Rename Distance.* file to DistanceEffect.*

third_party/WebKit/Source/platform/audio/Distance.cpp

-/*
- * Copyright (C) 2010 Google Inc. All rights reserved.
- *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions
- * are met:
- *
- * 1.  Redistributions of source code must retain the above copyright
- *     notice, this list of conditions and the following disclaimer.
- * 2.  Redistributions in binary form must reproduce the above copyright
- *     notice, this list of conditions and the following disclaimer in the
- *     documentation and/or other materials provided with the distribution.
- * 3.  Neither the name of Apple Computer, Inc. ("Apple") nor the names of
- *     its contributors may be used to endorse or promote products derived
- *     from this software without specific prior written permission.
- *
- * THIS SOFTWARE IS PROVIDED BY APPLE AND ITS CONTRIBUTORS "AS IS" AND ANY
- * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
- * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
- * DISCLAIMED. IN NO EVENT SHALL APPLE OR ITS CONTRIBUTORS BE LIABLE FOR ANY
- * DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
- * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
- * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
- * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
- * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
- * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
- */
-
-#include "platform/audio/Distance.h"
-
-#include <math.h>
-#include <algorithm>
-#include "platform/wtf/Assertions.h"
-#include "platform/wtf/MathExtras.h"
-
-namespace blink {
-
-DistanceEffect::DistanceEffect()
-    : model_(kModelInverse),
-      ref_distance_(1.0),
-      max_distance_(10000.0),
-      rolloff_factor_(1.0) {}
-
-double DistanceEffect::Gain(double distance) {
-  switch (model_) {
-    case kModelLinear:
-      return LinearGain(distance);
-    case kModelInverse:
-      return InverseGain(distance);
-    case kModelExponential:
-      return ExponentialGain(distance);
-  }
-  NOTREACHED();
-  return 0.0;
-}
-
-double DistanceEffect::LinearGain(double distance) {
-  // Clamp refDistance and distance according to the spec.
-  double dref = std::min(ref_distance_, max_distance_);
-  double dmax = std::max(ref_distance_, max_distance_);
-  distance = clampTo(distance, dref, dmax);
-
-  if (dref == dmax)
-    return 1 - rolloff_factor_;
-
-  // We want a gain that decreases linearly from m_refDistance to
-  // m_maxDistance. The gain is 1 at m_refDistance.
-  return (1.0 - clampTo(rolloff_factor_, 0.0, 1.0) * (distance - dref) /
-                    (dmax - dref));
-}
-
-double DistanceEffect::InverseGain(double distance) {
-  if (ref_distance_ == 0)
-    return 0;
-
-  // Clamp distance according to spec
-  distance = clampTo(distance, ref_distance_);
-
-  return ref_distance_ / (ref_distance_ + clampTo(rolloff_factor_, 0.0) *
-                                              (distance - ref_distance_));
-}
-
-double DistanceEffect::ExponentialGain(double distance) {
-  if (ref_distance_ == 0)
-    return 0;
-
-  // Clamp distance according to spec
-  distance = clampTo(distance, ref_distance_);
-
-  return pow(distance / ref_distance_, -clampTo(rolloff_factor_, 0.0));
-}
-
-}  // namespace blink