General-purpose computing on graphics processing units: Difference between revisions

Revision as of 07:28, 22 March 2006

Revision as of 20:35, 25 March 2006

Line 77:

====Scatter====

The scatter operation is onlymost possiblenaturally defined on the vertex processor. The vertex processor is able to adjust the position of the vertex, which allows the programmer to control where information is deposited on the grid. Other extensions are also possible, such as controlling how large an area the vertex affects. The fragment processor cannot perform a scatter operation because the ___location of each fragment on screen is fixed at the time of the fragment's creation and cannot be altered by the programmer.

The fragment processor cannot perform a direct scatter operation because the ___location of each fragment on the grid is fixed at the time of the fragment's creation and cannot be altered by the programmer. However, a logical scatter operation may sometimes be recast or implemented with an additional gather step. A scatter implementation would first emit both an output value and an output address. An immediately following gather operation uses address comparisons to see whether the output value maps to the current output slot.

====Gather====