Abstract: A method of allocating regions of memory including the steps of allocating a corresponding plurality of portions of memory for use by the process and marking regions of memory that are allocated with markers. A start of a region is marked with one of the markers and an end of a region is marked with a further one of the markers, the further one of the markers having a later relative time indication and marking a next allocated region. In response to determining that a region of allocated memory bounded by two of the markers is no longer required by the process, deleting an older of the two markers; and in response to detecting deletion of an oldest one of the markers, deallocating the region of memory up to a new oldest pending marker.

Abstract: In a graphics processing system, a command list reader first reads-in and identifies a portion of a command list. The primitives corresponding to the commands in the portion of the command list are then subjected to a Z-only processing pass. This allows a Z-buffer 16 and a hierarchical Z-pyramid 8 to be filled with the appropriate Z-values for the primitives in the portion of the primitive list. The primitives are then subjected to a second, normal rendering, processing pass, but the filled Z-buffer 16 and Z-pyramid from the first processing pass are used together with the Z-tests 7, 10 performed in the second processing pass to determine which primitive should be processed for each sampling point in the second processing pass.

Abstract: A method of allocating regions of memory including the steps of allocating a corresponding plurality of portions of memory for use by the process and marking regions of memory that are allocated with markers. A start of a region is marked with one of the markers and an end of a region is marked with a further one of the markers, the further one of the markers having a later relative time indication and marking a next allocated region. In response to determining that a region of allocated memory bounded by two of the markers is no longer required by the process, deleting an older of the two markers; and in response to detecting deletion of an oldest one of the markers, deallocating the region of memory up to a new oldest pending marker.

Abstract: In a graphics processing system, a command list reader 3 first reads-in and identifies a portion of a command list. The primitives corresponding to the commands in the portion of the command list are then subjected to a Z-only processing pass. This allows a Z-buffer 16 and a hierarchical Z-pyramid 8 to be filled with the appropriate Z-values for the primitives in the portion of the primitive list. The primitives are then subjected to a second, normal rendering, processing pass, but the filled Z-buffer 16 and Z-pyramid 8 from the first processing pass are used together with the Z-tests 7, 10 performed in the second processing pass to determine which primitive should be processed for each sampling point in the second processing pass.