This disclosure describes techniques for the determination of occluded and unoccluded spaces within a user interface. Per techniques of this disclosure, a viewport of a user interface is represented as a set of rectangles determined by recursive subdivision. The area of the viewport is based on a sum of the areas of each unoccluded rectangle in the set of rectangles. The efficient representation of the viewport with a small number of rectangles enables frequent recalculation of the viewport, e.g., even when the viewport is updated frequently in response to user actions such as scrolling.

Creative Commons License

Creative Commons License
This work is licensed under a Creative Commons Attribution 4.0 License.