Patent ID: 9182934
Filing Date: 2015-11-10
Classification: G06F,G09G,Y02D

Abstract:
1. A method of generating an output surface from one or more input surfaces in a data processing system, the method comprising: generating the output surface as a plurality of respective regions that together form the output surface, each respective region of the output surface being generated from a respective region or regions of one or more input surfaces; and when a new version of the output surface is to be generated, for at least one region of the output surface: (i) determining which region or regions of the input surface or surfaces contribute to the region of the output surface; (ii) checking whether the contributing region or regions of the input surface or surfaces have changed since the previous version of the output surface region was generated; and (iii) if there has been a change in the contributing region or regions of the input surface or surfaces since the previous version of the region in the output surface was generated, regenerating the region of the output surface, wherein there are two or more input surfaces and the method comprises performing steps (i) and (ii) for each input surface, and if there has been a change in the contributing region or regions of any of the input surfaces since the previous version of the output surface region was generated, regenerating the region of the output surface, and wherein the data processing system is a compositing window system, and the input surfaces each comprise respective input windows that are to be composited into an output window.