fix: adjust mania converts

src/mania/convert/mod.rs

@@ -1,7 +1,4 @@
-use rosu_map::{
-    section::{general::GameMode, hit_objects::CurveBuffers},
-    util::Pos,
-};
+use rosu_map::{section::general::GameMode, util::Pos};
 
 use crate::{
     model::{
@@ -15,8 +12,8 @@ use crate::{
 use self::{
     pattern::Pattern,
     pattern_generator::{
-        distance_object::DistanceObjectPatternGenerator,
         end_time_object::EndTimeObjectPatternGenerator, hit_object::HitObjectPatternGenerator,
+        path_object::PathObjectPatternGenerator,
     },
     pattern_type::PatternType,
 };
@@ -76,7 +73,6 @@ fn convert(map: &mut Beatmap) {
 
     let total_columns = map.cs as i32;
     let mut last_values = PrevValues::default();
-    let mut curve_bufs = CurveBuffers::default();
 
     // mean=668.7 | median=512
     let mut new_hit_objects = Vec::with_capacity(512);
@@ -108,9 +104,7 @@ fn convert(map: &mut Beatmap) {
                 last_values.pattern = new_pattern;
             }
             HitObjectKind::Slider(ref slider) => {
-                let curve = slider.curve(GameMode::Mania, &mut curve_bufs);
-
-                let mut gen = DistanceObjectPatternGenerator::new(
+                let mut gen = PathObjectPatternGenerator::new(
                     &mut random,
                     obj,
                     sound,
@@ -118,7 +112,7 @@ fn convert(map: &mut Beatmap) {
                     &last_values.pattern,
                     map,
                     slider.repeats,
-                    &curve,
+                    slider.expected_dist,
                     &slider.node_sounds,
                 );
 
@@ -195,24 +189,29 @@ fn target_columns(map: &Beatmap) -> f32 {
     let rounded_cs = map.cs.round_ties_even();
     let rounded_od = map.od.round_ties_even();
 
-    let slider_or_spinner_count = map
-        .hit_objects
-        .iter()
-        .filter(|h| matches!(h.kind, HitObjectKind::Slider(_) | HitObjectKind::Spinner(_)))
-        .count();
+    if !map.hit_objects.is_empty() {
+        let count_slider_or_spinner = map
+            .hit_objects
+            .iter()
+            .filter(|h| matches!(h.kind, HitObjectKind::Slider(_) | HitObjectKind::Spinner(_)))
+            .count();
 
-    let len = map.hit_objects.len();
-    let percent_slider_or_spinner = f64::from(slider_or_spinner_count as f32 / len as f32);
+        let len = map.hit_objects.len();
 
-    if percent_slider_or_spinner < 0.2 {
-        7.0
-    } else if percent_slider_or_spinner < 0.3 || rounded_cs >= 5.0 {
-        f32::from(6 + u8::from(rounded_od > 5.0))
-    } else if percent_slider_or_spinner > 0.6 {
-        f32::from(4 + u8::from(rounded_od > 4.0))
-    } else {
-        (rounded_od + 1.0).clamp(4.0, 7.0)
+        // * In osu!stable, this division appears as if it happens on floats, but due to release-mode
+        // * optimisations, it actually ends up happening on doubles.
+        let percent_slider_or_spinner = f64::from(count_slider_or_spinner as f64 / len as f64);
+
+        if percent_slider_or_spinner < 0.2 {
+            return 7.0;
+        } else if percent_slider_or_spinner < 0.3 || rounded_cs >= 5.0 {
+            return f32::from(6 + u8::from(rounded_od > 5.0));
+        } else if percent_slider_or_spinner > 0.6 {
+            return f32::from(4 + u8::from(rounded_od > 4.0));
+        }
     }
+
+    ((rounded_od as i32) + 1).min(7).max(4) as f32
 }
 
 #[cfg(test)]

src/mania/convert/pattern.rs

@@ -5,8 +5,8 @@ use rosu_map::util::Pos;
 use crate::model::hit_object::{HitObject, HitObjectKind, HoldNote};
 
 use super::pattern_generator::{
-    distance_object::DistanceObjectPatternGenerator,
     end_time_object::EndTimeObjectPatternGenerator, hit_object::HitObjectPatternGenerator,
+    path_object::PathObjectPatternGenerator,
 };
 
 #[derive(Default)]
@@ -87,7 +87,7 @@ impl Pattern {
     }
 
     pub fn new_slider_note(
-        generator: &DistanceObjectPatternGenerator<'_>,
+        generator: &PathObjectPatternGenerator<'_>,
         column: u8,
         start_time: i32,
         end_time: i32,
@@ -118,7 +118,7 @@ impl Pattern {
 
     pub fn add_slider_note(
         &mut self,
-        generator: &DistanceObjectPatternGenerator<'_>,
+        generator: &PathObjectPatternGenerator<'_>,
         column: u8,
         start_time: i32,
         end_time: i32,

src/mania/convert/pattern_generator/mod.rs

@@ -4,9 +4,9 @@ use crate::{
     util::random::Random,
 };
 
-pub(super) mod distance_object;
 pub(super) mod end_time_object;
 pub(super) mod hit_object;
+pub(super) mod path_object;
 
 pub struct PatternGenerator<'a> {
     pub hit_object: &'a HitObject,

src/mania/convert/pattern_generator/path_object.rs

@@ -1,6 +1,6 @@
 use std::cmp;
 
-use rosu_map::section::hit_objects::{hit_samples::HitSoundType, BorrowedCurve};
+use rosu_map::section::hit_objects::hit_samples::HitSoundType;
 
 use crate::{
     mania::{
@@ -17,7 +17,7 @@ use crate::{
 
 use super::PatternGenerator;
 
-pub struct DistanceObjectPatternGenerator<'h> {
+pub struct PathObjectPatternGenerator<'h> {
     pub segment_duration: i32,
     pub sample: HitSoundType,
     pub inner: PatternGenerator<'h>,
@@ -29,7 +29,7 @@ pub struct DistanceObjectPatternGenerator<'h> {
     node_sounds: &'h [HitSoundType],
 }
 
-impl<'h> DistanceObjectPatternGenerator<'h> {
+impl<'h> PathObjectPatternGenerator<'h> {
     #[allow(clippy::too_many_arguments)]
     pub fn new(
         random: &'h mut Random,
@@ -39,7 +39,7 @@ impl<'h> DistanceObjectPatternGenerator<'h> {
         prev_pattern: &'h Pattern,
         orig: &'h Beatmap,
         repeats: usize,
-        curve: &BorrowedCurve<'_>,
+        expected_dist: Option<f64>,
         node_sounds: &'h [HitSoundType],
     ) -> Self {
         let timing_beat_len = orig
@@ -67,9 +67,11 @@ impl<'h> DistanceObjectPatternGenerator<'h> {
         let span_count = (repeats + 1) as i32;
         let start_time = hit_object.start_time.round_ties_even() as i32;
 
+        let dist = expected_dist.unwrap_or(0.0);
+
         // * This matches stable's calculation.
         let end_time = (f64::from(start_time)
-            + curve.dist() * beat_len * f64::from(span_count) * 0.01 / orig.slider_multiplier)
+            + dist * beat_len * f64::from(span_count) * 0.01 / orig.slider_multiplier)
             .floor() as i32;
 
         let segment_duration = (end_time - start_time) / span_count;