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git-svn-id: https://reactphysics3d.googlecode.com/svn/trunk@248 92aac97c-a6ce-11dd-a772-7fcde58d38e6

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chappuis.daniel 2010-01-05 20:50:40 +00:00
parent 3fc211f954
commit 2cf0461241
1 changed files with 32 additions and 27 deletions
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59
sources/reactphysics3d/mathematics/mathematics.h
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@ -95,12 +95,25 @@ inline std::vector<reactphysics3d::Vector3D> movePoints(const std::vector<reactp
} }
*/ */
// TODO : Test this method
// Compute the distance between a point "P" and a line (given by a point "A" and a vector "v")
inline double computeDistanceBetweenPointAndLine(const reactphysics3d::Vector3D& P, const reactphysics3d::Vector3D& A, const reactphysics3d::Vector3D& v) {
assert(v.length() != 0);
return ((P-A).crossProduct(v).length() / (v.length()));
}
// TODO : Test this method
// Compute the orthogonal projection of a point "P" on a line (given by a point "A" and a vector "v")
inline reactphysics3d::Vector3D computeOrthogonalProjectionOfPointOntoALine(const reactphysics3d::Vector3D& P, const reactphysics3d::Vector3D& A, const reactphysics3d::Vector3D& v) {
return (A + ((P-A).scalarProduct(v) / (v.scalarProduct(v))) * v);
}
// TODO : Test this method // TODO : Test this method
// Compute the intersection between two parallel segments (the first segment is between the points "seg1PointA" and "seg1PointB" and the second // Compute the intersection between two parallel segments (the first segment is between the points "seg1PointA" and "seg1PointB" and the second
// segment is between the points "seg2PointA" and "seg2PointB"). The result is the segment intersection (represented by the points "resultPointA" // segment is between the points "seg2PointA" and "seg2PointB"). The result is the segment intersection (represented by the points "resultPointA"
// and "resultPointB". Because the two given segments don't have to be on the same exact line, the result intersection segment will a segment // and "resultPointB". Because the two given segments don't have to be on the same exact line, the result intersection segment will a segment
// halway between the first and the second given segments. // halway between the first and the second given segments.
inline void computeParallelSegmentsIntersection(const reactphysics3d::Vector3D& seg1PointA, const reactphysics3d::Vector3D& seg1PointB inline void computeParallelSegmentsIntersection(const reactphysics3d::Vector3D& seg1PointA, const reactphysics3d::Vector3D& seg1PointB,
const reactphysics3d::Vector3D& seg2PointA, const reactphysics3d::Vector3D& seg2PointB, const reactphysics3d::Vector3D& seg2PointA, const reactphysics3d::Vector3D& seg2PointB,
reactphysics3d::Vector3D& resultPointA, reactphysics3d::Vector3D& resultPointB) { reactphysics3d::Vector3D& resultPointA, reactphysics3d::Vector3D& resultPointB) {
// Compute the segment vectors // Compute the segment vectors
@ -111,46 +124,38 @@ inline void computeParallelSegmentsIntersection(const reactphysics3d::Vector3D&
assert(d1.isParallelWith(d2)); assert(d1.isParallelWith(d2));
// Compute the projection of the two points of the second segment onto the vector of segment 1 // Compute the projection of the two points of the second segment onto the vector of segment 1
double projSeg2PointA = d1.getUnit().scalarProduct(seg2PointA() - seg1PointA()); double projSeg2PointA = d1.getUnit().scalarProduct(seg2PointA - seg1PointA);
double projSeg2PointB = d1.getUnit().scalarProduct(seg2PointB() - seg1PointA()); double projSeg2PointB = d1.getUnit().scalarProduct(seg2PointB - seg1PointA);
// The projections intervals should intersect // The projections intervals should intersect
assert(!(projSeg2PointA < 0.0 && projSegment2PointB < 0.0)); assert(!(projSeg2PointA < 0.0 && projSeg2PointB < 0.0));
assert(!(projSeg2PointA > d1.length() && projSeg2PointB > d1.length())); assert(!(projSeg2PointA > d1.length() && projSeg2PointB > d1.length()));
// Compute the distance between the two segments // Compute the vector "v" from a point on the line 1 to the orthogonal point of the line 2
double distance = computeDistanceBetweenPointAndLine(seg2PointA, seg1PointA, d1); reactphysics3d::Vector3D point = computeOrthogonalProjectionOfPointOntoALine(seg2PointA, seg1PointA, d1);
reactphysics3d::Vector3D v = seg2PointA - point;
// Return the segment intersection according to the configuration of two projection intervals // Return the segment intersection according to the configuration of two projection intervals
if (projSeg2PointA >= 0 && projSeg2PointA <= d1.length() && projSeg2PointB >= d1.length()) { if (projSeg2PointA >= 0 && projSeg2PointA <= d1.length() && projSeg2PointB >= d1.length()) {
resultPointA = seg2PointA;
resultPointB = seg1PointB;
// Move the contact points halfway between the two segments // Move the contact points halfway between the two segments
resultPointA = seg2PointA - 0.5 * v;
resultPointB = seg1PointB + 0.5 * v;
} }
else if (projSeg2PointA <= 0 && projSeg2PointB >= 0 && projSeg2PointB <= d1.length()) { else if (projSeg2PointA <= 0 && projSeg2PointB >= 0 && projSeg2PointB <= d1.length()) {
resultPointA = seg1PointA; // Move the contact points halfway between the two segments
resultPointB = seg2PointB; resultPointA = seg1PointA + 0.5 * v;
resultPointB = seg2PointB - 0.5 * v;
} }
else if (projSeg2PointA <= 0 && projSeg2PointB >= d1.length()) { else if (projSeg2PointA <= 0 && projSeg2PointB >= d1.length()) {
resultPointA = seg1PointA; // Move the contact points halfway between the two segments
resultPointB = seg1PointB; resultPointA = seg1PointA + 0.5 * v;
resultPointB = seg1PointB + 0.5 * v;
} }
else if (projSegment2PointA <= segment1.getLength() && projSegment2PointB <= segment1.getLength()) { else if (projSeg2PointA <= d1.length() && projSeg2PointB <= d1.length()) {
resultPointA = seg2PointA; // Move the contact points halfway between the two segments
resultPointB = seg2PointB; resultPointA = seg2PointA - 0.5 * v;
resultPointB = seg2PointB - 0.5 * v;
} }
}
// Compute the distance between a point "pointP" and a line (given by a point "pointA" and a vector "v")
inline double computeDistanceBetweenPointAndLine(const reactphysics3d::Vector3D& pointP, const reactphysics3d::Vector3D& pointA, const reactphysics3d::Vector3D& v) {
assert(v.length() != 0);
return ((pointP-pointA).crossProduct(v).length() / (v.length()));
} }
#endif #endif