/**
* OpenAL cross platform audio library
* Copyright (C) 1999-2010 by authors.
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Library General Public
* License as published by the Free Software Foundation; either
* version 2 of the License, or (at your option) any later version.
*
* 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
* Library General Public License for more details.
*
* You should have received a copy of the GNU Library 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.
* Or go to http://www.gnu.org/copyleft/lgpl.html
*/
#include "config.h"
#include <algorithm>
#include <array>
#include <chrono>
#include <cmath>
#include <cstdio>
#include <cstring>
#include <functional>
#include <iterator>
#include <memory>
#include <new>
#include <numeric>
#include <string>
#include "AL/al.h"
#include "AL/alc.h"
#include "AL/alext.h"
#include "al/auxeffectslot.h"
#include "alcmain.h"
#include "alconfig.h"
#include "almalloc.h"
#include "alnumeric.h"
#include "aloptional.h"
#include "alspan.h"
#include "alstring.h"
#include "alu.h"
#include "ambdec.h"
#include "ambidefs.h"
#include "bformatdec.h"
#include "bs2b.h"
#include "devformat.h"
#include "hrtf.h"
#include "logging.h"
#include "math_defs.h"
#include "opthelpers.h"
#include "uhjfilter.h"
constexpr std::array<float,MAX_AMBI_CHANNELS> AmbiScale::FromN3D;
constexpr std::array<float,MAX_AMBI_CHANNELS> AmbiScale::FromSN3D;
constexpr std::array<float,MAX_AMBI_CHANNELS> AmbiScale::FromFuMa;
constexpr std::array<uint8_t,MAX_AMBI_CHANNELS> AmbiIndex::FromFuMa;
constexpr std::array<uint8_t,MAX_AMBI_CHANNELS> AmbiIndex::FromACN;
constexpr std::array<uint8_t,MAX_AMBI2D_CHANNELS> AmbiIndex::From2D;
constexpr std::array<uint8_t,MAX_AMBI_CHANNELS> AmbiIndex::From3D;
namespace {
using namespace std::placeholders;
using std::chrono::seconds;
using std::chrono::nanoseconds;
inline const char *GetLabelFromChannel(Channel channel)
{
switch(channel)
{
case FrontLeft: return "front-left";
case FrontRight: return "front-right";
case FrontCenter: return "front-center";
case LFE: return "lfe";
case BackLeft: return "back-left";
case BackRight: return "back-right";
case BackCenter: return "back-center";
case SideLeft: return "side-left";
case SideRight: return "side-right";
case UpperFrontLeft: return "upper-front-left";
case UpperFrontRight: return "upper-front-right";
case UpperBackLeft: return "upper-back-left";
case UpperBackRight: return "upper-back-right";
case LowerFrontLeft: return "lower-front-left";
case LowerFrontRight: return "lower-front-right";
case LowerBackLeft: return "lower-back-left";
case LowerBackRight: return "lower-back-right";
case Aux0: return "aux-0";
case Aux1: return "aux-1";
case Aux2: return "aux-2";
case Aux3: return "aux-3";
case Aux4: return "aux-4";
case Aux5: return "aux-5";
case Aux6: return "aux-6";
case Aux7: return "aux-7";
case Aux8: return "aux-8";
case Aux9: return "aux-9";
case Aux10: return "aux-10";
case Aux11: return "aux-11";
case Aux12: return "aux-12";
case Aux13: return "aux-13";
case Aux14: return "aux-14";
case Aux15: return "aux-15";
case MaxChannels: break;
}
return "(unknown)";
}
void AllocChannels(ALCdevice *device, const ALuint main_chans, const ALuint real_chans)
{
TRACE("Channel config, Main: %u, Real: %u\n", main_chans, real_chans);
/* Allocate extra channels for any post-filter output. */
const ALuint num_chans{main_chans + real_chans};
TRACE("Allocating %u channels, %zu bytes\n", num_chans,
num_chans*sizeof(device->MixBuffer[0]));
device->MixBuffer.resize(num_chans);
al::span<FloatBufferLine> buffer{device->MixBuffer.data(), device->MixBuffer.size()};
device->Dry.Buffer = buffer.first(main_chans);
buffer = buffer.subspan(main_chans);
if(real_chans != 0)
{
device->RealOut.Buffer = buffer.first(real_chans);
buffer = buffer.subspan(real_chans);
}
else
device->RealOut.Buffer = device->Dry.Buffer;
}
struct ChannelMap {
Channel ChanName;
ALfloat Config[MAX_AMBI2D_CHANNELS];
};
bool MakeSpeakerMap(ALCdevice *device, const AmbDecConf *conf, ALuint (&speakermap)[MAX_OUTPUT_CHANNELS])
{
auto map_spkr = [device](const AmbDecConf::SpeakerConf &speaker) -> ALuint
{
/* NOTE: AmbDec does not define any standard speaker names, however
* for this to work we have to by able to find the output channel
* the speaker definition corresponds to. Therefore, OpenAL Soft
* requires these channel labels to be recognized:
*
* LF = Front left
* RF = Front right
* LS = Side left
* RS = Side right
* LB = Back left
* RB = Back right
* CE = Front center
* CB = Back center
*
* Additionally, surround51 will acknowledge back speakers for side
* channels, and surround51rear will acknowledge side speakers for
* back channels, to avoid issues with an ambdec expecting 5.1 to
* use the side channels when the device is configured for back,
* and vice-versa.
*/
Channel ch{};
if(speaker.Name == "LF")
ch = FrontLeft;
else if(speaker.Name == "RF")
ch = FrontRight;
else if(speaker.Name == "CE")
ch = FrontCenter;
else if(speaker.Name == "LS")
{
if(device->FmtChans == DevFmtX51Rear)
ch = BackLeft;
else
ch = SideLeft;
}
else if(speaker.Name == "RS")
{
if(device->FmtChans == DevFmtX51Rear)
ch = BackRight;
else
ch = SideRight;
}
else if(speaker.Name == "LB")
{
if(device->FmtChans == DevFmtX51)
ch = SideLeft;
else
ch = BackLeft;
}
else if(speaker.Name == "RB")
{
if(device->FmtChans == DevFmtX51)
ch = SideRight;
else
ch = BackRight;
}
else if(speaker.Name == "CB")
ch = BackCenter;
else
{
const char *name{speaker.Name.c_str()};
unsigned int n;
char c;
if(sscanf(name, "AUX%u%c", &n, &c) == 1 && n < 16)
ch = static_cast<Channel>(Aux0+n);
else
{
ERR("AmbDec speaker label \"%s\" not recognized\n", name);
return INVALID_CHANNEL_INDEX;
}
}
const ALuint chidx{GetChannelIdxByName(device->RealOut, ch)};
if(chidx == INVALID_CHANNEL_INDEX)
ERR("Failed to lookup AmbDec speaker label %s\n", speaker.Name.c_str());
return chidx;
};
std::transform(conf->Speakers.begin(), conf->Speakers.end(), std::begin(speakermap), map_spkr);
/* Return success if no invalid entries are found. */
auto spkrmap_end = std::begin(speakermap) + conf->Speakers.size();
return std::find(std::begin(speakermap), spkrmap_end, INVALID_CHANNEL_INDEX) == spkrmap_end;
}
constexpr ChannelMap MonoCfg[1] = {
{ FrontCenter, { 1.0f } },
}, StereoCfg[2] = {
{ FrontLeft, { 5.00000000e-1f, 2.88675135e-1f, 5.52305643e-2f } },
{ FrontRight, { 5.00000000e-1f, -2.88675135e-1f, 5.52305643e-2f } },
}, QuadCfg[4] = {
{ BackLeft, { 3.53553391e-1f, 2.04124145e-1f, -2.04124145e-1f } },
{ FrontLeft, { 3.53553391e-1f, 2.04124145e-1f, 2.04124145e-1f } },
{ FrontRight, { 3.53553391e-1f, -2.04124145e-1f, 2.04124145e-1f } },
{ BackRight, { 3.53553391e-1f, -2.04124145e-1f, -2.04124145e-1f } },
}, X51SideCfg[4] = {
{ SideLeft, { 3.33000782e-1f, 1.89084803e-1f, -2.00042375e-1f, -2.12307769e-2f, -1.14579885e-2f } },
{ FrontLeft, { 1.88542860e-1f, 1.27709292e-1f, 1.66295695e-1f, 7.30571517e-2f, 2.10901184e-2f } },
{ FrontRight, { 1.88542860e-1f, -1.27709292e-1f, 1.66295695e-1f, -7.30571517e-2f, 2.10901184e-2f } },
{ SideRight, { 3.33000782e-1f, -1.89084803e-1f, -2.00042375e-1f, 2.12307769e-2f, -1.14579885e-2f } },
}, X51RearCfg[4] = {
{ BackLeft, { 3.33000782e-1f, 1.89084803e-1f, -2.00042375e-1f, -2.12307769e-2f, -1.14579885e-2f } },
{ FrontLeft, { 1.88542860e-1f, 1.27709292e-1f, 1.66295695e-1f, 7.30571517e-2f, 2.10901184e-2f } },
{ FrontRight, { 1.88542860e-1f, -1.27709292e-1f, 1.66295695e-1f, -7.30571517e-2f, 2.10901184e-2f } },
{ BackRight, { 3.33000782e-1f, -1.89084803e-1f, -2.00042375e-1f, 2.12307769e-2f, -1.14579885e-2f } },
}, X61Cfg[6] = {
{ SideLeft, { 2.04460341e-1f, 2.17177926e-1f, -4.39996780e-2f, -2.60790269e-2f, -6.87239792e-2f } },
{ FrontLeft, { 1.58923161e-1f, 9.21772680e-2f, 1.59658796e-1f, 6.66278083e-2f, 3.84686854e-2f } },
{ FrontRight, { 1.58923161e-1f, -9.21772680e-2f, 1.59658796e-1f, -6.66278083e-2f, 3.84686854e-2f } },
{ SideRight, { 2.04460341e-1f, -2.17177926e-1f, -4.39996780e-2f, 2.60790269e-2f, -6.87239792e-2f } },
{ BackCenter, { 2.50001688e-1f, 0.00000000e+0f, -2.50000094e-1f, 0.00000000e+0f, 6.05133395e-2f } },
}, X71Cfg[6] = {
{ BackLeft, { 2.04124145e-1f, 1.08880247e-1f, -1.88586120e-1f, -1.29099444e-1f, 7.45355993e-2f, 3.73460789e-2f, 0.00000000e+0f } },
{ SideLeft, { 2.04124145e-1f, 2.17760495e-1f, 0.00000000e+0f, 0.00000000e+0f, -1.49071198e-1f, -3.73460789e-2f, 0.00000000e+0f } },
{ FrontLeft, { 2.04124145e-1f, 1.08880247e-1f, 1.88586120e-1f, 1.29099444e-1f, 7.45355993e-2f, 3.73460789e-2f, 0.00000000e+0f } },
{ FrontRight, { 2.04124145e-1f, -1.08880247e-1f, 1.88586120e-1f, -1.29099444e-1f, 7.45355993e-2f, -3.73460789e-2f, 0.00000000e+0f } },
{ SideRight, { 2.04124145e-1f, -2.17760495e-1f, 0.00000000e+0f, 0.00000000e+0f, -1.49071198e-1f, 3.73460789e-2f, 0.00000000e+0f } },
{ BackRight, { 2.04124145e-1f, -1.08880247e-1f, -1.88586120e-1f, 1.29099444e-1f, 7.45355993e-2f, -3.73460789e-2f, 0.00000000e+0f } },
};
void InitNearFieldCtrl(ALCdevice *device, ALfloat ctrl_dist, ALuint order,
const al::span<const ALuint,MAX_AMBI_ORDER+1> chans_per_order)
{
/* NFC is only used when AvgSpeakerDist is greater than 0. */
const char *devname{device->DeviceName.c_str()};
if(!GetConfigValueBool(devname, "decoder", "nfc", 0) || !(ctrl_dist > 0.0f))
return;
device->AvgSpeakerDist = clampf(ctrl_dist, 0.1f, 10.0f);
TRACE("Using near-field reference distance: %.2f meters\n", device->AvgSpeakerDist);
auto iter = std::copy(chans_per_order.begin(), chans_per_order.begin()+order+1,
std::begin(device->NumChannelsPerOrder));
std::fill(iter, std::end(device->NumChannelsPerOrder), 0u);
}
void InitDistanceComp(ALCdevice *device, const AmbDecConf *conf,
const ALuint (&speakermap)[MAX_OUTPUT_CHANNELS])
{
auto get_max = std::bind(maxf, _1,
std::bind(std::mem_fn(&AmbDecConf::SpeakerConf::Distance), _2));
const ALfloat maxdist{
std::accumulate(conf->Speakers.begin(), conf->Speakers.end(), float{0.0f}, get_max)};
const char *devname{device->DeviceName.c_str()};
if(!GetConfigValueBool(devname, "decoder", "distance-comp", 1) || !(maxdist > 0.0f))
return;
const auto distSampleScale = static_cast<ALfloat>(device->Frequency)/SPEEDOFSOUNDMETRESPERSEC;
const auto ChanDelay = device->ChannelDelay.as_span();
size_t total{0u};
for(size_t i{0u};i < conf->Speakers.size();i++)
{
const AmbDecConf::SpeakerConf &speaker = conf->Speakers[i];
const ALuint chan{speakermap[i]};
/* Distance compensation only delays in steps of the sample rate. This
* is a bit less accurate since the delay time falls to the nearest
* sample time, but it's far simpler as it doesn't have to deal with
* phase offsets. This means at 48khz, for instance, the distance delay
* will be in steps of about 7 millimeters.
*/
ALfloat delay{std::floor((maxdist - speaker.Distance)*distSampleScale + 0.5f)};
if(delay > ALfloat{MAX_DELAY_LENGTH-1})
{
ERR("Delay for speaker \"%s\" exceeds buffer length (%f > %d)\n",
speaker.Name.c_str(), delay, MAX_DELAY_LENGTH-1);
delay = ALfloat{MAX_DELAY_LENGTH-1};
}
ChanDelay[chan].Length = static_cast<ALuint>(delay);
ChanDelay[chan].Gain = speaker.Distance / maxdist;
TRACE("Channel %u \"%s\" distance compensation: %u samples, %f gain\n", chan,
speaker.Name.c_str(), ChanDelay[chan].Length, ChanDelay[chan].Gain);
/* Round up to the next 4th sample, so each channel buffer starts
* 16-byte aligned.
*/
total += RoundUp(ChanDelay[chan].Length, 4);
}
if(total > 0)
{
device->ChannelDelay.setSampleCount(total);
ChanDelay[0].Buffer = device->ChannelDelay.getSamples();
auto set_bufptr = [](const DistanceComp::DistData &last, const DistanceComp::DistData &cur) -> DistanceComp::DistData
{
DistanceComp::DistData ret{cur};
ret.Buffer = last.Buffer + RoundUp(last.Length, 4);
return ret;
};
std::partial_sum(ChanDelay.begin(), ChanDelay.end(), ChanDelay.begin(), set_bufptr);
}
}
auto GetAmbiScales(AmbiNorm scaletype) noexcept -> const std::array<float,MAX_AMBI_CHANNELS>&
{
if(scaletype == AmbiNorm::FuMa) return AmbiScale::FromFuMa;
if(scaletype == AmbiNorm::SN3D) return AmbiScale::FromSN3D;
return AmbiScale::FromN3D;
}
auto GetAmbiLayout(AmbiLayout layouttype) noexcept -> const std::array<uint8_t,MAX_AMBI_CHANNELS>&
{
if(layouttype == AmbiLayout::FuMa) return AmbiIndex::FromFuMa;
return AmbiIndex::FromACN;
}
void InitPanning(ALCdevice *device)
{
al::span<const ChannelMap> chanmap;
ALuint coeffcount{};
switch(device->FmtChans)
{
case DevFmtMono:
chanmap = MonoCfg;
coeffcount = 1;
break;
case DevFmtStereo:
chanmap = StereoCfg;
coeffcount = 3;
break;
case DevFmtQuad:
chanmap = QuadCfg;
coeffcount = 3;
break;
case DevFmtX51:
chanmap = X51SideCfg;
coeffcount = 5;
break;
case DevFmtX51Rear:
chanmap = X51RearCfg;
coeffcount = 5;
break;
case DevFmtX61:
chanmap = X61Cfg;
coeffcount = 5;
break;
case DevFmtX71:
chanmap = X71Cfg;
coeffcount = 7;
break;
case DevFmtAmbi3D:
break;
}
if(device->FmtChans == DevFmtAmbi3D)
{
const char *devname{device->DeviceName.c_str()};
const std::array<uint8_t,MAX_AMBI_CHANNELS> &acnmap = GetAmbiLayout(device->mAmbiLayout);
const std::array<float,MAX_AMBI_CHANNELS> &n3dscale = GetAmbiScales(device->mAmbiScale);
/* For DevFmtAmbi3D, the ambisonic order is already set. */
const size_t count{AmbiChannelsFromOrder(device->mAmbiOrder)};
std::transform(acnmap.begin(), acnmap.begin()+count, std::begin(device->Dry.AmbiMap),
[&n3dscale](const uint8_t &acn) noexcept -> BFChannelConfig
{ return BFChannelConfig{1.0f/n3dscale[acn], acn}; }
);
AllocChannels(device, static_cast<ALuint>(count), 0);
ALfloat nfc_delay{ConfigValueFloat(devname, "decoder", "nfc-ref-delay").value_or(0.0f)};
if(nfc_delay > 0.0f)
{
static constexpr ALuint chans_per_order[MAX_AMBI_ORDER+1]{ 1, 3, 5, 7 };
InitNearFieldCtrl(device, nfc_delay * SPEEDOFSOUNDMETRESPERSEC, device->mAmbiOrder,
chans_per_order);
}
}
else
{
ChannelDec chancoeffs[MAX_OUTPUT_CHANNELS]{};
ALuint idxmap[MAX_OUTPUT_CHANNELS]{};
for(size_t i{0u};i < chanmap.size();++i)
{
const ALuint idx{GetChannelIdxByName(device->RealOut, chanmap[i].ChanName)};
if(idx == INVALID_CHANNEL_INDEX)
{
ERR("Failed to find %s channel in device\n",
GetLabelFromChannel(chanmap[i].ChanName));
continue;
}
idxmap[i] = idx;
std::copy_n(chanmap[i].Config, coeffcount, chancoeffs[i]);
}
/* For non-DevFmtAmbi3D, set the ambisonic order given the mixing
* channel count. Built-in speaker decoders are always 2D, so just
* reverse that calculation.
*/
device->mAmbiOrder = (coeffcount-1) / 2;
std::transform(AmbiIndex::From2D.begin(), AmbiIndex::From2D.begin()+coeffcount,
std::begin(device->Dry.AmbiMap),
[](const uint8_t &index) noexcept { return BFChannelConfig{1.0f, index}; }
);
AllocChannels(device, coeffcount, device->channelsFromFmt());
TRACE("Enabling %s-order%s ambisonic decoder\n",
(coeffcount > 5) ? "third" :
(coeffcount > 3) ? "second" : "first",
""
);
device->AmbiDecoder = al::make_unique<BFormatDec>(coeffcount,
static_cast<ALsizei>(chanmap.size()), chancoeffs, idxmap);
}
}
void InitCustomPanning(ALCdevice *device, bool hqdec, const AmbDecConf *conf,
const ALuint (&speakermap)[MAX_OUTPUT_CHANNELS])
{
static constexpr ALuint chans_per_order2d[MAX_AMBI_ORDER+1] = { 1, 2, 2, 2 };
static constexpr ALuint chans_per_order3d[MAX_AMBI_ORDER+1] = { 1, 3, 5, 7 };
if(!hqdec && conf->FreqBands != 1)
ERR("Basic renderer uses the high-frequency matrix as single-band (xover_freq = %.0fhz)\n",
conf->XOverFreq);
const ALuint order{(conf->ChanMask > AMBI_2ORDER_MASK) ? 3u :
(conf->ChanMask > AMBI_1ORDER_MASK) ? 2u : 1u};
device->mAmbiOrder = order;
ALuint count;
if((conf->ChanMask&AMBI_PERIPHONIC_MASK))
{
count = static_cast<ALuint>(AmbiChannelsFromOrder(order));
std::transform(AmbiIndex::From3D.begin(), AmbiIndex::From3D.begin()+count,
std::begin(device->Dry.AmbiMap),
[](const uint8_t &index) noexcept { return BFChannelConfig{1.0f, index}; }
);
}
else
{
count = static_cast<ALuint>(Ambi2DChannelsFromOrder(order));
std::transform(AmbiIndex::From2D.begin(), AmbiIndex::From2D.begin()+count,
std::begin(device->Dry.AmbiMap),
[](const uint8_t &index) noexcept { return BFChannelConfig{1.0f, index}; }
);
}
AllocChannels(device, count, device->channelsFromFmt());
TRACE("Enabling %s-band %s-order%s ambisonic decoder\n",
(!hqdec || conf->FreqBands == 1) ? "single" : "dual",
(conf->ChanMask > AMBI_2ORDER_MASK) ? "third" :
(conf->ChanMask > AMBI_1ORDER_MASK) ? "second" : "first",
(conf->ChanMask&AMBI_PERIPHONIC_MASK) ? " periphonic" : ""
);
device->AmbiDecoder = al::make_unique<BFormatDec>(conf, hqdec, count, device->Frequency,
speakermap);
auto accum_spkr_dist = std::bind(std::plus<float>{}, _1,
std::bind(std::mem_fn(&AmbDecConf::SpeakerConf::Distance), _2));
const ALfloat avg_dist{
std::accumulate(conf->Speakers.begin(), conf->Speakers.end(), 0.0f, accum_spkr_dist) /
static_cast<ALfloat>(conf->Speakers.size())};
InitNearFieldCtrl(device, avg_dist, order,
(conf->ChanMask&AMBI_PERIPHONIC_MASK) ? chans_per_order3d : chans_per_order2d);
InitDistanceComp(device, conf, speakermap);
}
void InitHrtfPanning(ALCdevice *device)
{
static constexpr AngularPoint AmbiPoints[]{
{ Deg2Rad( 35.264390f), Deg2Rad( -45.000000f) },
{ Deg2Rad( 35.264390f), Deg2Rad( 45.000000f) },
{ Deg2Rad( 35.264390f), Deg2Rad( 135.000000f) },
{ Deg2Rad( 35.264390f), Deg2Rad(-135.000000f) },
{ Deg2Rad(-35.264390f), Deg2Rad( -45.000000f) },
{ Deg2Rad(-35.264390f), Deg2Rad( 45.000000f) },
{ Deg2Rad(-35.264390f), Deg2Rad( 135.000000f) },
{ Deg2Rad(-35.264390f), Deg2Rad(-135.000000f) },
{ Deg2Rad( 0.000000f), Deg2Rad( -20.905157f) },
{ Deg2Rad( 0.000000f), Deg2Rad( 20.905157f) },
{ Deg2Rad( 0.000000f), Deg2Rad( 159.094843f) },
{ Deg2Rad( 0.000000f), Deg2Rad(-159.094843f) },
{ Deg2Rad( 20.905157f), Deg2Rad( -90.000000f) },
{ Deg2Rad(-20.905157f), Deg2Rad( -90.000000f) },
{ Deg2Rad(-20.905157f), Deg2Rad( 90.000000f) },
{ Deg2Rad( 20.905157f), Deg2Rad( 90.000000f) },
{ Deg2Rad( 69.094843f), Deg2Rad( 0.000000f) },
{ Deg2Rad(-69.094843f), Deg2Rad( 0.000000f) },
{ Deg2Rad(-69.094843f), Deg2Rad( 180.000000f) },
{ Deg2Rad( 69.094843f), Deg2Rad( 180.000000f) },
};
static constexpr ALfloat AmbiMatrix[][MAX_AMBI_CHANNELS]{
{ 5.00000000e-02f, 5.00000000e-02f, 5.00000000e-02f, 5.00000000e-02f, 6.45497224e-02f, 6.45497224e-02f, 0.00000000e+00f, 6.45497224e-02f, 0.00000000e+00f, 1.48264644e-02f, 6.33865691e-02f, 1.01126676e-01f, -7.36485380e-02f, -1.09260065e-02f, 7.08683387e-02f, -1.01622099e-01f },
{ 5.00000000e-02f, -5.00000000e-02f, 5.00000000e-02f, 5.00000000e-02f, -6.45497224e-02f, -6.45497224e-02f, 0.00000000e+00f, 6.45497224e-02f, 0.00000000e+00f, -1.48264644e-02f, -6.33865691e-02f, -1.01126676e-01f, -7.36485380e-02f, -1.09260065e-02f, 7.08683387e-02f, -1.01622099e-01f },
{ 5.00000000e-02f, -5.00000000e-02f, 5.00000000e-02f, -5.00000000e-02f, 6.45497224e-02f, -6.45497224e-02f, 0.00000000e+00f, -6.45497224e-02f, 0.00000000e+00f, -1.48264644e-02f, 6.33865691e-02f, -1.01126676e-01f, -7.36485380e-02f, 1.09260065e-02f, 7.08683387e-02f, 1.01622099e-01f },
{ 5.00000000e-02f, 5.00000000e-02f, 5.00000000e-02f, -5.00000000e-02f, -6.45497224e-02f, 6.45497224e-02f, 0.00000000e+00f, -6.45497224e-02f, 0.00000000e+00f, 1.48264644e-02f, -6.33865691e-02f, 1.01126676e-01f, -7.36485380e-02f, 1.09260065e-02f, 7.08683387e-02f, 1.01622099e-01f },
{ 5.00000000e-02f, 5.00000000e-02f, -5.00000000e-02f, 5.00000000e-02f, 6.45497224e-02f, -6.45497224e-02f, 0.00000000e+00f, -6.45497224e-02f, 0.00000000e+00f, 1.48264644e-02f, -6.33865691e-02f, 1.01126676e-01f, 7.36485380e-02f, -1.09260065e-02f, -7.08683387e-02f, -1.01622099e-01f },
{ 5.00000000e-02f, -5.00000000e-02f, -5.00000000e-02f, 5.00000000e-02f, -6.45497224e-02f, 6.45497224e-02f, 0.00000000e+00f, -6.45497224e-02f, 0.00000000e+00f, -1.48264644e-02f, 6.33865691e-02f, -1.01126676e-01f, 7.36485380e-02f, -1.09260065e-02f, -7.08683387e-02f, -1.01622099e-01f },
{ 5.00000000e-02f, -5.00000000e-02f, -5.00000000e-02f, -5.00000000e-02f, 6.45497224e-02f, 6.45497224e-02f, 0.00000000e+00f, 6.45497224e-02f, 0.00000000e+00f, -1.48264644e-02f, -6.33865691e-02f, -1.01126676e-01f, 7.36485380e-02f, 1.09260065e-02f, -7.08683387e-02f, 1.01622099e-01f },
{ 5.00000000e-02f, 5.00000000e-02f, -5.00000000e-02f, -5.00000000e-02f, -6.45497224e-02f, -6.45497224e-02f, 0.00000000e+00f, 6.45497224e-02f, 0.00000000e+00f, 1.48264644e-02f, 6.33865691e-02f, 1.01126676e-01f, 7.36485380e-02f, 1.09260065e-02f, -7.08683387e-02f, 1.01622099e-01f },
{ 5.00000000e-02f, 3.09016994e-02f, 0.00000000e+00f, 8.09016994e-02f, 6.45497224e-02f, 0.00000000e+00f, -5.59016994e-02f, 0.00000000e+00f, 7.21687836e-02f, 7.76323754e-02f, 0.00000000e+00f, -1.49775925e-01f, 0.00000000e+00f, -2.95083663e-02f, 0.00000000e+00f, 7.76323754e-02f },
{ 5.00000000e-02f, -3.09016994e-02f, 0.00000000e+00f, 8.09016994e-02f, -6.45497224e-02f, 0.00000000e+00f, -5.59016994e-02f, 0.00000000e+00f, 7.21687836e-02f, -7.76323754e-02f, 0.00000000e+00f, 1.49775925e-01f, 0.00000000e+00f, -2.95083663e-02f, 0.00000000e+00f, 7.76323754e-02f },
{ 5.00000000e-02f, -3.09016994e-02f, 0.00000000e+00f, -8.09016994e-02f, 6.45497224e-02f, 0.00000000e+00f, -5.59016994e-02f, 0.00000000e+00f, 7.21687836e-02f, -7.76323754e-02f, 0.00000000e+00f, 1.49775925e-01f, 0.00000000e+00f, 2.95083663e-02f, 0.00000000e+00f, -7.76323754e-02f },
{ 5.00000000e-02f, 3.09016994e-02f, 0.00000000e+00f, -8.09016994e-02f, -6.45497224e-02f, 0.00000000e+00f, -5.59016994e-02f, 0.00000000e+00f, 7.21687836e-02f, 7.76323754e-02f, 0.00000000e+00f, -1.49775925e-01f, 0.00000000e+00f, 2.95083663e-02f, 0.00000000e+00f, -7.76323754e-02f },
{ 5.00000000e-02f, 8.09016994e-02f, 3.09016994e-02f, 0.00000000e+00f, 0.00000000e+00f, 6.45497224e-02f, -3.45491503e-02f, 0.00000000e+00f, -8.44966837e-02f, -4.79794466e-02f, 0.00000000e+00f, -6.77901327e-02f, 3.03448665e-02f, 0.00000000e+00f, -1.65948192e-01f, 0.00000000e+00f },
{ 5.00000000e-02f, 8.09016994e-02f, -3.09016994e-02f, 0.00000000e+00f, 0.00000000e+00f, -6.45497224e-02f, -3.45491503e-02f, 0.00000000e+00f, -8.44966837e-02f, -4.79794466e-02f, 0.00000000e+00f, -6.77901327e-02f, -3.03448665e-02f, 0.00000000e+00f, 1.65948192e-01f, 0.00000000e+00f },
{ 5.00000000e-02f, -8.09016994e-02f, -3.09016994e-02f, 0.00000000e+00f, 0.00000000e+00f, 6.45497224e-02f, -3.45491503e-02f, 0.00000000e+00f, -8.44966837e-02f, 4.79794466e-02f, 0.00000000e+00f, 6.77901327e-02f, -3.03448665e-02f, 0.00000000e+00f, 1.65948192e-01f, 0.00000000e+00f },
{ 5.00000000e-02f, -8.09016994e-02f, 3.09016994e-02f, 0.00000000e+00f, 0.00000000e+00f, -6.45497224e-02f, -3.45491503e-02f, 0.00000000e+00f, -8.44966837e-02f, 4.79794466e-02f, 0.00000000e+00f, 6.77901327e-02f, 3.03448665e-02f, 0.00000000e+00f, -1.65948192e-01f, 0.00000000e+00f },
{ 5.00000000e-02f, 0.00000000e+00f, 8.09016994e-02f, 3.09016994e-02f, 0.00000000e+00f, 0.00000000e+00f, 9.04508497e-02f, 6.45497224e-02f, 1.23279000e-02f, 0.00000000e+00f, 0.00000000e+00f, 0.00000000e+00f, 7.94438918e-02f, 1.12611206e-01f, -2.42115150e-02f, 1.25611822e-01f },
{ 5.00000000e-02f, 0.00000000e+00f, -8.09016994e-02f, 3.09016994e-02f, 0.00000000e+00f, 0.00000000e+00f, 9.04508497e-02f, -6.45497224e-02f, 1.23279000e-02f, 0.00000000e+00f, 0.00000000e+00f, 0.00000000e+00f, -7.94438918e-02f, 1.12611206e-01f, 2.42115150e-02f, 1.25611822e-01f },
{ 5.00000000e-02f, 0.00000000e+00f, -8.09016994e-02f, -3.09016994e-02f, 0.00000000e+00f, 0.00000000e+00f, 9.04508497e-02f, 6.45497224e-02f, 1.23279000e-02f, 0.00000000e+00f, 0.00000000e+00f, 0.00000000e+00f, -7.94438918e-02f, -1.12611206e-01f, 2.42115150e-02f, -1.25611822e-01f },
{ 5.00000000e-02f, 0.00000000e+00f, 8.09016994e-02f, -3.09016994e-02f, 0.00000000e+00f, 0.00000000e+00f, 9.04508497e-02f, -6.45497224e-02f, 1.23279000e-02f, 0.00000000e+00f, 0.00000000e+00f, 0.00000000e+00f, 7.94438918e-02f, -1.12611206e-01f, -2.42115150e-02f, -1.25611822e-01f }
};
static constexpr ALfloat AmbiOrderHFGain1O[MAX_AMBI_ORDER+1]{
3.16227766e+00f, 1.82574186e+00f
}, AmbiOrderHFGain2O[MAX_AMBI_ORDER+1]{
2.35702260e+00f, 1.82574186e+00f, 9.42809042e-01f
}, AmbiOrderHFGain3O[MAX_AMBI_ORDER+1]{
1.86508671e+00f, 1.60609389e+00f, 1.14205530e+00f, 5.68379553e-01f
};
static constexpr ALuint ChansPerOrder[MAX_AMBI_ORDER+1]{ 1, 3, 5, 7 };
const ALfloat *AmbiOrderHFGain{AmbiOrderHFGain1O};
static_assert(al::size(AmbiPoints) == al::size(AmbiMatrix), "Ambisonic HRTF mismatch");
/* Don't bother with HOA when using full HRTF rendering. Nothing needs it,
* and it eases the CPU/memory load.
*/
device->mRenderMode = HrtfRender;
ALuint ambi_order{1};
if(auto modeopt = ConfigValueStr(device->DeviceName.c_str(), nullptr, "hrtf-mode"))
{
struct HrtfModeEntry {
char name[8];
RenderMode mode;
ALuint order;
};
static constexpr HrtfModeEntry hrtf_modes[]{
{ "full", HrtfRender, 1 },
{ "ambi1", NormalRender, 1 },
{ "ambi2", NormalRender, 2 },
{ "ambi3", NormalRender, 3 },
};
const char *mode{modeopt->c_str()};
if(al::strcasecmp(mode, "basic") == 0)
{
ERR("HRTF mode \"%s\" deprecated, substituting \"%s\"\n", mode, "ambi2");
mode = "ambi2";
}
auto match_entry = [mode](const HrtfModeEntry &entry) -> bool
{ return al::strcasecmp(mode, entry.name) == 0; };
auto iter = std::find_if(std::begin(hrtf_modes), std::end(hrtf_modes), match_entry);
if(iter == std::end(hrtf_modes))
ERR("Unexpected hrtf-mode: %s\n", mode);
else
{
device->mRenderMode = iter->mode;
ambi_order = iter->order;
}
}
TRACE("%s HRTF rendering enabled, using \"%s\"\n",
(device->mRenderMode == HrtfRender) ? "Full" :
(ambi_order >= 3) ? "Third-Order" :
(ambi_order == 2) ? "Second-Order" :
(ambi_order == 1) ? "First-Order" : "Unknown",
device->HrtfName.c_str());
if(ambi_order >= 3)
AmbiOrderHFGain = AmbiOrderHFGain3O;
else if(ambi_order == 2)
AmbiOrderHFGain = AmbiOrderHFGain2O;
else if(ambi_order == 1)
AmbiOrderHFGain = AmbiOrderHFGain1O;
device->mAmbiOrder = ambi_order;
const size_t count{AmbiChannelsFromOrder(ambi_order)};
device->mHrtfState = DirectHrtfState::Create(count);
std::transform(AmbiIndex::From3D.begin(), AmbiIndex::From3D.begin()+count,
std::begin(device->Dry.AmbiMap),
[](const uint8_t &index) noexcept { return BFChannelConfig{1.0f, index}; }
);
AllocChannels(device, static_cast<ALuint>(count), device->channelsFromFmt());
BuildBFormatHrtf(device->mHrtf, device->mHrtfState.get(), AmbiPoints, AmbiMatrix,
AmbiOrderHFGain);
HrtfEntry *Hrtf{device->mHrtf};
InitNearFieldCtrl(device, Hrtf->field[0].distance, ambi_order, ChansPerOrder);
}
void InitUhjPanning(ALCdevice *device)
{
/* UHJ is always 2D first-order. */
static constexpr size_t count{Ambi2DChannelsFromOrder(1)};
device->mAmbiOrder = 1;
auto acnmap_end = AmbiIndex::FromFuMa.begin() + count;
std::transform(AmbiIndex::FromFuMa.begin(), acnmap_end, std::begin(device->Dry.AmbiMap),
[](const uint8_t &acn) noexcept -> BFChannelConfig
{ return BFChannelConfig{1.0f/AmbiScale::FromFuMa[acn], acn}; }
);
AllocChannels(device, ALuint{count}, device->channelsFromFmt());
}
} // namespace
void aluInitRenderer(ALCdevice *device, ALint hrtf_id, HrtfRequestMode hrtf_appreq, HrtfRequestMode hrtf_userreq)
{
/* Hold the HRTF the device last used, in case it's used again. */
HrtfEntry *old_hrtf{device->mHrtf};
device->mHrtfState = nullptr;
device->mHrtf = nullptr;
device->HrtfName.clear();
device->mRenderMode = NormalRender;
if(device->FmtChans != DevFmtStereo)
{
if(old_hrtf)
old_hrtf->DecRef();
old_hrtf = nullptr;
if(hrtf_appreq == Hrtf_Enable)
device->HrtfStatus = ALC_HRTF_UNSUPPORTED_FORMAT_SOFT;
const char *layout{nullptr};
switch(device->FmtChans)
{
case DevFmtQuad: layout = "quad"; break;
case DevFmtX51: /* fall-through */
case DevFmtX51Rear: layout = "surround51"; break;
case DevFmtX61: layout = "surround61"; break;
case DevFmtX71: layout = "surround71"; break;
/* Mono, Stereo, and Ambisonics output don't use custom decoders. */
case DevFmtMono:
case DevFmtStereo:
case DevFmtAmbi3D:
break;
}
const char *devname{device->DeviceName.c_str()};
ALuint speakermap[MAX_OUTPUT_CHANNELS];
AmbDecConf *pconf{nullptr};
AmbDecConf conf{};
if(layout)
{
if(auto decopt = ConfigValueStr(devname, "decoder", layout))
{
if(!conf.load(decopt->c_str()))
ERR("Failed to load layout file %s\n", decopt->c_str());
else if(conf.Speakers.size() > MAX_OUTPUT_CHANNELS)
ERR("Unsupported speaker count %zu (max %d)\n", conf.Speakers.size(),
MAX_OUTPUT_CHANNELS);
else if(conf.ChanMask > AMBI_3ORDER_MASK)
ERR("Unsupported channel mask 0x%04x (max 0x%x)\n", conf.ChanMask,
AMBI_3ORDER_MASK);
else if(MakeSpeakerMap(device, &conf, speakermap))
pconf = &conf;
}
}
if(!pconf)
InitPanning(device);
else
{
int hqdec{GetConfigValueBool(devname, "decoder", "hq-mode", 1)};
InitCustomPanning(device, !!hqdec, pconf, speakermap);
}
if(device->AmbiDecoder)
device->PostProcess = &ALCdevice::ProcessAmbiDec;
return;
}
bool headphones{device->IsHeadphones != AL_FALSE};
if(device->Type != Loopback)
{
if(auto modeopt = ConfigValueStr(device->DeviceName.c_str(), nullptr, "stereo-mode"))
{
const char *mode{modeopt->c_str()};
if(al::strcasecmp(mode, "headphones") == 0)
headphones = true;
else if(al::strcasecmp(mode, "speakers") == 0)
headphones = false;
else if(al::strcasecmp(mode, "auto") != 0)
ERR("Unexpected stereo-mode: %s\n", mode);
}
}
if(hrtf_userreq == Hrtf_Default)
{
bool usehrtf = (headphones && hrtf_appreq != Hrtf_Disable) ||
(hrtf_appreq == Hrtf_Enable);
if(!usehrtf) goto no_hrtf;
device->HrtfStatus = ALC_HRTF_ENABLED_SOFT;
if(headphones && hrtf_appreq != Hrtf_Disable)
device->HrtfStatus = ALC_HRTF_HEADPHONES_DETECTED_SOFT;
}
else
{
if(hrtf_userreq != Hrtf_Enable)
{
if(hrtf_appreq == Hrtf_Enable)
device->HrtfStatus = ALC_HRTF_DENIED_SOFT;
goto no_hrtf;
}
device->HrtfStatus = ALC_HRTF_REQUIRED_SOFT;
}
if(device->HrtfList.empty())
device->HrtfList = EnumerateHrtf(device->DeviceName.c_str());
if(hrtf_id >= 0 && static_cast<ALuint>(hrtf_id) < device->HrtfList.size())
{
const EnumeratedHrtf &entry = device->HrtfList[static_cast<ALuint>(hrtf_id)];
HrtfEntry *hrtf{GetLoadedHrtf(entry.hrtf)};
if(hrtf && hrtf->sampleRate == device->Frequency)
{
device->mHrtf = hrtf;
device->HrtfName = entry.name;
}
else if(hrtf)
hrtf->DecRef();
}
if(!device->mHrtf)
{
auto find_hrtf = [device](const EnumeratedHrtf &entry) -> bool
{
HrtfEntry *hrtf{GetLoadedHrtf(entry.hrtf)};
if(!hrtf) return false;
if(hrtf->sampleRate != device->Frequency)
{
hrtf->DecRef();
return false;
}
device->mHrtf = hrtf;
device->HrtfName = entry.name;
return true;
};
std::find_if(device->HrtfList.cbegin(), device->HrtfList.cend(), find_hrtf);
}
if(device->mHrtf)
{
if(old_hrtf)
old_hrtf->DecRef();
old_hrtf = nullptr;
InitHrtfPanning(device);
device->PostProcess = &ALCdevice::ProcessHrtf;
return;
}
device->HrtfStatus = ALC_HRTF_UNSUPPORTED_FORMAT_SOFT;
no_hrtf:
if(old_hrtf)
old_hrtf->DecRef();
old_hrtf = nullptr;
device->mRenderMode = StereoPair;
if(device->Type != Loopback)
{
if(auto cflevopt = ConfigValueInt(device->DeviceName.c_str(), nullptr, "cf_level"))
{
if(*cflevopt > 0 && *cflevopt <= 6)
{
device->Bs2b = al::make_unique<bs2b>();
bs2b_set_params(device->Bs2b.get(), *cflevopt,
static_cast<int>(device->Frequency));
TRACE("BS2B enabled\n");
InitPanning(device);
device->PostProcess = &ALCdevice::ProcessBs2b;
return;
}
}
}
if(auto encopt = ConfigValueStr(device->DeviceName.c_str(), nullptr, "stereo-encoding"))
{
const char *mode{encopt->c_str()};
if(al::strcasecmp(mode, "uhj") == 0)
device->mRenderMode = NormalRender;
else if(al::strcasecmp(mode, "panpot") != 0)
ERR("Unexpected stereo-encoding: %s\n", mode);
}
if(device->mRenderMode == NormalRender)
{
device->Uhj_Encoder = al::make_unique<Uhj2Encoder>();
TRACE("UHJ enabled\n");
InitUhjPanning(device);
device->PostProcess = &ALCdevice::ProcessUhj;
return;
}
TRACE("Stereo rendering\n");
InitPanning(device);
device->PostProcess = &ALCdevice::ProcessAmbiDec;
}
void aluInitEffectPanning(ALeffectslot *slot, ALCdevice *device)
{
const size_t count{AmbiChannelsFromOrder(device->mAmbiOrder)};
slot->MixBuffer.resize(count);
slot->MixBuffer.shrink_to_fit();
auto acnmap_end = AmbiIndex::From3D.begin() + count;
auto iter = std::transform(AmbiIndex::From3D.begin(), acnmap_end, slot->Wet.AmbiMap.begin(),
[](const uint8_t &acn) noexcept -> BFChannelConfig
{ return BFChannelConfig{1.0f, acn}; }
);
std::fill(iter, slot->Wet.AmbiMap.end(), BFChannelConfig{});
slot->Wet.Buffer = {slot->MixBuffer.data(), slot->MixBuffer.size()};
}
void CalcAmbiCoeffs(const float y, const float z, const float x, const float spread,
const al::span<float,MAX_AMBI_CHANNELS> coeffs)
{
/* Zeroth-order */
coeffs[0] = 1.0f; /* ACN 0 = 1 */
/* First-order */
coeffs[1] = 1.732050808f * y; /* ACN 1 = sqrt(3) * Y */
coeffs[2] = 1.732050808f * z; /* ACN 2 = sqrt(3) * Z */
coeffs[3] = 1.732050808f * x; /* ACN 3 = sqrt(3) * X */
/* Second-order */
coeffs[4] = 3.872983346f * x * y; /* ACN 4 = sqrt(15) * X * Y */
coeffs[5] = 3.872983346f * y * z; /* ACN 5 = sqrt(15) * Y * Z */
coeffs[6] = 1.118033989f * (z*z*3.0f - 1.0f); /* ACN 6 = sqrt(5)/2 * (3*Z*Z - 1) */
coeffs[7] = 3.872983346f * x * z; /* ACN 7 = sqrt(15) * X * Z */
coeffs[8] = 1.936491673f * (x*x - y*y); /* ACN 8 = sqrt(15)/2 * (X*X - Y*Y) */
/* Third-order */
coeffs[9] = 2.091650066f * y * (x*x*3.0f - y*y); /* ACN 9 = sqrt(35/8) * Y * (3*X*X - Y*Y) */
coeffs[10] = 10.246950766f * z * x * y; /* ACN 10 = sqrt(105) * Z * X * Y */
coeffs[11] = 1.620185175f * y * (z*z*5.0f - 1.0f); /* ACN 11 = sqrt(21/8) * Y * (5*Z*Z - 1) */
coeffs[12] = 1.322875656f * z * (z*z*5.0f - 3.0f); /* ACN 12 = sqrt(7)/2 * Z * (5*Z*Z - 3) */
coeffs[13] = 1.620185175f * x * (z*z*5.0f - 1.0f); /* ACN 13 = sqrt(21/8) * X * (5*Z*Z - 1) */
coeffs[14] = 5.123475383f * z * (x*x - y*y); /* ACN 14 = sqrt(105)/2 * Z * (X*X - Y*Y) */
coeffs[15] = 2.091650066f * x * (x*x - y*y*3.0f); /* ACN 15 = sqrt(35/8) * X * (X*X - 3*Y*Y) */
/* Fourth-order */
/* ACN 16 = sqrt(35)*3/2 * X * Y * (X*X - Y*Y) */
/* ACN 17 = sqrt(35/2)*3/2 * (3*X*X - Y*Y) * Y * Z */
/* ACN 18 = sqrt(5)*3/2 * X * Y * (7*Z*Z - 1) */
/* ACN 19 = sqrt(5/2)*3/2 * Y * Z * (7*Z*Z - 3) */
/* ACN 20 = 3/8 * (35*Z*Z*Z*Z - 30*Z*Z + 3) */
/* ACN 21 = sqrt(5/2)*3/2 * X * Z * (7*Z*Z - 3) */
/* ACN 22 = sqrt(5)*3/4 * (X*X - Y*Y) * (7*Z*Z - 1) */
/* ACN 23 = sqrt(35/2)*3/2 * (X*X - 3*Y*Y) * X * Z */
/* ACN 24 = sqrt(35)*3/8 * (X*X*X*X - 6*X*X*Y*Y + Y*Y*Y*Y) */
if(spread > 0.0f)
{
/* Implement the spread by using a spherical source that subtends the
* angle spread. See:
* http://www.ppsloan.org/publications/StupidSH36.pdf - Appendix A3
*
* When adjusted for N3D normalization instead of SN3D, these
* calculations are:
*
* ZH0 = -sqrt(pi) * (-1+ca);
* ZH1 = 0.5*sqrt(pi) * sa*sa;
* ZH2 = -0.5*sqrt(pi) * ca*(-1+ca)*(ca+1);
* ZH3 = -0.125*sqrt(pi) * (-1+ca)*(ca+1)*(5*ca*ca - 1);
* ZH4 = -0.125*sqrt(pi) * ca*(-1+ca)*(ca+1)*(7*ca*ca - 3);
* ZH5 = -0.0625*sqrt(pi) * (-1+ca)*(ca+1)*(21*ca*ca*ca*ca - 14*ca*ca + 1);
*
* The gain of the source is compensated for size, so that the
* loudness doesn't depend on the spread. Thus:
*
* ZH0 = 1.0f;
* ZH1 = 0.5f * (ca+1.0f);
* ZH2 = 0.5f * (ca+1.0f)*ca;
* ZH3 = 0.125f * (ca+1.0f)*(5.0f*ca*ca - 1.0f);
* ZH4 = 0.125f * (ca+1.0f)*(7.0f*ca*ca - 3.0f)*ca;
* ZH5 = 0.0625f * (ca+1.0f)*(21.0f*ca*ca*ca*ca - 14.0f*ca*ca + 1.0f);
*/
const float ca{std::cos(spread * 0.5f)};
/* Increase the source volume by up to +3dB for a full spread. */
const float scale{std::sqrt(1.0f + spread/al::MathDefs<float>::Tau())};
const float ZH0_norm{scale};
const float ZH1_norm{scale * 0.5f * (ca+1.f)};
const float ZH2_norm{scale * 0.5f * (ca+1.f)*ca};
const float ZH3_norm{scale * 0.125f * (ca+1.f)*(5.f*ca*ca-1.f)};
/* Zeroth-order */
coeffs[0] *= ZH0_norm;
/* First-order */
coeffs[1] *= ZH1_norm;
coeffs[2] *= ZH1_norm;
coeffs[3] *= ZH1_norm;
/* Second-order */
coeffs[4] *= ZH2_norm;
coeffs[5] *= ZH2_norm;
coeffs[6] *= ZH2_norm;
coeffs[7] *= ZH2_norm;
coeffs[8] *= ZH2_norm;
/* Third-order */
coeffs[9] *= ZH3_norm;
coeffs[10] *= ZH3_norm;
coeffs[11] *= ZH3_norm;
coeffs[12] *= ZH3_norm;
coeffs[13] *= ZH3_norm;
coeffs[14] *= ZH3_norm;
coeffs[15] *= ZH3_norm;
}
}
void ComputePanGains(const MixParams *mix, const float*RESTRICT coeffs, const float ingain,
const al::span<float,MAX_OUTPUT_CHANNELS> gains)
{
auto ambimap = mix->AmbiMap.cbegin();
auto iter = std::transform(ambimap, ambimap+mix->Buffer.size(), gains.begin(),
[coeffs,ingain](const BFChannelConfig &chanmap) noexcept -> float
{ return chanmap.Scale * coeffs[chanmap.Index] * ingain; }
);
std::fill(iter, gains.end(), 0.0f);
}