Add camera zoom

core/edge_scroll_camera.gd

@@ -1,6 +1,7 @@
 ## Scrolls the camera when the mouse cursor reaches the screen edge.
 ## Attach to a Camera2D node. Requires an OrthographicCamera2D or ViewportContainer
 ## to determine screen bounds at runtime.
+@tool
 extends Camera2D
 
 ## Speed at which the camera scrolls (pixels per second).
@@ -18,6 +19,15 @@ extends Camera2D
 ## Maximum bounds when clamping (in world space).
 @export var clamp_max: Vector2 = Vector2.ZERO
 
+## Zoom sensitivity per mouse wheel tick.
+@export var zoom_sensitivity: float = 0.1
+
+## Minimum zoom level.
+@export var zoom_min: float = 0.25
+
+## Maximum zoom level.
+@export var zoom_max: float = 3.0
+
 var _screen_rect: Rect2
 
 
@@ -29,6 +39,10 @@ func _ready() -> void:
 
 
 func _process(delta: float) -> void:
+	if Engine.is_editor_hint():
+		queue_redraw()
+		return
+
 	if is_zero_approx(scroll_speed):
 		return
 
@@ -58,11 +72,46 @@ func _get_scroll_direction(mouse_pos: Vector2) -> Vector2:
 	return direction.normalized()
 
 
+func _draw() -> void:
+	if not Engine.is_editor_hint():
+		return
+	if not clamp_enabled:
+		return
+
+	var rect_size: Vector2 = clamp_max - clamp_min
+	draw_rect(Rect2(clamp_min, rect_size), Color(1, 0.4, 0, 0.35))
+	draw_rect(Rect2(clamp_min, rect_size), Color(1, 0.6, 0.2, 0.8), false, 2.0)
+
+
 func _clamp_position() -> void:
 	position.x = clampf(position.x, clamp_min.x, clamp_max.x)
 	position.y = clampf(position.y, clamp_min.y, clamp_max.y)
 
 
+func _unhandled_input(event: InputEvent) -> void:
+	if Engine.is_editor_hint():
+		return
+
+	if event is InputEventMouseButton:
+		var mouse_event: InputEventMouseButton = event
+		if mouse_event.button_index == MOUSE_BUTTON_WHEEL_UP:
+			_zoom(zoom_sensitivity, mouse_event.position)
+		elif mouse_event.button_index == MOUSE_BUTTON_WHEEL_DOWN:
+			_zoom(-zoom_sensitivity, mouse_event.position)
+
+
+func _zoom(change: float, mouse_pos: Vector2) -> void:
+	var new_zoom_value: float = clampf(zoom.x + change, zoom_min, zoom_max)
+	if is_equal_approx(new_zoom_value, zoom.x):
+		return
+
+	var viewport_center: Vector2 = get_viewport_rect().size / 2.0
+	var offset: Vector2 = mouse_pos - viewport_center
+	var world_point: Vector2 = position + offset / zoom
+	zoom = Vector2(new_zoom_value, new_zoom_value)
+	position = world_point - offset / zoom
+
+
 func _update_screen_rect() -> void:
 	var viewport: Viewport = get_viewport()
 	if viewport != null: