Initial community commit

Src/external_dependencies/openmpt-trunk/common/Dither.h

@@ -0,0 +1,86 @@
+/*
+ * Dither.h
+ * --------
+ * Purpose: Dithering when converting to lower resolution sample formats.
+ * Notes  : (currently none)
+ * Authors: Olivier Lapicque
+ *          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 "mpt/base/macros.hpp"
+#include "mpt/string/types.hpp"
+#include "openmpt/soundbase/Dither.hpp"
+#include "openmpt/soundbase/DitherModPlug.hpp"
+#include "openmpt/soundbase/DitherNone.hpp"
+#include "openmpt/soundbase/DitherSimple.hpp"
+
+#include "mptRandom.h"
+
+#include <vector>
+#include <variant>
+
+#include <cstddef>
+
+
+OPENMPT_NAMESPACE_BEGIN
+
+
+using Dither_Default = Dither_Simple;
+
+
+class DitherNamesOpenMPT
+{
+public:
+	static mpt::ustring GetModeName(std::size_t mode)
+	{
+		mpt::ustring result;
+		switch(mode)
+		{
+			case 0:
+				// no dither
+				result = MPT_USTRING("no");
+				break;
+			case 1:
+				// chosen by OpenMPT code, might change
+				result = MPT_USTRING("default");
+				break;
+			case 2:
+				// rectangular, 0.5 bit depth, no noise shaping (original ModPlug Tracker)
+				result = MPT_USTRING("0.5 bit");
+				break;
+			case 3:
+				// rectangular, 1 bit depth, simple 1st order noise shaping
+				result = MPT_USTRING("1 bit");
+				break;
+			default:
+				result = MPT_USTRING("");
+				break;
+		}
+		return result;
+	}
+};
+
+
+using DithersOpenMPT =
+	Dithers<std::variant<MultiChannelDither<Dither_None>, MultiChannelDither<Dither_Default>, MultiChannelDither<Dither_ModPlug>, MultiChannelDither<Dither_Simple>>, DitherNamesOpenMPT, 4, 1, 0, mpt::good_prng>;
+
+
+struct DithersWrapperOpenMPT
+	: DithersOpenMPT
+{
+	template <typename Trd>
+	DithersWrapperOpenMPT(Trd &rd, std::size_t mode = DithersOpenMPT::DefaultDither, std::size_t channels = DithersOpenMPT::DefaultChannels)
+		: DithersOpenMPT(rd, mode, channels)
+	{
+		return;
+	}
+};
+
+
+OPENMPT_NAMESPACE_END