AudioStream

/* -*-c++-*- OpenSceneGraph - Copyright (C) 1998-2006 Robert Osfield 
 *
 * This library is open source and may be redistributed and/or modified under  
 * the terms of the OpenSceneGraph Public License (OSGPL) version 0.0 or 
 * (at your option) any later version.  The full license is in LICENSE file
 * included with this distribution, and on the openscenegraph.org website.
 * 
 * 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 
 * OpenSceneGraph Public License for more details.
*/

#ifndef OSG_AUDIOSTREAM
#define OSG_AUDIOSTREAM 1

#include <osg/Image>
#include <stdlib.h>

namespace osg {

/** Pure virtual AudioSink bass class that is used to connect the audio system with AudioStreams. */
class OSG_EXPORT AudioSink : public osg::Object
{
public:

    AudioSink();

    virtual const char * libraryName() const { return "osg"; }
    virtual const char * className() const { return "AudioSinkInterface"; }

    virtual void play() = 0;
    virtual void pause()  = 0;
    virtual void stop()  = 0;

    virtual bool playing() const = 0;

    virtual double getDelay() const { return _delay; }
    virtual void setDelay(const double delay) { _delay = delay; }

    virtual void setVolume(float) {}
    virtual float getVolume() const { return 0.0f; }

private:

    virtual AudioSink * cloneType() const { return 0; }
    virtual AudioSink * clone(const osg::CopyOp &) const { return 0; }

    double  _delay;
};

/** Pure virtual AudioStream base class. Subclasses provide mechanism for reading/generating audio data*/
class OSG_EXPORT AudioStream : public osg::Object
{
    public:
        AudioStream();

        /** Copy constructor using CopyOp to manage deep vs shallow copy. */
        AudioStream(const AudioStream& audio,const CopyOp& copyop=CopyOp::SHALLOW_COPY);

        virtual bool isSameKindAs(const Object* obj) const { return dynamic_cast<const AudioStream*>(obj)!=0; }
        virtual const char* libraryName() const { return "osg"; }
        virtual const char* className() const { return "AudioStream"; }

        virtual void setAudioSink(osg::AudioSink* audio_sink) = 0;
        
        virtual void consumeAudioBuffer(void * const buffer, const size_t size) = 0;
        
        virtual int audioFrequency() const = 0;
        virtual int audioNbChannels() const = 0;

        enum SampleFormat
        {
            SAMPLE_FORMAT_U8,
            SAMPLE_FORMAT_S16,
            SAMPLE_FORMAT_S24,
            SAMPLE_FORMAT_S32,
            SAMPLE_FORMAT_F32
        };

        virtual SampleFormat audioSampleFormat() const = 0;
};

} // namespace

#endif