raze-gles/source/audiolib/src/mixst.cpp

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/*
Copyright (C) 2009 Jonathon Fowler <jf@jonof.id.au>
This program is free software; you can redistribute it and/or
modify it under the terms of the GNU General Public License
as published by the Free Software Foundation; either version 2
of the License, or (at your option) any later version.
This program 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 General Public License for more details.
You should have received a copy of the GNU General Public License
along with this program; if not, write to the Free Software
Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
*/
#include "_multivc.h"
/*
length = count of samples to mix
position = offset of starting sample in source
rate = resampling increment
volume = direct volume adjustment, 1.0 = no change
*/
// 8-bit stereo source, 16-bit mono output
void MV_Mix16BitMono8Stereo(struct VoiceNode *voice, uint32_t length)
{
auto const source = (uint8_t const *)voice->sound;
int16_t * dest = (int16_t *)MV_MixDestination;
uint32_t position = voice->position;
uint32_t const rate = voice->RateScale;
float const volume = voice->volume;
while (length--)
{
uint8_t const usample0 = SCALE_SAMPLE(source[(position >> 16) << 1], volume);
uint8_t const usample1 = SCALE_SAMPLE(source[((position >> 16) << 1) + 1], volume);
position += rate;
*dest = (int16_t)clamp(((MV_LeftVolume[usample0] + MV_LeftVolume[usample1]) >> 1) + *dest, INT16_MIN, INT16_MAX);
dest += MV_SampleSize >> 1;
}
MV_MixPosition = position;
MV_MixDestination = (char *)dest;
}
// 8-bit stereo source, 16-bit stereo output
void MV_Mix16BitStereo8Stereo(struct VoiceNode *voice, uint32_t length)
{
auto const source = (uint8_t const *)voice->sound;
int16_t * dest = (int16_t *)MV_MixDestination;
uint32_t position = voice->position;
uint32_t const rate = voice->RateScale;
float const volume = voice->volume;
while (length--)
{
uint8_t const usample0 = SCALE_SAMPLE(source[(position >> 16) << 1], volume);
uint8_t const usample1 = SCALE_SAMPLE(source[((position >> 16) << 1) + 1], volume);
position += rate;
*dest = (int16_t)clamp(MV_LeftVolume[usample0] + *dest, INT16_MIN, INT16_MAX);
*(dest + (MV_RightChannelOffset >> 1))
= (int16_t)clamp(MV_RightVolume[usample1] + *(dest + (MV_RightChannelOffset >> 1)), INT16_MIN, INT16_MAX);
dest += MV_SampleSize >> 1;
}
MV_MixPosition = position;
MV_MixDestination = (char *)dest;
}
// 16-bit stereo source, 16-bit mono output
void MV_Mix16BitMono16Stereo(struct VoiceNode *voice, uint32_t length)
{
auto const source = (int16_t const *)voice->sound;
int16_t * dest = (int16_t *)MV_MixDestination;
uint32_t position = voice->position;
uint32_t const rate = voice->RateScale;
float const volume = voice->volume;
while (length--)
{
int16_t const isample0 = B_LITTLE16(source[(position >> 16) << 1]);
int16_t const isample1 = B_LITTLE16(source[((position >> 16) << 1) + 1]);
split16_t const usample0{FLIP_SIGN(SCALE_SAMPLE(isample0, volume))};
split16_t const usample1{FLIP_SIGN(SCALE_SAMPLE(isample1, volume))};
position += rate;
int32_t const sample0 = (MV_LeftVolume[usample0.l()] >> 8) + MV_LeftVolume[usample0.h()] + 128;
int32_t const sample1 = (MV_LeftVolume[usample1.l()] >> 8) + MV_LeftVolume[usample1.h()] + 128;
*dest = (int16_t)clamp(((sample0 + sample1) >> 1) + *dest, INT16_MIN, INT16_MAX);
dest += MV_SampleSize >> 1;
}
MV_MixPosition = position;
MV_MixDestination = (char *)dest;
}
// 16-bit stereo source, 16-bit stereo output
void MV_Mix16BitStereo16Stereo(struct VoiceNode *voice, uint32_t length)
{
auto const source = (int16_t const *)voice->sound;
int16_t * dest = (int16_t *)MV_MixDestination;
uint32_t position = voice->position;
uint32_t const rate = voice->RateScale;
float const volume = voice->volume;
while (length--)
{
int16_t const isample0 = B_LITTLE16(source[(position >> 16) << 1]);
int16_t const isample1 = B_LITTLE16(source[((position >> 16) << 1) + 1]);
split16_t const usample0{FLIP_SIGN(SCALE_SAMPLE(isample0, volume))};
split16_t const usample1{FLIP_SIGN(SCALE_SAMPLE(isample1, volume))};
position += rate;
int32_t const sample0 = (MV_LeftVolume[usample0.l()] >> 8) + MV_LeftVolume[usample0.h()] + 128;
int32_t const sample1 = (MV_RightVolume[usample1.l()] >> 8) + MV_RightVolume[usample1.h()] + 128;
*dest = (int16_t)clamp(sample0 + *dest, INT16_MIN, INT16_MAX);
*(dest + (MV_RightChannelOffset >> 1))
= (int16_t)clamp(sample1 + *(dest + (MV_RightChannelOffset >> 1)), INT16_MIN, INT16_MAX);
dest += MV_SampleSize >> 1;
}
MV_MixPosition = position;
MV_MixDestination = (char *)dest;
}