PPD<->Raster Question

[Rick Bird]

I'm trying to work on a driver for Kodak 7250 printer for Linux..  Mostly working of the existing cupskodak souceforge project.. However they left alot out honestly for what the printer offers..  Currently trying to figure out the Photo printing side.

I setup the tray options in my ppd file to be Main & Photo(using InputSlot).. those show, thats great.  Probably after that is.. How do i tell what tray its accessing in the Raster API for when they're trying to print, so I can issue the right command to printer depending upon what tray is selected?