diff options
Diffstat (limited to 'alc/effects/modulator.cpp')
| -rw-r--r-- | alc/effects/modulator.cpp | 150 |
1 files changed, 90 insertions, 60 deletions
diff --git a/alc/effects/modulator.cpp b/alc/effects/modulator.cpp index 14ee5004..f99ba19c 100644 --- a/alc/effects/modulator.cpp +++ b/alc/effects/modulator.cpp @@ -45,43 +45,49 @@ namespace { using uint = unsigned int; -#define MAX_UPDATE_SAMPLES 128 +inline float Sin(uint index, float scale) +{ return std::sin(static_cast<float>(index) * scale); } -#define WAVEFORM_FRACBITS 24 -#define WAVEFORM_FRACONE (1<<WAVEFORM_FRACBITS) -#define WAVEFORM_FRACMASK (WAVEFORM_FRACONE-1) +inline float Saw(uint index, float scale) +{ return static_cast<float>(index)*scale - 1.0f; } -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 Square(uint index, float scale) +{ return (static_cast<float>(index)*scale < 0.5f)*2.0f - 1.0f; } -inline float Saw(uint index) -{ return static_cast<float>(index)*(2.0f/WAVEFORM_FRACONE) - 1.0f; } +inline float One(uint, float) +{ return 1.0f; } -inline float Square(uint index) -{ return static_cast<float>(static_cast<int>((index>>(WAVEFORM_FRACBITS-2))&2) - 1); } +struct ModulatorState final : public EffectState { + template<float (&func)(uint,float)> + void Modulate(size_t todo) + { + const uint range{mRange}; + const float scale{mIndexScale}; + uint index{mIndex}; -inline float One(uint) { return 1.0f; } + ASSUME(range > 1); + ASSUME(todo > 0); -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); + for(size_t i{0};i < todo;) + { + size_t rem{minz(todo-i, range-index)}; + do { + mModSamples[i++] = func(index++, scale); + } while(--rem); + if(index == range) + index = 0; + } + mIndex = index; } -} - -struct ModulatorState final : public EffectState { - void (*mGetSamples)(float*RESTRICT, uint, const uint, size_t){}; + void (ModulatorState::*mGenModSamples)(size_t){}; uint mIndex{0}; - uint mStep{1}; + uint mRange{1}; + float mIndexScale{0.0f}; + + alignas(16) FloatBufferLine mModSamples{}; + alignas(16) FloatBufferLine mBuffer{}; struct { uint mTargetChannel{InvalidChannelIndex}; @@ -102,6 +108,13 @@ struct ModulatorState final : public EffectState { DEF_NEWDEL(ModulatorState) }; +template<> +void ModulatorState::Modulate<One>(size_t todo) +{ + std::fill_n(mModSamples.begin(), todo, 1.0f); + mIndex = 0; +} + void ModulatorState::deviceUpdate(const DeviceBase*, const BufferStorage*) { for(auto &e : mChans) @@ -117,17 +130,46 @@ void ModulatorState::update(const ContextBase *context, const EffectSlot *slot, { 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>; + /* The effective frequency will be adjusted to have a whole number of + * samples per cycle (at 48khz, that allows 8000, 6857.14, 6000, 5333.33, + * 4800, etc). We could do better by using fixed-point stepping over a sin + * function, with additive synthesis for the square and sawtooth waveforms, + * but that may need a more efficient sin function since it needs to do + * many iterations per sample. + */ + const float samplesPerCycle{props->Modulator.Frequency > 0.0f + ? static_cast<float>(device->Frequency)/props->Modulator.Frequency + 0.5f + : 1.0f}; + const uint range{static_cast<uint>(clampf(samplesPerCycle, 1.0f, + static_cast<float>(device->Frequency)))}; + mIndex = static_cast<uint>(uint64_t{mIndex} * range / mRange); + mRange = range; + + if(mRange == 1) + { + mIndexScale = 0.0f; + mGenModSamples = &ModulatorState::Modulate<One>; + } else if(props->Modulator.Waveform == ModulatorWaveform::Sinusoid) - mGetSamples = Modulate<Sin>; + { + mIndexScale = al::numbers::pi_v<float>*2.0f / static_cast<float>(mRange); + mGenModSamples = &ModulatorState::Modulate<Sin>; + } else if(props->Modulator.Waveform == ModulatorWaveform::Sawtooth) - mGetSamples = Modulate<Saw>; + { + mIndexScale = 2.0f / static_cast<float>(mRange-1); + mGenModSamples = &ModulatorState::Modulate<Saw>; + } else /*if(props->Modulator.Waveform == ModulatorWaveform::Square)*/ - mGetSamples = Modulate<Square>; + { + /* For square wave, the range should be even (there should be an equal + * number of high and low samples). An odd number of samples per cycle + * would need a more complex value generator. + */ + mRange = (mRange+1) & ~1u; + mIndexScale = 1.0f / static_cast<float>(mRange-1); + mGenModSamples = &ModulatorState::Modulate<Square>; + } float f0norm{props->Modulator.HighPassCutoff / static_cast<float>(device->Frequency)}; f0norm = clampf(f0norm, 1.0f/512.0f, 0.49f); @@ -147,34 +189,22 @@ void ModulatorState::update(const ContextBase *context, const EffectSlot *slot, 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; + (this->*mGenModSamples)(samplesToDo); - auto chandata = std::begin(mChans); - for(const auto &input : samplesIn) + auto chandata = std::begin(mChans); + for(const auto &input : samplesIn) + { + const size_t outidx{chandata->mTargetChannel}; + if(outidx != InvalidChannelIndex) { - 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; - } + chandata->mFilter.process({input.data(), samplesToDo}, mBuffer.data()); + for(size_t i{0u};i < samplesToDo;++i) + mBuffer[i] *= mModSamples[i]; - base += td; + MixSamples({mBuffer.data(), samplesToDo}, samplesOut[outidx].data(), + chandata->mCurrentGain, chandata->mTargetGain, minz(samplesToDo, 64)); + } + ++chandata; } } |