Modify QMatrix4x4 and QQuaternion to use qreal internally

Some concerns were expressed about the float precision of QMatrix4x4,
which this change addresses by using qreal instead.

The QVector2D/3D/4D classes still use float internally, so that they
can be used directly in large arrays of vertex values to be uploaded
to an OpenGL server.

QQuaternion is a client-side class, and it should produce rotations
that are consistent with QMatrix4x4.  So its precision was changed too.

A consequence of this change is that the following no longer works
in a portable fashion:

    QMatrix4x4 mat;
    ...
    glLoadMatrixf(mat.constData());

The caller must now repack the argument to convert from qreal to GLfloat.

Reviewed-by: Michael Goddard
Reviewed-by: Andreas

1 files changed, 102 insertions, 107 deletions

diff --git a/src/gui/math3d/qgenericmatrix.h b/src/gui/math3d/qgenericmatrix.h
index fe7ba5f..39c4ed8 100644
--- a/src/gui/math3d/qgenericmatrix.h
+++ b/src/gui/math3d/qgenericmatrix.h
@@ -51,103 +51,103 @@ QT_BEGIN_NAMESPACE
 
 QT_MODULE(Gui)
 
-template <int N, int M, typename T, typename InnerT = T>
+template <int N, int M, typename T>
 class QGenericMatrix
 {
 public:
     QGenericMatrix();
-    QGenericMatrix(const QGenericMatrix<N, M, T, InnerT>& other);
+    QGenericMatrix(const QGenericMatrix<N, M, T>& other);
     explicit QGenericMatrix(const T *values);
 
-    T operator()(int row, int column) const;
-    InnerT& operator()(int row, int column);
+    const T& operator()(int row, int column) const;
+    T& operator()(int row, int column);
 
     bool isIdentity() const;
     void setIdentity();
 
     void fill(T value);
 
-    QGenericMatrix<M, N, T, InnerT> transposed() const;
+    QGenericMatrix<M, N, T> transposed() const;
 
-    QGenericMatrix<N, M, T, InnerT>& operator+=(const QGenericMatrix<N, M, T, InnerT>& other);
-    QGenericMatrix<N, M, T, InnerT>& operator-=(const QGenericMatrix<N, M, T, InnerT>& other);
-    QGenericMatrix<N, M, T, InnerT>& operator*=(T factor);
-    QGenericMatrix<N, M, T, InnerT>& operator/=(T divisor);
-    bool operator==(const QGenericMatrix<N, M, T, InnerT>& other) const;
-    bool operator!=(const QGenericMatrix<N, M, T, InnerT>& other) const;
+    QGenericMatrix<N, M, T>& operator+=(const QGenericMatrix<N, M, T>& other);
+    QGenericMatrix<N, M, T>& operator-=(const QGenericMatrix<N, M, T>& other);
+    QGenericMatrix<N, M, T>& operator*=(T factor);
+    QGenericMatrix<N, M, T>& operator/=(T divisor);
+    bool operator==(const QGenericMatrix<N, M, T>& other) const;
+    bool operator!=(const QGenericMatrix<N, M, T>& other) const;
 
     void toValueArray(T *values);
 
-    InnerT *data() { return m[0]; }
-    const InnerT *data() const { return m[0]; }
-    const InnerT *constData() const { return m[0]; }
+    T *data() { return m[0]; }
+    const T *data() const { return m[0]; }
+    const T *constData() const { return m[0]; }
 
 #if !defined(Q_NO_TEMPLATE_FRIENDS)
-    template<int NN, int MM, typename TT, typename ITT>
-    friend QGenericMatrix<NN, MM, TT, ITT> operator+(const QGenericMatrix<NN, MM, TT, ITT>& m1, const QGenericMatrix<NN, MM, TT, ITT>& m2);
-    template<int NN, int MM, typename TT, typename ITT>
-    friend QGenericMatrix<NN, MM, TT, ITT> operator-(const QGenericMatrix<NN, MM, TT, ITT>& m1, const QGenericMatrix<NN, MM, TT, ITT>& m2);
-    template<int NN, int M1, int M2, typename TT, typename ITT>
-    friend QGenericMatrix<M1, M2, TT, ITT> operator*(const QGenericMatrix<NN, M2, TT, ITT>& m1, const QGenericMatrix<M1, NN, TT, ITT>& m2);
-    template<int NN, int MM, typename TT, typename ITT>
-    friend QGenericMatrix<NN, MM, TT, ITT> operator-(const QGenericMatrix<NN, MM, TT, ITT>& matrix);
-    template<int NN, int MM, typename TT, typename ITT>
-    friend QGenericMatrix<NN, MM, TT, ITT> operator*(TT factor, const QGenericMatrix<NN, MM, TT, ITT>& matrix);
-    template<int NN, int MM, typename TT, typename ITT>
-    friend QGenericMatrix<NN, MM, TT, ITT> operator*(const QGenericMatrix<NN, MM, TT, ITT>& matrix, TT factor);
-    template<int NN, int MM, typename TT, typename ITT>
-    friend QGenericMatrix<NN, MM, TT, ITT> operator/(const QGenericMatrix<NN, MM, TT, ITT>& matrix, TT divisor);
+    template<int NN, int MM, typename TT>
+    friend QGenericMatrix<NN, MM, TT> operator+(const QGenericMatrix<NN, MM, TT>& m1, const QGenericMatrix<NN, MM, TT>& m2);
+    template<int NN, int MM, typename TT>
+    friend QGenericMatrix<NN, MM, TT> operator-(const QGenericMatrix<NN, MM, TT>& m1, const QGenericMatrix<NN, MM, TT>& m2);
+    template<int NN, int M1, int M2, typename TT>
+    friend QGenericMatrix<M1, M2, TT> operator*(const QGenericMatrix<NN, M2, TT>& m1, const QGenericMatrix<M1, NN, TT>& m2);
+    template<int NN, int MM, typename TT>
+    friend QGenericMatrix<NN, MM, TT> operator-(const QGenericMatrix<NN, MM, TT>& matrix);
+    template<int NN, int MM, typename TT>
+    friend QGenericMatrix<NN, MM, TT> operator*(TT factor, const QGenericMatrix<NN, MM, TT>& matrix);
+    template<int NN, int MM, typename TT>
+    friend QGenericMatrix<NN, MM, TT> operator*(const QGenericMatrix<NN, MM, TT>& matrix, TT factor);
+    template<int NN, int MM, typename TT>
+    friend QGenericMatrix<NN, MM, TT> operator/(const QGenericMatrix<NN, MM, TT>& matrix, TT divisor);
 
 private:
 #endif
-    InnerT m[N][M];    // Column-major order to match OpenGL.
+    T m[N][M];    // Column-major order to match OpenGL.
 
     QGenericMatrix(int) {}       // Construct without initializing identity matrix.
 
 #if !defined(Q_NO_TEMPLATE_FRIENDS)
-    template <int NN, int MM, typename TT, typename ITT>
+    template <int NN, int MM, typename TT>
     friend class QGenericMatrix;
 #endif
 };
 
-template <int N, int M, typename T, typename InnerT>
-Q_INLINE_TEMPLATE QGenericMatrix<N, M, T, InnerT>::QGenericMatrix()
+template <int N, int M, typename T>
+Q_INLINE_TEMPLATE QGenericMatrix<N, M, T>::QGenericMatrix()
 {
     setIdentity();
 }
 
-template <int N, int M, typename T, typename InnerT>
-Q_INLINE_TEMPLATE QGenericMatrix<N, M, T, InnerT>::QGenericMatrix(const QGenericMatrix<N, M, T, InnerT>& other)
+template <int N, int M, typename T>
+Q_INLINE_TEMPLATE QGenericMatrix<N, M, T>::QGenericMatrix(const QGenericMatrix<N, M, T>& other)
 {
     for (int col = 0; col < N; ++col)
         for (int row = 0; row < M; ++row)
             m[col][row] = other.m[col][row];
 }
 
-template <int N, int M, typename T, typename InnerT>
-Q_OUTOFLINE_TEMPLATE QGenericMatrix<N, M, T, InnerT>::QGenericMatrix(const T *values)
+template <int N, int M, typename T>
+Q_OUTOFLINE_TEMPLATE QGenericMatrix<N, M, T>::QGenericMatrix(const T *values)
 {
     for (int col = 0; col < N; ++col)
         for (int row = 0; row < M; ++row)
             m[col][row] = values[row * N + col];
 }
 
-template <int N, int M, typename T, typename InnerT>
-Q_INLINE_TEMPLATE T QGenericMatrix<N, M, T, InnerT>::operator()(int row, int column) const
+template <int N, int M, typename T>
+Q_INLINE_TEMPLATE const T& QGenericMatrix<N, M, T>::operator()(int row, int column) const
 {
     Q_ASSERT(row >= 0 && row < M && column >= 0 && column < N);
-    return T(m[column][row]);
+    return m[column][row];
 }
 
-template <int N, int M, typename T, typename InnerT>
-Q_INLINE_TEMPLATE InnerT& QGenericMatrix<N, M, T, InnerT>::operator()(int row, int column)
+template <int N, int M, typename T>
+Q_INLINE_TEMPLATE T& QGenericMatrix<N, M, T>::operator()(int row, int column)
 {
     Q_ASSERT(row >= 0 && row < M && column >= 0 && column < N);
     return m[column][row];
 }
 
-template <int N, int M, typename T, typename InnerT>
-Q_OUTOFLINE_TEMPLATE bool QGenericMatrix<N, M, T, InnerT>::isIdentity() const
+template <int N, int M, typename T>
+Q_OUTOFLINE_TEMPLATE bool QGenericMatrix<N, M, T>::isIdentity() const
 {
     for (int col = 0; col < N; ++col) {
         for (int row = 0; row < M; ++row) {
@@ -163,8 +163,8 @@ Q_OUTOFLINE_TEMPLATE bool QGenericMatrix<N, M, T, InnerT>::isIdentity() const
     return true;
 }
 
-template <int N, int M, typename T, typename InnerT>
-Q_OUTOFLINE_TEMPLATE void QGenericMatrix<N, M, T, InnerT>::setIdentity()
+template <int N, int M, typename T>
+Q_OUTOFLINE_TEMPLATE void QGenericMatrix<N, M, T>::setIdentity()
 {
     for (int col = 0; col < N; ++col) {
         for (int row = 0; row < M; ++row) {
@@ -176,51 +176,50 @@ Q_OUTOFLINE_TEMPLATE void QGenericMatrix<N, M, T, InnerT>::setIdentity()
     }
 }
 
-template <int N, int M, typename T, typename InnerT>
-Q_OUTOFLINE_TEMPLATE void QGenericMatrix<N, M, T, InnerT>::fill(T value)
+template <int N, int M, typename T>
+Q_OUTOFLINE_TEMPLATE void QGenericMatrix<N, M, T>::fill(T value)
 {
     for (int col = 0; col < N; ++col)
         for (int row = 0; row < M; ++row)
             m[col][row] = value;
 }
 
-template <int N, int M, typename T, typename InnerT>
-Q_OUTOFLINE_TEMPLATE QGenericMatrix<M, N, T, InnerT> QGenericMatrix<N, M, T, InnerT>::transposed() const
+template <int N, int M, typename T>
+Q_OUTOFLINE_TEMPLATE QGenericMatrix<M, N, T> QGenericMatrix<N, M, T>::transposed() const
 {
-    QGenericMatrix<M, N, T, InnerT> result(1);
+    QGenericMatrix<M, N, T> result(1);
     for (int row = 0; row < M; ++row)
         for (int col = 0; col < N; ++col)
             result.m[row][col] = m[col][row];
     return result;
 }
 
-template <int N, int M, typename T, typename InnerT>
-Q_OUTOFLINE_TEMPLATE QGenericMatrix<N, M, T, InnerT>& QGenericMatrix<N, M, T, InnerT>::operator+=(const QGenericMatrix<N, M, T, InnerT>& other)
+template <int N, int M, typename T>
+Q_OUTOFLINE_TEMPLATE QGenericMatrix<N, M, T>& QGenericMatrix<N, M, T>::operator+=(const QGenericMatrix<N, M, T>& other)
 {
     for (int index = 0; index < N * M; ++index)
         m[0][index] += other.m[0][index];
     return *this;
 }
 
-template <int N, int M, typename T, typename InnerT>
-Q_OUTOFLINE_TEMPLATE QGenericMatrix<N, M, T, InnerT>& QGenericMatrix<N, M, T, InnerT>::operator-=(const QGenericMatrix<N, M, T, InnerT>& other)
+template <int N, int M, typename T>
+Q_OUTOFLINE_TEMPLATE QGenericMatrix<N, M, T>& QGenericMatrix<N, M, T>::operator-=(const QGenericMatrix<N, M, T>& other)
 {
     for (int index = 0; index < N * M; ++index)
         m[0][index] -= other.m[0][index];
     return *this;
 }
 
-template <int N, int M, typename T, typename InnerT>
-Q_OUTOFLINE_TEMPLATE QGenericMatrix<N, M, T, InnerT>& QGenericMatrix<N, M, T, InnerT>::operator*=(T factor)
+template <int N, int M, typename T>
+Q_OUTOFLINE_TEMPLATE QGenericMatrix<N, M, T>& QGenericMatrix<N, M, T>::operator*=(T factor)
 {
-    InnerT f(factor);
     for (int index = 0; index < N * M; ++index)
-        m[0][index] *= f;
+        m[0][index] *= factor;
     return *this;
 }
 
-template <int N, int M, typename T, typename InnerT>
-Q_OUTOFLINE_TEMPLATE bool QGenericMatrix<N, M, T, InnerT>::operator==(const QGenericMatrix<N, M, T, InnerT>& other) const
+template <int N, int M, typename T>
+Q_OUTOFLINE_TEMPLATE bool QGenericMatrix<N, M, T>::operator==(const QGenericMatrix<N, M, T>& other) const
 {
     for (int index = 0; index < N * M; ++index) {
         if (m[0][index] != other.m[0][index])
@@ -229,8 +228,8 @@ Q_OUTOFLINE_TEMPLATE bool QGenericMatrix<N, M, T, InnerT>::operator==(const QGen
     return true;
 }
 
-template <int N, int M, typename T, typename InnerT>
-Q_OUTOFLINE_TEMPLATE bool QGenericMatrix<N, M, T, InnerT>::operator!=(const QGenericMatrix<N, M, T, InnerT>& other) const
+template <int N, int M, typename T>
+Q_OUTOFLINE_TEMPLATE bool QGenericMatrix<N, M, T>::operator!=(const QGenericMatrix<N, M, T>& other) const
 {
     for (int index = 0; index < N * M; ++index) {
         if (m[0][index] != other.m[0][index])
@@ -239,40 +238,39 @@ Q_OUTOFLINE_TEMPLATE bool QGenericMatrix<N, M, T, InnerT>::operator!=(const QGen
     return false;
 }
 
-template <int N, int M, typename T, typename InnerT>
-Q_OUTOFLINE_TEMPLATE QGenericMatrix<N, M, T, InnerT>& QGenericMatrix<N, M, T, InnerT>::operator/=(T divisor)
+template <int N, int M, typename T>
+Q_OUTOFLINE_TEMPLATE QGenericMatrix<N, M, T>& QGenericMatrix<N, M, T>::operator/=(T divisor)
 {
-    InnerT d(divisor);
     for (int index = 0; index < N * M; ++index)
-        m[0][index] /= d;
+        m[0][index] /= divisor;
     return *this;
 }
 
-template <int N, int M, typename T, typename InnerT>
-Q_OUTOFLINE_TEMPLATE QGenericMatrix<N, M, T, InnerT> operator+(const QGenericMatrix<N, M, T, InnerT>& m1, const QGenericMatrix<N, M, T, InnerT>& m2)
+template <int N, int M, typename T>
+Q_OUTOFLINE_TEMPLATE QGenericMatrix<N, M, T> operator+(const QGenericMatrix<N, M, T>& m1, const QGenericMatrix<N, M, T>& m2)
 {
-    QGenericMatrix<N, M, T, InnerT> result(1);
+    QGenericMatrix<N, M, T> result(1);
     for (int index = 0; index < N * M; ++index)
         result.m[0][index] = m1.m[0][index] + m2.m[0][index];
     return result;
 }
 
-template <int N, int M, typename T, typename InnerT>
-Q_OUTOFLINE_TEMPLATE QGenericMatrix<N, M, T, InnerT> operator-(const QGenericMatrix<N, M, T, InnerT>& m1, const QGenericMatrix<N, M, T, InnerT>& m2)
+template <int N, int M, typename T>
+Q_OUTOFLINE_TEMPLATE QGenericMatrix<N, M, T> operator-(const QGenericMatrix<N, M, T>& m1, const QGenericMatrix<N, M, T>& m2)
 {
-    QGenericMatrix<N, M, T, InnerT> result(1);
+    QGenericMatrix<N, M, T> result(1);
     for (int index = 0; index < N * M; ++index)
         result.m[0][index] = m1.m[0][index] - m2.m[0][index];
     return result;
 }
 
-template <int N, int M1, int M2, typename T, typename InnerT>
-Q_OUTOFLINE_TEMPLATE QGenericMatrix<M1, M2, T, InnerT> operator*(const QGenericMatrix<N, M2, T, InnerT>& m1, const QGenericMatrix<M1, N, T, InnerT>& m2)
+template <int N, int M1, int M2, typename T>
+Q_OUTOFLINE_TEMPLATE QGenericMatrix<M1, M2, T> operator*(const QGenericMatrix<N, M2, T>& m1, const QGenericMatrix<M1, N, T>& m2)
 {
-    QGenericMatrix<M1, M2, T, InnerT> result(1);
+    QGenericMatrix<M1, M2, T> result(1);
     for (int row = 0; row < M2; ++row) {
         for (int col = 0; col < M1; ++col) {
-            InnerT sum(0.0f);
+            T sum(0.0f);
             for (int j = 0; j < N; ++j)
                 sum += m1.m[j][row] * m2.m[col][j];
             result.m[col][row] = sum;
@@ -281,47 +279,44 @@ Q_OUTOFLINE_TEMPLATE QGenericMatrix<M1, M2, T, InnerT> operator*(const QGenericM
     return result;
 }
 
-template <int N, int M, typename T, typename InnerT>
-Q_OUTOFLINE_TEMPLATE QGenericMatrix<N, M, T, InnerT> operator-(const QGenericMatrix<N, M, T, InnerT>& matrix)
+template <int N, int M, typename T>
+Q_OUTOFLINE_TEMPLATE QGenericMatrix<N, M, T> operator-(const QGenericMatrix<N, M, T>& matrix)
 {
-    QGenericMatrix<N, M, T, InnerT> result(1);
+    QGenericMatrix<N, M, T> result(1);
     for (int index = 0; index < N * M; ++index)
         result.m[0][index] = -matrix.m[0][index];
     return result;
 }
 
-template <int N, int M, typename T, typename InnerT>
-Q_OUTOFLINE_TEMPLATE QGenericMatrix<N, M, T, InnerT> operator*(T factor, const QGenericMatrix<N, M, T, InnerT>& matrix)
+template <int N, int M, typename T>
+Q_OUTOFLINE_TEMPLATE QGenericMatrix<N, M, T> operator*(T factor, const QGenericMatrix<N, M, T>& matrix)
 {
-    InnerT f(factor);
-    QGenericMatrix<N, M, T, InnerT> result(1);
+    QGenericMatrix<N, M, T> result(1);
     for (int index = 0; index < N * M; ++index)
-        result.m[0][index] = matrix.m[0][index] * f;
+        result.m[0][index] = matrix.m[0][index] * factor;
     return result;
 }
 
-template <int N, int M, typename T, typename InnerT>
-Q_OUTOFLINE_TEMPLATE QGenericMatrix<N, M, T, InnerT> operator*(const QGenericMatrix<N, M, T, InnerT>& matrix, T factor)
+template <int N, int M, typename T>
+Q_OUTOFLINE_TEMPLATE QGenericMatrix<N, M, T> operator*(const QGenericMatrix<N, M, T>& matrix, T factor)
 {
-    InnerT f(factor);
-    QGenericMatrix<N, M, T, InnerT> result(1);
+    QGenericMatrix<N, M, T> result(1);
     for (int index = 0; index < N * M; ++index)
-        result.m[0][index] = matrix.m[0][index] * f;
+        result.m[0][index] = matrix.m[0][index] * factor;
     return result;
 }
 
-template <int N, int M, typename T, typename InnerT>
-Q_OUTOFLINE_TEMPLATE QGenericMatrix<N, M, T, InnerT> operator/(const QGenericMatrix<N, M, T, InnerT>& matrix, T divisor)
+template <int N, int M, typename T>
+Q_OUTOFLINE_TEMPLATE QGenericMatrix<N, M, T> operator/(const QGenericMatrix<N, M, T>& matrix, T divisor)
 {
-    InnerT d(divisor);
-    QGenericMatrix<N, M, T, InnerT> result(1);
+    QGenericMatrix<N, M, T> result(1);
     for (int index = 0; index < N * M; ++index)
-        result.m[0][index] = matrix.m[0][index] / d;
+        result.m[0][index] = matrix.m[0][index] / divisor;
     return result;
 }
 
-template <int N, int M, typename T, typename InnerT>
-Q_OUTOFLINE_TEMPLATE void QGenericMatrix<N, M, T, InnerT>::toValueArray(T *values)
+template <int N, int M, typename T>
+Q_OUTOFLINE_TEMPLATE void QGenericMatrix<N, M, T>::toValueArray(T *values)
 {
     for (int col = 0; col < N; ++col)
         for (int row = 0; row < M; ++row)
@@ -329,22 +324,22 @@ Q_OUTOFLINE_TEMPLATE void QGenericMatrix<N, M, T, InnerT>::toValueArray(T *value
 }
 
 // Define aliases for the useful variants of QGenericMatrix.
-typedef QGenericMatrix<2, 2, qreal, float> QMatrix2x2;
-typedef QGenericMatrix<2, 3, qreal, float> QMatrix2x3;
-typedef QGenericMatrix<2, 4, qreal, float> QMatrix2x4;
-typedef QGenericMatrix<3, 2, qreal, float> QMatrix3x2;
-typedef QGenericMatrix<3, 3, qreal, float> QMatrix3x3;
-typedef QGenericMatrix<3, 4, qreal, float> QMatrix3x4;
-typedef QGenericMatrix<4, 2, qreal, float> QMatrix4x2;
-typedef QGenericMatrix<4, 3, qreal, float> QMatrix4x3;
+typedef QGenericMatrix<2, 2, qreal> QMatrix2x2;
+typedef QGenericMatrix<2, 3, qreal> QMatrix2x3;
+typedef QGenericMatrix<2, 4, qreal> QMatrix2x4;
+typedef QGenericMatrix<3, 2, qreal> QMatrix3x2;
+typedef QGenericMatrix<3, 3, qreal> QMatrix3x3;
+typedef QGenericMatrix<3, 4, qreal> QMatrix3x4;
+typedef QGenericMatrix<4, 2, qreal> QMatrix4x2;
+typedef QGenericMatrix<4, 3, qreal> QMatrix4x3;
 
 #ifndef QT_NO_DEBUG_STREAM
 
-template <int N, int M, typename T, typename InnerT>
-QDebug operator<<(QDebug dbg, const QGenericMatrix<N, M, T, InnerT> &m)
+template <int N, int M, typename T>
+QDebug operator<<(QDebug dbg, const QGenericMatrix<N, M, T> &m)
 {
     dbg.nospace() << "QGenericMatrix<" << N << ", " << M
-        << ", " << QTypeInfo<T>::name() << ", " << QTypeInfo<InnerT>::name()
+        << ", " << QTypeInfo<T>::name()
         << ">(" << endl << qSetFieldWidth(10);
     for (int row = 0; row < M; ++row) {
         for (int col = 0; col < N; ++col)