Rename Powermap to CurveMap, bugfix, unit testsdevelopcurve_map

5 files changed, 172 insertions, 128 deletions

diff --git a/src/Makefile.am b/src/Makefile.am
index a8bdb59..e2a2583 100644
--- a/src/Makefile.am
+++ b/src/Makefile.am
@@ -67,7 +67,7 @@ libdg_la_SOURCES = \
 	$(top_srcdir)/src/midimapper.cc \
 	$(top_srcdir)/src/path.cc \
 	$(top_srcdir)/src/powerlist.cc \
-	$(top_srcdir)/src/powermap.cc \
+	$(top_srcdir)/src/curvemap.cc \
 	$(top_srcdir)/src/powermapfilter.cc \
 	$(top_srcdir)/src/random.cc \
 	$(top_srcdir)/src/sample.cc \
@@ -126,7 +126,7 @@ EXTRA_DIST = \
 	path.h \
 	platform.h \
 	powerlist.h \
-	powermap.h \
+	curvemap.h \
 	powermapfilter.h \
 	random.h \
 	range.h \
diff --git a/src/powermap.cc b/src/curvemap.cc
index 2bb45b7..073dde4 100644
--- a/src/powermap.cc
+++ b/src/curvemap.cc
@@ -24,7 +24,7 @@
  *  along with DrumGizmo; if not, write to the Free Software
  *  Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA.
  */
-#include "powermap.h"
+#include "curvemap.h"
 
 #include <cassert>
 #include <cmath>
@@ -32,31 +32,31 @@
 namespace
 {
 
-using Power = Powermap::Power;
-using PowerPair = Powermap::PowerPair;
+using CurveValue = CurveMap::CurveValue;
+using CurveValuePair = CurveMap::CurveValuePair;
 
-Power h00(Power x)
+CurveValue h00(CurveValue x)
 {
 	return (1 + 2 * x) * pow(1 - x, 2);
 }
 
-Power h10(Power x)
+CurveValue h10(CurveValue x)
 {
 	return x * pow(1 - x, 2);
 }
 
-Power h01(Power x)
+CurveValue h01(CurveValue x)
 {
 	return x * x * (3 - 2 * x);
 }
 
-Power h11(Power x)
+CurveValue h11(CurveValue x)
 {
 	return x * x * (x - 1);
 }
 
-Power computeValue(const Power x, const PowerPair& P0, const PowerPair& P1,
-                   const Power m0, const Power m1)
+CurveValue computeValue(const CurveValue x, const CurveValuePair& P0, const CurveValuePair& P1,
+                        const CurveValue m0, const CurveValue m1)
 {
 	const auto x0 = P0.in;
 	const auto x1 = P1.in;
@@ -74,21 +74,22 @@ Power computeValue(const Power x, const PowerPair& P0, const PowerPair& P1,
 
 } // end anonymous namespace
 
-Powermap::Powermap()
-{
-	reset();
-}
+constexpr std::array<CurveValuePair, 3> CurveMap::default_fixed;
 
-Power Powermap::map(Power in)
+CurveValue CurveMap::map(CurveValue in)
 {
 	assert(in >= 0. && in <= 1.);
+	if (invert)
+	{
+		in = 1.0 - in;
+	}
 
 	if (spline_needs_update)
 	{
 		updateSpline();
 	}
 
-	Power out;
+	CurveValue out;
 	if (in < fixed[0].in)
 	{
 		out = shelf ? fixed[0].out
@@ -113,84 +114,100 @@ Power Powermap::map(Power in)
 	return out;
 }
 
-void Powermap::reset()
+void CurveMap::reset()
 {
-	setFixed0({eps, eps});
-	setFixed1({.5, .5});
-	setFixed2({1 - eps, 1 - eps});
-	// FIXME: better false?
-	shelf = true;
+	*this = CurveMap{};
 
 	updateSpline();
 }
 
-void Powermap::setFixed0(PowerPair new_value)
+void CurveMap::setFixed0(CurveValuePair new_value)
 {
-	if (fixed[0] != new_value)
+	auto prev = fixed[0];
+	fixed[0].in = clamp(new_value.in, eps, fixed[1].in - eps);
+	fixed[0].out = clamp(new_value.out, eps, fixed[1].out - eps);
+	if (fixed[0] != prev)
 	{
 		spline_needs_update = true;
-		fixed[0].in = clamp(new_value.in, eps, fixed[1].in - eps);
-		fixed[0].out = clamp(new_value.out, eps, fixed[1].out - eps);
 	}
 }
 
-void Powermap::setFixed1(PowerPair new_value)
+void CurveMap::setFixed1(CurveValuePair new_value)
 {
-	if (fixed[1] != new_value)
+	auto prev = fixed[1];
+	fixed[1].in = clamp(new_value.in, fixed[0].in + eps, fixed[2].in - eps);
+	fixed[1].out = clamp(new_value.out, fixed[0].out + eps, fixed[2].out - eps);
+	if (fixed[1] != prev)
 	{
 		spline_needs_update = true;
-		fixed[1].in = clamp(new_value.in, fixed[0].in + eps, fixed[2].in - eps);
-		fixed[1].out = clamp(new_value.out, fixed[0].out + eps, fixed[2].out - eps);
 	}
 }
 
-void Powermap::setFixed2(PowerPair new_value)
+void CurveMap::setFixed2(CurveValuePair new_value)
 {
-	if (fixed[2] != new_value)
+	auto prev = fixed[2];
+	fixed[2].in = clamp(new_value.in, fixed[1].in + eps, 1 - eps);
+	fixed[2].out = clamp(new_value.out, fixed[1].out + eps, 1 - eps);
+	if (fixed[2] != prev)
 	{
 		spline_needs_update = true;
-		fixed[2].in = clamp(new_value.in, fixed[1].in + eps, 1 - eps);
-		fixed[2].out = clamp(new_value.out, fixed[1].out + eps, 1 - eps);
 	}
 }
 
-void Powermap::setShelf(bool enable)
+void CurveMap::setInvert(bool enable)
+{
+	if (invert != enable)
+	{
+		spline_needs_update = true;
+		invert = enable;
+	}
+}
+
+void CurveMap::setShelf(bool enable)
 {
 	if (shelf != enable)
 	{
 		spline_needs_update = true;
-		this->shelf = enable;
+		shelf = enable;
 	}
 }
 
-PowerPair Powermap::getFixed0() const
+CurveValuePair CurveMap::getFixed0() const
 {
 	return fixed[0];
 }
 
-PowerPair Powermap::getFixed1() const
+CurveValuePair CurveMap::getFixed1() const
 {
 	return fixed[1];
 }
 
-PowerPair Powermap::getFixed2() const
+CurveValuePair CurveMap::getFixed2() const
 {
 	return fixed[2];
 }
 
+bool CurveMap::getInvert() const {
+	return invert;
+}
+
+bool CurveMap::getShelf() const {
+	return shelf;
+}
+
 // This mostly followes the wikipedia article for monotone cubic splines:
 // https://en.wikipedia.org/wiki/Monotone_cubic_interpolation
-void Powermap::updateSpline()
+void CurveMap::updateSpline()
 {
 	assert(0. <= fixed[0].in && fixed[0].in < fixed[1].in &&
 	       fixed[1].in < fixed[2].in && fixed[2].in <= 1.);
 	assert(0. <= fixed[0].out && fixed[0].out <= fixed[1].out &&
 	       fixed[1].out <= fixed[2].out && fixed[2].out <= 1.);
 
-	Powers X = shelf ? Powers{fixed[0].in, fixed[1].in, fixed[2].in}
-	                 : Powers{0., fixed[0].in, fixed[1].in, fixed[2].in, 1.};
-	Powers Y = shelf ? Powers{fixed[0].out, fixed[1].out, fixed[2].out}
-	                 : Powers{0., fixed[0].out, fixed[1].out, fixed[2].out, 1.};
+	CurveValues X = shelf ? CurveValues{fixed[0].in, fixed[1].in, fixed[2].in}
+	                 : CurveValues{0., fixed[0].in, fixed[1].in, fixed[2].in, 1.};
+	CurveValues Y = shelf ? CurveValues{fixed[0].out, fixed[1].out, fixed[2].out}
+	                 : CurveValues{0., fixed[0].out, fixed[1].out, fixed[2].out, 1.};
 
 	auto slopes = calcSlopes(X, Y);
 
@@ -215,12 +232,12 @@ void Powermap::updateSpline()
 
 // This follows the monotone cubic spline algorithm of Steffen, from:
 // "A Simple Method for Monotonic Interpolation in One Dimension"
-std::vector<float> Powermap::calcSlopes(const Powers& X, const Powers& Y)
+std::vector<float> CurveMap::calcSlopes(const CurveValues& X, const CurveValues& Y)
 {
-	Powers m(X.size());
+	CurveValues m(X.size());
 
-	Powers d(X.size() - 1);
-	Powers h(X.size() - 1);
+	CurveValues d(X.size() - 1);
+	CurveValues h(X.size() - 1);
 	for (std::size_t i = 0; i < d.size(); ++i)
 	{
 		h[i] = X[i + 1] - X[i];
@@ -245,7 +262,16 @@ std::vector<float> Powermap::calcSlopes(const Powers& X, const Powers& Y)
 	return m;
 }
 
-Power Powermap::clamp(Power in, Power min, Power max) const
+CurveValue CurveMap::clamp(CurveValue in, CurveValue min, CurveValue max) const
 {
 	return std::max(min, std::min(in, max));
 }
+
+bool CurveMap::operator==(const CurveMap& other) const
+{
+	return getFixed0() == other.getFixed0() &&
+		getFixed1() == other.getFixed1() &&
+		getFixed2() == other.getFixed2() &&
+		getShelf() == other.getShelf() &&
+		getInvert() == other.getInvert();
+}
diff --git a/src/curvemap.h b/src/curvemap.h
new file mode 100644
index 0000000..926543d
--- /dev/null
+++ b/src/curvemap.h
@@ -0,0 +1,94 @@
+/* -*- 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
diff --git a/src/powermap.h b/src/powermap.h
deleted file mode 100644
index 3a406cc..0000000
--- a/src/powermap.h
+++ /dev/null
@@ -1,76 +0,0 @@
-/* -*- Mode: c++ -*- */
-/***************************************************************************
- *            powermap.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 Powermap
-{
-public:
-	using Power = float;
-	using Powers = std::vector<Power>;
-	struct PowerPair
-	{
-		Power in;
-		Power out;
-
-		bool operator!=(const PowerPair& other)
-		{
-			return in != other.in || out != other.out;
-		}
-	};
-
-	Powermap();
-
-	Power map(Power in);
-	void reset();
-
-	void setFixed0(PowerPair new_value);
-	void setFixed1(PowerPair new_value);
-	void setFixed2(PowerPair new_value);
-	void setShelf(bool enable);
-
-	PowerPair getFixed0() const;
-	PowerPair getFixed1() const;
-	PowerPair getFixed2() const;
-
-private:
-	// input parameters (state of this class)
-	std::array<PowerPair, 3> fixed;
-	bool shelf;
-
-	// spline parameters (deterministically computed from the input parameters)
-	bool spline_needs_update;
-	std::array<float, 5> m;
-	const Power eps = 1e-4;
-
-	void updateSpline();
-	std::vector<float> calcSlopes(const Powers& X, const Powers& P);
-
-	Power clamp(Power in, Power min, Power max) const;
-};
diff --git a/src/powermapfilter.h b/src/powermapfilter.h
index 263f809..b9dfe5b 100644
--- a/src/powermapfilter.h
+++ b/src/powermapfilter.h
@@ -27,7 +27,7 @@
 #pragma once
 
 #include "inputfilter.h"
-#include "powermap.h"
+#include "curvemap.h"
 
 struct Settings;
 
@@ -43,5 +43,5 @@ public:
 
 private:
 	Settings& settings;
-	Powermap powermap;
+	CurveMap powermap;
 };