toc@batcomputer.tn.cornell.edu (Timothy F. O'Connor) (10/10/89)
Is it possible to directly read the contents of the z-buffer on the HP Turbo SRX? I know that the z-buffer memory can be read, 8 bits at a time, using bank_switch(3G) and block_read(3G). Unfortunately, these routines are fairly slow. I'd really like the z-buffer analog to the frame buffer's R_GET_FRAME_BUFFER gescape. (As briefly outlined in the HP 98731 device driver manual, the R_GET_FRAME_BUFFER gescape returns the starting address of the frame buffer, allowing all 24 bits of the frame buffer to be read at one time). Many thanks, Tim (toc@wisdom.graphics.cornell.edu)
blaho@hpfcdq.HP.COM (Bruce Blaho) (10/12/89)
>Is it possible to directly read the contents of the z-buffer on the >HP Turbo SRX? I know that the z-buffer memory can be read, 8 bits at a >time, using bank_switch(3G) and block_read(3G). Unfortunately, these >routines are fairly slow. > >I'd really like the z-buffer analog to the frame buffer's R_GET_FRAME_BUFFER >gescape. (As briefly outlined in the HP 98731 device driver manual, the >R_GET_FRAME_BUFFER gescape returns the starting address of the frame buffer, >allowing all 24 bits of the frame buffer to be read at one time). > >Many thanks, >Tim (toc@wisdom.graphics.cornell.edu) >---------- Tim, You should be able to use the same method to read the zbuffer. The zbuffer will be mapped into the same address space as the frame buffer when you have selected it with bank_switch. Use the same starting address you got from R_GET_FRAME_BUFFER. Bruce Blaho HP Workstation Group Graphics Technology Division, Software Lab