alc/effects/dedicated.cpp

   1 /**
   2  * OpenAL cross platform audio library
   3  * Copyright (C) 2011 by Chris Robinson.
   4  * This library is free software; you can redistribute it and/or
   5  *  modify it under the terms of the GNU Library General Public
   6  *  License as published by the Free Software Foundation; either
   7  *  version 2 of the License, or (at your option) any later version.
   8  *
   9  * This library is distributed in the hope that it will be useful,
  10  *  but WITHOUT ANY WARRANTY; without even the implied warranty of
  11  *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  12  *  Library General Public License for more details.
  13  *
  14  * You should have received a copy of the GNU Library General Public
  15  *  License along with this library; if not, write to the
  16  *  Free Software Foundation, Inc.,
  17  *  51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
  18  * Or go to http://www.gnu.org/copyleft/lgpl.html
  19  */
  20
  21 #include "config.h"
  22
  23 #include <algorithm>
  24 #include <array>
  25 #include <cstdlib>
  26 #include <variant>
  27
  28 #include "alc/effects/base.h"
  29 #include "alspan.h"
  30 #include "core/bufferline.h"
  31 #include "core/devformat.h"
  32 #include "core/device.h"
  33 #include "core/effects/base.h"
  34 #include "core/effectslot.h"
  35 #include "core/mixer.h"
  36 #include "intrusive_ptr.h"
  37
  38 struct BufferStorage;
  39 struct ContextBase;
  40
  41
  42 namespace {
  43
  44 using uint = unsigned int;
  45
  46 struct DedicatedState final : public EffectState {
  47     /* The "dedicated" effect can output to the real output, so should have
  48      * gains for all possible output channels and not just the main ambisonic
  49      * buffer.
  50      */
  51     std::array<float,MaxOutputChannels> mCurrentGains{};
  52     std::array<float,MaxOutputChannels> mTargetGains{};
  53
  54
  55     void deviceUpdate(const DeviceBase *device, const BufferStorage *buffer) final;
  56     void update(const ContextBase *context, const EffectSlot *slot, const EffectProps *props_,
  57         const EffectTarget target) final;
  58     void process(const size_t samplesToDo, const al::span<const FloatBufferLine> samplesIn,
  59         const al::span<FloatBufferLine> samplesOut) final;
  60 };
  61
  62 void DedicatedState::deviceUpdate(const DeviceBase*, const BufferStorage*)
  63 {
  64     std::fill(mCurrentGains.begin(), mCurrentGains.end(), 0.0f);
  65 }
  66
  67 void DedicatedState::update(const ContextBase*, const EffectSlot *slot,
  68     const EffectProps *props_, const EffectTarget target)
  69 {
  70     std::fill(mTargetGains.begin(), mTargetGains.end(), 0.0f);
  71
  72     auto &props = std::get<DedicatedProps>(*props_);
  73     const float Gain{slot->Gain * props.Gain};
  74
  75     if(props.Target == DedicatedProps::Dialog)
  76     {
  77         /* Dialog goes to the front-center speaker if it exists, otherwise it
  78          * plays from the front-center location.
  79          */
  80         const size_t idx{target.RealOut ? target.RealOut->ChannelIndex[FrontCenter]
  81             : InvalidChannelIndex};
  82         if(idx != InvalidChannelIndex)
  83         {
  84             mOutTarget = target.RealOut->Buffer;
  85             mTargetGains[idx] = Gain;
  86         }
  87         else
  88         {
  89             static constexpr auto coeffs = CalcDirectionCoeffs(std::array{0.0f, 0.0f, -1.0f});
  90
  91             mOutTarget = target.Main->Buffer;
  92             ComputePanGains(target.Main, coeffs, Gain, mTargetGains);
  93         }
  94     }
  95     else if(props.Target == DedicatedProps::Lfe)
  96     {
  97         const size_t idx{target.RealOut ? target.RealOut->ChannelIndex[LFE] : InvalidChannelIndex};
  98         if(idx != InvalidChannelIndex)
  99         {
 100             mOutTarget = target.RealOut->Buffer;
 101             mTargetGains[idx] = Gain;
 102         }
 103     }
 104 }
 105
 106 void DedicatedState::process(const size_t samplesToDo, const al::span<const FloatBufferLine> samplesIn, const al::span<FloatBufferLine> samplesOut)
 107 {
 108     MixSamples(al::span{samplesIn[0]}.first(samplesToDo), samplesOut, mCurrentGains, mTargetGains,
 109         samplesToDo, 0);
 110 }
 111
 112
 113 struct DedicatedStateFactory final : public EffectStateFactory {
 114     al::intrusive_ptr<EffectState> create() override
 115     { return al::intrusive_ptr<EffectState>{new DedicatedState{}}; }
 116 };
 117
 118 } // namespace
 119
 120 EffectStateFactory *DedicatedStateFactory_getFactory()
 121 {
 122     static DedicatedStateFactory DedicatedFactory{};
 123     return &DedicatedFactory;
 124 }