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MATH: Fix Line3d::intersectLine2d to perform a segment intersection test

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It was previously doing a line vs line segment intersection test
This commit is contained in:
Bastien Bouclet 2015-08-09 19:07:06 +02:00
parent 58f8e6426a
commit f3f4275ad1
1 changed files with 9 additions and 2 deletions
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11
math/line3d.cpp
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@ -51,19 +51,25 @@ Math::Vector3d Line3d::middle() const {
bool Line3d::intersectLine2d(const Line3d &other, Math::Vector3d *pos, bool useXZ) {
float denom, nume_a;
float denom, nume_a, nume_b;
if (useXZ) {
denom = ((other._end.z() - other._begin.z()) * (_end.x() - _begin.x())) -
((other._end.x() - other._begin.x()) * (_end.z() - _begin.z()));
nume_a = ((other._end.x() - other._begin.x()) * (_begin.z() - other._begin.z())) -
((other._end.z() - other._begin.z()) * (_begin.x() - other._begin.x()));
nume_b = ((_end.x() - _begin.x()) * (_begin.z() - other._begin.z())) -
((_end.z() - _begin.z()) * (_begin.x() - other._begin.x()));
} else {
denom = ((other._end.y() - other._begin.y()) * (_end.x() - _begin.x())) -
((other._end.x() - other._begin.x()) * (_end.y() - _begin.y()));
nume_a = ((other._end.x() - other._begin.x()) * (_begin.y() - other._begin.y())) -
((other._end.y() - other._begin.y()) * (_begin.x() - other._begin.x()));
nume_b = ((_end.x() - _begin.x()) * (_begin.y() - other._begin.y())) -
((_end.y() - _begin.y()) * (_begin.x() - other._begin.x()));
}
if (denom == 0.0f) {
@ -71,8 +77,9 @@ bool Line3d::intersectLine2d(const Line3d &other, Math::Vector3d *pos, bool useX
}
float ua = nume_a / denom;
float ub = nume_b / denom;
if (ua < 0 || ua > 1)
if (ua < 0 || ua > 1 || ub < 0 || ub > 1)
return false;
// Get the intersection point.