First Commit

externals/openal-soft/alc/effects/modulator.cpp

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+/**
+ * OpenAL cross platform audio library
+ * Copyright (C) 2009 by Chris Robinson.
+ * 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 <cstdlib>
+#include <iterator>
+
+#include "alc/effects/base.h"
+#include "almalloc.h"
+#include "alnumbers.h"
+#include "alnumeric.h"
+#include "alspan.h"
+#include "core/ambidefs.h"
+#include "core/bufferline.h"
+#include "core/context.h"
+#include "core/devformat.h"
+#include "core/device.h"
+#include "core/effectslot.h"
+#include "core/filters/biquad.h"
+#include "core/mixer.h"
+#include "intrusive_ptr.h"
+
+
+namespace {
+
+using uint = unsigned int;
+
+#define MAX_UPDATE_SAMPLES 128
+
+#define WAVEFORM_FRACBITS  24
+#define WAVEFORM_FRACONE   (1<<WAVEFORM_FRACBITS)
+#define WAVEFORM_FRACMASK  (WAVEFORM_FRACONE-1)
+
+inline float Sin(uint index)
+{
+    constexpr float scale{al::numbers::pi_v<float>*2.0f / WAVEFORM_FRACONE};
+    return std::sin(static_cast<float>(index) * scale);
+}
+
+inline float Saw(uint index)
+{ return static_cast<float>(index)*(2.0f/WAVEFORM_FRACONE) - 1.0f; }
+
+inline float Square(uint index)
+{ return static_cast<float>(static_cast<int>((index>>(WAVEFORM_FRACBITS-2))&2) - 1); }
+
+inline float One(uint) { return 1.0f; }
+
+template<float (&func)(uint)>
+void Modulate(float *RESTRICT dst, uint index, const uint step, size_t todo)
+{
+    for(size_t i{0u};i < todo;i++)
+    {
+        index += step;
+        index &= WAVEFORM_FRACMASK;
+        dst[i] = func(index);
+    }
+}
+
+
+struct ModulatorState final : public EffectState {
+    void (*mGetSamples)(float*RESTRICT, uint, const uint, size_t){};
+
+    uint mIndex{0};
+    uint mStep{1};
+
+    struct {
+        uint mTargetChannel{InvalidChannelIndex};
+
+        BiquadFilter mFilter;
+
+        float mCurrentGain{};
+        float mTargetGain{};
+    } mChans[MaxAmbiChannels];
+
+
+    void deviceUpdate(const DeviceBase *device, const BufferStorage *buffer) override;
+    void update(const ContextBase *context, const EffectSlot *slot, const EffectProps *props,
+        const EffectTarget target) override;
+    void process(const size_t samplesToDo, const al::span<const FloatBufferLine> samplesIn,
+        const al::span<FloatBufferLine> samplesOut) override;
+
+    DEF_NEWDEL(ModulatorState)
+};
+
+void ModulatorState::deviceUpdate(const DeviceBase*, const BufferStorage*)
+{
+    for(auto &e : mChans)
+    {
+        e.mTargetChannel = InvalidChannelIndex;
+        e.mFilter.clear();
+        e.mCurrentGain = 0.0f;
+    }
+}
+
+void ModulatorState::update(const ContextBase *context, const EffectSlot *slot,
+    const EffectProps *props, const EffectTarget target)
+{
+    const DeviceBase *device{context->mDevice};
+
+    const float step{props->Modulator.Frequency / static_cast<float>(device->Frequency)};
+    mStep = fastf2u(clampf(step*WAVEFORM_FRACONE, 0.0f, float{WAVEFORM_FRACONE-1}));
+
+    if(mStep == 0)
+        mGetSamples = Modulate<One>;
+    else if(props->Modulator.Waveform == ModulatorWaveform::Sinusoid)
+        mGetSamples = Modulate<Sin>;
+    else if(props->Modulator.Waveform == ModulatorWaveform::Sawtooth)
+        mGetSamples = Modulate<Saw>;
+    else /*if(props->Modulator.Waveform == ModulatorWaveform::Square)*/
+        mGetSamples = Modulate<Square>;
+
+    float f0norm{props->Modulator.HighPassCutoff / static_cast<float>(device->Frequency)};
+    f0norm = clampf(f0norm, 1.0f/512.0f, 0.49f);
+    /* Bandwidth value is constant in octaves. */
+    mChans[0].mFilter.setParamsFromBandwidth(BiquadType::HighPass, f0norm, 1.0f, 0.75f);
+    for(size_t i{1u};i < slot->Wet.Buffer.size();++i)
+        mChans[i].mFilter.copyParamsFrom(mChans[0].mFilter);
+
+    mOutTarget = target.Main->Buffer;
+    auto set_channel = [this](size_t idx, uint outchan, float outgain)
+    {
+        mChans[idx].mTargetChannel = outchan;
+        mChans[idx].mTargetGain = outgain;
+    };
+    target.Main->setAmbiMixParams(slot->Wet, slot->Gain, set_channel);
+}
+
+void ModulatorState::process(const size_t samplesToDo, const al::span<const FloatBufferLine> samplesIn, const al::span<FloatBufferLine> samplesOut)
+{
+    for(size_t base{0u};base < samplesToDo;)
+    {
+        alignas(16) float modsamples[MAX_UPDATE_SAMPLES];
+        const size_t td{minz(MAX_UPDATE_SAMPLES, samplesToDo-base)};
+
+        mGetSamples(modsamples, mIndex, mStep, td);
+        mIndex += static_cast<uint>(mStep * td);
+        mIndex &= WAVEFORM_FRACMASK;
+
+        auto chandata = std::begin(mChans);
+        for(const auto &input : samplesIn)
+        {
+            const size_t outidx{chandata->mTargetChannel};
+            if(outidx != InvalidChannelIndex)
+            {
+                alignas(16) float temps[MAX_UPDATE_SAMPLES];
+
+                chandata->mFilter.process({&input[base], td}, temps);
+                for(size_t i{0u};i < td;i++)
+                    temps[i] *= modsamples[i];
+
+                MixSamples({temps, td}, samplesOut[outidx].data()+base, chandata->mCurrentGain,
+                    chandata->mTargetGain, samplesToDo-base);
+            }
+            ++chandata;
+        }
+
+        base += td;
+    }
+}
+
+
+struct ModulatorStateFactory final : public EffectStateFactory {
+    al::intrusive_ptr<EffectState> create() override
+    { return al::intrusive_ptr<EffectState>{new ModulatorState{}}; }
+};
+
+} // namespace
+
+EffectStateFactory *ModulatorStateFactory_getFactory()
+{
+    static ModulatorStateFactory ModulatorFactory{};
+    return &ModulatorFactory;
+}