Add position filter.

5 files changed, 110 insertions, 0 deletions

diff --git a/src/Makefile.am b/src/Makefile.am
index a8bdb59..31ce8da 100644
--- a/src/Makefile.am
+++ b/src/Makefile.am
@@ -76,6 +76,7 @@ libdg_la_SOURCES = \
 	$(top_srcdir)/src/staminafilter.cc \
 	$(top_srcdir)/src/thread.cc \
 	$(top_srcdir)/src/velocityfilter.cc \
+	$(top_srcdir)/src/positionfilter.cc \
 	$(top_srcdir)/src/versionstr.cc
 
 EXTRA_DIST = \
@@ -140,6 +141,7 @@ EXTRA_DIST = \
 	thread.h \
 	translation.h \
 	velocityfilter.h \
+	positionfilter.h \
 	versionstr.h \
 	zrwrapper.h
 
diff --git a/src/inputprocessor.cc b/src/inputprocessor.cc
index deae8ad..fa3498c 100644
--- a/src/inputprocessor.cc
+++ b/src/inputprocessor.cc
@@ -36,6 +36,7 @@
 #include "powermapfilter.h"
 #include "staminafilter.h"
 #include "velocityfilter.h"
+#include "positionfilter.h"
 
 #include "cpp11fix.h"
 
@@ -93,6 +94,7 @@ InputProcessor::InputProcessor(Settings& settings,
 	filters.emplace_back(std::make_unique<StaminaFilter>(settings));
 	filters.emplace_back(std::make_unique<LatencyFilter>(settings, random));
 	filters.emplace_back(std::make_unique<VelocityFilter>(settings, random));
+	filters.emplace_back(std::make_unique<PositionFilter>(settings, random));
 	filters.emplace_back(std::make_unique<Reporter>(settings, original_velocity));
 }
 
diff --git a/src/positionfilter.cc b/src/positionfilter.cc
new file mode 100644
index 0000000..8d2f987
--- /dev/null
+++ b/src/positionfilter.cc
@@ -0,0 +1,48 @@
+/* -*- Mode: c++ -*- */
+/***************************************************************************
+ *            positionfilter.cc
+ *
+ *  Sat 13 Feb 2021 12:46:41 CET
+ *  Copyright 2019 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.
+ */
+#include "positionfilter.h"
+
+#include "random.h"
+#include "settings.h"
+
+PositionFilter::PositionFilter(Settings& settings, Random& random)
+	: settings(settings), random(random)
+{
+}
+
+bool PositionFilter::filter(event_t& event, size_t pos)
+{
+	if (settings.enable_velocity_modifier.load())
+	{
+		float mean = event.position;
+		float stddev = settings.position_stddev.load();
+		// the 30.0f were determined empirically
+		event.position = random.normalDistribution(mean, stddev / 30.0f); // FIXME: right magic value?
+	}
+
+	return true;
+}
diff --git a/src/positionfilter.h b/src/positionfilter.h
new file mode 100644
index 0000000..ac989f6
--- /dev/null
+++ b/src/positionfilter.h
@@ -0,0 +1,52 @@
+/* -*- Mode: c++ -*- */
+/***************************************************************************
+ *            positionfilter.h
+ *
+ *  Sat 13 Feb 2021 12:46:41 CET
+ *  Copyright 2019 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 <cstddef>
+#include <map>
+#include <utility>
+
+#include "inputfilter.h"
+#include "instrument.h"
+
+struct Settings;
+class Random;
+
+class PositionFilter
+	: public InputFilter
+{
+public:
+	PositionFilter(Settings& settings, Random& random);
+
+	bool filter(event_t& event, std::size_t pos) override;
+
+	// Note getLatency not overloaded because this filter doesn't add latency.
+
+private:
+	Settings& settings;
+	Random& random;
+};
diff --git a/src/settings.h b/src/settings.h
index a423ae3..5c2e4ee 100644
--- a/src/settings.h
+++ b/src/settings.h
@@ -76,6 +76,7 @@ struct Settings
 	static float constexpr velocity_modifier_falloff_default = 0.5f;
 	static float constexpr velocity_modifier_weight_default = 0.25f;
 	static float constexpr velocity_stddev_default = .45f;
+	static float constexpr position_stddev_default = 0.f; // FIXME: set to something sensible
 	static float constexpr sample_selection_f_close_default = .85f;
 	static float constexpr sample_selection_f_position_default = 1.f;
 	static float constexpr sample_selection_f_diverse_default = .16f;
@@ -83,6 +84,7 @@ struct Settings
 	Atomic<float> velocity_modifier_falloff{velocity_modifier_falloff_default};
 	Atomic<float> velocity_modifier_weight{velocity_modifier_weight_default};
 	Atomic<float> velocity_stddev{velocity_stddev_default};
+	Atomic<float> position_stddev{position_stddev_default};
 	Atomic<float> sample_selection_f_close{sample_selection_f_close_default};
 	Atomic<float> sample_selection_f_position{sample_selection_f_position_default};
 	Atomic<float> sample_selection_f_diverse{sample_selection_f_diverse_default};
@@ -202,6 +204,7 @@ struct SettingsGetter
 	SettingRef<float> velocity_modifier_falloff;
 	SettingRef<float> velocity_modifier_weight;
 	SettingRef<float> velocity_stddev;
+	SettingRef<float> position_stddev;
 	SettingRef<float> sample_selection_f_close;
 	SettingRef<float> sample_selection_f_position;
 	SettingRef<float> sample_selection_f_diverse;
@@ -278,6 +281,7 @@ struct SettingsGetter
 		, velocity_modifier_falloff{settings.velocity_modifier_falloff}
 		, velocity_modifier_weight{settings.velocity_modifier_weight}
 		, velocity_stddev{settings.velocity_stddev}
+		, position_stddev{settings.position_stddev}
 		, sample_selection_f_close{settings.sample_selection_f_close}
 		, sample_selection_f_position{settings.sample_selection_f_position}
 		, sample_selection_f_diverse{settings.sample_selection_f_diverse}
@@ -349,6 +353,7 @@ public:
 	Notifier<float> velocity_modifier_falloff;
 	Notifier<float> velocity_modifier_weight;
 	Notifier<float> velocity_stddev;
+	Notifier<float> position_stddev;
 	Notifier<float> sample_selection_f_close;
 	Notifier<float> sample_selection_f_position;
 	Notifier<float> sample_selection_f_diverse;
@@ -429,6 +434,7 @@ public:
 		EVAL(velocity_modifier_falloff);
 		EVAL(velocity_modifier_weight);
 		EVAL(velocity_stddev);
+		EVAL(position_stddev);
 		EVAL(sample_selection_f_close);
 		EVAL(sample_selection_f_position);
 		EVAL(sample_selection_f_diverse);