write some sonnet code

BallanceTasSonnet/src/utils/fps_converter.rs

@@ -0,0 +1,27 @@
+use thiserror::Error as TeError;
+
+#[derive(Debug, TeError)]
+pub enum Error {
+    #[error("delta time should not be zero or negative value")]
+    BadDeltaTime,
+    #[error("fps should should not be zero or negative value")]
+    BadFps,
+}
+
+type Result<T> = std::result::Result<T, Error>;
+
+pub fn to_fps(delta: f32) -> Result<f32> {
+    if delta <= 0f32 {
+        Err(Error::BadDeltaTime)
+    } else {
+        Ok(1f32 / delta)
+    }
+}
+
+pub fn to_delta(fps: f32) -> Result<f32> {
+    if fps <= 0f32 {
+        Err(Error::BadFps)
+    } else {
+        Ok(1f32 / fps)
+    }
+}