From b5076fb392894e71b44b4762d0567354ef1c8a9e Mon Sep 17 00:00:00 2001 From: Sarah Smith Date: Wed, 16 Feb 2011 14:58:28 +1000 Subject: Add a "note well" to QVectorXD re float precision. Several bug-reports ask for clarifications/warnings in the doc for this class, since it stores in float, but has a qreal interface (as per qt convention). Change-Id: I32ffcde3733866942134e881567eef367a5620f5 Task-number: QTBUG-8216 Reviewed-by: Rhys Weatherley --- src/gui/math3d/qvector2d.cpp | 5 +++++ src/gui/math3d/qvector3d.cpp | 5 +++++ src/gui/math3d/qvector4d.cpp | 5 +++++ 3 files changed, 15 insertions(+) diff --git a/src/gui/math3d/qvector2d.cpp b/src/gui/math3d/qvector2d.cpp index 7f5a937..1fccfc9 100644 --- a/src/gui/math3d/qvector2d.cpp +++ b/src/gui/math3d/qvector2d.cpp @@ -60,6 +60,11 @@ QT_BEGIN_NAMESPACE The QVector2D class can also be used to represent vertices in 2D space. We therefore do not need to provide a separate vertex class. + \bold{Note:} By design values in the QVector2D instance are stored as \c float. + This means that on platforms where the \c qreal arguments to QVector2D + functions are represented by \c double values, it is possible to + lose precision. + \sa QVector3D, QVector4D, QQuaternion */ diff --git a/src/gui/math3d/qvector3d.cpp b/src/gui/math3d/qvector3d.cpp index 2414b5f..7bf0400 100644 --- a/src/gui/math3d/qvector3d.cpp +++ b/src/gui/math3d/qvector3d.cpp @@ -63,6 +63,11 @@ QT_BEGIN_NAMESPACE The QVector3D class can also be used to represent vertices in 3D space. We therefore do not need to provide a separate vertex class. + \bold{Note:} By design values in the QVector3D instance are stored as \c float. + This means that on platforms where the \c qreal arguments to QVector3D + functions are represented by \c double values, it is possible to + lose precision. + \sa QVector2D, QVector4D, QQuaternion */ diff --git a/src/gui/math3d/qvector4d.cpp b/src/gui/math3d/qvector4d.cpp index 74dedc4..23befc0 100644 --- a/src/gui/math3d/qvector4d.cpp +++ b/src/gui/math3d/qvector4d.cpp @@ -59,6 +59,11 @@ QT_BEGIN_NAMESPACE The QVector4D class can also be used to represent vertices in 4D space. We therefore do not need to provide a separate vertex class. + \bold{Note:} By design values in the QVector4D instance are stored as \c float. + This means that on platforms where the \c qreal arguments to QVector4D + functions are represented by \c double values, it is possible to + lose precision. + \sa QQuaternion, QVector2D, QVector3D */ -- cgit v0.12