Initial community commit

Src/external_dependencies/openmpt-trunk/soundlib/AudioReadTarget.h

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+/*
+ * AudioReadTarget.h
+ * -----------------
+ * Purpose: Callback class implementations for audio data read via CSoundFile::Read.
+ * Notes  : (currently none)
+ * Authors: OpenMPT Devs
+ * The OpenMPT source code is released under the BSD license. Read LICENSE for more details.
+ */
+
+#pragma once
+
+#include "openmpt/all/BuildSettings.hpp"
+
+#include "Sndfile.h"
+#include "mpt/audio/span.hpp"
+#include "openmpt/soundbase/SampleFormat.hpp"
+#include "openmpt/soundbase/CopyMix.hpp"
+#include "openmpt/soundbase/Dither.hpp"
+#include "MixerLoops.h"
+#include "Mixer.h"
+#include "../common/Dither.h"
+
+#include <type_traits>
+
+
+OPENMPT_NAMESPACE_BEGIN
+
+
+template <typename Taudio_span, typename TDithers = DithersOpenMPT>
+class AudioTargetBuffer
+	: public IAudioTarget
+{
+private:
+	std::size_t countRendered;
+	TDithers &dithers;
+protected:
+	Taudio_span outputBuffer;
+public:
+	AudioTargetBuffer(Taudio_span buf, TDithers &dithers_)
+		: countRendered(0)
+		, dithers(dithers_)
+		, outputBuffer(buf)
+	{
+		return;
+	}
+	std::size_t GetRenderedCount() const { return countRendered; }
+public:
+	void Process(mpt::audio_span_interleaved<MixSampleInt> buffer) override
+	{
+		std::visit(
+			[&](auto &ditherInstance)
+			{
+				ConvertBufferMixInternalFixedToBuffer<MixSampleIntTraits::mix_fractional_bits, false>(mpt::make_audio_span_with_offset(outputBuffer, countRendered), buffer, ditherInstance, buffer.size_channels(), buffer.size_frames());
+			},
+			dithers.Variant()
+		);
+		countRendered += buffer.size_frames();
+	}
+	void Process(mpt::audio_span_interleaved<MixSampleFloat> buffer) override
+	{
+		std::visit(
+			[&](auto &ditherInstance)
+			{
+				ConvertBufferMixInternalToBuffer<false>(mpt::make_audio_span_with_offset(outputBuffer, countRendered), buffer, ditherInstance, buffer.size_channels(), buffer.size_frames());
+			},
+			dithers.Variant()
+		);
+		countRendered += buffer.size_frames();
+	}
+};
+
+
+template <typename Taudio_span, typename TDithers = DithersOpenMPT>
+class AudioTargetBufferWithGain
+	: public AudioTargetBuffer<Taudio_span>
+{
+private:
+	using Tbase = AudioTargetBuffer<Taudio_span>;
+private:
+	const float gainFactor;
+public:
+	AudioTargetBufferWithGain(Taudio_span buf, TDithers &dithers, float gainFactor_)
+		: Tbase(buf, dithers)
+		, gainFactor(gainFactor_)
+	{
+		return;
+	}
+public:
+	void Process(mpt::audio_span_interleaved<MixSampleInt> buffer) override
+	{
+		const std::size_t countRendered_ = Tbase::GetRenderedCount();
+		if constexpr(!std::is_floating_point<typename Taudio_span::sample_type>::value)
+		{
+			int32 gainFactor16_16 = mpt::saturate_round<int32>(gainFactor * (1 << 16));
+			if(gainFactor16_16 != (1<<16))
+			{
+				// only apply gain when != +/- 0dB
+				// no clipping prevention is done here
+				for(std::size_t frame = 0; frame < buffer.size_frames(); ++frame)
+				{
+					for(std::size_t channel = 0; channel < buffer.size_channels(); ++channel)
+					{
+						buffer(channel, frame) = Util::muldiv(buffer(channel, frame), gainFactor16_16, 1 << 16);
+					}
+				}
+			}
+		}
+		Tbase::Process(buffer);
+		if constexpr(std::is_floating_point<typename Taudio_span::sample_type>::value)
+		{
+			if(gainFactor != 1.0f)
+			{
+				// only apply gain when != +/- 0dB
+				for(std::size_t frame = 0; frame < buffer.size_frames(); ++frame)
+				{
+					for(std::size_t channel = 0; channel < buffer.size_channels(); ++channel)
+					{
+						Tbase::outputBuffer(channel, countRendered_ + frame) *= gainFactor;
+					}
+				}
+			}
+		}
+	}
+	void Process(mpt::audio_span_interleaved<MixSampleFloat> buffer) override
+	{
+		if(gainFactor != 1.0f)
+		{
+			// only apply gain when != +/- 0dB
+			for(std::size_t frame = 0; frame < buffer.size_frames(); ++frame)
+			{
+				for(std::size_t channel = 0; channel < buffer.size_channels(); ++channel)
+				{
+					buffer(channel, frame) *= gainFactor;
+				}
+			}
+		}
+		Tbase::Process(buffer);
+	}
+};
+
+
+OPENMPT_NAMESPACE_END