From 9efc032b9a48c3cb1ff500e408a06b25a0ee589e Mon Sep 17 00:00:00 2001
From: oan <oan@opencascade.com>
Date: Wed, 3 Jan 2024 02:39:35 +0000
Subject: [PATCH] 0033560: PARASOLID Import - XT importer raises exception
SIGFPE Arithmetic Exception
Prevent division by zero in exceptional cases when vector of parameters contains only a single value.
---
src/Approx/Approx_BSplComputeLine.gxx | 10 ++++++----
src/BSplCLib/BSplCLib_2.cxx | 17 ++++++++++++++---
2 files changed, 20 insertions(+), 7 deletions(-)
diff --git a/src/Approx/Approx_BSplComputeLine.gxx b/src/Approx/Approx_BSplComputeLine.gxx
index 75315e89a8..36930088ea 100644
--- a/src/Approx/Approx_BSplComputeLine.gxx
+++ b/src/Approx/Approx_BSplComputeLine.gxx
@@ -808,8 +808,11 @@ void Approx_BSplComputeLine::Parameters(const MultiLine& Line,
const Standard_Integer aNbp = lastP - firstP + 1;
+ // The first parameter should always be zero according to all the logic below,
+ // so division by any value will give zero anyway, so it should never be scaled
+ // to avoid case when there is only one parameter in the array thus division by zero happens.
+ TheParameters(firstP) = 0.0;
if (aNbp == 2) {
- TheParameters(firstP) = 0.0;
TheParameters(lastP) = 1.0;
}
else if (Par == Approx_ChordLength || Par == Approx_Centripetal)
@@ -820,7 +823,6 @@ void Approx_BSplComputeLine::Parameters(const MultiLine& Line,
if (nbP3d == 0) mynbP3d = 1;
if (nbP2d == 0) mynbP2d = 1;
- TheParameters(firstP) = 0.0;
dist = 0.0;
TColgp_Array1OfPnt tabP(1, mynbP3d);
TColgp_Array1OfPnt tabPP(1, mynbP3d);
@@ -861,10 +863,10 @@ void Approx_BSplComputeLine::Parameters(const MultiLine& Line,
TheParameters(i) = TheParameters(i - 1) + Sqrt(dist);
}
}
- for (i = firstP; i <= lastP; i++) TheParameters(i) /= TheParameters(lastP);
+ for (i = firstP + 1; i <= lastP; i++) TheParameters(i) /= TheParameters(lastP);
}
else {
- for (i = firstP; i <= lastP; i++) {
+ for (i = firstP + 1; i <= lastP; i++) {
TheParameters(i) = (Standard_Real(i) - firstP) /
(Standard_Real(lastP - Standard_Real(firstP)));
}
diff --git a/src/BSplCLib/BSplCLib_2.cxx b/src/BSplCLib/BSplCLib_2.cxx
index 0ae8628e5c..b6a4496af1 100644
--- a/src/BSplCLib/BSplCLib_2.cxx
+++ b/src/BSplCLib/BSplCLib_2.cxx
@@ -515,8 +515,13 @@ BSplCLib::EvalBsplineBasis
//
// this should be always invertible if ii is correctly computed
//
- Factor = (Parameter - FlatKnots(ii - qq + pp + 1))
- / (FlatKnots(ii + pp) - FlatKnots(ii - qq + pp + 1)) ;
+ const Standard_Real aScale = (FlatKnots(ii + pp) - FlatKnots(ii - qq + pp + 1));
+ if (Abs (aScale) < gp::Resolution())
+ {
+ return 2;
+ }
+
+ Factor = (Parameter - FlatKnots(ii - qq + pp + 1)) / aScale;
Saved = Factor * BsplineBasis(1,pp) ;
BsplineBasis(1,pp) *= (1.0e0 - Factor) ;
BsplineBasis(1,pp) += BsplineBasis(1,qq) ;
@@ -536,7 +541,13 @@ BSplCLib::EvalBsplineBasis
}
for (pp = 1 ; pp <= qq - 1 ; pp++) {
- Inverse = 1.0e0 / (FlatKnots(ii + pp) - FlatKnots(ii - qq + pp + 1)) ;
+ const Standard_Real aScale = (FlatKnots(ii + pp) - FlatKnots(ii - qq + pp + 1));
+ if (Abs (aScale) < gp::Resolution())
+ {
+ return 2;
+ }
+
+ Inverse = 1.0e0 / aScale;
Factor = (Parameter - FlatKnots(ii - qq + pp + 1)) * Inverse ;
Saved = Factor * BsplineBasis(1,pp) ;
BsplineBasis(1,pp) *= (1.0e0 - Factor) ;