From 5bbd2acc25b039fb8b27e4fca530b1e4451d3eaa Mon Sep 17 00:00:00 2001
From: ansgar <ansgar@5a81b35b-ba03-0410-adc8-b2c5c5119f08>
Date: Wed, 28 Apr 2010 02:32:40 +0000
Subject: [PATCH] fixed a precision issue with rotmat->quat conversion
git-svn-id: https://dng.biozentrum.unibas.ch/svn/openstructure/trunk@2124 5a81b35b-ba03-0410-adc8-b2c5c5119f08
---
modules/geom/src/quat.cc | 19 +++++++++++--------
1 file changed, 11 insertions(+), 8 deletions(-)
diff --git a/modules/geom/src/quat.cc b/modules/geom/src/quat.cc
index 73f57fb63..abfa6c80f 100644
--- a/modules/geom/src/quat.cc
+++ b/modules/geom/src/quat.cc
@@ -184,17 +184,20 @@ Vec3 find_vector_for_BOD(const Vec3& xyz, const Vec3& uvw)
Quat extract_from_rotmat(const Mat3& rot)
{
- if ((fabs(rot(0,0) - 1.0) <= std::numeric_limits<Real>::epsilon()) &&
- (fabs(rot(1,1) - 1.0) <= std::numeric_limits<Real>::epsilon()) &&
- (fabs(rot(2,2) - 1.0) <= std::numeric_limits<Real>::epsilon())) {
+ if ((std::abs(rot(0,0) - Real(1.0)) <= std::numeric_limits<Real>::epsilon()) &&
+ (std::abs(rot(1,1) - Real(1.0)) <= std::numeric_limits<Real>::epsilon()) &&
+ (std::abs(rot(2,2) - Real(1.0)) <= std::numeric_limits<Real>::epsilon())) {
return Quat(1.0,0.0,0.0,0.0);
}
- Real cos_theta = (rot(0,0)+rot(1,1)+rot(2,2)-1.0)*0.5;
- Real stuff = (cos_theta+1.0)*0.5;
+ Real cos_theta = (rot(0,0)+rot(1,1)+rot(2,2)-Real(1.0))*Real(0.5);
+ Real stuff = (cos_theta+Real(1.0))*Real(0.5);
+ if(stuff<Real(0.0) || stuff>Real(1.0)) {
+ return Quat(1.0,0.0,0.0,0.0);
+ }
Real cos_theta_sur_2 = sqrt(stuff);
- Real sin_theta_sur_2 = sqrt(1.0-stuff);
-
+ Real sin_theta_sur_2 = sqrt(Real(1.0)-stuff);
+
Vec3 xyz = find_invariant_vector(rot);
Vec3 uvw = find_orthogonal_vector(xyz);
Vec3 rst = find_vector_for_BOD(xyz,uvw);
@@ -216,7 +219,7 @@ Quat extract_from_rotmat(const Mat3& rot)
if(desambiguator >= 1.0) {
q = Quat(0.0, +xyz[0], +xyz[1], +xyz[2]);
} else {
- q = Quat(0, -xyz[0], -xyz[1], -xyz[2]);
+ q = Quat(0.0, -xyz[0], -xyz[1], -xyz[2]);
}
}
--
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