Clamp PannerNode rolloffFactor to nominal range

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
@@ skipping 10 matching lines @@
  * 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 "wtf/Assertions.h"
+#include "wtf/MathExtras.h"
 #include <math.h>
 #include <algorithm>
 
 namespace blink {
 
 DistanceEffect::DistanceEffect()
     : m_model(ModelInverse),
       m_isClamped(true),
       m_refDistance(1.0),
       m_maxDistance(10000.0),
@@ skipping 16 matching lines @@
       return exponentialGain(distance);
   }
   ASSERT_NOT_REACHED();
   return 0.0;
 }
 
 double DistanceEffect::linearGain(double distance) {
   // We want a gain that decreases linearly from m_refDistance to
   // m_maxDistance. The gain is 1 at m_refDistance.
   return (1.0 -
-          m_rolloffFactor * (distance - m_refDistance) /
+          clampTo(m_rolloffFactor, 0.0, 1.0) * (distance - m_refDistance) /
               (m_maxDistance - m_refDistance));
 }
 
 double DistanceEffect::inverseGain(double distance) {
   return m_refDistance /
-         (m_refDistance + m_rolloffFactor * (distance - m_refDistance));
+         (m_refDistance +
+          clampTo(m_rolloffFactor, 0.0) * (distance - m_refDistance));
 }
 
 double DistanceEffect::exponentialGain(double distance) {
-  return pow(distance / m_refDistance, -m_rolloffFactor);
+  return pow(distance / m_refDistance, -clampTo(m_rolloffFactor, 0.0));
 }
 
 }  // namespace blink