diff options
Diffstat (limited to 'src/gui/math3d/qmatrix4x4.cpp')
| -rw-r--r-- | src/gui/math3d/qmatrix4x4.cpp | 22 |
1 files changed, 20 insertions, 2 deletions
diff --git a/src/gui/math3d/qmatrix4x4.cpp b/src/gui/math3d/qmatrix4x4.cpp index ed1b13d..00e8f15 100644 --- a/src/gui/math3d/qmatrix4x4.cpp +++ b/src/gui/math3d/qmatrix4x4.cpp @@ -1430,6 +1430,24 @@ QMatrix QMatrix4x4::toAffine() const m[3][0], m[3][1]); } +/*! + Returns the conventional Qt 2D transformation matrix that + corresponds to this matrix. + + The returned QTransform is formed by simply dropping the + third row and third column of the QMatrix4x4. This is suitable + for implementing orthographic projections where the z co-ordinate + should be dropped rather than projected. + + \sa toAffine() +*/ +QTransform QMatrix4x4::toTransform() const +{ + return QTransform(m[0][0], m[0][1], m[0][3], + m[1][0], m[1][1], m[1][3], + m[3][0], m[3][1], m[3][3]); +} + static const qreal inv_dist_to_plane = 1. / 1024.; /*! @@ -1437,8 +1455,8 @@ static const qreal inv_dist_to_plane = 1. / 1024.; corresponds to this matrix. If \a distanceToPlane is non-zero, it indicates a projection - factor to use to adjust for the z co-ordinate. The default - value of 1024 corresponds to the projection factor used + factor to use to adjust for the z co-ordinate. The value of + 1024 corresponds to the projection factor used by QTransform::rotate() for the x and y axes. If \a distanceToPlane is zero, then the returned QTransform |