feat: include latest taiko changes

src/taiko/attributes.rs

@@ -15,6 +15,9 @@ pub struct TaikoDifficultyAttributes {
     pub great_hit_window: f64,
     /// The perceived hit window for an n100 inclusive of rate-adjusting mods (DT/HT/etc)
     pub ok_hit_window: f64,
+    /// The ratio of stamina difficulty from mono-color (single color) streams to total
+    /// stamina difficulty.
+    pub mono_stamina_factor: f64,
     /// The final star rating.
     pub stars: f64,
     /// The maximum combo.

src/taiko/difficulty/gradual.rs

@@ -153,6 +153,8 @@ impl Iterator for TaikoGradualDifficulty {
                 Skill::new(&mut self.skills.rhythm, &self.diff_objects).process(&borrowed);
                 Skill::new(&mut self.skills.color, &self.diff_objects).process(&borrowed);
                 Skill::new(&mut self.skills.stamina, &self.diff_objects).process(&borrowed);
+                Skill::new(&mut self.skills.single_color_stamina, &self.diff_objects)
+                    .process(&borrowed);
 
                 if borrowed.base_hit_type.is_hit() {
                     self.attrs.max_combo += 1;
@@ -231,6 +233,8 @@ impl Iterator for TaikoGradualDifficulty {
         let mut rhythm = Skill::new(&mut self.skills.rhythm, &self.diff_objects);
         let mut color = Skill::new(&mut self.skills.color, &self.diff_objects);
         let mut stamina = Skill::new(&mut self.skills.stamina, &self.diff_objects);
+        let mut single_color_stamina =
+            Skill::new(&mut self.skills.single_color_stamina, &self.diff_objects);
 
         for _ in 0..take {
             loop {
@@ -239,6 +243,7 @@ impl Iterator for TaikoGradualDifficulty {
                 rhythm.process(&borrowed);
                 color.process(&borrowed);
                 stamina.process(&borrowed);
+                single_color_stamina.process(&borrowed);
 
                 if borrowed.base_hit_type.is_hit() {
                     self.attrs.max_combo += 1;

src/taiko/difficulty/mod.rs

@@ -142,11 +142,14 @@ impl DifficultyValues {
             let mut rhythm = Skill::new(&mut skills.rhythm, &diff_objects);
             let mut color = Skill::new(&mut skills.color, &diff_objects);
             let mut stamina = Skill::new(&mut skills.stamina, &diff_objects);
+            let mut single_color_stamina =
+                Skill::new(&mut skills.single_color_stamina, &diff_objects);
 
             for hit_object in diff_objects.iter().take(n_diff_objects) {
                 rhythm.process(&hit_object.get());
                 color.process(&hit_object.get());
                 stamina.process(&hit_object.get());
+                single_color_stamina.process(&hit_object.get());
             }
         }
 
@@ -157,15 +160,32 @@ impl DifficultyValues {
         let color_rating = skills.color.as_difficulty_value() * COLOR_SKILL_MULTIPLIER;
         let rhythm_rating = skills.rhythm.as_difficulty_value() * RHYTHM_SKILL_MULTIPLIER;
         let stamina_rating = skills.stamina.as_difficulty_value() * STAMINA_SKILL_MULTIPLIER;
+        let mono_stamina_rating =
+            skills.single_color_stamina.as_difficulty_value() * STAMINA_SKILL_MULTIPLIER;
+        let mono_stamina_factor = if stamina_rating.abs() >= f64::EPSILON {
+            (mono_stamina_rating / stamina_rating).powf(5.0)
+        } else {
+            1.0
+        };
         let combined_rating =
             combined_difficulty_value(skills.color, skills.rhythm, skills.stamina);
 
-        let star_rating = rescale(combined_rating * 1.4);
+        let mut star_rating = rescale(combined_rating * 1.4);
+
+        // * TODO: This is temporary measure as we don't detect abuse of multiple-input playstyles of converts within the current system.
+        if attrs.is_convert {
+            star_rating *= 0.925;
+            // * For maps with low colour variance and high stamina requirement, multiple inputs are more likely to be abused.
+            if color_rating < 2.0 && stamina_rating > 8.0 {
+                star_rating *= 0.80;
+            }
+        }
 
         attrs.stamina = stamina_rating;
         attrs.rhythm = rhythm_rating;
         attrs.color = color_rating;
         attrs.peak = combined_rating;
+        attrs.mono_stamina_factor = mono_stamina_factor;
         attrs.stars = star_rating;
     }
 

src/taiko/difficulty/skills/mod.rs

@@ -9,14 +9,16 @@ pub struct TaikoSkills {
     pub rhythm: Rhythm,
     pub color: Color,
     pub stamina: Stamina,
+    pub single_color_stamina: Stamina,
 }
 
 impl TaikoSkills {
     pub fn new() -> Self {
         Self {
             rhythm: Rhythm::default(),
             color: Color::default(),
-            stamina: Stamina::default(),
+            stamina: Stamina::new(false),
+            single_color_stamina: Stamina::new(true),
         }
     }
 }

src/taiko/difficulty/skills/stamina.rs

@@ -1,24 +1,34 @@
 use crate::{
     any::difficulty::{
         object::IDifficultyObject,
-        skills::{strain_decay, ISkill, Skill, StrainDecaySkill},
+        skills::{strain_decay, ISkill, Skill, StrainDecaySkill, StrainSkill},
     },
     taiko::{
         difficulty::object::{TaikoDifficultyObject, TaikoDifficultyObjects},
         object::HitType,
     },
-    util::strains_vec::StrainsVec,
+    util::{strains_vec::StrainsVec, sync::Weak},
 };
 
 const SKILL_MULTIPLIER: f64 = 1.1;
 const STRAIN_DECAY_BASE: f64 = 0.4;
 
-#[derive(Clone, Default)]
+#[derive(Clone)]
 pub struct Stamina {
-    inner: StrainDecaySkill,
+    inner: StrainSkill,
+    single_color: bool,
+    curr_strain: f64,
 }
 
 impl Stamina {
+    pub fn new(single_color: bool) -> Self {
+        Self {
+            inner: StrainSkill::default(),
+            single_color,
+            curr_strain: 0.0,
+        }
+    }
+
     pub fn get_curr_strain_peaks(self) -> StrainsVec {
         self.inner.get_curr_strain_peaks()
     }
@@ -36,6 +46,10 @@ impl ISkill for Stamina {
 
 impl Skill<'_, Stamina> {
     fn calculate_initial_strain(&mut self, time: f64, curr: &TaikoDifficultyObject) -> f64 {
+        if self.inner.single_color {
+            return 0.0;
+        }
+
         let prev_start_time = curr
             .previous(0, &self.diff_objects.objects)
             .map_or(0.0, |prev| prev.get().start_time);
@@ -44,27 +58,27 @@ impl Skill<'_, Stamina> {
     }
 
     const fn curr_strain(&self) -> f64 {
-        self.inner.inner.curr_strain
+        self.inner.curr_strain
     }
 
     fn curr_strain_mut(&mut self) -> &mut f64 {
-        &mut self.inner.inner.curr_strain
+        &mut self.inner.curr_strain
     }
 
     const fn curr_section_peak(&self) -> f64 {
-        self.inner.inner.inner.curr_section_peak
+        self.inner.inner.curr_section_peak
     }
 
     fn curr_section_peak_mut(&mut self) -> &mut f64 {
-        &mut self.inner.inner.inner.curr_section_peak
+        &mut self.inner.inner.curr_section_peak
     }
 
     const fn curr_section_end(&self) -> f64 {
-        self.inner.inner.inner.curr_section_end
+        self.inner.inner.curr_section_end
     }
 
     fn curr_section_end_mut(&mut self) -> &mut f64 {
-        &mut self.inner.inner.inner.curr_section_end
+        &mut self.inner.inner.curr_section_end
     }
 
     pub fn process(&mut self, curr: &TaikoDifficultyObject) {
@@ -86,13 +100,30 @@ impl Skill<'_, Stamina> {
 
     fn strain_value_at(&mut self, curr: &TaikoDifficultyObject) -> f64 {
         *self.curr_strain_mut() *= strain_decay(curr.delta_time, STRAIN_DECAY_BASE);
-        *self.curr_strain_mut() += self.strain_value_of(curr) * SKILL_MULTIPLIER;
-
-        self.curr_strain()
-    }
-
-    fn strain_value_of(&self, curr: &TaikoDifficultyObject) -> f64 {
-        StaminaEvaluator::evaluate_diff_of(curr, self.diff_objects)
+        *self.curr_strain_mut() +=
+            StaminaEvaluator::evaluate_diff_of(curr, self.diff_objects) * SKILL_MULTIPLIER;
+
+        // Safely prevents previous strains from shifting as new notes are added.
+        let index = curr
+            .color
+            .mono_streak
+            .as_ref()
+            .and_then(Weak::upgrade)
+            .and_then(|mono| {
+                mono.get().hit_objects.iter().position(|h| {
+                    let Some(h) = h.upgrade() else { return false };
+                    let h = h.get();
+
+                    h.idx == curr.idx
+                })
+            })
+            .unwrap_or(0);
+
+        if self.inner.single_color {
+            self.curr_strain() / (1.0 + ((-(index as isize - 10)) as f64 / 2.0).exp())
+        } else {
+            self.curr_strain()
+        }
     }
 }
 

src/taiko/performance/mod.rs

@@ -416,12 +416,12 @@ impl TaikoPerformanceInner<'_> {
 
         let mut multiplier = 1.13;
 
-        if self.mods.hd() {
+        if self.mods.hd() && !self.attrs.is_convert {
             multiplier *= 1.075;
         }
 
         if self.mods.ez() {
-            multiplier *= 0.975;
+            multiplier *= 0.95;
         }
 
         let diff_value =
@@ -459,10 +459,10 @@ impl TaikoPerformanceInner<'_> {
         diff_value *= 0.986_f64.powf(effective_miss_count);
 
         if self.mods.ez() {
-            diff_value *= 0.985;
+            diff_value *= 0.9;
         }
 
-        if self.mods.hd() && !self.attrs.is_convert {
+        if self.mods.hd() {
             diff_value *= 1.025;
         }
 
@@ -471,11 +471,19 @@ impl TaikoPerformanceInner<'_> {
         }
 
         if self.mods.fl() {
-            diff_value *= 1.05 * len_bonus;
+            diff_value *=
+                (1.05 - (self.attrs.mono_stamina_factor / 50.0).min(1.0) * len_bonus).max(1.0);
         }
 
+        // * Scale accuracy more harshly on nearly-completely mono (single coloured) speed maps.
+        let acc_scaling_exp = f64::from(2) + self.attrs.mono_stamina_factor;
+        let acc_scaling_shift = f64::from(300) - f64::from(100) * self.attrs.mono_stamina_factor;
+
         diff_value
-            * (special_functions::erf(400.0 / (2.0_f64.sqrt() * estimated_unstable_rate))).powf(2.0)
+            * (special_functions::erf(
+                acc_scaling_shift / (2.0_f64.sqrt() * estimated_unstable_rate),
+            ))
+            .powf(acc_scaling_exp)
     }
 
     fn compute_accuracy_value(&self, estimated_unstable_rate: Option<f64>) -> f64 {

tests/difficulty.rs

@@ -71,6 +71,7 @@ macro_rules! test_cases {
         rhythm: $rhythm:literal,
         color: $color:literal,
         peak: $peak:literal,
+        mono_stamina_factor: $mono_stamina_factor:literal,
         great_hit_window: $great_hit_window:literal,
         ok_hit_window: $ok_hit_window:literal,
         stars: $stars:literal,
@@ -82,6 +83,7 @@ macro_rules! test_cases {
             rhythm: $rhythm,
             color: $color,
             peak: $peak,
+            mono_stamina_factor: $mono_stamina_factor,
             great_hit_window: $great_hit_window,
             ok_hit_window: $ok_hit_window,
             stars: $stars,
@@ -362,6 +364,7 @@ fn basic_taiko() {
                 rhythm: 0.20130047251681948,
                 color: 1.0487315549761433,
                 peak: 1.8422453377400778,
+                mono_stamina_factor: 2.66403971858592e-07,
                 great_hit_window: 35.0,
                 ok_hit_window: 80.0,
                 stars: 2.914589700180437,
@@ -373,6 +376,7 @@ fn basic_taiko() {
                 rhythm: 0.20130047251681948,
                 color: 1.0487315549761433,
                 peak: 1.8422453377400778,
+                mono_stamina_factor: 2.66403971858592e-07,
                 great_hit_window: 29.0,
                 ok_hit_window: 68.0,
                 stars: 2.914589700180437,
@@ -384,6 +388,7 @@ fn basic_taiko() {
                 rhythm: 0.4448175371191029,
                 color: 1.363762496098889,
                 peak: 2.625066421324458,
+                mono_stamina_factor: 2.515617502055679e-07,
                 great_hit_window: 23.333333333333332,
                 ok_hit_window: 53.333333333333336,
                 stars: 3.942709244618132,
@@ -403,9 +408,10 @@ fn convert_taiko() {
                 rhythm: 1.4696991260446617,
                 color: 2.303228172964907,
                 peak: 4.117779264387738,
+                mono_stamina_factor: 0.0016957378202796742,
                 great_hit_window: 23.59999942779541,
                 ok_hit_window: 57.19999885559082,
-                stars: 5.660149021515273,
+                stars: 5.235637844901627,
                 max_combo: 908,
                 is_convert: true,
             };
@@ -414,9 +420,10 @@ fn convert_taiko() {
                 rhythm: 1.4696991260446617,
                 color: 2.303228172964907,
                 peak: 4.117779264387738,
+                mono_stamina_factor: 0.0016957378202796742,
                 great_hit_window: 20.0,
-                ok_hit_window: 50.0,
-                stars: 5.660149021515273,
+                ok_hit_window: 50.0
+                stars: 5.235637844901627,
                 max_combo: 908,
                 is_convert: true,
             };
@@ -425,9 +432,10 @@ fn convert_taiko() {
                 rhythm: 2.002843919169095,
                 color: 3.1864894777399986,
                 peak: 6.103209631166694,
+                mono_stamina_factor: 0.0017075184344987763,
                 great_hit_window: 15.733332951863607,
                 ok_hit_window: 38.13333257039388,
-                stars: 7.578560915020682,
+                stars: 7.010168846394131,
                 max_combo: 908,
                 is_convert: true,
             };