provided a way for partial plays

src/mania/mod.rs

@@ -10,8 +10,12 @@ const SECTION_LEN: f32 = 400.0;
 const STAR_SCALING_FACTOR: f32 = 0.018;
 
 /// Star calculation for osu!mania maps
-pub fn stars(map: &Beatmap, mods: impl Mods) -> f32 {
-    if map.hit_objects.len() < 2 {
+///
+/// In case of a partial play, e.g. a fail, one can specify the amount of passed objects.
+pub fn stars(map: &Beatmap, mods: impl Mods, passed_objects: Option<usize>) -> f32 {
+    let take = passed_objects.unwrap_or_else(|| map.hit_objects.len());
+
+    if take < 2 {
         return 0.0;
     }
 
@@ -22,6 +26,7 @@ pub fn stars(map: &Beatmap, mods: impl Mods) -> f32 {
     let mut hit_objects = map
         .hit_objects
         .iter()
+        .take(take)
         .skip(1)
         .zip(map.hit_objects.iter())
         .map(|(base, prev)| DifficultyHitObject::new(base, prev, map.cs, clock_rate));
@@ -84,7 +89,7 @@ mod tests {
     #[test]
     #[ignore]
     fn mania_single() {
-        let file = match File::open("E:/Games/osu!/beatmaps/1355822.osu") {
+        let file = match File::open("./maps/1355822.osu") {
             Ok(file) => file,
             Err(why) => panic!("Could not open file: {}", why),
         };
@@ -94,10 +99,6 @@ mod tests {
             Err(why) => panic!("Error while parsing map: {}", why),
         };
 
-        // println!("timings:\n{:#?}", map.timing_points);
-        // println!("---");
-        // println!("difficulties:\n{:#?}", map.difficulty_points);
-
         let result = PpCalculator::new(&map).mods(256).calculate();
 
         println!("Stars: {}", result.stars);

src/mania/pp.rs

@@ -17,12 +17,12 @@ impl PpProvider for Beatmap {
     }
 }
 
-// TODO: Allow partial plays
 pub struct PpCalculator<'m> {
     map: &'m Beatmap,
     stars: Option<f32>,
     mods: u32,
     score: Option<f32>,
+    passed_objects: Option<usize>,
 }
 
 impl<'m> PpCalculator<'m> {
@@ -33,6 +33,7 @@ impl<'m> PpCalculator<'m> {
             stars: None,
             mods: 0,
             score: None,
+            passed_objects: None,
         }
     }
 
@@ -50,6 +51,8 @@ impl<'m> PpCalculator<'m> {
         self
     }
 
+    /// Score of a play.
+    /// On NM its between 0 and 1,000,000, on EZ between 0 and 500,000, etc
     #[inline]
     pub fn score(mut self, score: u32) -> Self {
         self.score.replace(score as f32);
@@ -57,8 +60,18 @@ impl<'m> PpCalculator<'m> {
         self
     }
 
+    /// Amount of passed objects for partial plays, e.g. a fail.
+    #[inline]
+    pub fn passed_objects(mut self, passed_objects: usize) -> Self {
+        self.passed_objects.replace(passed_objects);
+
+        self
+    }
+
     pub fn calculate(self) -> PpResult {
-        let stars = self.stars.unwrap_or_else(|| stars(self.map, self.mods));
+        let stars = self
+            .stars
+            .unwrap_or_else(|| stars(self.map, self.mods, self.passed_objects));
 
         let ez = self.mods.ez();
         let nf = self.mods.nf();

src/mania/strain.rs

@@ -43,17 +43,12 @@ impl Strain {
 
     #[inline]
     pub(crate) fn save_current_peak(&mut self) {
-        // TODO: Remove branching
-        if self.prev_time.is_some() {
-            self.strain_peaks.push(self.current_section_peak);
-        }
+        self.strain_peaks.push(self.current_section_peak);
     }
 
     #[inline]
     pub(crate) fn start_new_section_from(&mut self, time: f32) {
-        if let Some(prev) = self.prev_time {
-            self.current_section_peak = self.peak_strain(time - prev);
-        }
+        self.current_section_peak = self.peak_strain(time - self.prev_time.unwrap());
     }
 
     #[inline]