摘要 |
A method for rendering of three dimensional images on a video subsystem which does not include clearing of the Z buffer at each frame includes establishment of a Z buffer and a sequence number in memory, where the sequence number is incremented with each successive frame rendered and the Z buffer is cleared when the sequence number reaches a predetermined value; the Z buffer is thus recycled a number of times between clears. In a more elaborate implementation, the precision of the Z buffer is adjusted to permit clearing of the Z buffer to occur either as the result of the sequence number reaching a predetermined value or as the result of the accrual of a predetermined amount of time allocated for clearing, referred to as scheduling. The scheduling method can be applied to a wide range of accounting tasks within a system. In addition, a related method for recycling the image buffer is also disclosed in which multiple colormap ID's are used to distinguish data included in a current frame from data in a prior frame, where the colormap ID's associated with the prior frames all map to the background color, leaving to be displayed only the data of the current frame.
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