added hitresult proptesting

src/catch/performance/mod.rs

@@ -554,3 +554,219 @@ fn accuracy(
 
     f64::from(numerator) / f64::from(denominator)
 }
+
+#[cfg(test)]
+mod test {
+    use std::sync::OnceLock;
+
+    use proptest::prelude::*;
+
+    use crate::Beatmap;
+
+    use super::*;
+
+    static ATTRS: OnceLock<CatchDifficultyAttributes> = OnceLock::new();
+
+    const N_FRUITS: u32 = 728;
+    const N_DROPLETS: u32 = 2;
+    const N_TINY_DROPLETS: u32 = 291;
+
+    fn attrs() -> CatchDifficultyAttributes {
+        ATTRS
+            .get_or_init(|| {
+                let converted = Beatmap::from_path("./resources/2118524.osu")
+                    .unwrap()
+                    .unchecked_into_converted::<Catch>();
+
+                let attrs = ModeDifficulty::new().calculate(&converted);
+
+                assert_eq!(N_FRUITS, attrs.n_fruits);
+                assert_eq!(N_DROPLETS, attrs.n_droplets);
+                assert_eq!(N_TINY_DROPLETS, attrs.n_tiny_droplets);
+
+                attrs
+            })
+            .to_owned()
+    }
+
+    /// Checks all remaining hitresult combinations w.r.t. the given parameters
+    /// and returns the [`CatchScoreState`] that matches `acc` the best.
+    ///
+    /// Very slow but accurate.
+    fn brute_force_best(
+        acc: f64,
+        n_fruits: Option<u32>,
+        n_droplets: Option<u32>,
+        n_tiny_droplets: Option<u32>,
+        n_tiny_droplet_misses: Option<u32>,
+        n_misses: u32,
+    ) -> CatchScoreState {
+        let n_misses = cmp::min(n_misses, N_FRUITS + N_DROPLETS);
+
+        let mut best_state = CatchScoreState {
+            max_combo: N_FRUITS + N_DROPLETS - n_misses,
+            n_misses,
+            ..Default::default()
+        };
+
+        let mut best_dist = f64::INFINITY;
+
+        let (new_fruits, new_droplets) = match (n_fruits, n_droplets) {
+            (Some(mut n_fruits), Some(mut n_droplets)) => {
+                let n_remaining =
+                    (N_FRUITS + N_DROPLETS).saturating_sub(n_fruits + n_droplets + n_misses);
+
+                let new_droplets = cmp::min(n_remaining, N_DROPLETS.saturating_sub(n_droplets));
+                n_droplets += new_droplets;
+                n_fruits += n_remaining - new_droplets;
+
+                n_fruits = cmp::min(
+                    n_fruits,
+                    (N_FRUITS + N_DROPLETS).saturating_sub(n_droplets + n_misses),
+                );
+                n_droplets = cmp::min(n_droplets, N_FRUITS + N_DROPLETS - n_fruits - n_misses);
+
+                (n_fruits, n_droplets)
+            }
+            (Some(mut n_fruits), None) => {
+                let n_droplets = N_DROPLETS
+                    .saturating_sub(n_misses.saturating_sub(N_FRUITS.saturating_sub(n_fruits)));
+                n_fruits = N_FRUITS + N_DROPLETS - n_misses - n_droplets;
+
+                (n_fruits, n_droplets)
+            }
+            (None, Some(mut n_droplets)) => {
+                let n_fruits = N_FRUITS
+                    .saturating_sub(n_misses.saturating_sub(N_DROPLETS.saturating_sub(n_droplets)));
+                n_droplets = N_FRUITS + N_DROPLETS - n_misses - n_fruits;
+
+                (n_fruits, n_droplets)
+            }
+            (None, None) => {
+                let n_droplets = N_DROPLETS.saturating_sub(n_misses);
+                let n_fruits = N_FRUITS - (n_misses - (N_DROPLETS.saturating_sub(n_droplets)));
+
+                (n_fruits, n_droplets)
+            }
+        };
+
+        best_state.n_fruits = new_fruits;
+        best_state.n_droplets = new_droplets;
+
+        let (min_tiny_droplets, max_tiny_droplets) = match (n_tiny_droplets, n_tiny_droplet_misses)
+        {
+            (Some(n_tiny_droplets), Some(n_tiny_droplet_misses)) => {
+                match (n_tiny_droplets + n_tiny_droplet_misses).cmp(&N_TINY_DROPLETS) {
+                    Ordering::Equal => (
+                        cmp::min(N_TINY_DROPLETS, n_tiny_droplets),
+                        cmp::min(N_TINY_DROPLETS, n_tiny_droplets),
+                    ),
+                    Ordering::Less | Ordering::Greater => (0, N_TINY_DROPLETS),
+                }
+            }
+            (Some(n_tiny_droplets), None) => (
+                cmp::min(N_TINY_DROPLETS, n_tiny_droplets),
+                cmp::min(N_TINY_DROPLETS, n_tiny_droplets),
+            ),
+            (None, Some(n_tiny_droplet_misses)) => (
+                N_TINY_DROPLETS.saturating_sub(n_tiny_droplet_misses),
+                N_TINY_DROPLETS.saturating_sub(n_tiny_droplet_misses),
+            ),
+            (None, None) => (0, N_TINY_DROPLETS),
+        };
+
+        for new_tiny_droplets in min_tiny_droplets..=max_tiny_droplets {
+            let new_tiny_droplet_misses = N_TINY_DROPLETS - new_tiny_droplets;
+
+            let curr_acc = accuracy(
+                new_fruits,
+                new_droplets,
+                new_tiny_droplets,
+                new_tiny_droplet_misses,
+                n_misses,
+            );
+
+            let curr_dist = (acc - curr_acc).abs();
+
+            if curr_dist < best_dist {
+                best_dist = curr_dist;
+                best_state.n_tiny_droplets = new_tiny_droplets;
+                best_state.n_tiny_droplet_misses = new_tiny_droplet_misses;
+            }
+        }
+
+        best_state
+    }
+
+    proptest! {
+        #![proptest_config(ProptestConfig::with_cases(1000))]
+
+        #[test]
+        fn hitresults(
+            acc in 0.0..=1.0,
+            n_fruits in prop::option::weighted(0.10, 0_u32..=N_FRUITS + 10),
+            n_droplets in prop::option::weighted(0.10, 0_u32..=N_DROPLETS + 10),
+            n_tiny_droplets in prop::option::weighted(0.10, 0_u32..=N_TINY_DROPLETS + 10),
+            n_tiny_droplet_misses in prop::option::weighted(0.10, 0_u32..=N_TINY_DROPLETS + 10),
+            n_misses in prop::option::weighted(0.15, 0_u32..=N_FRUITS + N_DROPLETS + 10),
+        ) {
+            let mut state = CatchPerformance::from(attrs())
+                .accuracy(acc * 100.0);
+
+            if let Some(n_fruits) = n_fruits {
+                state = state.fruits(n_fruits);
+            }
+
+            if let Some(n_droplets) = n_droplets {
+                state = state.droplets(n_droplets);
+            }
+
+            if let Some(n_tiny_droplets) = n_tiny_droplets {
+                state = state.tiny_droplets(n_tiny_droplets);
+            }
+
+            if let Some(n_tiny_droplet_misses) = n_tiny_droplet_misses {
+                state = state.tiny_droplet_misses(n_tiny_droplet_misses);
+            }
+
+            if let Some(n_misses) = n_misses {
+                state = state.misses(n_misses);
+            }
+
+            let state = state.generate_state();
+
+            let expected = brute_force_best(
+                acc,
+                n_fruits,
+                n_droplets,
+                n_tiny_droplets,
+                n_tiny_droplet_misses,
+                n_misses.unwrap_or(0),
+            );
+
+            assert_eq!(state, expected);
+        }
+    }
+
+    #[test]
+    fn fruits_missing_objects() {
+        let state = CatchPerformance::from(attrs())
+            .fruits(N_FRUITS - 10)
+            .droplets(N_DROPLETS - 1)
+            .tiny_droplets(N_TINY_DROPLETS - 50)
+            .tiny_droplet_misses(20)
+            .misses(2)
+            .generate_state();
+
+        let expected = CatchScoreState {
+            max_combo: N_FRUITS + N_DROPLETS - 2,
+            n_fruits: N_FRUITS - 2,
+            n_droplets: N_DROPLETS,
+            n_tiny_droplets: N_TINY_DROPLETS - 20,
+            n_tiny_droplet_misses: 20,
+            n_misses: 2,
+        };
+
+        assert_eq!(state, expected);
+    }
+}

src/mania/performance/mod.rs

@@ -186,14 +186,14 @@ impl<'map> ManiaPerformance<'map> {
 
         let priority = self.hitresult_priority;
 
-        let n_misses = self.n_misses.map_or(0, |n| n.min(n_objects));
+        let n_misses = self.n_misses.map_or(0, |n| cmp::min(n, n_objects));
         let n_remaining = n_objects - n_misses;
 
-        let mut n320 = self.n320.map_or(0, |n| n.min(n_remaining));
+        let mut n320 = self.n320.map_or(0, |n| cmp::min(n, n_remaining));
-        let mut n300 = self.n300.map_or(0, |n| n.min(n_remaining));
+        let mut n300 = self.n300.map_or(0, |n| cmp::min(n, n_remaining));
-        let mut n200 = self.n200.map_or(0, |n| n.min(n_remaining));
+        let mut n200 = self.n200.map_or(0, |n| cmp::min(n, n_remaining));
-        let mut n100 = self.n100.map_or(0, |n| n.min(n_remaining));
+        let mut n100 = self.n100.map_or(0, |n| cmp::min(n, n_remaining));
-        let mut n50 = self.n50.map_or(0, |n| n.min(n_remaining));
+        let mut n50 = self.n50.map_or(0, |n| cmp::min(n, n_remaining));
 
         if let Some(acc) = self.acc {
             let target_total = acc * f64::from(6 * n_objects);
@@ -380,18 +380,21 @@ impl<'map> ManiaPerformance<'map> {
                     let mut best_dist = f64::INFINITY;
                     let mut n3x0 = n_objects.saturating_sub(n320 + n300 + n200 + n_misses);
 
-                    let min_n3x0 = (((target_total - f64::from(2 * (n_remaining + n200))) / 4.0)
+                    let min_n3x0 = cmp::min(
-                        .floor() as u32)
+                        ((target_total - f64::from(2 * (n_remaining + n200))) / 4.0).floor() as u32,
-                        .min(n_remaining - n200);
+                        n_remaining - n200,
+                    );
 
-                    let max_n3x0 = (((target_total - f64::from(n_remaining + 3 * n200)) / 5.0)
+                    let max_n3x0 = cmp::min(
-                        .ceil() as u32)
+                        ((target_total - f64::from(n_remaining + 3 * n200)) / 5.0).ceil() as u32,
-                        .min(n_remaining - n200);
+                        n_remaining - n200,
+                    );
 
                     let (min_n3x0, max_n3x0) = match (self.n320, self.n300) {
-                        (Some(_), Some(_)) => {
+                        (Some(_), Some(_)) => (
-                            (n_remaining.min(n320 + n300), n_remaining.min(n320 + n300))
+                            cmp::min(n_remaining, n320 + n300),
-                        }
+                            cmp::min(n_remaining, n320 + n300),
+                        ),
                         (Some(_), None) => (min_n3x0.max(n320), max_n3x0.max(n320)),
                         (None, Some(_)) => (min_n3x0.max(n300), max_n3x0.max(n300)),
                         (None, None) => (min_n3x0, max_n3x0),
@@ -451,9 +454,10 @@ impl<'map> ManiaPerformance<'map> {
                     );
 
                     let (min_n3x0, max_n3x0) = match (self.n320, self.n300) {
-                        (Some(_), Some(_)) => {
+                        (Some(_), Some(_)) => (
-                            (n_remaining.min(n320 + n300), n_remaining.min(n320 + n300))
+                            cmp::min(n_remaining, n320 + n300),
-                        }
+                            cmp::min(n_remaining, n320 + n300),
+                        ),
                         (Some(_), None) => (min_n3x0.max(n320), max_n3x0.max(n320)),
                         (None, Some(_)) => (min_n3x0.max(n300), max_n3x0.max(n300)),
                         (None, None) => (min_n3x0, max_n3x0),
@@ -513,9 +517,10 @@ impl<'map> ManiaPerformance<'map> {
                     );
 
                     let (min_n3x0, max_n3x0) = match (self.n320, self.n300) {
-                        (Some(_), Some(_)) => {
+                        (Some(_), Some(_)) => (
-                            (n_remaining.min(n320 + n300), n_remaining.min(n320 + n300))
+                            cmp::min(n_remaining, n320 + n300),
-                        }
+                            cmp::min(n_remaining, n320 + n300),
+                        ),
                         (Some(_), None) => (min_n3x0.max(n320), max_n3x0.max(n320)),
                         (None, Some(_)) => (min_n3x0.max(n300), max_n3x0.max(n300)),
                         (None, None) => (min_n3x0, max_n3x0),
@@ -587,9 +592,10 @@ impl<'map> ManiaPerformance<'map> {
                     );
 
                     let (min_n3x0, max_n3x0) = match (self.n320, self.n300) {
-                        (Some(_), Some(_)) => {
+                        (Some(_), Some(_)) => (
-                            (n_remaining.min(n320 + n300), n_remaining.min(n320 + n300))
+                            cmp::min(n_remaining, n320 + n300),
-                        }
+                            cmp::min(n_remaining, n320 + n300),
+                        ),
                         (Some(_), None) => (min_n3x0.max(n320), max_n3x0.max(n320)),
                         (None, Some(_)) => (min_n3x0.max(n300), max_n3x0.max(n300)),
                         (None, None) => (min_n3x0, max_n3x0),
@@ -931,3 +937,361 @@ fn accuracy(n320: u32, n300: u32, n200: u32, n100: u32, n50: u32, n_misses: u32)
 
     f64::from(numerator) / f64::from(denominator)
 }
+
+#[cfg(test)]
+mod tests {
+    use std::{cmp::Ordering, sync::OnceLock};
+
+    use proptest::prelude::*;
+
+    use crate::Beatmap;
+
+    use super::*;
+
+    static ATTRS: OnceLock<ManiaDifficultyAttributes> = OnceLock::new();
+
+    const N_OBJECTS: u32 = 594;
+
+    fn attrs() -> ManiaDifficultyAttributes {
+        ATTRS
+            .get_or_init(|| {
+                let converted = Beatmap::from_path("./resources/1638954.osu")
+                    .unwrap()
+                    .unchecked_into_converted::<Mania>();
+
+                let attrs = ModeDifficulty::new().calculate(&converted);
+
+                assert_eq!(N_OBJECTS, converted.map.hit_objects.len() as u32);
+
+                attrs
+            })
+            .to_owned()
+    }
+
+    /// Checks most remaining hitresult combinations w.r.t. the given parameters
+    /// and returns the [`ManiaScoreState`] that matches `acc` the best.
+    ///
+    /// Very slow but accurate. Only slight optimizations have been applied so
+    /// that it doesn't run unreasonably long.
+    #[allow(clippy::too_many_arguments, clippy::too_many_lines)]
+    fn brute_force_best(
+        acc: f64,
+        n320: Option<u32>,
+        n300: Option<u32>,
+        n200: Option<u32>,
+        n100: Option<u32>,
+        n50: Option<u32>,
+        n_misses: u32,
+        best_case: bool,
+    ) -> ManiaScoreState {
+        let n_misses = cmp::min(n_misses, N_OBJECTS);
+
+        let mut best_state = ManiaScoreState {
+            n_misses,
+            ..Default::default()
+        };
+
+        let mut best_dist = f64::INFINITY;
+        let mut best_custom_acc = 0.0;
+
+        let n_remaining = N_OBJECTS - n_misses;
+
+        let multiple_given = (usize::from(n320.is_some())
+            + usize::from(n300.is_some())
+            + usize::from(n200.is_some())
+            + usize::from(n100.is_some())
+            + usize::from(n50.is_some()))
+            > 1;
+
+        let max_left = N_OBJECTS
+            .saturating_sub(n200.unwrap_or(0) + n100.unwrap_or(0) + n50.unwrap_or(0) + n_misses);
+
+        let min_n3x0 = cmp::min(
+            max_left,
+            (acc * f64::from(3 * N_OBJECTS) - f64::from(2 * n_remaining)).floor() as u32,
+        );
+
+        let max_n3x0 = cmp::min(
+            max_left,
+            ((acc * f64::from(6 * N_OBJECTS) - f64::from(n_remaining)) / 5.0).ceil() as u32,
+        );
+
+        let (min_n3x0, max_n3x0) = match (n320, n300) {
+            (Some(n320), Some(n300)) => (
+                cmp::min(n_remaining, n320 + n300),
+                cmp::min(n_remaining, n320 + n300),
+            ),
+            (Some(n320), None) => (
+                cmp::max(cmp::min(n_remaining, n320), min_n3x0),
+                cmp::max(max_n3x0, cmp::min(n320, n_remaining)),
+            ),
+            (None, Some(n300)) => (
+                cmp::max(cmp::min(n_remaining, n300), min_n3x0),
+                cmp::max(max_n3x0, cmp::min(n300, n_remaining)),
+            ),
+            (None, None) => (min_n3x0, max_n3x0),
+        };
+
+        for new3x0 in min_n3x0..=max_n3x0 {
+            let max_left =
+                n_remaining.saturating_sub(new3x0 + n100.unwrap_or(0) + n50.unwrap_or(0));
+
+            let (min_n200, max_n200) = match (n200, n100, n50) {
+                (Some(n200), ..) if multiple_given => {
+                    (cmp::min(n_remaining, n200), cmp::min(n_remaining, n200))
+                }
+                (Some(n200), ..) => (cmp::min(max_left, n200), cmp::min(max_left, n200)),
+                (None, Some(_), Some(_)) => (max_left, max_left),
+                _ => (0, max_left),
+            };
+
+            for new200 in min_n200..=max_n200 {
+                let max_left = n_remaining.saturating_sub(new3x0 + new200 + n50.unwrap_or(0));
+
+                let (min_n100, max_n100) = match (n100, n50) {
+                    (Some(n100), _) if multiple_given => {
+                        (cmp::min(n_remaining, n100), cmp::min(n_remaining, n100))
+                    }
+                    (Some(n100), _) => (cmp::min(max_left, n100), cmp::min(max_left, n100)),
+                    (None, Some(_)) => (max_left, max_left),
+                    (None, None) => (0, max_left),
+                };
+
+                for new100 in min_n100..=max_n100 {
+                    let max_left = n_remaining.saturating_sub(new3x0 + new200 + new100);
+
+                    let new50 = match n50 {
+                        Some(n50) if multiple_given => cmp::min(n_remaining, n50),
+                        Some(n50) => cmp::min(max_left, n50),
+                        None => max_left,
+                    };
+
+                    let (new320, new300) = match (n320, n300) {
+                        (Some(n320), Some(n300)) => {
+                            (cmp::min(n_remaining, n320), cmp::min(n_remaining, n300))
+                        }
+                        (Some(n320), None) => (
+                            cmp::min(n320, n_remaining),
+                            new3x0 - cmp::min(n320, n_remaining),
+                        ),
+                        (None, Some(n300)) => (
+                            new3x0 - cmp::min(n300, n_remaining),
+                            cmp::min(n300, n_remaining),
+                        ),
+                        (None, None) if best_case => (new3x0, 0),
+                        (None, None) => (0, new3x0),
+                    };
+
+                    let curr_acc = accuracy(new320, new300, new200, new100, new50, n_misses);
+                    let curr_dist = (acc - curr_acc).abs();
+
+                    let curr_custom_acc =
+                        custom_accuracy(new320, new300, new200, new100, new50, N_OBJECTS);
+
+                    match curr_dist.partial_cmp(&best_dist).expect("non-NaN") {
+                        Ordering::Less => {
+                            best_dist = curr_dist;
+                            best_custom_acc = curr_custom_acc;
+                            best_state.n320 = new320;
+                            best_state.n300 = new300;
+                            best_state.n200 = new200;
+                            best_state.n100 = new100;
+                            best_state.n50 = new50;
+                        }
+                        Ordering::Equal if curr_custom_acc < best_custom_acc => {
+                            best_custom_acc = curr_custom_acc;
+                            best_state.n320 = new320;
+                            best_state.n300 = new300;
+                            best_state.n200 = new200;
+                            best_state.n100 = new100;
+                            best_state.n50 = new50;
+                        }
+                        _ => {}
+                    }
+                }
+            }
+        }
+
+        if best_state.n320 + best_state.n300 + best_state.n200 + best_state.n100 + best_state.n50
+            < n_remaining
+        {
+            let n_remaining = n_remaining
+                - (best_state.n320
+                    + best_state.n300
+                    + best_state.n200
+                    + best_state.n100
+                    + best_state.n50);
+
+            if best_case {
+                match (n320, n300, n200, n100, n50) {
+                    (None, ..) => best_state.n320 += n_remaining,
+                    (_, None, ..) => best_state.n300 += n_remaining,
+                    (_, _, None, ..) => best_state.n200 += n_remaining,
+                    (.., None, _) => best_state.n100 += n_remaining,
+                    (.., None) => best_state.n50 += n_remaining,
+                    _ => best_state.n320 += n_remaining,
+                }
+            } else {
+                match (n50, n100, n200, n300, n320) {
+                    (None, ..) => best_state.n50 += n_remaining,
+                    (_, None, ..) => best_state.n100 += n_remaining,
+                    (_, _, None, ..) => best_state.n200 += n_remaining,
+                    (.., None, _) => best_state.n300 += n_remaining,
+                    (.., None) => best_state.n320 += n_remaining,
+                    _ => best_state.n50 += n_remaining,
+                }
+            }
+        }
+
+        if best_case {
+            if n320.is_none() && n200.is_none() && n100.is_none() {
+                let n = best_state.n200 / 2;
+                best_state.n320 += n;
+                best_state.n200 -= 2 * n;
+                best_state.n100 += n;
+            }
+
+            if n100.is_none() && n50.is_none() {
+                let n = if n320.is_none() && n300.is_none() {
+                    let n = cmp::min(best_state.n320 + best_state.n300, best_state.n50 / 4);
+
+                    let removed320 = cmp::min(best_state.n320, n);
+                    let removed300 = n - removed320;
+
+                    best_state.n320 -= removed320;
+                    best_state.n300 -= removed300;
+
+                    n
+                } else if n320.is_none() {
+                    let n = cmp::min(best_state.n320, best_state.n50 / 4);
+                    best_state.n320 -= n;
+
+                    n
+                } else if n300.is_none() {
+                    let n = cmp::min(best_state.n300, best_state.n50 / 4);
+                    best_state.n300 -= n;
+
+                    n
+                } else {
+                    0
+                };
+
+                best_state.n100 += 5 * n;
+                best_state.n50 -= 4 * n;
+            }
+        } else if n320.is_none() && n200.is_none() && n100.is_none() {
+            let n = cmp::min(best_state.n320, best_state.n100);
+            best_state.n320 -= n;
+            best_state.n200 += 2 * n;
+            best_state.n100 -= n;
+        }
+
+        best_state
+    }
+
+    proptest! {
+        #![proptest_config(ProptestConfig::with_cases(100))]
+
+        #[test]
+        fn mania_hitresults(
+            acc in 0.0..=1.0,
+            n320 in prop::option::weighted(0.10, 0_u32..=N_OBJECTS + 10),
+            n300 in prop::option::weighted(0.10, 0_u32..=N_OBJECTS + 10),
+            n200 in prop::option::weighted(0.10, 0_u32..=N_OBJECTS + 10),
+            n100 in prop::option::weighted(0.10, 0_u32..=N_OBJECTS + 10),
+            n50 in prop::option::weighted(0.10, 0_u32..=N_OBJECTS + 10),
+            n_misses in prop::option::weighted(0.15, 0_u32..=N_OBJECTS + 10),
+            best_case in prop::bool::ANY,
+        ) {
+            let priority = if best_case {
+                HitResultPriority::BestCase
+            } else {
+                HitResultPriority::WorstCase
+            };
+
+            let mut state = ManiaPerformance::from(attrs())
+                .accuracy(acc * 100.0)
+                .hitresult_priority(priority);
+
+            if let Some(n320) = n320 {
+                state = state.n320(n320);
+            }
+
+            if let Some(n300) = n300 {
+                state = state.n300(n300);
+            }
+
+            if let Some(n200) = n200 {
+                state = state.n200(n200);
+            }
+
+            if let Some(n100) = n100 {
+                state = state.n100(n100);
+            }
+
+            if let Some(n50) = n50 {
+                state = state.n50(n50);
+            }
+
+            if let Some(n_misses) = n_misses {
+                state = state.n_misses(n_misses);
+            }
+
+            let state = state.generate_state();
+
+            let expected = brute_force_best(
+                acc,
+                n320,
+                n300,
+                n200,
+                n100,
+                n50,
+                n_misses.unwrap_or(0),
+                best_case,
+            );
+
+            assert_eq!(state, expected);
+        }
+    }
+
+    #[test]
+    fn hitresults_n320_n_misses_best() {
+        let state = ManiaPerformance::from(attrs())
+            .n320(500)
+            .n_misses(2)
+            .hitresult_priority(HitResultPriority::BestCase)
+            .generate_state();
+
+        let expected = ManiaScoreState {
+            n320: 500,
+            n300: 92,
+            n200: 0,
+            n100: 0,
+            n50: 0,
+            n_misses: 2,
+        };
+
+        assert_eq!(state, expected);
+    }
+
+    #[test]
+    fn hitresults_n100_n50_n_misses_worst() {
+        let state = ManiaPerformance::from(attrs())
+            .n100(200)
+            .n50(50)
+            .n_misses(2)
+            .hitresult_priority(HitResultPriority::WorstCase)
+            .generate_state();
+
+        let expected = ManiaScoreState {
+            n320: 0,
+            n300: 0,
+            n200: 342,
+            n100: 200,
+            n50: 50,
+            n_misses: 2,
+        };
+
+        assert_eq!(state, expected);
+    }
+}

src/osu/performance/mod.rs

@@ -224,12 +224,12 @@ impl<'map> OsuPerformance<'map> {
         let n_objects = self.passed_objects.unwrap_or(attrs.n_objects());
         let priority = self.hitresult_priority;
 
-        let n_misses = self.n_misses.map_or(0, |n| n.min(n_objects));
+        let n_misses = self.n_misses.map_or(0, |n| cmp::min(n, n_objects));
         let n_remaining = n_objects - n_misses;
 
-        let mut n300 = self.n300.map_or(0, |n| n.min(n_remaining));
+        let mut n300 = self.n300.map_or(0, |n| cmp::min(n, n_remaining));
-        let mut n100 = self.n100.map_or(0, |n| n.min(n_remaining));
+        let mut n100 = self.n100.map_or(0, |n| cmp::min(n, n_remaining));
-        let mut n50 = self.n50.map_or(0, |n| n.min(n_remaining));
+        let mut n50 = self.n50.map_or(0, |n| cmp::min(n, n_remaining));
 
         if let Some(acc) = self.acc {
             let target_total = acc * f64::from(6 * n_objects);
@@ -249,12 +249,12 @@ impl<'map> OsuPerformance<'map> {
                 (Some(_), None, None) => {
                     let mut best_dist = f64::MAX;
 
-                    n300 = n300.min(n_remaining);
+                    n300 = cmp::min(n300, n_remaining);
                     let n_remaining = n_remaining - n300;
 
                     let raw_n100 = target_total - f64::from(n_remaining + 6 * n300);
-                    let min_n100 = n_remaining.min(raw_n100.floor() as u32);
+                    let min_n100 = cmp::min(n_remaining, raw_n100.floor() as u32);
-                    let max_n100 = n_remaining.min(raw_n100.ceil() as u32);
+                    let max_n100 = cmp::min(n_remaining, raw_n100.ceil() as u32);
 
                     for new100 in min_n100..=max_n100 {
                         let new50 = n_remaining - new100;
@@ -270,12 +270,12 @@ impl<'map> OsuPerformance<'map> {
                 (None, Some(_), None) => {
                     let mut best_dist = f64::MAX;
 
-                    n100 = n100.min(n_remaining);
+                    n100 = cmp::min(n100, n_remaining);
                     let n_remaining = n_remaining - n100;
 
                     let raw_n300 = (target_total - f64::from(n_remaining + 2 * n100)) / 5.0;
-                    let min_n300 = n_remaining.min(raw_n300.floor() as u32);
+                    let min_n300 = cmp::min(n_remaining, raw_n300.floor() as u32);
-                    let max_n300 = n_remaining.min(raw_n300.ceil() as u32);
+                    let max_n300 = cmp::min(n_remaining, raw_n300.ceil() as u32);
 
                     for new300 in min_n300..=max_n300 {
                         let new50 = n_remaining - new300;
@@ -291,15 +291,15 @@ impl<'map> OsuPerformance<'map> {
                 (None, None, Some(_)) => {
                     let mut best_dist = f64::MAX;
 
-                    n50 = n50.min(n_remaining);
+                    n50 = cmp::min(n50, n_remaining);
                     let n_remaining = n_remaining - n50;
 
                     let raw_n300 = (target_total + f64::from(2 * n_misses + n50)
                         - f64::from(2 * n_objects))
                         / 4.0;
 
-                    let min_n300 = n_remaining.min(raw_n300.floor() as u32);
+                    let min_n300 = cmp::min(n_remaining, raw_n300.floor() as u32);
-                    let max_n300 = n_remaining.min(raw_n300.ceil() as u32);
+                    let max_n300 = cmp::min(n_remaining, raw_n300.ceil() as u32);
 
                     for new300 in min_n300..=max_n300 {
                         let new100 = n_remaining - new300;
@@ -340,7 +340,7 @@ impl<'map> OsuPerformance<'map> {
                     match priority {
                         HitResultPriority::BestCase => {
                             // Shift n50 to n100 by sacrificing n300
-                            let n = n300.min(n50 / 4);
+                            let n = cmp::min(n300, n50 / 4);
                             n300 -= n;
                             n100 += 5 * n;
                             n50 -= 4 * n;
@@ -376,9 +376,9 @@ impl<'map> OsuPerformance<'map> {
 
         let max_possible_combo = max_combo.saturating_sub(n_misses);
 
-        let max_combo = self
+        let max_combo = self.combo.map_or(max_possible_combo, |combo| {
-            .combo
+            cmp::min(combo, max_possible_combo)
-            .map_or(max_possible_combo, |combo| combo.min(max_possible_combo));
+        });
 
         OsuScoreState {
             max_combo,
@@ -623,10 +623,10 @@ impl OsuPerformanceInner {
         let estimate_diff_sliders = f64::from(self.attrs.n_sliders) * 0.15;
 
         if self.attrs.n_sliders > 0 {
-            let estimate_slider_ends_dropped = f64::from(
+            let estimate_slider_ends_dropped = f64::from(cmp::min(
-                (self.state.n100 + self.state.n50 + self.state.n_misses)
+                self.state.n100 + self.state.n50 + self.state.n_misses,
-                    .min(self.attrs.max_combo.saturating_sub(self.state.max_combo)),
+                self.attrs.max_combo.saturating_sub(self.state.max_combo),
-            )
+            ))
             .clamp(0.0, estimate_diff_sliders);
             let slider_nerf_factor = (1.0 - self.attrs.slider_factor)
                 * (1.0 - estimate_slider_ends_dropped / estimate_diff_sliders).powi(3)
@@ -833,3 +833,272 @@ fn accuracy(n300: u32, n100: u32, n50: u32, n_misses: u32) -> f64 {
 
     f64::from(numerator) / f64::from(denominator)
 }
+
+#[cfg(test)]
+mod test {
+    use std::sync::OnceLock;
+
+    use proptest::prelude::*;
+
+    use crate::Beatmap;
+
+    use super::*;
+
+    static ATTRS: OnceLock<OsuDifficultyAttributes> = OnceLock::new();
+
+    const N_OBJECTS: u32 = 601;
+
+    fn attrs() -> OsuDifficultyAttributes {
+        ATTRS
+            .get_or_init(|| {
+                let converted = Beatmap::from_path("./resources/2785319.osu")
+                    .unwrap()
+                    .unchecked_into_converted::<Osu>();
+
+                let attrs = ModeDifficulty::new().calculate(&converted);
+
+                assert_eq!(
+                    (attrs.n_circles, attrs.n_sliders, attrs.n_spinners),
+                    (307, 293, 1)
+                );
+                assert_eq!(
+                    attrs.n_circles + attrs.n_sliders + attrs.n_spinners,
+                    N_OBJECTS,
+                );
+
+                attrs
+            })
+            .to_owned()
+    }
+
+    /// Checks all remaining hitresult combinations w.r.t. the given parameters
+    /// and returns the [`OsuScoreState`] that matches `acc` the best.
+    ///
+    /// Very slow but accurate.
+    fn brute_force_best(
+        acc: f64,
+        n300: Option<u32>,
+        n100: Option<u32>,
+        n50: Option<u32>,
+        n_misses: u32,
+        best_case: bool,
+    ) -> OsuScoreState {
+        let n_misses = cmp::min(n_misses, N_OBJECTS);
+
+        let mut best_state = OsuScoreState {
+            n_misses,
+            ..Default::default()
+        };
+
+        let mut best_dist = f64::INFINITY;
+
+        let n_remaining = N_OBJECTS - n_misses;
+
+        let (min_n300, max_n300) = match (n300, n100, n50) {
+            (Some(n300), ..) => (cmp::min(n_remaining, n300), cmp::min(n_remaining, n300)),
+            (None, Some(n100), Some(n50)) => (
+                n_remaining.saturating_sub(n100 + n50),
+                n_remaining.saturating_sub(n100 + n50),
+            ),
+            (None, ..) => (
+                0,
+                n_remaining.saturating_sub(n100.unwrap_or(0) + n50.unwrap_or(0)),
+            ),
+        };
+
+        for new300 in min_n300..=max_n300 {
+            let (min_n100, max_n100) = match (n100, n50) {
+                (Some(n100), _) => (cmp::min(n_remaining, n100), cmp::min(n_remaining, n100)),
+                (None, Some(n50)) => (
+                    n_remaining.saturating_sub(new300 + n50),
+                    n_remaining.saturating_sub(new300 + n50),
+                ),
+                (None, None) => (0, n_remaining - new300),
+            };
+
+            for new100 in min_n100..=max_n100 {
+                let new50 = match n50 {
+                    Some(n50) => cmp::min(n_remaining, n50),
+                    None => n_remaining.saturating_sub(new300 + new100),
+                };
+
+                let curr_acc = accuracy(new300, new100, new50, n_misses);
+                let curr_dist = (acc - curr_acc).abs();
+
+                if curr_dist < best_dist {
+                    best_dist = curr_dist;
+                    best_state.n300 = new300;
+                    best_state.n100 = new100;
+                    best_state.n50 = new50;
+                }
+            }
+        }
+
+        if best_state.n300 + best_state.n100 + best_state.n50 < n_remaining {
+            let remaining = n_remaining - (best_state.n300 + best_state.n100 + best_state.n50);
+
+            if best_case {
+                best_state.n300 += remaining;
+            } else {
+                best_state.n50 += remaining;
+            }
+        }
+
+        if n300.is_none() && n100.is_none() && n50.is_none() {
+            if best_case {
+                let n = cmp::min(best_state.n300, best_state.n50 / 4);
+                best_state.n300 -= n;
+                best_state.n100 += 5 * n;
+                best_state.n50 -= 4 * n;
+            } else {
+                let n = best_state.n100 / 5;
+                best_state.n300 += n;
+                best_state.n100 -= 5 * n;
+                best_state.n50 += 4 * n;
+            }
+        }
+
+        best_state
+    }
+
+    proptest! {
+        #![proptest_config(ProptestConfig::with_cases(1000))]
+
+        #[test]
+        fn hitresults(
+            acc in 0.0..=1.0,
+            n300 in prop::option::weighted(0.10, 0_u32..=N_OBJECTS + 10),
+            n100 in prop::option::weighted(0.10, 0_u32..=N_OBJECTS + 10),
+            n50 in prop::option::weighted(0.10, 0_u32..=N_OBJECTS + 10),
+            n_misses in prop::option::weighted(0.15, 0_u32..=N_OBJECTS + 10),
+            best_case in prop::bool::ANY,
+        ) {
+            let attrs = attrs();
+            let max_combo = attrs.max_combo();
+
+            let priority = if best_case {
+                HitResultPriority::BestCase
+            } else {
+                HitResultPriority::WorstCase
+            };
+
+            let mut state = OsuPerformance::from(attrs)
+                .accuracy(acc * 100.0)
+                .hitresult_priority(priority);
+
+            if let Some(n300) = n300 {
+                state = state.n300(n300);
+            }
+
+            if let Some(n100) = n100 {
+                state = state.n100(n100);
+            }
+
+            if let Some(n50) = n50 {
+                state = state.n50(n50);
+            }
+
+            if let Some(n_misses) = n_misses {
+                state = state.n_misses(n_misses);
+            }
+
+            let state = state.generate_state();
+
+            let mut expected = brute_force_best(
+                acc,
+                n300,
+                n100,
+                n50,
+                n_misses.unwrap_or(0),
+                best_case,
+            );
+            expected.max_combo = max_combo.saturating_sub(n_misses.map_or(0, |n| cmp::min(n, N_OBJECTS)));
+
+            assert_eq!(state, expected);
+        }
+    }
+
+    #[test]
+    fn hitresults_n300_n100_n_misses_best() {
+        let state = OsuPerformance::from(attrs())
+            .combo(500)
+            .n300(300)
+            .n100(20)
+            .n_misses(2)
+            .hitresult_priority(HitResultPriority::BestCase)
+            .generate_state();
+
+        let expected = OsuScoreState {
+            max_combo: 500,
+            n300: 300,
+            n100: 20,
+            n50: 279,
+            n_misses: 2,
+        };
+
+        assert_eq!(state, expected);
+    }
+
+    #[test]
+    fn hitresults_n300_n50_n_misses_best() {
+        let state = OsuPerformance::from(attrs())
+            .combo(500)
+            .n300(300)
+            .n50(10)
+            .n_misses(2)
+            .hitresult_priority(HitResultPriority::BestCase)
+            .generate_state();
+
+        let expected = OsuScoreState {
+            max_combo: 500,
+            n300: 300,
+            n100: 289,
+            n50: 10,
+            n_misses: 2,
+        };
+
+        assert_eq!(state, expected);
+    }
+
+    #[test]
+    fn hitresults_n50_n_misses_worst() {
+        let state = OsuPerformance::from(attrs())
+            .combo(500)
+            .n50(10)
+            .n_misses(2)
+            .hitresult_priority(HitResultPriority::WorstCase)
+            .generate_state();
+
+        let expected = OsuScoreState {
+            max_combo: 500,
+            n300: 0,
+            n100: 589,
+            n50: 10,
+            n_misses: 2,
+        };
+
+        assert_eq!(state, expected);
+    }
+
+    #[test]
+    fn hitresults_n300_n100_n50_n_misses_worst() {
+        let state = OsuPerformance::from(attrs())
+            .combo(500)
+            .n300(300)
+            .n100(50)
+            .n50(10)
+            .n_misses(2)
+            .hitresult_priority(HitResultPriority::WorstCase)
+            .generate_state();
+
+        let expected = OsuScoreState {
+            max_combo: 500,
+            n300: 300,
+            n100: 50,
+            n50: 249,
+            n_misses: 2,
+        };
+
+        assert_eq!(state, expected);
+    }
+}

src/taiko/performance/mod.rs

@@ -190,8 +190,8 @@ impl<'map> TaikoPerformance<'map> {
                     let mut best_dist = f64::MAX;
 
                     let raw_n300 = target_total - f64::from(n_remaining);
-                    let min_n300 = n_remaining.min(raw_n300.floor() as u32);
+                    let min_n300 = cmp::min(n_remaining, raw_n300.floor() as u32);
-                    let max_n300 = n_remaining.min(raw_n300.ceil() as u32);
+                    let max_n300 = cmp::min(n_remaining, raw_n300.ceil() as u32);
 
                     for new300 in min_n300..=max_n300 {
                         let new100 = n_remaining - new300;
@@ -224,9 +224,9 @@ impl<'map> TaikoPerformance<'map> {
 
         let max_possible_combo = max_combo.saturating_sub(n_misses);
 
-        let max_combo = self
+        let max_combo = self.combo.map_or(max_possible_combo, |combo| {
-            .combo
+            cmp::min(combo, max_possible_combo)
-            .map_or(max_possible_combo, |combo| combo.min(max_possible_combo));
+        });
 
         TaikoScoreState {
             max_combo,
@@ -522,3 +522,180 @@ fn accuracy(n300: u32, n100: u32, n_misses: u32) -> f64 {
 
     f64::from(numerator) / f64::from(denominator)
 }
+
+#[cfg(test)]
+mod test {
+    use std::sync::OnceLock;
+
+    use proptest::prelude::*;
+
+    use crate::Beatmap;
+
+    use super::*;
+
+    static ATTRS: OnceLock<TaikoDifficultyAttributes> = OnceLock::new();
+
+    const MAX_COMBO: u32 = 289;
+
+    fn attrs() -> TaikoDifficultyAttributes {
+        ATTRS
+            .get_or_init(|| {
+                let converted = Beatmap::from_path("./resources/1028484.osu")
+                    .unwrap()
+                    .unchecked_into_converted::<Taiko>();
+
+                let attrs = ModeDifficulty::new().calculate(&converted);
+
+                assert_eq!(MAX_COMBO, attrs.max_combo);
+
+                attrs
+            })
+            .to_owned()
+    }
+
+    /// Checks all remaining hitresult combinations w.r.t. the given parameters
+    /// and returns the [`TaikoScoreState`] that matches `acc` the best.
+    ///
+    /// Very slow but accurate.
+    fn brute_force_best(
+        acc: f64,
+        n300: Option<u32>,
+        n100: Option<u32>,
+        n_misses: u32,
+        best_case: bool,
+    ) -> TaikoScoreState {
+        let n_misses = cmp::min(n_misses, MAX_COMBO);
+
+        let mut best_state = TaikoScoreState {
+            n_misses,
+            ..Default::default()
+        };
+
+        let mut best_dist = f64::INFINITY;
+
+        let n_objects = MAX_COMBO;
+        let n_remaining = n_objects - n_misses;
+
+        let (min_n300, max_n300) = match (n300, n100) {
+            (Some(n300), _) => (cmp::min(n_remaining, n300), cmp::min(n_remaining, n300)),
+            (None, Some(n100)) => (
+                n_remaining.saturating_sub(n100),
+                n_remaining.saturating_sub(n100),
+            ),
+            (None, None) => (0, n_remaining),
+        };
+
+        for new300 in min_n300..=max_n300 {
+            let new100 = match n100 {
+                Some(n100) => cmp::min(n_remaining, n100),
+                None => n_remaining - new300,
+            };
+
+            let curr_acc = accuracy(new300, new100, n_misses);
+            let curr_dist = (acc - curr_acc).abs();
+
+            if curr_dist < best_dist {
+                best_dist = curr_dist;
+                best_state.n300 = new300;
+                best_state.n100 = new100;
+            }
+        }
+
+        if best_state.n300 + best_state.n100 < n_remaining {
+            let remaining = n_remaining - (best_state.n300 + best_state.n100);
+
+            if best_case {
+                best_state.n300 += remaining;
+            } else {
+                best_state.n100 += remaining;
+            }
+        }
+
+        best_state
+    }
+
+    proptest! {
+        #![proptest_config(ProptestConfig::with_cases(1000))]
+
+        #[test]
+        fn hitresults(
+            acc in 0.0..=1.0,
+            n300 in prop::option::weighted(0.10, 0_u32..=MAX_COMBO + 10),
+            n100 in prop::option::weighted(0.10, 0_u32..=MAX_COMBO + 10),
+            n_misses in prop::option::weighted(0.15, 0_u32..=MAX_COMBO + 10),
+            best_case in prop::bool::ANY,
+        ) {
+            let priority = if best_case {
+                HitResultPriority::BestCase
+            } else {
+                HitResultPriority::WorstCase
+            };
+
+            let mut state = TaikoPerformance::from(attrs())
+                .accuracy(acc * 100.0)
+                .hitresult_priority(priority);
+
+            if let Some(n300) = n300 {
+                state = state.n300(n300);
+            }
+
+            if let Some(n100) = n100 {
+                state = state.n100(n100);
+            }
+
+            if let Some(n_misses) = n_misses {
+                state = state.n_misses(n_misses);
+            }
+
+            let state = state.generate_state();
+
+            let mut expected = brute_force_best(
+                acc,
+                n300,
+                n100,
+                n_misses.unwrap_or(0),
+                best_case,
+            );
+            expected.max_combo = MAX_COMBO.saturating_sub(n_misses.unwrap_or(0));
+
+            assert_eq!(state, expected);
+        }
+    }
+
+    #[test]
+    fn hitresults_n300_n_misses_best() {
+        let state = TaikoPerformance::from(attrs())
+            .combo(100)
+            .n300(150)
+            .n_misses(2)
+            .hitresult_priority(HitResultPriority::BestCase)
+            .generate_state();
+
+        let expected = TaikoScoreState {
+            max_combo: 100,
+            n300: 150,
+            n100: 137,
+            n_misses: 2,
+        };
+
+        assert_eq!(state, expected);
+    }
+
+    #[test]
+    fn hitresults_n_misses_best() {
+        let state = TaikoPerformance::from(attrs())
+            .combo(100)
+            .n_misses(2)
+            .hitresult_priority(HitResultPriority::BestCase)
+            .generate_state();
+
+        let expected = TaikoScoreState {
+            max_combo: 100,
+            n300: 287,
+            n100: 0,
+            n_misses: 2,
+        };
+
+        assert_eq!(state, expected);
+    }
+}