Initial community commit

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

@@ -0,0 +1,143 @@
+/*
+ * Resampler.h
+ * -----------
+ * Purpose: Holds the tables for all available resamplers.
+ * 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 "WindowedFIR.h"
+#include "Mixer.h"
+#include "MixerSettings.h"
+#include "Paula.h"
+
+
+OPENMPT_NAMESPACE_BEGIN
+
+
+#ifdef LIBOPENMPT_BUILD
+// All these optimizations are not applicable to the tracker
+// because cutoff and firtype are configurable there.
+
+// Cache resampler tables across resampler object creation.
+// A C++11-style function-static singleton is holding the cached values.
+#define MPT_RESAMPLER_TABLES_CACHED
+
+// Prime the tables cache when the library is loaded.
+// Caching gets triggered via a global object that primes the cache during
+//  construction.
+// This is only really useful with MPT_RESAMPLER_TABLES_CACHED.
+//#define MPT_RESAMPLER_TABLES_CACHED_ONSTARTUP
+
+#endif // LIBOPENMPT_BUILD
+
+
+#define SINC_WIDTH       8
+
+#define SINC_PHASES_BITS 12
+#define SINC_PHASES      (1<<SINC_PHASES_BITS)
+
+#ifdef MPT_INTMIXER
+typedef int16 SINC_TYPE;
+#define SINC_QUANTSHIFT 15
+#else
+typedef mixsample_t SINC_TYPE;
+#endif // MPT_INTMIXER
+
+#define SINC_MASK (SINC_PHASES-1)
+static_assert((SINC_MASK & 0xffff) == SINC_MASK); // exceeding fractional freq
+
+
+class CResamplerSettings
+{
+public:
+	ResamplingMode SrcMode = Resampling::Default();
+	double gdWFIRCutoff = 0.97;
+	uint8 gbWFIRType = WFIR_KAISER4T;
+	Resampling::AmigaFilter emulateAmiga = Resampling::AmigaFilter::Off;
+public:
+	constexpr CResamplerSettings() = default;
+	bool operator == (const CResamplerSettings &cmp) const
+	{
+#if MPT_COMPILER_CLANG
+#pragma clang diagnostic push
+#pragma clang diagnostic ignored "-Wfloat-equal"
+#endif // MPT_COMPILER_CLANG
+		return SrcMode == cmp.SrcMode && gdWFIRCutoff == cmp.gdWFIRCutoff && gbWFIRType == cmp.gbWFIRType && emulateAmiga == cmp.emulateAmiga;
+#if MPT_COMPILER_CLANG
+#pragma clang diagnostic pop
+#endif // MPT_COMPILER_CLANG
+	}
+	bool operator != (const CResamplerSettings &cmp) const { return !(*this == cmp); }
+};
+
+
+class CResampler
+{
+public:
+	CResamplerSettings m_Settings;
+	CWindowedFIR m_WindowedFIR;
+	static const int16 FastSincTable[256 * 4];
+
+#ifdef MODPLUG_TRACKER
+	static bool StaticTablesInitialized;
+	#define RESAMPLER_TABLE static
+#else
+	// no global data which has to be initialized by hand in the library
+	#define RESAMPLER_TABLE 
+#endif // MODPLUG_TRACKER
+
+	RESAMPLER_TABLE SINC_TYPE gKaiserSinc[SINC_PHASES * 8];     // Upsampling
+	RESAMPLER_TABLE SINC_TYPE gDownsample13x[SINC_PHASES * 8];  // Downsample 1.333x
+	RESAMPLER_TABLE SINC_TYPE gDownsample2x[SINC_PHASES * 8];   // Downsample 2x
+	RESAMPLER_TABLE Paula::BlepTables blepTables;               // Amiga BLEP resampler
+
+#ifndef MPT_INTMIXER
+	RESAMPLER_TABLE mixsample_t FastSincTablef[256 * 4];	// Cubic spline LUT
+	RESAMPLER_TABLE mixsample_t LinearTablef[256];		// Linear interpolation LUT
+#endif // !defined(MPT_INTMIXER)
+
+#undef RESAMPLER_TABLE
+
+private:
+	CResamplerSettings m_OldSettings;
+public:
+	CResampler(bool fresh_generate=false)
+	{
+		if(fresh_generate)
+		{
+			InitializeTablesFromScratch(true);
+		} else
+		{
+			InitializeTables();
+		}
+	}
+	void InitializeTables()
+	{
+		#if defined(MPT_RESAMPLER_TABLES_CACHED)
+			InitializeTablesFromCache();
+		#else
+			InitializeTablesFromScratch(true);
+		#endif
+	}
+	void UpdateTables()
+	{
+		InitializeTablesFromScratch(false);
+	}
+
+private:
+	void InitFloatmixerTables();
+	void InitializeTablesFromScratch(bool force=false);
+#ifdef MPT_RESAMPLER_TABLES_CACHED
+	void InitializeTablesFromCache();
+#endif
+};
+
+
+OPENMPT_NAMESPACE_END