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authorSarah Smith <sarah.j.smith@nokia.com>2011-07-25 14:38:08 +1000
committerQt by Nokia <qt-info@nokia.com>2011-07-26 03:27:34 +0200
commit750147f5c9ab892f1892fe33718fc4c402f2f73c (patch)
treec6626c73d2f4797d11962711c4ba3c5665afa04e /src
parentac22379a75b2e252ae0fe6fe2585e3beb2096be9 (diff)
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 <qt_sanity_bot@ovi.com> Reviewed-by: Julian de Bhal <julian.debhal@nokia.com>
Diffstat (limited to 'src')
-rw-r--r--src/gui/math3d/qmatrix4x4.cpp16
1 files changed, 16 insertions, 0 deletions
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()
*/