Patent ID: 8842131
Filing Date: 2014-09-23
Classification: G09G

Abstract:
1. A method, comprising: traversing a user interface tree of widgets corresponding to widgets requiring clipping that are present in a scene to be rendered; for each encountered widget, performing layer allocation operations comprising: allocating a bit from a stencil buffer to the selected layer and incrementing a value of the selected layer to account for the widget being allocated to the selected layer; generating, by a processor, a reference layer comprising a logical OR of the current value of all layers; generating a draw test mask comprising bits of the stencil buffer that are allocated to all layers; applying the draw test mask to the stencil buffer; passing contents of the stencil buffer to a frame buffer for drawing a pixel; generating a write mask that contains bits allocated to the current laver, the write mask preventing writing to other layers; and applying both the stencil test mask and the draw test mask to the reference layer and the current value of the stencil buffer before the pixel is drawn.