add camera zooming

scripts/main_camera.gd

@@ -1,18 +1,39 @@
 extends Camera3D
 
 const MOVE_SPEED: float = 2
+const ZOOM_SPEED: float = 0.25
 ## How many pixels the mouse needs to be away
 ## from the screen edge to move the camera.
 const EDGE_THRESHOLD: float = 10
 
+@export var zoom_in_height: float = 1
+@export var zoom_in_fov: float = 60
+@export var zoom_in_angle: float = -0.1 * PI
+
+@export var zoom_out_height: float = 3
+@export var zoom_out_fov: float = 70
+@export var zoom_out_angle: float = -0.25 * PI
+
 var mouse_position: Vector2 = Vector2()
+## 0 = zoomed in. 1 = zoomed out.
+var zoom_value: float = 0.25
 
 func _process(delta: float) -> void:
 	handle_movement(delta)
+	handle_zoom()
 
 func _input(event: InputEvent) -> void:
 	if event is InputEventMouseMotion:
 		mouse_position = (event as InputEventMouseMotion).position
+	
+	if event is InputEventMouseButton:
+		var button_event := event as InputEventMouseButton
+		if button_event.pressed:
+			if button_event.button_index == MOUSE_BUTTON_WHEEL_UP:
+				zoom_value -= ZOOM_SPEED
+			elif button_event.button_index == MOUSE_BUTTON_WHEEL_DOWN:
+				zoom_value += ZOOM_SPEED
+			zoom_value = clamp(zoom_value, 0, 1)
 
 func handle_movement(delta: float) -> void:
 	var viewport_size := get_viewport().get_visible_rect().size
@@ -41,4 +62,9 @@ func handle_movement(delta: float) -> void:
 	)
 
 	var velocity := direction * MOVE_SPEED
-	position += velocity * delta
+	position += velocity * delta
+
+func handle_zoom() -> void:
+	fov = lerp(zoom_in_fov, zoom_out_fov, zoom_value)
+	rotation.x = lerp(zoom_in_angle, zoom_out_angle, zoom_value)
+	position.y = lerp(zoom_in_height, zoom_out_height, zoom_value)