| 摘要 |
A graphics controller (IMC) which performs pointer-based and/or display list-based video refresh operations that enable screen refresh data to be assembled on a per window basis, thereby greatly increasing the performance of the graphical display. The graphics controller maintains pointers to various buffers in system memory comprising video or graphics display information. The graphics controller manipulates respective object information workspace memory areas corresponding to each object or window, wherein the workspace areas specify data types, color depths, 3D depth values, alpha blending information, screen position, etc. for the respective window or object on the screen. Each workspace area also includes static and dynamic pointers which point to the location in system memory where the pixel data for the respective window or object is stored. The graphics controller utilizes this information, as well as information received from the software driver regarding screen changes, to assemble a display refresh list in system memory. This information is used during the screen refresh to display the various windows or objects on the screen very quickly and efficiently. Thus, the video display can be updated with new video data without requiring any system bus data transfers, which are required in prior art computer system architectures. The graphics controller dynamically adjusts the display refresh list for movement of objects and changes in relative depth priority which appear on the display. Thus the video data for the various windows and objects is stored in respective memory areas in the system memory, and pointers assembled in the display refresh list are used to reference this data during screen updates. Therefore, data is not required to be moved in or out of a frame buffer to reflect screen changes. Rather, in many instances, either the video data for a respective window or object is changed, or only the pointers in the display refresh list are manipulated, to affect a screen change.
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