Patent attributes
Image processing is performed on a plurality of layers including at least one line display layer or at least one sprite display layer, from which a plurality of attribute data regarding lines or sprites are sequentially read out so as to produce a plurality of display data, which are then written over each other in a buffer memory, so that the corresponding images are displayed on the screen of a display. With respect to overlapped regions at which plural lines or sprites overlap each other, plural display data are written over each other in the buffer memory in accordance with a first-in-first-out principle. In line processing, image data regarding different lines are subjected to alpha blending and are then written into the buffer memory. In sprite processing, image data regarding different sprites are subjected to rendering and alpha blending and are then written into the buffer memory.