Keep layered portrait preview bounds finite

Tests/Unit/layered_portrait_coverage_test.gd

@@ -0,0 +1,46 @@
+class_name LayeredPortraitCoverageTest
+extends GdUnitTestSuite
+
+
+func test_coverage_uses_local_transforms_before_entering_tree() -> void:
+	var portrait := CanvasGroup.new()
+	portrait.set_script(preload(
+		"res://addons/dialogic/Modules/LayeredPortrait/layered_portrait.gd"
+	))
+	# Reproduce the invalid preview transform reported after selecting an empty
+	# portrait. Coverage must depend only on transforms below the portrait root.
+	portrait.position = Vector2(INF, INF)
+	var layer := Node2D.new()
+	layer.position = Vector2(30, 20)
+	portrait.add_child(layer)
+
+	var sprite := Sprite2D.new()
+	sprite.texture = ImageTexture.create_from_image(
+		Image.create(20, 10, false, Image.FORMAT_RGBA8)
+	)
+	sprite.position = Vector2(5, 7)
+	layer.add_child(sprite)
+
+	var coverage: Rect2 = portrait._find_largest_coverage_rect()
+	assert_bool(coverage.position.is_finite()).is_true()
+	assert_bool(coverage.size.is_finite()).is_true()
+	assert_vector(coverage.size).is_equal(Vector2(20, 10))
+	portrait.free()
+
+
+func test_coverage_includes_scaled_and_rotated_sprite_corners() -> void:
+	var portrait := CanvasGroup.new()
+	portrait.set_script(preload(
+		"res://addons/dialogic/Modules/LayeredPortrait/layered_portrait.gd"
+	))
+	var sprite := Sprite2D.new()
+	sprite.texture = ImageTexture.create_from_image(
+		Image.create(20, 10, false, Image.FORMAT_RGBA8)
+	)
+	sprite.scale = Vector2(2, 1)
+	sprite.rotation = PI / 2.0
+	portrait.add_child(sprite)
+
+	var coverage: Rect2 = portrait._find_largest_coverage_rect()
+	assert_vector(coverage.size).is_equal_approx(Vector2(10, 40), Vector2(0.001, 0.001))
+	portrait.free()

addons/dialogic/Modules/LayeredPortrait/layered_portrait.gd

@@ -215,24 +215,34 @@ func _find_largest_coverage_rect() -> Rect2:
 		return _cached_coverage_rect
 
 	var coverage_rect := Rect2(0, 0, 0, 0)
+	var has_coverage := false
 
 	for sprite: Sprite2D in _find_sprites_recursively(self):
-		var sprite_size := sprite.get_rect().size
-		var sprite_position: Vector2 = sprite.global_position-self.global_position
-
-		if sprite.centered:
-			sprite_position -= sprite_size/2
-
-		var sprite_width := sprite_size.x * sprite.scale.x
-		var sprite_height := sprite_size.y * sprite.scale.y
-
-		var texture_rect := Rect2(
-			sprite_position.x,
-			sprite_position.y,
-			sprite_width,
-			sprite_height
+		# Global transforms can be invalid for tool nodes while the editor is
+		# rebuilding a portrait preview. Build the transform from local values so
+		# coverage stays finite even before the nodes enter the scene tree.
+		var relative_transform := sprite.transform
+		var parent := sprite.get_parent()
+		while parent != self:
+			if parent is Node2D:
+				relative_transform = parent.transform * relative_transform
+			parent = parent.get_parent()
+
+		var sprite_rect := sprite.get_rect()
+		var first_corner := relative_transform * sprite_rect.position
+		var texture_rect := Rect2(first_corner, Vector2.ZERO)
+		texture_rect = texture_rect.expand(relative_transform * sprite_rect.end)
+		texture_rect = texture_rect.expand(
+			relative_transform * Vector2(sprite_rect.end.x, sprite_rect.position.y)
+		)
+		texture_rect = texture_rect.expand(
+			relative_transform * Vector2(sprite_rect.position.x, sprite_rect.end.y)
 		)
-		coverage_rect = coverage_rect.merge(texture_rect)
+		if has_coverage:
+			coverage_rect = coverage_rect.merge(texture_rect)
+		else:
+			coverage_rect = texture_rect
+			has_coverage = true
 
 	coverage_rect.position = _reposition_with_rect(coverage_rect)