a few more formatters

src/formatters.rs

@@ -7,6 +7,28 @@ pub fn f32_rounded(digits: usize) -> Arc<dyn Fn(f32) -> String + Send + Sync> {
     Arc::new(move |x| format!("{:.digits$}", x))
 }
 
+/// Turn an `f32` value from linear to dBFS (reference value 1)
+pub fn f32_lin_to_db(digits: usize) -> Arc<dyn Fn(f32) -> String + Send + Sync> {
+    Arc::new(move |x| format!("{:.digits$}", x.log10() * 20.0))
+}
+
+/// Turn an `f32` value from dBFS (reference value 1) to linear
+pub fn f32_db_to_lin(digits: usize) -> Arc<dyn Fn(f32) -> String + Send + Sync> {
+    Arc::new(move |x| format!("{:.digits$}", 10f32.powf(x / 20.0)))
+}
+
+/// Round an `f32` value and divide it by 1000 when it gets over 1000
+pub fn f32_hertz_then_khz(digits: usize) -> Arc<dyn Fn(f32) -> String + Send + Sync> {
+    Arc::new(move |x| {
+        if x < 1000.0 {
+            format!("{:.digits$}", x)
+        } else {
+            let digits = digits + 1;
+            format!("{:.digits$}", x / 1000.0)
+        }
+    })
+}
+
 /// Format a `[0, 1]` number as a percentage. Does not include the percent sign, you should specify
 /// this as the parameter's unit.
 pub fn f32_percentage(digits: usize) -> Arc<dyn Fn(f32) -> String + Send + Sync> {