libGLESv2/mathutil.h

//
// Copyright (c) 2002-2010 The ANGLE Project Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.
//

// mathutil.h: Math and bit manipulation functions.

#ifndef LIBGLESV2_MATHUTIL_H_
#define LIBGLESV2_MATHUTIL_H_

#include <math.h>

namespace gl
{
inline bool isPow2(int x)
{
    return (x & (x - 1)) == 0 && (x != 0);
}

inline int log2(int x)
{
    int r = 0;
    while((x >> r) > 1) r++;
    return r;
}

inline float clamp01(float x)
{
    return x < 0 ? 0 : (x > 1 ? 1 : x);
}

template<const int n>
inline unsigned int unorm(float x)
{
    const unsigned int max = 0xFFFFFFFF >> (32 - n);

    if(x > 1)
    {
        return max;
    }
    else if(x < 0)
    {
        return 0;
    }
    else
    {
        return (unsigned int)(max * x + 0.5f);
    }
}
}

#endif   // LIBGLESV2_MATHUTIL_H_