add remove point

src/music.rs

@@ -35,6 +35,17 @@ impl Music {
             &mut self.poly_frame.last_mut().unwrap().1
         }
     }
+    fn find_index_frame(&mut self, delta: f32) -> usize {
+        if let Some(i) = self
+            .poly_frame
+            .windows(2)
+            .position(|w| w[0].0 <= delta && delta < w[1].0)
+        {
+            i
+        } else {
+            self.poly_frame.len() - 1
+        }
+    }
     // ~~~~~~~~~~~~~~~~~~~~~~~~~~~~PUBLIC~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
     pub fn current_frame(&self, delta: f32) -> &PolygonFrame {
         if let Some(i) = self
@@ -121,6 +132,12 @@ impl Music {
         self.poly_frame
             .insert(pos, (delta, self.current_frame(delta).clone()));
     }
+    pub fn remove_point(&mut self, delta: f32) {
+        let i = self.find_index_frame(delta);
+        if i != 0 {
+            self.poly_frame.remove(i);
+        }
+    }
 
     pub fn add_polygon(&mut self, delta: f32, polygon_name: String) {
         let current_frame = self.find_poly_frame(delta);