Add: global factor controlling fps base interval

crates/sprimo-runtime-core/src/lib.rs

@@ -8,6 +8,9 @@ use tokio::runtime::Runtime;
 use tokio::sync::{mpsc, Mutex};
 use tracing::warn;
 
+const TAURI_ANIMATION_SLOWDOWN_FACTOR_MIN: u8 = 1;
+const TAURI_ANIMATION_SLOWDOWN_FACTOR_MAX: u8 = 20;
+
 #[derive(Debug, Error)]
 pub enum RuntimeCoreError {
     #[error("{0}")]
@@ -104,6 +107,32 @@ impl RuntimeCore {
         self.persist_config()
     }
 
+    pub fn frontend_tauri_animation_slowdown_factor(&self) -> Result<u8, RuntimeCoreError> {
+        let guard = self
+            .config
+            .read()
+            .map_err(|_| RuntimeCoreError::ConfigPoisoned)?;
+        Ok(clamp_tauri_animation_slowdown_factor(
+            guard.frontend.tauri_animation_slowdown_factor,
+        ))
+    }
+
+    pub fn set_frontend_tauri_animation_slowdown_factor(
+        &self,
+        value: u8,
+    ) -> Result<u8, RuntimeCoreError> {
+        let clamped = clamp_tauri_animation_slowdown_factor(value);
+        {
+            let mut guard = self
+                .config
+                .write()
+                .map_err(|_| RuntimeCoreError::ConfigPoisoned)?;
+            guard.frontend.tauri_animation_slowdown_factor = clamped;
+        }
+        self.persist_config()?;
+        Ok(clamped)
+    }
+
     pub fn api_config(&self) -> ApiConfig {
         self.api_config.clone()
     }
@@ -257,6 +286,13 @@ fn default_animation_for_state(state: sprimo_protocol::v1::FrontendState) -> &'s
     }
 }
 
+fn clamp_tauri_animation_slowdown_factor(value: u8) -> u8 {
+    value.clamp(
+        TAURI_ANIMATION_SLOWDOWN_FACTOR_MIN,
+        TAURI_ANIMATION_SLOWDOWN_FACTOR_MAX,
+    )
+}
+
 fn log_api_error(err: ApiServerError) {
     warn!(%err, "runtime core api server exited");
 }
@@ -331,4 +367,36 @@ mod tests {
         core.set_frontend_debug_overlay_visible(true).expect("set");
         assert!(core.frontend_debug_overlay_visible().expect("get"));
     }
+
+    #[test]
+    fn frontend_tauri_animation_slowdown_factor_roundtrips() {
+        let temp = TempDir::new().expect("tempdir");
+        let path = temp.path().join("config.toml");
+        let core = RuntimeCore::new_with_config(path, AppConfig::default(), CapabilityFlags::default())
+            .expect("core init");
+        let persisted = core
+            .set_frontend_tauri_animation_slowdown_factor(6)
+            .expect("set");
+        assert_eq!(persisted, 6);
+        assert_eq!(
+            core.frontend_tauri_animation_slowdown_factor().expect("get"),
+            6
+        );
+    }
+
+    #[test]
+    fn frontend_tauri_animation_slowdown_factor_clamps() {
+        let temp = TempDir::new().expect("tempdir");
+        let path = temp.path().join("config.toml");
+        let core = RuntimeCore::new_with_config(path, AppConfig::default(), CapabilityFlags::default())
+            .expect("core init");
+        let persisted = core
+            .set_frontend_tauri_animation_slowdown_factor(0)
+            .expect("set");
+        assert_eq!(persisted, 1);
+        assert_eq!(
+            core.frontend_tauri_animation_slowdown_factor().expect("get"),
+            1
+        );
+    }
 }