src/corelib/kernel/qmath.h
changeset 0 1918ee327afb
child 3 41300fa6a67c
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/src/corelib/kernel/qmath.h	Mon Jan 11 14:00:40 2010 +0000
@@ -0,0 +1,167 @@
+/****************************************************************************
+**
+** Copyright (C) 2009 Nokia Corporation and/or its subsidiary(-ies).
+** All rights reserved.
+** Contact: Nokia Corporation (qt-info@nokia.com)
+**
+** This file is part of the QtCore module of the Qt Toolkit.
+**
+** $QT_BEGIN_LICENSE:LGPL$
+** No Commercial Usage
+** This file contains pre-release code and may not be distributed.
+** You may use this file in accordance with the terms and conditions
+** contained in the Technology Preview License Agreement accompanying
+** this package.
+**
+** GNU Lesser General Public License Usage
+** Alternatively, this file may be used under the terms of the GNU Lesser
+** General Public License version 2.1 as published by the Free Software
+** Foundation and appearing in the file LICENSE.LGPL included in the
+** packaging of this file.  Please review the following information to
+** ensure the GNU Lesser General Public License version 2.1 requirements
+** will be met: http://www.gnu.org/licenses/old-licenses/lgpl-2.1.html.
+**
+** In addition, as a special exception, Nokia gives you certain additional
+** rights.  These rights are described in the Nokia Qt LGPL Exception
+** version 1.1, included in the file LGPL_EXCEPTION.txt in this package.
+**
+** If you have questions regarding the use of this file, please contact
+** Nokia at qt-info@nokia.com.
+**
+**
+**
+**
+**
+**
+**
+**
+** $QT_END_LICENSE$
+**
+****************************************************************************/
+
+#ifndef QMATH_H
+#define QMATH_H
+
+#include <math.h>
+
+#include <QtCore/qglobal.h>
+
+QT_BEGIN_HEADER
+
+QT_BEGIN_NAMESPACE
+
+QT_MODULE(Core)
+
+#define QT_SINE_TABLE_SIZE 256
+
+extern Q_CORE_EXPORT const qreal qt_sine_table[QT_SINE_TABLE_SIZE];
+
+inline int qCeil(qreal v)
+{
+#ifdef QT_USE_MATH_H_FLOATS
+    if (sizeof(qreal) == sizeof(float))
+        return int(ceilf(float(v)));
+    else
+#endif
+        return int(ceil(v));
+}
+
+inline int qFloor(qreal v)
+{
+#ifdef QT_USE_MATH_H_FLOATS
+    if (sizeof(qreal) == sizeof(float))
+        return int(floorf(float(v)));
+    else
+#endif
+        return int(floor(v));
+}
+
+inline qreal qSin(qreal v)
+{
+#ifdef QT_USE_MATH_H_FLOATS
+    if (sizeof(qreal) == sizeof(float))
+        return sinf(float(v));
+    else
+#endif
+        return sin(v);
+}
+
+inline qreal qCos(qreal v)
+{
+#ifdef QT_USE_MATH_H_FLOATS
+    if (sizeof(qreal) == sizeof(float))
+        return cosf(float(v));
+    else
+#endif
+        return cos(v);
+}
+
+inline qreal qAcos(qreal v)
+{
+#ifdef QT_USE_MATH_H_FLOATS
+    if (sizeof(qreal) == sizeof(float))
+        return acosf(float(v));
+    else
+#endif
+        return acos(v);
+}
+
+inline qreal qSqrt(qreal v)
+{
+#ifdef QT_USE_MATH_H_FLOATS
+    if (sizeof(qreal) == sizeof(float))
+        return sqrtf(float(v));
+    else
+#endif
+        return sqrt(v);
+}
+
+inline qreal qLn(qreal v)
+{
+#ifdef QT_USE_MATH_H_FLOATS
+    if (sizeof(qreal) == sizeof(float))
+        return logf(float(v));
+    else
+#endif
+        return log(v);
+}
+
+inline qreal qPow(qreal x, qreal y)
+{
+#ifdef QT_USE_MATH_H_FLOATS
+    if (sizeof(qreal) == sizeof(float))
+        return powf(float(x), float(y));
+    else
+#endif
+        return pow(x, y);
+}
+
+#ifndef M_PI
+#define M_PI (3.14159265358979323846)
+#endif
+
+inline qreal qFastSin(qreal x)
+{
+    int si = int(x * (0.5 * QT_SINE_TABLE_SIZE / M_PI)); // Would be more accurate with qRound, but slower.
+    qreal d = x - si * (2.0 * M_PI / QT_SINE_TABLE_SIZE);
+    int ci = si + QT_SINE_TABLE_SIZE / 4;
+    si &= QT_SINE_TABLE_SIZE - 1;
+    ci &= QT_SINE_TABLE_SIZE - 1;
+    return qt_sine_table[si] + (qt_sine_table[ci] - 0.5 * qt_sine_table[si] * d) * d;
+}
+
+inline qreal qFastCos(qreal x)
+{
+    int ci = int(x * (0.5 * QT_SINE_TABLE_SIZE / M_PI)); // Would be more accurate with qRound, but slower.
+    qreal d = x - ci * (2.0 * M_PI / QT_SINE_TABLE_SIZE);
+    int si = ci + QT_SINE_TABLE_SIZE / 4;
+    si &= QT_SINE_TABLE_SIZE - 1;
+    ci &= QT_SINE_TABLE_SIZE - 1;
+    return qt_sine_table[si] - (qt_sine_table[ci] + 0.5 * qt_sine_table[si] * d) * d;
+}
+
+QT_END_NAMESPACE
+
+QT_END_HEADER
+
+#endif // QMATH_H