ghost interacts with house battery

src/activities/house/mod.rs

@@ -3,7 +3,7 @@ mod grid;
 mod player;
 mod room;
 
-use comfy::{main_camera_mut, random_i32, vec2, EngineContext};
+use comfy::{main_camera_mut, random_i32, vec2, EngineContext, RandomRange as _};
 use grid::Grid;
 use log::error;
 use player::Player;
@@ -36,6 +36,7 @@ impl HouseState {
 		}
 
 		let player = Player::new(rooms.first().unwrap());
+		let max_charge = f32::gen_range(2_000.0, 5_000.0);
 		HouseState {
 			current_room_id: 0,
 			room_count,
@@ -43,8 +44,8 @@ impl HouseState {
 			player,
 			human_layer: false,
 			// TODO this should be lower depending on the time elapsed
-			charge: 1000.0,
-			max_charge: 1000.0
+			charge: max_charge,
+			max_charge
 		}
 	}
 }

src/activities/overworld/mod.rs

@@ -1,4 +1,8 @@
-use crate::{activities::Activity, game::ZLayer, State};
+use crate::{
+	activities::Activity,
+	game::{ZLayer, GHOST_DISCHARGE_RATE, GHOST_DISCHARGE_RATE_MOVEMENT},
+	State
+};
 use comfy::{
 	delta, draw_circle, draw_rect_outline, draw_sprite, error, info, is_key_down,
 	main_camera_mut, EngineContext, IVec2, KeyCode, Vec2, RED, WHITE
@@ -177,9 +181,9 @@ pub fn update(state: &mut State, ctx: &mut EngineContext<'_>) {
 	// energie lost
 	{
 		let ghost = &mut state.ghost;
-		ghost.charge -= 70.0 * ctx.delta;
+		ghost.charge -= GHOST_DISCHARGE_RATE * ctx.delta;
 		if ghost.overworld_movement_pending != Vec2::ZERO {
-			ghost.charge -= 70.0 * ctx.delta;
+			ghost.charge -= GHOST_DISCHARGE_RATE_MOVEMENT * ctx.delta;
 		}
 	}
 

src/game.rs

@@ -107,12 +107,53 @@ pub fn setup(_state: &mut State, ctx: &mut EngineContext<'_>) {
 	//house::setup(state, ctx);
 }
 
-pub fn update(state: &mut State, engine: &mut EngineContext<'_>) {
-	state.score += engine.delta * 10.0;
+/// The amount of energy a ghost consumes idle.
+pub const GHOST_DISCHARGE_RATE: f32 = 70.0;
+/// The amount of energy additionally consumed by a moving ghost.
+pub const GHOST_DISCHARGE_RATE_MOVEMENT: f32 = 70.0;
+/// The amount of energy a house consumes idle.
+pub const HOUSE_DISCHARGE_RATE: f32 = 30.0;
+/// The amount of energy a ghost can charge when inside a house.
+pub const GHOST_CHARGE_RATE: f32 = 200.0;
+
+pub fn update(state: &mut State, ctx: &mut EngineContext<'_>) {
+	// Update the score. It's based on time.
+	state.score += ctx.delta * 10.0;
+
+	// Update the currently active activity.
 	match state.activity {
-		Activity::House(_) => house::update(state, engine),
-		Activity::Overworld => overworld::update(state, engine)
+		Activity::House(_) => house::update(state, ctx),
+		Activity::Overworld => overworld::update(state, ctx)
 	}
+
+	// We update the charge of houses here - the charge will always decrease, even if the
+	// house is not the current activity.
+	for (house_pos, house) in &mut state.houses {
+		house.charge -= ctx.delta * HOUSE_DISCHARGE_RATE;
+
+		match state.activity {
+			Activity::House(pos) if *house_pos == pos => {
+				// The ghost is currently inside the house. Increase its discarge rate.
+				house.charge -= ctx.delta * GHOST_DISCHARGE_RATE;
+				if house.charge < 0.0 {
+					state.ghost.charge += house.charge;
+					house.charge = 0.0;
+				}
+
+				// And possibly also charge the ghost when inside a house.
+				if state.ghost.charge < state.ghost.max_charge {
+					let charge_transfer = (ctx.delta * GHOST_CHARGE_RATE)
+						.min(state.ghost.max_charge - state.ghost.charge)
+						.min(house.charge);
+					state.ghost.charge += charge_transfer;
+					house.charge -= charge_transfer;
+				}
+			},
+			_ => {}
+		}
+	}
+
+	// Make sure the ghost's charge never drops below 0.
 	state.ghost.charge = state.ghost.charge.max(0.0);
 }