Abstract: The present invention discloses methods and apparatus for implementing automatic graphics operations with selectable triggering mechanism. One mechanism is hardware related, using the vertical counter in the video control section of the graphics processor. The other mechanism is software related, using the host to directly command the graphics processor. The graphics operations are specified in the header file written by the host in the frame buffer memory. Several header files can be chained together to form a sequence of header files corresponding to very complex graphics operations. Automatic graphics operations, therefore, can be completed without further host intervention resulting in powerful graphics, video, and animation performance.

Abstract: A method and apparatus is disclosed for reading display data from the same area in display memory and processing the display data as video pixel data or graphics pixel data depending on the state of at least one tag bit stored with the data. The apparatus receives display data from display memory, separates at least one tag bit from the display data and uses at least one tag bit in a controller to enable processing display data as video pixel data or graphics pixel data in each processing step. Video pixels may be corrected for missing color components with stored value if previous or next pixel in pipeline is graphics. Display memory and display memory bandwidth may be conserved by enabling video pixel data formats and graphics pixel data formats to be stored within the same display memory area.

Abstract: A display controller for a computer or the like stored display data in a tiled format in a display memory. Tile shape may be dynamically altered depending upon display mode (resolution, pixel depth, or the like) or other display factors. Tile shape (height versus width) may be optimized for different types of display (e.g., video, text, graphics, or the like). A display memory address conversion apparatus may receive pixel position data (e.g., from a BIT BLT engine or the like) and tile shape data and convert pixel position data to a tiled display memory address.

Abstract: A method and apparatus to stretch video images in a graphics controller chip of a computer system. The graphics controller chip fetches four pixel data comprising two pixel data each from a first scan line and a second scan line of a source video image, and generates a set of additional pixels in a rectangular area defined by the four pixels. The graphics controller chip stores the pixels of rectangular portions in a display memory, and displays the pixel data of the stretched video image in a scan line order.