/**
 * @file windows_volume_catcher.cpp
 * @brief A Windows implementation of volume level control of all audio channels opened by a process.
 *
 * @cond
 * $LicenseInfo:firstyear=2010&license=viewerlgpl$
 * Second Life Viewer Source Code
 * Copyright (C) 2010, Linden Research, Inc.
 *
 * This library is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Lesser General Public
 * License as published by the Free Software Foundation;
 * version 2.1 of the License only.
 *
 * 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 GNU
 * Lesser General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public
 * License along with this library; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301  USA
 *
 * Linden Research, Inc., 945 Battery Street, San Francisco, CA  94111  USA
 * $/LicenseInfo$
 * @endcond
 */

#include "volume_catcher.h"
#include "llsingleton.h"
#include <windows.h>
#include <mmeapi.h>
class VolumeCatcherImpl : public LLSingleton<VolumeCatcherImpl>
{
    LLSINGLETON(VolumeCatcherImpl);
    // This is a singleton class -- both callers and the component implementation should use getInstance() to find the instance.
    ~VolumeCatcherImpl();

public:

    void setVolume(F32 volume);
    void setPan(F32 pan);

private:
    F32     mVolume;
    F32     mPan;
};

VolumeCatcherImpl::VolumeCatcherImpl()
:   mVolume(1.0f),          // default volume is max
    mPan(0.f)               // default pan is centered
{
}

VolumeCatcherImpl::~VolumeCatcherImpl()
{
}

void VolumeCatcherImpl::setVolume(F32 volume)
{
    mVolume = volume;

    // set both left/right to same volume
    // TODO: use pan value to set independently
    DWORD left_channel = (DWORD)(mVolume * 65535.0f);
    DWORD right_channel = (DWORD)(mVolume * 65535.0f);
    DWORD hw_volume = left_channel << 16 | right_channel;
    ::waveOutSetVolume(NULL, hw_volume);
}

void VolumeCatcherImpl::setPan(F32 pan)
{   // remember pan for calculating individual channel levels later
    mPan = pan;
}

/////////////////////////////////////////////////////

VolumeCatcher::VolumeCatcher()
{
    pimpl = VolumeCatcherImpl::getInstance();
}

VolumeCatcher::~VolumeCatcher()
{
    // Let the instance persist until exit.
}

void VolumeCatcher::setVolume(F32 volume)
{
    pimpl->setVolume(volume);
}

void VolumeCatcher::setPan(F32 pan)
{
    pimpl->setPan(pan);
}

void VolumeCatcher::pump()
{
    // No periodic tasks are necessary for this implementation.
}