Add qDegreesToRadians and qRadiansToDegrees math functions

Change-Id: I6e9fd76f2d2860f46531a72349b46193b8eeaaa7
Reviewed-by: Samuel Rødal <samuel.rodal@digia.com>

2 files changed, 107 insertions, 0 deletions

diff --git a/src/corelib/kernel/qmath.cpp b/src/corelib/kernel/qmath.cpp
index 1d6fcc2cd6..8f900e2101 100644
--- a/src/corelib/kernel/qmath.cpp
+++ b/src/corelib/kernel/qmath.cpp
@@ -1,6 +1,7 @@
 /****************************************************************************
 **
 ** Copyright (C) 2013 Digia Plc and/or its subsidiary(-ies).
+** Copyright (C) 2013 Laszlo Papp <lpapp@kde.org>
 ** Contact: http://www.qt-project.org/legal
 **
 ** This file is part of the QtCore module of the Qt Toolkit.
@@ -302,4 +303,90 @@ const qreal qt_sine_table[QT_SINE_TABLE_SIZE] = {
     qreal(-0.024541228522912448)
 };
 
+/*!
+    \headerfile <QtMath>
+    \title Generic Math Declarations
+    \ingroup funclists
+
+    \brief The <QtMath> header file includes generic math declarations.
+
+    The global declarations include \l{functions}.
+
+    These functions are partly convenience definitions for basic
+    operations, for instance not available in the Standard Template Library et
+    al.
+*/
+
+/*!
+    \fn float qDegreesToRadians(float degrees)
+    \relates <QtMath>
+    \since 5.1
+
+    \brief The function converts the \a degrees in float to radians.
+
+    The purpose of the function is to aid the conversion as such a convenient
+    function is not part of the Standard Template Library, i.e. in <cmath> or
+    elsewhere.
+
+    Example:
+
+    \snippet code/src_corelib_kernel_qmath.cpp 0
+
+    \sa qRadiansToDegrees()
+*/
+
+/*!
+    \fn double qDegreesToRadians(double degrees)
+    \relates <QtMath>
+    \since 5.1
+
+    \brief The function converts the \a degrees in double to radians.
+
+    The purpose of the function is to aid the conversion as such a convenient
+    function is not part of the Standard Template Library, i.e. in <cmath> or
+    elsewhere.
+
+    Example:
+
+    \snippet code/src_corelib_kernel_qmath.cpp 1
+
+    \sa qRadiansToDegrees()
+*/
+
+/*!
+    \fn float qRadiansToDegrees(float radians)
+    \relates <QtMath>
+    \since 5.1
+
+    \brief The function converts the \a radians in float to degrees.
+
+    The purpose of the function is to aid the conversion as such a convenient
+    function is not part of the Standard Template Library, i.e. in <cmath> or
+    elsewhere.
+
+    Example:
+
+    \snippet code/src_corelib_kernel_qmath.cpp 2
+
+    \sa qDegreesToRadians()
+*/
+
+/*!
+    \fn double qRadiansToDegrees(double radians)
+    \relates <QtMath>
+    \since 5.1
+
+    \brief The function converts the \a radians in double to degrees.
+
+    The purpose of the function is to aid the conversion as such a convenient
+    function is not part of the Standard Template Library, i.e. in <cmath> or
+    elsewhere.
+
+    Example:
+
+    \snippet code/src_corelib_kernel_qmath.cpp 3
+
+    \sa qDegreesToRadians()
+*/
+
 QT_END_NAMESPACE
diff --git a/src/corelib/kernel/qmath.h b/src/corelib/kernel/qmath.h
index 75ec55f845..21e23b9eb0 100644
--- a/src/corelib/kernel/qmath.h
+++ b/src/corelib/kernel/qmath.h
@@ -266,6 +266,26 @@ inline qreal qFastCos(qreal x)
     return qt_sine_table[si] - (qt_sine_table[ci] + 0.5 * qt_sine_table[si] * d) * d;
 }
 
+Q_DECL_CONSTEXPR inline float qDegreesToRadians(float degrees)
+{
+    return degrees * float(M_PI/180);
+}
+
+Q_DECL_CONSTEXPR inline double qDegreesToRadians(double degrees)
+{
+    return degrees * (M_PI / 180);
+}
+
+Q_DECL_CONSTEXPR inline float qRadiansToDegrees(float radians)
+{
+    return radians * float(180/M_PI);
+}
+
+Q_DECL_CONSTEXPR inline double qRadiansToDegrees(double radians)
+{
+    return radians * (180 / M_PI);
+}
+
 QT_END_NAMESPACE
 
 #endif // QMATH_H