Missed variables in window_to_world method (#46)

* fix: Missed variables

* ref: Unused variable

orthographic/camera.lua

@@ -727,6 +727,10 @@ function M.window_to_world(camera_id, window)
 	local view = camera.view or MATRIX4
 	local projection = camera.projection or MATRIX4
 	local viewport = camera.viewport or VECTOR4
+	local viewport_width = viewport.z * DISPLAY_WIDTH / WINDOW_WIDTH
+	local viewport_height = viewport.w * DISPLAY_HEIGHT / WINDOW_HEIGHT
+	local viewport_left = viewport.x * DISPLAY_WIDTH / WINDOW_WIDTH
+	local viewport_bottom = viewport.y * DISPLAY_HEIGHT / WINDOW_HEIGHT
 	local scale_x = window.x * dpi_ratio * DISPLAY_WIDTH / WINDOW_WIDTH
 	local scale_y = window.y * dpi_ratio * DISPLAY_HEIGHT / WINDOW_HEIGHT
 
@@ -823,7 +827,6 @@ function M.screen_to_world_bounds(camera_id)
 	local camera = cameras[camera_id]
 	local view = camera.view or MATRIX4
 	local projection = camera.projection or MATRIX4
-	local viewport = camera.viewport or VECTOR4
 	local inv = vmath.inv(projection * view)
 	local bl_x, bl_y = unproject_xyz(inv, 0, 0, 0)
 	local br_x, br_y = unproject_xyz(inv, DISPLAY_WIDTH, 0, 0)