private TabletopParams CreateFeatureParamsForSection(int section)
{
int numSections = sectionsProvider.NumSections();
double sectionLengthSeconds = sectionModel.TotalLength.TotalSeconds;
//first decide if it has a tabletop at all.
//the chance of it being something at all rises from 0% to 100%.
double progression = ((float)section + 1) / numSections; // <= 1
//if it's a tabletop:
double topLength =
randomizer.ProportionAlong(sectionModel.FeatureLengthVariation, progression,
sectionModel.MinFeatureLength.TotalSeconds,
sectionModel.MaxFeatureLength.TotalSeconds);
double maxRampLength = Math.Min(sectionModel.MaxRampLength.TotalSeconds, (sectionLengthSeconds - topLength) / 2);
if (sectionModel.MinRampLength.TotalSeconds > maxRampLength)
{
throw new InvalidOperationException($"MinRampLength must be <= maxRampLength. MinTabletopLength could be too high.");
}
// could feasibly be MinRampLength at the start of the track. Desirable? Yes, because other parameters constrain the dramaticness at the start.
double rampLength =
randomizer.ProportionAlong(sectionModel.RampLengthVariation, progression,
maxRampLength,
sectionModel.MinRampLength.TotalSeconds); // Max is first as shorter ramps are more dramatic (nearer the end of the track)
var result = new TabletopParams
{
RampLength = rampLength,
TopLength = topLength,
RampsUseSin2 = true
};
return(result);
}
private double CreateTopFrequency(int section)
{
var numSections = sectionsProvider.NumSections();
double progression = (float)section / numSections; // <= 1
//20% of being a fall, 80% chance a rise
var isRise = randomizer.GetRandom() > 1 - pulseFrequency.ChanceOfHigh;
var frequencyLimit = isRise ? pulseFrequency.High : pulseFrequency.Low;
var topFrequency = randomizer.ProportionAlong(pulseFrequency.Variation, progression,
pulseFrequency.Quiescent,
frequencyLimit);
if (topFrequency <= 0)
{
throw new InvalidOperationException("TopFrequency must be > 0");
}
return(topFrequency);
}
private double Wetness(double t, int n)
{
if (wetness == null)
{
return(0);
}
if (sections == null)
{
return(wetness.Maximum);
}
// rise in a sin^2 fashion from MinWetness to MaxWetness
var section = sectionsProvider.Section(n);
var maxForSection = maxWetnessForSectionCache.GetOrAdd(section, s =>
{
var numSections = sectionsProvider.NumSections();
var progression = (double)s / Math.Max(1, numSections - 1); // <= 1
var max = randomizer.ProportionAlong(wetness.Variation, progression,
wetness.Minimum, wetness.Maximum);
return(max);
});
double value;
if (wetness.LinkToFeature)
{
var isThisFeature = featureChooser.IsFeature(n, nameof(FeatureProbabilityModel.Wetness));
value = isThisFeature ?
featureProvider.FeatureValue(t, n, wetness.Minimum, maxForSection)
: wetness.Minimum;
}
else
{
value = maxForSection;
}
return(value);
}