#include "global.h"
#include "RageSoundUtil.h"
#include "RageUtil.h"

/* Some of these functions assume a channel count: */
static const int channels = 2;

/* Pan buffer left or right; fPos is -1...+1.  Buffer is assumed to be stereo. */
void RageSoundUtil::Pan( int16_t *buffer, int frames, float fPos )
{
	if( fPos == 0 )
		return; /* no change */

	bool bSwap = fPos < 0;
	if( bSwap )
		fPos = -fPos;

	float fLeftFactors[2] ={ 1-fPos, 0 };
	float fRightFactors[2] =
	{
		SCALE( fPos, 0, 1, 0.5f, 0 ),
		SCALE( fPos, 0, 1, 0.5f, 1 )
	};

	if( bSwap )
	{
		swap( fLeftFactors[0], fRightFactors[0] );
		swap( fLeftFactors[1], fRightFactors[1] );
	}

	ASSERT_M( channels == 2, ssprintf("%i", channels) );
	for( int samp = 0; samp < frames; ++samp )
	{
		int16_t l = int16_t(buffer[0]*fLeftFactors[0] + buffer[1]*fLeftFactors[1]);
		int16_t r = int16_t(buffer[0]*fRightFactors[0] + buffer[1]*fRightFactors[1]);
		buffer[0] = l;
		buffer[1] = r;
		buffer += 2;
	}
}

void RageSoundUtil::Fade( int16_t *buffer, int frames, float fStartVolume, float fEndVolume  )
{
	/* If the whole buffer is full volume, skip. */
	if( fStartVolume > .9999f && fEndVolume > .9999f )
		return;

	for( int samp = 0; samp < frames; ++samp )
	{
		float fVolPercent = SCALE( samp, 0, frames, fStartVolume, fEndVolume );

		fVolPercent = clamp( fVolPercent, 0.f, 1.f );
		for(int i = 0; i < channels; ++i)
		{
			*buffer = short(*buffer * fVolPercent);
			buffer++;
		}
	}
}

/* Dupe mono to stereo in-place; do it in reverse, to handle overlap. */
void RageSoundUtil::ConvertMonoToStereoInPlace( int16_t *data, int iFrames )
{
	int16_t *input = data;
	int16_t *output = input;
	input += iFrames;
	output += iFrames * 2;
	while( iFrames-- )
	{
		input -= 1;
		output -= 2;
		output[0] = input[0];
		output[1] = input[0];
	}
}

/*
 * Copyright (c) 2002-2004 Glenn Maynard
 * All rights reserved.
 *
 * Permission is hereby granted, free of charge, to any person obtaining a
 * copy of this software and associated documentation files (the
 * "Software"), to deal in the Software without restriction, including
 * without limitation the rights to use, copy, modify, merge, publish,
 * distribute, and/or sell copies of the Software, and to permit persons to
 * whom the Software is furnished to do so, provided that the above
 * copyright notice(s) and this permission notice appear in all copies of
 * the Software and that both the above copyright notice(s) and this
 * permission notice appear in supporting documentation.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
 * OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
 * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT OF
 * THIRD PARTY RIGHTS. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR HOLDERS
 * INCLUDED IN THIS NOTICE BE LIABLE FOR ANY CLAIM, OR ANY SPECIAL INDIRECT
 * OR CONSEQUENTIAL DAMAGES, OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS
 * OF USE, DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR
 * OTHER TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR
 * PERFORMANCE OF THIS SOFTWARE.
 */