Printer Driver Questions

  • Thread starter Thread starter Peter Olcott
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Peter Olcott

I need to know exactly how the GDI system communicates with the printer
pertaining to text and fonts. At exactly what step is the text rasterized? How
does the printer know the characteristics of the font being printed, does it
receive (a) The font, and text (b) rasterized pixels, or (c) vector data?
 
I am not doing homework. Here is what I found:
http://computer.howstuffworks.com/laser-printer5.htm
http://en.wikipedia.org/wiki/Printer_Control_Language

There are several details that I could not determine with google searches:
(1) When data is sent to the printer is there any segregation into glyphs, or is
it a single contiguous stream of data?
(2) What form (vector, pixel or font+text) is the data typically in when
Microsoft Word sends its output to an HP laser printer?
(3) What form (vector, pixel or font+text) is the data typically in when Adobe
PDF sends its data to an HP laser printer?
 
Perhaps explain/detail the problem since you are apparently using an HP
printer, which is a pretty std sort of printer
 
I am not having a problem with an HP printer. I can't provide any further
details, these must be kept confidential.
 
Your original question was too general.
It seems that there are at least four basic flavors of printers. Some
printers function in more than one flavor.
GDI (or printers that only accept data in a graphics dot oriented format.
Postscript
Mfrs printer language specific, such as Epson's Esc P2
Ascii (Some dot matrix, teletype, formed character printers)
Others that defy easy categorization into the above
Page printers, character printers, line printers, etc. can belong to one or
more of the basic "flavors"
And, printers that have capabilities of some of the above, possibly via
emulation. Plotters can fall into this category as well.
Special purpose printers (devices) that are not really part of the above
categories, and may have some printer like capability, but really have a
main use other than a "printer" An example might be a device used to print
or cut out letters for signs. Another might be a device that drives a high
speed bit used to "mill" 3d objects, such as a desk top name plate or a
carving.

In the absence of applications that do "non standard" things, the object to
be printed usually exists as a GDI image. The application usually converts
the object to a GDI or vector image, or very occasionally these days, to
ascii.

The printer driver then converts the GDI compliant object data into
something usable by the printer.

To really get into this sort of thing, you will need to obtain various SDKs,
either by download from MSDN, or by subscription.

Usually, special purpose software related to printing either behaves as any
other application that has printing requirements, or in some way modifies
data during the printing process as the data moves between the various
printing modules (system and device specific) Since device mfrs seldom
release enough information to determine how a specific printer driver
behaves, you go into a trial and error mode, even with full windows
development documentation and software.

It's not uncommon to need to make windows think your software is a printer
driver module, and make the mfrs printer driver think your software is part
of windows, if you are doing something out of the normal flow of things.

"I can't provide any further details, these must be kept confidential."
 
I need to know exactly how the GDI system communicates with the
printer pertaining to text and fonts. At exactly what step is the text
Click to expand...
Get the DDK or WDK and read the documentation on printer drivers. GDI does
not communicate with printers.
rasterized? How does the printer know the characteristics of the font
being printed, does it receive (a) The font, and text (b) rasterized
pixels, or (c) vector data?
Click to expand...

The text may not be rasterized at all. The answer to the other question
is, "It depends".

ScottR
 
Chuck said:
Your original question was too general.
It seems that there are at least four basic flavors of printers. Some
printers function in more than one flavor.
GDI (or printers that only accept data in a graphics dot oriented format.
Postscript
Mfrs printer language specific, such as Epson's Esc P2
Ascii (Some dot matrix, teletype, formed character printers)
Others that defy easy categorization into the above
Page printers, character printers, line printers, etc. can belong to one or
more of the basic "flavors"
And, printers that have capabilities of some of the above, possibly via
emulation. Plotters can fall into this category as well.
Special purpose printers (devices) that are not really part of the above
categories, and may have some printer like capability, but really have a
main use other than a "printer" An example might be a device used to print
or cut out letters for signs. Another might be a device that drives a high
speed bit used to "mill" 3d objects, such as a desk top name plate or a
carving.

In the absence of applications that do "non standard" things, the object to
be printed usually exists as a GDI image. The application usually converts
the object to a GDI or vector image, or very occasionally these days, to
ascii.

The printer driver then converts the GDI compliant object data into
something usable by the printer.
Click to expand...

When Microsoft Word sends its data to a PCL capable printer, what form is this
data in, (raster, vector, GDI) ?
When adobe acrobat sends its data to a PCL capable printer, what form is this
data in, (raster, vector, GDI) ?
In either any of these cases are Glyphs in any way segregated from one another,
or are overlapping glyphs simply contiguous chunks of data?
 
Scott Robins said:
Get the DDK or WDK and read the documentation on printer drivers. GDI does
not communicate with printers.

The text may not be rasterized at all. The answer to the other question
is, "It depends".

ScottR
Click to expand...

In the case of Microsoft Word or Adobe Acrobat sending their data to a PCL
capable printer is the data in (raster, vector, or GDI) format? In any of these
cases are the Glyphs segregated from each other, or are overlapping glyphs
contiguous chunks of data?
 
Scott Robins said:
Get the DDK or WDK and read the documentation on printer drivers. GDI does
not communicate with printers.

The text may not be rasterized at all. The answer to the other question
is, "It depends".

ScottR
Click to expand...

Apparently (for PCL printers) the text is sent to the printer as text. I used MS
Word Print-To-File, and was able to locate the text embedded within this file.
It looks like it also downloaded the soft fonts to the printer, too. I can't
tell whether or not they were rasterized or in vector format.
 
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