From cf0b8b4568bd7df489426cb2bd88e69a2f73d6a2 Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?Andr=C3=A9=20Nusser?= Date: Sun, 12 May 2019 22:20:35 +0200 Subject: Delete old sample selection algorithm and do slight adaption. The slight adaption was the one deva and I talked about on IRC. --- src/sample_selection.cc | 104 +++--------------------------------------------- src/sample_selection.h | 24 +++-------- 2 files changed, 11 insertions(+), 117 deletions(-) diff --git a/src/sample_selection.cc b/src/sample_selection.cc index 1c35c87..ce50cfa 100644 --- a/src/sample_selection.cc +++ b/src/sample_selection.cc @@ -37,12 +37,6 @@ namespace { -// Minimum sample set size. -// Smaller means wider 'velocity groups'. -// Limited by sample set size, ie. only kicks in if sample set size is smaller -// than this number. -std::size_t const MIN_SAMPLE_SET_SIZE = 26u; - float pow2(float f) { return f*f; @@ -51,13 +45,8 @@ float pow2(float f) } // end anonymous namespace SampleSelection::SampleSelection(Settings& settings, Random& rand, const PowerList& powerlist) - : settings(settings), rand(rand), powerlist(powerlist), alg(SelectionAlg::Objective) -{ -} - -void SampleSelection::setSelectionAlg(SelectionAlg alg) + : settings(settings), rand(rand), powerlist(powerlist) { - this->alg = alg; } void SampleSelection::finalise() @@ -66,90 +55,6 @@ void SampleSelection::finalise() } const Sample* SampleSelection::get(level_t level, std::size_t pos) -{ - // TODO: switch objective to default at some point - switch (alg) - { - case SelectionAlg::Objective: - return getObjective(level, pos); - break; - case SelectionAlg::Old: - default: - return getOld(level, pos); - } -} - -// FIXME: remove before release and adapt everything -const Sample* SampleSelection::getOld(level_t level, std::size_t pos) -{ - auto velocity_stddev = settings.velocity_stddev.load(); - - const auto& samples = powerlist.getPowerListItems(); - if(!samples.size()) - { - return nullptr; // No samples to choose from. - } - - int retry = settings.sample_selection_retry_count.load(); - - Sample* sample{nullptr}; - - auto power_max = powerlist.getMaxPower(); - auto power_min = powerlist.getMinPower(); - float power_span = power_max - power_min; - - // Width is limited to at least 10. Fixes problem with instrument with a - // sample set smaller than MIN_SAMPLE_SET_SIZE. - float width = std::max(samples.size(), MIN_SAMPLE_SET_SIZE); - - // Spread out at most ~2 samples away from center if all samples have a - // uniform distribution over the power spectrum (which they probably don't). - float mean_stepwidth = power_span / width; - - // Cut off mean value with stddev/2 in both ends in order to make room for - // downwards expansion on velocity 0 and upwards expansion on velocity 1. - float mean = level * (power_span - mean_stepwidth) + (mean_stepwidth / 2.0); - float stddev = velocity_stddev * mean_stepwidth; - - std::size_t index{0}; - float power{0.f}; - - // note: loop is executed once + #retry - do - { - --retry; - - // Select normal distributed value between - // (stddev/2) and (power_span-stddev/2) - float lvl = rand.normalDistribution(mean, stddev); - - // Adjust this value to be in range - // (power_min+stddev/2) and (power_max-stddev/2) - lvl += power_min; - - DEBUG(rand, - "level: %f, lvl: %f (mean: %.2f, stddev: %.2f, mean_stepwidth: %f, power_min: %f, power_max: %f)\n", - level, lvl, mean, stddev, mean_stepwidth, power_min, power_max); - - for (std::size_t i = 0; i < samples.size(); ++i) - { - auto const& item = samples[i]; - if (sample == nullptr || std::fabs(item.power - lvl) < std::fabs(power - lvl)) - { - sample = item.sample; - index = i; - power = item.power; - } - } - } while (lastsample == sample && retry >= 0); - - DEBUG(rand, "Chose sample with index: %d, power %f", (int)index, power); - - lastsample = sample; - return sample; -} - -const Sample* SampleSelection::getObjective(level_t level, std::size_t pos) { const auto& samples = powerlist.getPowerListItems(); if(!samples.size()) @@ -162,9 +67,9 @@ const Sample* SampleSelection::getObjective(level_t level, std::size_t pos) float power_span = power_max - power_min; float mean = level - .5f/127.f; // XXX: this should actually be done when reading the events - float stddev = settings.enable_velocity_modifier.load() ? - settings.velocity_stddev.load()/127.0f : 0.; - float lvl = power_min + rand.normalDistribution(mean, stddev)*power_span; + float stddev = settings.velocity_stddev.load(); + // the 20.0f we determined empirically + float lvl = power_min + rand.normalDistribution(mean, stddev / 20.0f) * power_span; std::size_t index_opt = 0; float power_opt{0.f}; @@ -242,4 +147,5 @@ const Sample* SampleSelection::getObjective(level_t level, std::size_t pos) last[index_opt] = pos; return samples[index_opt].sample; + } diff --git a/src/sample_selection.h b/src/sample_selection.h index 2134cdd..8da4e0d 100644 --- a/src/sample_selection.h +++ b/src/sample_selection.h @@ -34,30 +34,18 @@ class PowerList; class Random; struct Settings; -enum class SelectionAlg -{ - Old, - Objective, -}; - class SampleSelection { +public: + SampleSelection(Settings& settings, Random& rand, const PowerList& powerlist); + + void finalise(); + const Sample* get(level_t level, std::size_t pos); + private: Settings& settings; Random& rand; const PowerList& powerlist; - Sample* lastsample; std::vector last; - - SelectionAlg alg; - const Sample* getOld(level_t level, std::size_t pos); - const Sample* getObjective(level_t level, std::size_t pos); - -public: - SampleSelection(Settings& settings, Random& rand, const PowerList& powerlist); - - void setSelectionAlg(SelectionAlg alg); - void finalise(); - const Sample* get(level_t level, std::size_t pos); }; -- cgit v1.2.3