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authorAndré Nusser <andre.nusser@googlemail.com>2019-05-12 23:55:17 +0200
committerAndré Nusser <andre.nusser@googlemail.com>2019-05-12 23:55:17 +0200
commit87af0143d46bab272c1a72f075f2d718887238b3 (patch)
treed4e9de5a4183d88d121e7b8f327448f17fc6909c /src/velocityfilter.cc
parent16e2b1c230064788e28930ef27903a5164afa74f (diff)
Move stddev to own filter.
Diffstat (limited to 'src/velocityfilter.cc')
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1 files changed, 50 insertions, 0 deletions
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+/* -*- Mode: c++ -*- */
+/***************************************************************************
+ * velocityfilter.cc
+ *
+ * Sun May 12 16:01:41 CEST 2019
+ * 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 "velocityfilter.h"
+
+#include "random.h"
+#include "settings.h"
+
+VelocityFilter::VelocityFilter(Settings& settings, Random& random, Instruments const& instruments)
+ : settings(settings), random(random), instruments(instruments)
+{
+}
+
+bool VelocityFilter::filter(event_t& event, size_t pos)
+{
+ auto power_max = instruments[event.instrument]->getMaxPower();
+ auto power_min = instruments[event.instrument]->getMinPower();
+ float power_span = power_max - power_min;
+
+ float mean = event.velocity - .5f/127.f; // XXX: this should actually be done when reading the events
+ float stddev = settings.velocity_stddev.load();
+ // the 20.0f we determined empirically
+ float lvl = power_min + random.normalDistribution(mean, stddev / 20.0f) * power_span;
+
+ event.velocity = lvl;
+ return true;
+}