0.1.0-0-pre.3

crates/engines/engine-v1-common/src/input.rs

@@ -0,0 +1,61 @@
+// file: crates/engines/engine-v1-common/src/input.rs
+// version: 1
+
+/// Platform-independent snapshot of logical input actions for one update.
+#[derive(Clone, Copy, Debug, Default, Eq, PartialEq)]
+pub struct InputState {
+    left: bool,
+    right: bool,
+    up: bool,
+    down: bool,
+    primary: bool,
+    secondary: bool,
+    pause: bool,
+}
+
+impl InputState {
+    /// Creates a snapshot with no active action.
+    #[must_use]
+    pub const fn none() -> Self {
+        return Self { left: false, right: false, up: false, down: false, primary: false, secondary: false, pause: false };
+    }
+
+    /// Returns a copy with the selected logical action set to the requested state.
+    #[must_use]
+    pub const fn with_action(mut self, action: crate::GameAction, active: bool) -> Self {
+        match action {
+            crate::GameAction::Left => self.left = active,
+            crate::GameAction::Right => self.right = active,
+            crate::GameAction::Up => self.up = active,
+            crate::GameAction::Down => self.down = active,
+            crate::GameAction::Primary => self.primary = active,
+            crate::GameAction::Secondary => self.secondary = active,
+            crate::GameAction::Pause => self.pause = active,
+        }
+        return self;
+    }
+
+    /// Reports whether the selected logical action is active.
+    #[must_use]
+    pub const fn is_active(self, action: crate::GameAction) -> bool {
+        return match action {
+            crate::GameAction::Left => self.left,
+            crate::GameAction::Right => self.right,
+            crate::GameAction::Up => self.up,
+            crate::GameAction::Down => self.down,
+            crate::GameAction::Primary => self.primary,
+            crate::GameAction::Secondary => self.secondary,
+            crate::GameAction::Pause => self.pause,
+        };
+    }
+}
+
+#[cfg(test)]
+mod unit_tests {
+    #[test]
+    fn action_state_is_independent() {
+        let state = crate::InputState::none().with_action(crate::GameAction::Primary, true);
+        assert!(state.is_active(crate::GameAction::Primary));
+        assert!(!state.is_active(crate::GameAction::Secondary));
+    }
+}