1 files changed, 68 insertions, 0 deletions
diff --git a/Source/WebCore/platform/audio/HRTFPanner.h b/Source/WebCore/platform/audio/HRTFPanner.h
new file mode 100644
index 0000000..6c13d48
--- /dev/null
+++ b/Source/WebCore/platform/audio/HRTFPanner.h
@@ -0,0 +1,68 @@
+/*
+ * 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.
+ *
+ * THIS SOFTWARE IS PROVIDED BY APPLE INC. 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 INC. 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 HRTFPanner_h
+#define HRTFPanner_h
+
+#include "DelayDSPKernel.h"
+#include "FFTConvolver.h"
+#include "Panner.h"
+
+namespace WebCore {
+
+class HRTFPanner : public Panner {
+public:
+    explicit HRTFPanner(double sampleRate);
+    virtual ~HRTFPanner();
+
+    // Panner
+    virtual void pan(double azimuth, double elevation, AudioBus* inputBus, AudioBus* outputBus, size_t framesToProcess);
+    virtual void reset();
+
+    size_t fftSize() { return fftSizeForSampleRate(m_sampleRate); }
+    static size_t fftSizeForSampleRate(double sampleRate);
+
+    double sampleRate() const { return m_sampleRate; }
+    
+private:
+    // Given an azimuth angle in the range -180 -> +180, returns the corresponding azimuth index for the database,
+    // and azimuthBlend which is an interpolation value from 0 -> 1.
+    int calculateDesiredAzimuthIndexAndBlend(double azimuth, double& azimuthBlend);
+
+    double m_sampleRate;
+    
+    // m_isFirstRender and m_azimuthIndex are used to avoid harshly changing from rendering at one azimuth angle to another angle very far away.
+    // Changing the azimuth gradually produces a smoother sound.
+    bool m_isFirstRender;
+    int m_azimuthIndex;
+
+    FFTConvolver m_convolverL;
+    FFTConvolver m_convolverR;
+    DelayDSPKernel m_delayLineL;
+    DelayDSPKernel m_delayLineR;
+};
+
+} // namespace WebCore
+
+#endif // HRTFPanner_h