Efficiently Path-Clipping Layered UI Content for Mobile Devices
Publication Date: 2014-Jul-31
The IP.com Prior Art Database
Techniques for reducing overdraw for blended opaque, partially transparent, and transparent user interface (UI) components are disclosed. First, opaque portions of a blended UI component are drawn into both (i) a color buffer; .e.g., a display, display buffer, video memory, video buffer; and (ii) a depth buffer; e.g., a Z-buffer, a depth buffer, a stencil buffer, a combined stencil/depth buffer. Then, the partially and/or wholly transparent portions of the blended UI component can be drawn to the color buffer only. Subsequently remaining, indivisible or trivially sized partially or completely transparent portions of the blended UI component can be drawn into the color buffer only. When the components are divided in this manner, a significantly higher portion of the drawing area is covered by purely opaque drawing operations and is fit for inclusion into the depth buffer. This allows more content to be rejected for drawing by the depth buffer, thereby avoiding overdraw.