added TaikoGradualPerformanceAttributes

src/taiko/gradual_difficulty.rs

@@ -379,7 +379,7 @@ mod tests {
     #[cfg(not(any(feature = "async_tokio", feature = "async_std")))]
     #[test]
     fn iter_end_eq_regular() {
-        let map = Beatmap::from_path("./maps/222766.osu").expect("failed to parse map");
+        let map = Beatmap::from_path("./maps/1028484.osu").expect("failed to parse map");
         let mods = 64;
         let regular = crate::taiko::stars(&map, mods, None);
 

src/taiko/gradual_performance.rs

@@ -0,0 +1,262 @@
+use crate::{Beatmap, TaikoPP};
+
+use super::{TaikoGradualDifficultyAttributes, TaikoPerformanceAttributes};
+
+// TODO: Benchmark if Copy is faster than Clone
+/// Aggregation for a score's current state i.e. what was the
+/// maximum combo so far and what are the current hitresults.
+#[derive(Copy, Clone, Debug, Default)]
+pub struct TaikoScoreState {
+    /// Maximum combo that the score has had so far.
+    /// **Not** the maximum possible combo of the map so far.
+    pub max_combo: usize,
+    /// Amount of current 300s.
+    pub n300: usize,
+    /// Amount of current 100s.
+    pub n100: usize,
+    /// Amount of current misses.
+    pub misses: usize,
+}
+
+impl TaikoScoreState {
+    /// Create a new empty score state.
+    pub fn new() -> Self {
+        Self::default()
+    }
+}
+
+/// Gradually calculate the performance attributes of an osu!taiko map.
+///
+/// After each hit object you can call
+/// [`process_next_object`](`TaikoGradualPerformanceAttributes::process_next_object`)
+/// and it will return the resulting current [`TaikoPerformanceAttributes`].
+/// To process multiple objects at once, use
+/// [`process_next_n_objects`](`TaikoGradualPerformanceAttributes::process_next_n_objects`) instead.
+///
+/// Both methods require an [`TaikoScoreState`] that contains the current
+/// hitresults as well as the maximum combo so far.
+///
+/// If you only want to calculate difficulty attributes use
+/// [`TaikoGradualDifficultyAttributes`](crate::taiko::TaikoGradualDifficultyAttributes) instead.
+///
+/// # Example
+///
+/// ```
+/// use rosu_pp::{Beatmap, taiko::{TaikoGradualPerformanceAttributes, TaikoScoreState}};
+///
+/// # /*
+/// let map: Beatmap = ...
+/// # */
+/// # let map = Beatmap::default();
+///
+/// let mods = 64; // DT
+/// let mut gradual_perf = TaikoGradualPerformanceAttributes::new(&map, mods);
+/// let mut state = TaikoScoreState::new(); // empty state, everything is on 0.
+///
+/// // The first 10 hitresults are 300s
+/// for _ in 0..10 {
+///     state.n300 += 1;
+///     state.max_combo += 1;
+///
+///     # /*
+///     let performance = gradual_perf.process_next_object(state).unwrap();
+///     println!("PP: {}", performance.pp);
+///     # */
+///     # let _ = gradual_perf.process_next_object(state);
+/// }
+///
+/// // Then comes a miss.
+/// // Note that state's max combo won't be incremented for
+/// // the next few objects because the combo is reset.
+/// state.misses += 1;
+/// # /*
+/// let performance = gradual_perf.process_next_object(state).unwrap();
+/// println!("PP: {}", performance.pp);
+/// # */
+/// # let _ = gradual_perf.process_next_object(state);
+///
+/// // The next 10 objects will be a mixture of 300s and 100s.
+/// // Notice how all 10 objects will be processed in one go.
+/// state.n300 += 3;
+/// state.n100 += 7;
+/// # /*
+/// let performance = gradual_perf.process_next_n_objects(state, 10).unwrap();
+/// println!("PP: {}", performance.pp);
+/// # */
+/// # let _ = gradual_perf.process_next_n_objects(state, 10);
+///
+/// // Now comes another 300. Note that the max combo gets incremented again.
+/// state.n300 += 1;
+/// state.max_combo += 1;
+/// # /*
+/// let performance = gradual_perf.process_next_object(state).unwrap();
+/// println!("PP: {}", performance.pp);
+/// # */
+/// # let _ = gradual_perf.process_next_object(state);
+///
+/// // Skip to the end
+/// # /*
+/// state.max_combo = ...
+/// state.n300 = ...
+/// state.n100 = ...
+/// state.misses = ...
+/// let final_performance = gradual_perf.process_next_n_objects(state, usize::MAX).unwrap();
+/// println!("PP: {}", performance.pp);
+/// # */
+/// # let _ = gradual_perf.process_next_n_objects(state, usize::MAX);
+///
+/// // Once the final performance was calculated,
+/// // attempting to process further objects will return `None`.
+/// assert!(gradual_perf.process_next_object(state).is_none());
+/// ```
+#[derive(Clone, Debug)]
+pub struct TaikoGradualPerformanceAttributes<'map> {
+    difficulty: TaikoGradualDifficultyAttributes<'map>,
+    performance: TaikoPP<'map>,
+}
+
+impl<'map> TaikoGradualPerformanceAttributes<'map> {
+    /// Create a new gradual performance calculator for osu!taiko maps.
+    pub fn new(map: &'map Beatmap, mods: u32) -> Self {
+        let difficulty = TaikoGradualDifficultyAttributes::new(map, mods);
+        let performance = TaikoPP::new(map).mods(mods).passed_objects(0);
+
+        Self {
+            difficulty,
+            performance,
+        }
+    }
+
+    /// Process the next hit object and calculate the
+    /// performance attributes for the resulting score.
+    pub fn process_next_object(
+        &mut self,
+        state: TaikoScoreState,
+    ) -> Option<TaikoPerformanceAttributes> {
+        self.process_next_n_objects(state, 1)
+    }
+
+    /// Same as [`process_next_object`](`TaikoGradualPerformanceAttributes::process_next_object`)
+    /// but instead of processing only one object it process `n` many.
+    ///
+    /// If `n` is 0 it will be considered as 1.
+    /// If there are still objects to be processed but `n` is larger than the amount
+    /// of remaining objects, `n` will be considered as the amount of remaining objects.
+    pub fn process_next_n_objects(
+        &mut self,
+        state: TaikoScoreState,
+        n: usize,
+    ) -> Option<TaikoPerformanceAttributes> {
+        let n = n.min(self.difficulty.len()).saturating_sub(1);
+        let difficulty = self.difficulty.nth(n)?;
+
+        let _ = self.performance.n300.insert(state.n300);
+        let _ = self.performance.n100.insert(state.n100);
+        self.performance.n_misses = state.misses;
+
+        let performance = self
+            .performance
+            .clone()
+            .attributes(difficulty)
+            .combo(state.max_combo)
+            .passed_objects(self.difficulty.idx)
+            .calculate();
+
+        Some(performance)
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    #[cfg(not(any(feature = "async_tokio", feature = "async_std")))]
+    #[test]
+    fn correct_empty() {
+        let map = Beatmap::from_path("./maps/1028484.osu").expect("failed to parse map");
+        let mods = 64;
+
+        let mut gradual = TaikoGradualPerformanceAttributes::new(&map, mods);
+        let state = TaikoScoreState::default();
+
+        assert!(gradual.process_next_n_objects(state, usize::MAX).is_some());
+        assert!(gradual.process_next_object(state).is_none());
+    }
+
+    #[cfg(not(any(feature = "async_tokio", feature = "async_std")))]
+    #[test]
+    fn next_and_next_n() {
+        let map = Beatmap::from_path("./maps/1028484.osu").expect("failed to parse map");
+        let mods = 64;
+        let state = TaikoScoreState::default();
+
+        let mut gradual1 = TaikoGradualPerformanceAttributes::new(&map, mods);
+        let mut gradual2 = TaikoGradualPerformanceAttributes::new(&map, mods);
+
+        for _ in 0..50 {
+            let _ = gradual1.process_next_object(state);
+            let _ = gradual2.process_next_object(state);
+        }
+
+        let n = 200;
+
+        for _ in 1..n {
+            let _ = gradual1.process_next_object(state);
+        }
+
+        let state = TaikoScoreState {
+            max_combo: 246,
+            n300: 200,
+            n100: 40,
+            misses: 6,
+        };
+
+        let next = gradual1.process_next_object(state);
+        let next_n = gradual2.process_next_n_objects(state, n);
+
+        assert_eq!(next_n, next);
+    }
+
+    #[cfg(not(any(feature = "async_tokio", feature = "async_std")))]
+    #[test]
+    fn gradual_end_eq_regular() {
+        let map = Beatmap::from_path("./maps/1028484.osu").expect("failed to parse map");
+        let mods = 64;
+        let regular = TaikoPP::new(&map).mods(mods).calculate();
+
+        let mut gradual = TaikoGradualPerformanceAttributes::new(&map, mods);
+
+        let state = TaikoScoreState {
+            max_combo: 289,
+            n300: 289,
+            n100: 0,
+            misses: 0,
+        };
+
+        let gradual_end = gradual.process_next_n_objects(state, usize::MAX).unwrap();
+
+        assert_eq!(regular, gradual_end);
+    }
+
+    #[cfg(not(any(feature = "async_tokio", feature = "async_std")))]
+    #[test]
+    fn gradual_eq_regular_passed() {
+        let map = Beatmap::from_path("./maps/1028484.osu").expect("failed to parse map");
+        let mods = 64;
+        let n = 250;
+        let regular = TaikoPP::new(&map).mods(mods).passed_objects(n).calculate();
+
+        let mut gradual = TaikoGradualPerformanceAttributes::new(&map, mods);
+
+        let state = TaikoScoreState {
+            max_combo: 246,
+            n300: 246,
+            n100: 0,
+            misses: 0,
+        };
+
+        let gradual = gradual.process_next_n_objects(state, n).unwrap();
+
+        assert_eq!(regular, gradual);
+    }
+}

src/taiko/mod.rs

@@ -2,6 +2,7 @@
 
 mod difficulty_object;
 mod gradual_difficulty;
+mod gradual_performance;
 mod hitobject_rhythm;
 mod limited_queue;
 mod pp;
@@ -12,6 +13,7 @@ mod stamina_cheese;
 
 use difficulty_object::DifficultyObject;
 pub use gradual_difficulty::*;
+pub use gradual_performance::*;
 use hitobject_rhythm::{closest_rhythm, HitObjectRhythm};
 use limited_queue::LimitedQueue;
 pub use pp::*;
@@ -227,7 +229,7 @@ impl TaikoDifficultyAttributes {
 }
 
 /// The result of a performance calculation on an osu!taiko map.
-#[derive(Clone, Debug, Default)]
+#[derive(Clone, Debug, Default, PartialEq)]
 pub struct TaikoPerformanceAttributes {
     /// The difficulty attributes that were used for the performance calculation
     pub difficulty: TaikoDifficultyAttributes,

src/taiko/pp.rs

@@ -38,11 +38,11 @@ pub struct TaikoPP<'map> {
     mods: u32,
     combo: Option<usize>,
     acc: f64,
-    n_misses: usize,
     passed_objects: Option<usize>,
 
-    n300: Option<usize>,
-    n100: Option<usize>,
+    pub(crate) n300: Option<usize>,
+    pub(crate) n100: Option<usize>,
+    pub(crate) n_misses: usize,
 }
 
 impl<'map> TaikoPP<'map> {