From 750147f5c9ab892f1892fe33718fc4c402f2f73c Mon Sep 17 00:00:00 2001 From: Sarah Smith Date: Mon, 25 Jul 2011 14:38:08 +1000 Subject: Improve doc to avoid row vs col major confusion. There has been a few reports of user confusion from the fact that the constData and data functions return results in column-major format. There is nothing in the doc anywhere that states this, and nothing states that the class is especially for OpenGL which would give a clue at least. Change-Id: I3a9afde0fbeb8b9d2bcba6a387620b60a56774b9 Reviewed-on: http://codereview.qt.nokia.com/2066 Reviewed-by: Qt Sanity Bot Reviewed-by: Julian de Bhal --- src/gui/math3d/qmatrix4x4.cpp | 16 ++++++++++++++++ 1 file changed, 16 insertions(+) (limited to 'src/gui/math3d') diff --git a/src/gui/math3d/qmatrix4x4.cpp b/src/gui/math3d/qmatrix4x4.cpp index 837bd519b8..cef92af66b 100644 --- a/src/gui/math3d/qmatrix4x4.cpp +++ b/src/gui/math3d/qmatrix4x4.cpp @@ -55,6 +55,20 @@ QT_BEGIN_NAMESPACE \since 4.6 \ingroup painting-3D + The QMatrix4x4 class in general is treated as a row-major matrix, in that the + constructors and operator() functions take data in row-major format, as is + familiar in C-style usage. + + Internally the data is stored as column-major format, so as to be optimal for + passing to OpenGL functions, which expect column-major data. + + When using these functions be aware that they return data in \bold{column-major} + format: + \list + \o data() + \o constData() + \endlist + \sa QVector3D, QGenericMatrix */ @@ -1725,6 +1739,7 @@ QRectF QMatrix4x4::mapRect(const QRectF& rect) const \fn const qreal *QMatrix4x4::data() const Returns a constant pointer to the raw data of this matrix. + This raw data is stored in column-major format. \sa constData() */ @@ -1733,6 +1748,7 @@ QRectF QMatrix4x4::mapRect(const QRectF& rect) const \fn const qreal *QMatrix4x4::constData() const Returns a constant pointer to the raw data of this matrix. + This raw data is stored in column-major format. \sa data() */ -- cgit v1.2.3