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0026249: Visualization, TKV3d - fix possible division by zero in SelectMgr_RectangularFrustum

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Added zero-length check for triangle normal in SelectMgr_RectangularFrustum::Overlaps
This commit is contained in:
vpa 2015-08-03 18:41:56 +03:00 committed by bugmaster
parent c3282ec170
commit 7e17e8f08d
1 changed files with 19 additions and 1 deletions
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20
src/SelectMgr/SelectMgr_RectangularFrustum.cxx
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@ -692,7 +692,25 @@ Standard_Boolean SelectMgr_RectangularFrustum::Overlaps (const gp_Pnt& thePnt1,
SelectMgr_Vec3 aTrEdges[3] = { SelectMgr_Vec3 (thePnt2.X() - thePnt1.X(), thePnt2.Y() - thePnt1.Y(), thePnt2.Z() - thePnt1.Z()),
SelectMgr_Vec3 (thePnt3.X() - thePnt2.X(), thePnt3.Y() - thePnt2.Y(), thePnt3.Z() - thePnt2.Z()),
SelectMgr_Vec3 (thePnt1.X() - thePnt3.X(), thePnt1.Y() - thePnt3.Y(), thePnt1.Z() - thePnt3.Z()) };
SelectMgr_Vec3 anEdge = (aPnt1 - myNearPickedPnt) * (1.0 / DOT (aTriangleNormal, myViewRayDir));
Standard_Real anAlpha = DOT (aTriangleNormal, myViewRayDir);
if (Abs (anAlpha) < gp::Resolution())
{
// handle degenerated triangles: in this case, there is no possible way to detect overlap correctly.
if (aTriangleNormal.SquareModulus() < gp::Resolution())
{
theDepth = std::numeric_limits<Standard_Real>::max();
return Standard_False;
}
// handle the case when triangle normal and selecting frustum direction are orthogonal: for this case, overlap
// is detected correctly, and distance to triangle's plane can be measured as distance to its arbitrary vertex.
const SelectMgr_Vec3 aDiff = myNearPickedPnt - aPnt1;
theDepth = DOT (aTriangleNormal, aDiff);
return Standard_True;
}
SelectMgr_Vec3 anEdge = (aPnt1 - myNearPickedPnt) * (1.0 / anAlpha);
Standard_Real aTime = DOT (aTriangleNormal, anEdge);