedFace.mU)>IR(det)) return FALSE; + + // Prepare to test V parameter + IcePoint qvec = tvec^edge1; + + // Calculate V parameter and test bounds + mStabbedFace.mV = mDir|qvec; + if(IS_NEGATIVE_FLOAT(mStabbedFace.mV) || mStabbedFace.mU+mStabbedFace.mV>det) return FALSE; + + // Calculate t, scale parameters, ray intersects triangle + mStabbedFace.mDistance = edge2|qvec; + // Det > 0 so we can early exit here + // Intersection IcePoint is valid if distance is positive (else it can just be a face behind the orig IcePoint) + if(IS_NEGATIVE_FLOAT(mStabbedFace.mDistance)) return FALSE; + // Else go on + float OneOverDet = 1.0f / det; + mStabbedFace.mDistance *= OneOverDet; + mStabbedFace.mU *= OneOverDet; + mStabbedFace.mV *= OneOverDet; + } + else + { + // the non-culling branch + if(det>-LOCAL_EPSILON && det<LOCAL_EPSILON) return FALSE; + float OneOverDet = 1.0f / det; + + // Calculate distance from vert0 to ray origin + IcePoint tvec = mOrigin - vert0; + + // Calculate U parameter and test bounds + mStabbedFace.mU = (tvec|pvec) * OneOverDet; +// if(IR(u)&0x80000000 || u>1.0f) return FALSE; + if(IS_NEGATIVE_FLOAT(mStabbedFace.mU) || IR(mStabbedFace.mU)>IEEE_1_0) return FALSE; + + // prepare to test V parameter + IcePoint qvec = tvec^edge1; + + // Calculate V parameter and test bounds + mStabbedFace.mV = (mDir|qvec) * OneOverDet; + if(IS_NEGATIVE_FLOAT(mStabbedFace.mV) || mStabbedFace.mU+mStabbedFace.mV>1.0f) return FALSE; + + // Calculate t, ray intersects triangle + mStabbedFace.mDistance = (edge2|qvec) * OneOverDet; + // Intersection IcePoint is valid if distance is positive (else it can just be a face behind the orig IcePoint) + if(IS_NEGATIVE_FLOAT(mStabbedFace.mDistance)) return FALSE; + } + return TRUE; +} |