diff options
| -rw-r--r-- | src/gui/math3d/qmatrix4x4.cpp | 46 | ||||
| -rw-r--r-- | src/gui/math3d/qmatrix4x4.h | 7 | ||||
| -rw-r--r-- | tests/auto/gui/math3d/qmatrixnxn/tst_qmatrixnxn.cpp | 35 |
3 files changed, 88 insertions, 0 deletions
diff --git a/src/gui/math3d/qmatrix4x4.cpp b/src/gui/math3d/qmatrix4x4.cpp index 0b3c5b4cb9..5d7a176fe5 100644 --- a/src/gui/math3d/qmatrix4x4.cpp +++ b/src/gui/math3d/qmatrix4x4.cpp @@ -1542,6 +1542,52 @@ void QMatrix4x4::lookAt(const QVector3D& eye, const QVector3D& center, const QVe #endif /*! + \fn void QMatrix4x4::viewport(const QRectF &rect) + \overload + + Sets up viewport transform for viewport bounded by \a rect and with near and far set + to 0 and 1 respectively. +*/ + +/*! + Multiplies this matrix by another that performs the scale and bias + transformation used by OpenGL to transform from normalized device + coordinates (NDC) to viewport (window) coordinates. That is it maps + points from the cube ranging over [-1, 1] in each dimension to the + viewport with it's near-lower-left corner at (\a left, \a bottom, \a nearPlane) + and with size (\a width, \a height, \a farPlane - \a nearPlane). + + This matches the transform used by the fixed function OpenGL viewport + transform controlled by the functions glViewport() and glDepthRange(). + */ +void QMatrix4x4::viewport(float left, float bottom, float width, float height, float nearPlane, float farPlane) +{ + const float w2 = width / 2.0f; + const float h2 = height / 2.0f; + + QMatrix4x4 m(1); + m.m[0][0] = w2; + m.m[1][0] = 0.0f; + m.m[2][0] = 0.0f; + m.m[3][0] = left + w2; + m.m[0][1] = 0.0f; + m.m[1][1] = h2; + m.m[2][1] = 0.0f; + m.m[3][1] = bottom + h2; + m.m[0][2] = 0.0f; + m.m[1][2] = 0.0f; + m.m[2][2] = (farPlane - nearPlane) / 2.0f; + m.m[3][2] = (nearPlane + farPlane) / 2.0f; + m.m[0][3] = 0.0f; + m.m[1][3] = 0.0f; + m.m[2][3] = 0.0f; + m.m[3][3] = 1.0f; + m.flagBits = General; + + *this *= m; +} + +/*! \deprecated Flips between right-handed and left-handed coordinate systems diff --git a/src/gui/math3d/qmatrix4x4.h b/src/gui/math3d/qmatrix4x4.h index d4ba7d64d8..c42ccc2dc5 100644 --- a/src/gui/math3d/qmatrix4x4.h +++ b/src/gui/math3d/qmatrix4x4.h @@ -148,6 +148,8 @@ public: #ifndef QT_NO_VECTOR3D void lookAt(const QVector3D& eye, const QVector3D& center, const QVector3D& up); #endif + void viewport(const QRectF &rect); + void viewport(float left, float bottom, float width, float height, float nearPlane = 0.0f, float farPlane = 1.0f); void flipCoordinates(); void copyDataTo(float *values) const; @@ -1077,6 +1079,11 @@ inline float *QMatrix4x4::data() return *m; } +inline void QMatrix4x4::viewport(const QRectF &rect) +{ + viewport(rect.x(), rect.y(), rect.width(), rect.height()); +} + #ifndef QT_NO_DEBUG_STREAM Q_GUI_EXPORT QDebug operator<<(QDebug dbg, const QMatrix4x4 &m); #endif diff --git a/tests/auto/gui/math3d/qmatrixnxn/tst_qmatrixnxn.cpp b/tests/auto/gui/math3d/qmatrixnxn/tst_qmatrixnxn.cpp index 98f1c1c8f9..e492a8f7bf 100644 --- a/tests/auto/gui/math3d/qmatrixnxn/tst_qmatrixnxn.cpp +++ b/tests/auto/gui/math3d/qmatrixnxn/tst_qmatrixnxn.cpp @@ -147,6 +147,7 @@ private slots: void ortho(); void frustum(); void perspective(); + void viewport(); void flipCoordinates(); void convertGeneric(); @@ -2794,6 +2795,40 @@ void tst_QMatrixNxN::perspective() QVERIFY(m5.isIdentity()); } +// Test viewport transformations +void tst_QMatrixNxN::viewport() +{ + // Uses default depth range of 0->1 + QMatrix4x4 m1; + m1.viewport(0.0f, 0.0f, 1024.0f, 768.0f); + + // Lower left + QVector4D p1 = m1 * QVector4D(-1.0f, -1.0f, 0.0f, 1.0f); + QVERIFY(qFuzzyIsNull(p1.x())); + QVERIFY(qFuzzyIsNull(p1.y())); + QVERIFY(qFuzzyCompare(p1.z(), 0.5f)); + + // Lower right + QVector4D p2 = m1 * QVector4D(1.0f, -1.0f, 0.0f, 1.0f); + QVERIFY(qFuzzyCompare(p2.x(), 1024.0f)); + QVERIFY(qFuzzyIsNull(p2.y())); + + // Upper right + QVector4D p3 = m1 * QVector4D(1.0f, 1.0f, 0.0f, 1.0f); + QVERIFY(qFuzzyCompare(p3.x(), 1024.0f)); + QVERIFY(qFuzzyCompare(p3.y(), 768.0f)); + + // Upper left + QVector4D p4 = m1 * QVector4D(-1.0f, 1.0f, 0.0f, 1.0f); + QVERIFY(qFuzzyIsNull(p4.x())); + QVERIFY(qFuzzyCompare(p4.y(), 768.0f)); + + // Center + QVector4D p5 = m1 * QVector4D(0.0f, 0.0f, 0.0f, 1.0f); + QVERIFY(qFuzzyCompare(p5.x(), 1024.0f / 2.0f)); + QVERIFY(qFuzzyCompare(p5.y(), 768.0f / 2.0f)); +} + // Test left-handed vs right-handed coordinate flipping. void tst_QMatrixNxN::flipCoordinates() { |