I’m currently porting printer software to qnx and wish to create black and white bitmaps from a set of field descriptions mixing text and bitmaps to create an image to be printed. While there are a whole load of bitmap routines written for the original system I was hoping that it would be possible to use photon to create a PHimage or use the Pg routines and add to that without actually having to connect it to a device so I could then either add it to an image container or output to the printer.
Any suggestions as to how I can do this as despite having found answers to various questions by brute force searching of the qnx unhelp files I have so far failed to find anything that can do this and may have to retire to a croft in Scotland and farm sheep instead. 
Photon does provide a nice way to do this. You build a Photon Screen but don’t display it. Instead you send it to a printer. I think the thing to search for in the docs is “Printer Context”. If you undestand the Photon model, it makes a lot of sense. Photon programs just send draw commands to a display driver in Photon space. There are routines to point the screen at a printer driver instead. Of course you have to deal with other issues, eg. which printer, color or B&B, resolution etc.
Was hoping for some sort of Null context as regrettably the printer in question is bare inkjet heads on factory conveyor belts for which i’m writing the software and there’s no real justification for going to the extent of writing full blown drvers given that it’s the sole function of the device with no requirement for say a PC to treat it as a one shot printer.
Thanks for the suggestion though.
Hmm Memory context seems to be the thing sort of with a palette set for 1 byte per pixel possibly though the memory usage might be prohibitive for a 4 head image (potentially 8 heads but I suspect that given the amount of hardware testing we do here that printing on 8 heads simultaneously would cause a reset due to the power supplies not handling it)