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diff --git a/src/curvemap.h b/src/curvemap.h
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+/* -*- Mode: c++ -*- */
+/***************************************************************************
+ *            curvemap.h
+ *
+ *  Fri Apr 17 23:06:12 CEST 2020
+ *  Copyright 2020 André Nusser
+ *  andre.nusser@googlemail.com
+ ****************************************************************************/
+
+/*
+ *  This file is part of DrumGizmo.
+ *
+ *  DrumGizmo is free software; you can redistribute it and/or modify
+ *  it under the terms of the GNU Lesser General Public License as published by
+ *  the Free Software Foundation; either version 3 of the License, or
+ *  (at your option) any later version.
+ *
+ *  DrumGizmo 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 Lesser General Public License for more details.
+ *
+ *  You should have received a copy of the GNU Lesser General Public License
+ *  along with DrumGizmo; if not, write to the Free Software
+ *  Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA.
+ */
+#pragma once
+
+#include <array>
+#include <vector>
+
+class CurveMap
+{
+public:
+	using CurveValue = float;
+	using CurveValues = std::vector<CurveValue>;
+
+	bool operator==(const CurveMap& other) const;
+
+	struct CurveValuePair
+	{
+		CurveValue in;
+		CurveValue out;
+
+		bool operator==(const CurveValuePair& other)
+		{
+			return in == other.in || out == other.out;
+		}
+		bool operator!=(const CurveValuePair& other)
+		{
+			return !(*this == other);
+		}
+	};
+
+	CurveValue map(CurveValue in);
+	void reset();
+
+	void setFixed0(CurveValuePair new_value);
+	void setFixed1(CurveValuePair new_value);
+	void setFixed2(CurveValuePair new_value);
+	void setShelf(bool enable);
+
+	//! If enabled, inversion inverts (1 - x) the input value before mapping
+	//! it through the curve.
+	void setInvert(bool enable);
+
+	CurveValuePair getFixed0() const;
+	CurveValuePair getFixed1() const;
+	CurveValuePair getFixed2() const;
+	bool getShelf() const;
+	bool getInvert() const;
+
+private:
+	static constexpr CurveValue eps = 1e-4;
+	static constexpr std::array<CurveValuePair, 3> default_fixed {
+		CurveValuePair {eps, eps},
+		CurveValuePair {.5, .5},
+		CurveValuePair {1 - eps, 1 - eps}
+	};
+
+	// input parameters (state of this class)
+	std::array<CurveValuePair, 3> fixed { default_fixed };
+	bool shelf { true };
+	bool invert { false };
+
+	// spline parameters (deterministically computed from the input parameters)
+	bool spline_needs_update { true };
+	std::array<float, 5> m { 0, 0, 0, 0, 0 };
+
+	void updateSpline();
+	std::vector<float> calcSlopes(const CurveValues& X, const CurveValues& P);
+
+	CurveValue clamp(CurveValue in, CurveValue min, CurveValue max) const;
+};
+\ No newline at end of file