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#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);
*/
/*
    double y = (double)v;
    double x, z, tempf;
    unsigned long *tfptr = ((unsigned long *)&tempf) + 1;
    tempf = y;
    *tfptr = (0xbfcdd90a - *tfptr)>>1;
    x = tempf;
    z = y*0.5;
    x = (1.5*x) - (x*x)*(x*z);
        //x = (1.5*x) - (x*x)*(x*z); // comment out if presicion is good enough
        //x = (1.5*x) - (x*x)*(x*z);
        //x = (1.5*x) - (x*x)*(x*z);
        //x = (1.5*x) - (x*x)*(x*z);
    return x*y;
*/
    float y = (float)v;
    float xhalf = 0.5f*y;
    int i = *(int*)&y;
    i = 0x5f3759df - (i >> 1);
    y = *(float*)&i;
    y = y*(1.5f - xhalf*y*y);
    //y = y*(1.5f - xhalf*y*y);
    return 1.f/y;
}

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