Implement freeze

README.md

@@ -32,8 +32,6 @@ Batch conversion is possible with the included shell script `batch_convert.sh`
  * Since *osu!mania* does not support shock arrows, it either ignores them or
    (by default) replaces them with a two-key combination (↑↓ or ←→); you can
    change this with the (`--shock-action` option)
- * Freezes do not work (I do not know how to get the start time yet) and
-   therefore are disabled in code (`ddr::ssq::FREEZE`)
  * Known problems listed for unxwb (for wave banks without entry names having
    2 entries, which often are preview and full song, the longest one is used by
    default).

src/ddr/ssq.rs

@@ -13,7 +13,6 @@ use crate::mini_parser::{MiniParser, MiniParserError};
 use crate::utils;
 
 const MEASURE_LENGTH: i32 = 4096;
-const FREEZE: bool = false;
 
 #[derive(Error, Debug)]
 pub enum Error {
@@ -231,6 +230,10 @@ impl Chart {
 
         let mut parsed_steps = Vec::new();
 
+        // indices of (normal) steps that start a freeze (they are not needed after processing all
+        // steps as they are already included in the freezes)
+        let mut freeze_steps = Vec::new();
+
         for step in 0..count {
             let beats = measure_to_beats(measures[step]);
 
@@ -256,12 +259,10 @@ impl Chart {
                         continue;
                     }
 
-                    if FREEZE {
                     match Self::find_last(parsed_steps.clone(), &row) {
                         Some(last_step) => {
                             parsed_steps.push(Step::Freeze {
-                                    start: if let Step::Step { beats, .. } = parsed_steps[last_step]
-                                    {
+                                start: if let Step::Step { beats, .. } = parsed_steps[last_step] {
                                     beats
                                 } else {
                                     unreachable!()
@@ -270,19 +271,13 @@ impl Chart {
                                 row,
                             });
 
-                                parsed_steps.remove(last_step);
+                            freeze_steps.push(last_step);
                         }
                         None => {
-                                warn!(
-                                    "Could not find previous step for freeze, adding normal step"
-                                );
+                            warn!("Could not find previous step for freeze, adding normal step");
                             parsed_steps.push(Step::Step { beats, row });
                         }
                     }
-                    } else {
-                        trace!("Freeze disabled, adding normal step");
-                        parsed_steps.push(Step::Step { beats, row });
-                    }
                 } else {
                     debug!(
                         "Encountered unknown extra step with type {}, ignoring",
@@ -300,6 +295,12 @@ impl Chart {
             }
         }
 
+        // remove steps that start a freeze
+        freeze_steps.dedup();
+        for i in freeze_steps.iter().rev() {
+            parsed_steps.remove(*i);
+        }
+
         debug!("Parsed {} steps", parsed_steps.len());
 
         Ok(Self {
@@ -376,10 +377,6 @@ pub struct SSQ {
 
 impl SSQ {
     pub fn parse(data: &[u8]) -> Result<Self, Error> {
-        debug!(
-            "Configuration: measure length: {}, use freezes: {}",
-            MEASURE_LENGTH, FREEZE
-        );
         let mut cursor = Cursor::new(data);
 
         let mut ssq = Self {