feat: compact strains (#32)

* store zero strains compactly

* added docs

* added proptest

* add feature to store strains compactly

* update ci

* rename CompactZerosVec to StrainsVec

* add size_hint for iter

* rename iter

* minor adjustments

* more minor adjustments

src/osu/difficulty/skills/aim.rs

@@ -6,7 +6,7 @@ use crate::{
         skills::{strain_decay, ISkill, Skill},
     },
     osu::difficulty::object::OsuDifficultyObject,
-    util::float_ext::FloatExt,
+    util::{float_ext::FloatExt, strains_vec::StrainsVec},
 };
 
 use super::strain::OsuStrainSkill;
@@ -30,7 +30,7 @@ impl Aim {
         }
     }
 
-    pub fn get_curr_strain_peaks(self) -> Vec<f64> {
+    pub fn get_curr_strain_peaks(self) -> StrainsVec {
         self.inner.get_curr_strain_peaks()
     }
 

src/osu/difficulty/skills/flashlight.rs

@@ -6,7 +6,7 @@ use crate::{
         skills::{strain_decay, ISkill, Skill, StrainSkill},
     },
     osu::{difficulty::object::OsuDifficultyObject, object::OsuObjectKind},
-    util::mods::Mods,
+    util::{mods::Mods, strains_vec::StrainsVec},
 };
 
 use super::strain::OsuStrainSkill;
@@ -33,7 +33,7 @@ impl Flashlight {
         }
     }
 
-    pub fn get_curr_strain_peaks(self) -> Vec<f64> {
+    pub fn get_curr_strain_peaks(self) -> StrainsVec {
         self.inner.get_curr_strain_peaks()
     }
 
@@ -48,8 +48,7 @@ impl Flashlight {
     }
 
     fn static_difficulty_value(skill: StrainSkill) -> f64 {
-        skill.get_curr_strain_peaks().into_iter().sum::<f64>()
-            * OsuStrainSkill::DIFFICULTY_MULTIPLER
+        skill.get_curr_strain_peaks().sum() * OsuStrainSkill::DIFFICULTY_MULTIPLER
     }
 }
 

src/osu/difficulty/skills/speed.rs

@@ -6,6 +6,7 @@ use crate::{
         skills::{strain_decay, ISkill, Skill},
     },
     osu::difficulty::object::OsuDifficultyObject,
+    util::strains_vec::StrainsVec,
 };
 
 use super::strain::OsuStrainSkill;
@@ -37,7 +38,7 @@ impl Speed {
         }
     }
 
-    pub fn get_curr_strain_peaks(self) -> Vec<f64> {
+    pub fn get_curr_strain_peaks(self) -> StrainsVec {
         self.inner.get_curr_strain_peaks()
     }
 

src/osu/difficulty/skills/strain.rs

@@ -1,4 +1,4 @@
-use crate::any::difficulty::skills::StrainSkill;
+use crate::{any::difficulty::skills::StrainSkill, util::strains_vec::StrainsVec};
 
 #[derive(Clone, Default)]
 pub struct OsuStrainSkill {
@@ -21,7 +21,7 @@ impl OsuStrainSkill {
         self.inner.start_new_section_from(initial_strain);
     }
 
-    pub fn get_curr_strain_peaks(self) -> Vec<f64> {
+    pub fn get_curr_strain_peaks(self) -> StrainsVec {
         self.inner.get_curr_strain_peaks()
     }
 
@@ -36,10 +36,8 @@ impl OsuStrainSkill {
         let mut weight = 1.0;
 
         let mut peaks = self.get_curr_strain_peaks();
-        peaks.retain(|&strain| strain > 0.0);
-        peaks.sort_by(|a, b| b.total_cmp(a));
 
-        let peaks_iter = peaks.iter_mut().take(reduced_section_count);
+        let peaks_iter = peaks.sorted_non_zero_iter_mut().take(reduced_section_count);
 
         for (i, strain) in peaks_iter.enumerate() {
             let clamped = f64::from((i as f32 / reduced_section_count as f32).clamp(0.0, 1.0));
@@ -47,9 +45,9 @@ impl OsuStrainSkill {
             *strain *= lerp(reduced_strain_baseline, 1.0, scale);
         }
 
-        peaks.sort_by(|a, b| b.total_cmp(a));
+        peaks.sort_desc();
 
-        for strain in peaks {
+        for strain in peaks.iter() {
             difficulty += strain * weight;
             weight *= decay_weight;
         }

src/osu/strains.rs

@@ -38,9 +38,9 @@ pub fn strains(difficulty: &Difficulty, converted: &OsuBeatmap<'_>) -> OsuStrain
     } = DifficultyValues::calculate(difficulty, converted);
 
     OsuStrains {
-        aim: aim.get_curr_strain_peaks(),
-        aim_no_sliders: aim_no_sliders.get_curr_strain_peaks(),
-        speed: speed.get_curr_strain_peaks(),
-        flashlight: flashlight.get_curr_strain_peaks(),
+        aim: aim.get_curr_strain_peaks().into_vec(),
+        aim_no_sliders: aim_no_sliders.get_curr_strain_peaks().into_vec(),
+        speed: speed.get_curr_strain_peaks().into_vec(),
+        flashlight: flashlight.get_curr_strain_peaks().into_vec(),
     }
 }