third_party/WebKit/Source/platform/geometry/FloatPoint3D.cpp

/*
    Copyright (C) 2004, 2005, 2006 Nikolas Zimmermann <wildfox@kde.org>
                  2004, 2005 Rob Buis <buis@kde.org>
                  2005 Eric Seidel <eric@webkit.org>

    This library is free software; you can redistribute it and/or
    modify it under the terms of the GNU Library General Public
    License as published by the Free Software Foundation; either
    version 2 of the License, or (at your option) any later version.

    This library is distributed in the hope that it will be useful,
    but WITHOUT ANY WARRANTY; without even the implied warranty of
    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
    Library General Public License for more details.

    You should have received a copy of the GNU Library General Public License
    aint with this library; see the file COPYING.LIB.  If not, write to
    the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
    Boston, MA 02110-1301, USA.
*/

#include "platform/geometry/FloatPoint3D.h"

#include "wtf/MathExtras.h"
#include "wtf/text/WTFString.h"
#include <math.h>

namespace blink {

void FloatPoint3D::normalize() {
  float tempLength = length();

  if (tempLength) {
    m_x /= tempLength;
    m_y /= tempLength;
    m_z /= tempLength;
  }
}

float FloatPoint3D::angleBetween(const FloatPoint3D& y) const {
  float xLength = this->length();
  float yLength = y.length();

  if (xLength && yLength) {
    float cosAngle = this->dot(y) / (xLength * yLength);
    // Due to round-off |cosAngle| can have a magnitude greater than 1.  Clamp
    // the value to [-1, 1] before computing the angle.
    return acos(clampTo(cosAngle, -1.0, 1.0));
  }
  return 0;
}

String FloatPoint3D::toString() const {
  return String::format("%lg,%lg,%lg", x(), y(), z());
}

}  // namespace blink