I'm using GhostScript.NET for C# to convert PDF to PostScript (ps2write device) and i want to show progress of rendering (processor.StartProcessing()), since large files take a long time
I know that mswinpr2 shows progress of rendering, but ps2write not.
Is it possible to do this with ps2write?
PostScript programs can be of arbitrary length, and indeed because they are programs, its entirely possible to read the entire program from disk, and yet still have considerable work to do in order to produce the output.
All the mswinpr2 devvice's progress indicates is the percentage of the program which has been read so far, which is reasonably reliable but not 100% accurate.
The ps2weite device doesn't actually render at all, in general. It interprets the input, creating a sequence of graphics primitives which it then uses to create a new PostScript program.
Since there is no way to know when (or indeed, if) the PostScript program will reach a halting state, you can't tell what the progress is.
If the input is a PostScript program, then you can feed the program in a portion at a time, and calculate a progress as the amount read / size of file * 100.
If the input is a PDF file you can't do that, because the PDF interpreter needs random access to the whole file.
So in summary; if the input is PostScript then you can calculate a sort of progress, if the input is PDF then there is no realistic way to determine a progress. The best you can do is determine the number of pages in the PDF file and count the number of pages processed so far.
