/// <summary>
/// Returns the partial star rating of the beatmap, calculated using peak strains from all sections of the map.
/// </summary>
/// <remarks>
/// For each section, the peak strains of all separate skills are combined into a single peak strain for the section.
/// The resulting partial rating of the beatmap is a weighted sum of the combined peaks (higher peaks are weighted more).
/// </remarks>
private double locallyCombinedDifficulty(Colour colour, Rhythm rhythm, Stamina staminaRight, Stamina staminaLeft, double staminaPenalty)
{
List <double> peaks = new List <double>();
var colourPeaks = colour.GetCurrentStrainPeaks().ToList();
var rhythmPeaks = rhythm.GetCurrentStrainPeaks().ToList();
var staminaRightPeaks = staminaRight.GetCurrentStrainPeaks().ToList();
var staminaLeftPeaks = staminaLeft.GetCurrentStrainPeaks().ToList();
for (int i = 0; i < colourPeaks.Count; i++)
{
double colourPeak = colourPeaks[i] * colour_skill_multiplier;
double rhythmPeak = rhythmPeaks[i] * rhythm_skill_multiplier;
double staminaPeak = (staminaRightPeaks[i] + staminaLeftPeaks[i]) * stamina_skill_multiplier * staminaPenalty;
peaks.Add(norm(2, colourPeak, rhythmPeak, staminaPeak));
}
double difficulty = 0;
double weight = 1;
foreach (double strain in peaks.OrderByDescending(d => d))
{
difficulty += strain * weight;
weight *= 0.9;
}
return(difficulty);
}
/// <summary>
/// Returns the partial star rating of the beatmap, calculated using peak strains from all sections of the map.
/// </summary>
/// <remarks>
/// For each section, the peak strains of all separate skills are combined into a single peak strain for the section.
/// The resulting partial rating of the beatmap is a weighted sum of the combined peaks (higher peaks are weighted more).
/// </remarks>
private double locallyCombinedDifficulty(Colour colour, Rhythm rhythm, Stamina stamina, double staminaPenalty)
{
List <double> peaks = new List <double>();
var colourPeaks = colour.GetCurrentStrainPeaks().ToList();
var rhythmPeaks = rhythm.GetCurrentStrainPeaks().ToList();
var staminaPeaks = stamina.GetCurrentStrainPeaks().ToList();
for (int i = 0; i < colourPeaks.Count; i++)
{
double colourPeak = colourPeaks[i] * colour_skill_multiplier;
double rhythmPeak = rhythmPeaks[i] * rhythm_skill_multiplier;
double staminaPeak = staminaPeaks[i] * stamina_skill_multiplier * staminaPenalty;
double peak = norm(2, colourPeak, rhythmPeak, staminaPeak);
// Sections with 0 strain are excluded to avoid worst-case time complexity of the following sort (e.g. /b/2351871).
// These sections will not contribute to the difficulty.
if (peak > 0)
{
peaks.Add(peak);
}
}
double difficulty = 0;
double weight = 1;
foreach (double strain in peaks.OrderByDescending(d => d))
{
difficulty += strain * weight;
weight *= 0.9;
}
return(difficulty);
}
