| 摘要 |
A method comprises, when an output surface is to be composited from input surfaces by a composition processor: determining whether two or more input surfaces can be combined into a single secondary surface for provision to a composition processor; and when it is determined that they can be combined, providing data representing the secondary surface to the composition processor indicating the input surfaces which contribute to the secondary surface. The determining may comprise determining whether any input surfaces do not overlap each other, and/or if they at least partly overlap, whether the foremost surface is opaque where the surfaces overlap. Attributes of the surfaces may be used to determine whether and/or which surfaces can be combined to form a secondary surface. The method may comprise generating data representing the secondary surface, comprising determining for each of one or more groups of lines traversing the secondary surface the lines comprising segments of points which input surface is to form the surface at each point along the lines of the group; and providing for each group data identifying the input surface to form the secondary surface at each segment of the lines. |
