Clientside Backpack UI (#84)

crates/shared/src/backpack/mod.rs

@@ -1,8 +1,15 @@
+#[cfg(feature = "client")]
+use crate::{
+    backpack::backpack_ui::BackpackUiState, control::BackpackButtonPress, player::LocalPlayer,
+    protocol::PlaySound,
+};
 use crate::{
     cash::CashCollectEvent, global_observer, head_drop::HeadCollected, heads::HeadState,
     heads_database::HeadsDatabase,
 };
 use bevy::prelude::*;
+#[cfg(feature = "client")]
+use bevy_replicon::prelude::ClientTriggerExt;
 use serde::{Deserialize, Serialize};
 pub use ui_head_state::UiHeadState;
 
@@ -35,17 +42,116 @@ impl Backpack {
     }
 }
 
-#[derive(Event)]
-pub struct BackbackSwapEvent(pub usize);
+#[derive(Event, Serialize, Deserialize)]
+pub struct BackpackSwapEvent(pub usize);
 
 pub fn plugin(app: &mut App) {
     app.register_type::<Backpack>();
 
     app.add_plugins(backpack_ui::plugin);
 
+    #[cfg(feature = "client")]
+    app.add_systems(FixedUpdate, (backpack_inputs, sync_on_change));
+
     global_observer!(app, on_head_collect);
 }
 
+#[cfg(feature = "client")]
+#[allow(clippy::too_many_arguments)]
+fn backpack_inputs(
+    backpacks: Single<(&Backpack, &mut BackpackUiState), With<LocalPlayer>>,
+    mut backpack_inputs: MessageReader<BackpackButtonPress>,
+    mut commands: Commands,
+    time: Res<Time>,
+) {
+    let (backpack, mut state) = backpacks.into_inner();
+
+    for input in backpack_inputs.read() {
+        match input {
+            BackpackButtonPress::Toggle => {
+                if state.count == 0 {
+                    return;
+                }
+
+                state.open = !state.open;
+                commands.trigger(PlaySound::Backpack { open: state.open });
+            }
+            BackpackButtonPress::Swap => {
+                if !state.open {
+                    return;
+                }
+
+                commands.client_trigger(BackpackSwapEvent(state.current_slot));
+            }
+            BackpackButtonPress::Left => {
+                if !state.open {
+                    return;
+                }
+
+                if state.current_slot > 0 {
+                    state.current_slot -= 1;
+
+                    commands.trigger(PlaySound::Selection);
+                    sync_backpack_ui(backpack, &mut state, time.elapsed_secs());
+                }
+            }
+            BackpackButtonPress::Right => {
+                if !state.open {
+                    return;
+                }
+
+                if state.current_slot < state.count.saturating_sub(1) {
+                    state.current_slot += 1;
+
+                    commands.trigger(PlaySound::Selection);
+                    sync_backpack_ui(backpack, &mut state, time.elapsed_secs());
+                }
+            }
+        }
+    }
+}
+
+#[cfg(feature = "client")]
+fn sync_on_change(
+    backpack: Query<Ref<Backpack>>,
+    mut state: Single<&mut BackpackUiState>,
+    time: Res<Time>,
+) {
+    for backpack in backpack.iter() {
+        if backpack.is_changed() || backpack.reloading() {
+            sync_backpack_ui(&backpack, &mut state, time.elapsed_secs());
+        }
+    }
+}
+
+#[cfg(feature = "client")]
+fn sync_backpack_ui(backpack: &Backpack, state: &mut BackpackUiState, time: f32) {
+    use crate::backpack::backpack_ui::BACKPACK_HEAD_SLOTS;
+
+    state.count = backpack.heads.len();
+
+    state.scroll = state
+        .scroll
+        .min(state.count.saturating_sub(BACKPACK_HEAD_SLOTS));
+
+    if state.current_slot >= state.scroll + BACKPACK_HEAD_SLOTS {
+        state.scroll = state.current_slot.saturating_sub(BACKPACK_HEAD_SLOTS - 1);
+    }
+    if state.current_slot < state.scroll {
+        state.scroll = state.current_slot;
+    }
+
+    for i in 0..BACKPACK_HEAD_SLOTS {
+        if let Some(head) = backpack.heads.get(i + state.scroll) {
+            use crate::backpack::ui_head_state::UiHeadState;
+
+            state.heads[i] = Some(UiHeadState::new(*head, time));
+        } else {
+            state.heads[i] = None;
+        }
+    }
+}
+
 fn on_head_collect(
     trigger: On<HeadCollected>,
     mut cmds: Commands,