1 files changed, 119 insertions, 0 deletions
diff --git a/Source/WebCore/webaudio/AudioParamTimeline.h b/Source/WebCore/webaudio/AudioParamTimeline.h
new file mode 100644
index 000000000..22ea89081
--- /dev/null
+++ b/Source/WebCore/webaudio/AudioParamTimeline.h
@@ -0,0 +1,119 @@
+/*
+ * Copyright (C) 2011 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.
+ */
+
+#ifndef AudioParamTimeline_h
+#define AudioParamTimeline_h
+
+#include "AudioContext.h"
+#include <wtf/Float32Array.h>
+#include <wtf/PassRefPtr.h>
+#include <wtf/RefCounted.h>
+#include <wtf/Threading.h>
+#include <wtf/Vector.h>
+
+namespace WebCore {
+
+class AudioParamTimeline {
+public:
+    AudioParamTimeline()
+        : m_currentEventIndex(0)
+        , m_value(0)
+    {
+    }
+
+    void setValueAtTime(float value, float time);
+    void linearRampToValueAtTime(float value, float time);
+    void exponentialRampToValueAtTime(float value, float time);
+    void setTargetValueAtTime(float targetValue, float time, float timeConstant);
+    void setValueCurveAtTime(Float32Array* curve, float time, float duration);
+    void cancelScheduledValues(float startTime);
+
+    // hasValue is set to true if a valid timeline value is returned.
+    // otherwise defaultValue is returned.
+    float valueForContextTime(AudioContext*, float defaultValue, bool& hasValue);
+
+    // Given the time range, calculates parameter values into the values buffer
+    // and returns the last parameter value calculated for "values" or the defaultValue if none were calculated.
+    // controlRate is the rate (number per second) at which parameter values will be calculated.
+    // It should equal sampleRate for sample-accurate parameter changes, and otherwise will usually match
+    // the render quantum size such that the parameter value changes once per render quantum.
+    float valuesForTimeRange(float startTime, float endTime, float defaultValue, float* values, unsigned numberOfValues, float sampleRate, float controlRate);
+
+    bool hasValues() { return m_events.size(); }
+
+private:
+    class ParamEvent {
+    public:
+        enum Type {
+            SetValue,
+            LinearRampToValue,
+            ExponentialRampToValue,
+            SetTargetValue,
+            SetValueCurve,
+            LastType
+        };
+
+        ParamEvent(Type type, float value, float time, float timeConstant, float duration, PassRefPtr<Float32Array> curve)
+            : m_type(type)
+            , m_value(value)
+            , m_time(time)
+            , m_timeConstant(timeConstant)
+            , m_duration(duration)
+            , m_curve(curve)
+        {
+        }
+
+        unsigned type() const { return m_type; }
+        float value() const { return m_value; }
+        float time() const { return m_time; }
+        float timeConstant() const { return m_timeConstant; }
+        float duration() const { return m_duration; }
+        Float32Array* curve() { return m_curve.get(); }
+
+    private:
+        unsigned m_type;
+        float m_value;
+        float m_time;
+        float m_timeConstant;
+        float m_duration;
+        RefPtr<Float32Array> m_curve;
+    };
+
+    void insertEvent(const ParamEvent&);
+    float valuesForTimeRangeImpl(float startTime, float endTime, float defaultValue, float* values, unsigned numberOfValues, float sampleRate, float controlRate);
+
+    Vector<ParamEvent> m_events;
+    unsigned m_currentEventIndex;
+    float m_value;
+
+    Mutex m_eventsLock;
+};
+
+} // namespace WebCore
+
+#endif // AudioParamTimeline_h