Path: utzoo!utgpu!news-server.csri.toronto.edu!rpi!zaphod.mps.ohio-state.edu!sdd.hp.com!hp-pcd!hp-vcd!robertt
From: robertt@hp-vcd.HP.COM (Bob Taylor)
Newsgroups: comp.windows.ms
Subject: Re: Color printing from Win3
Message-ID: <920010@hp-vcd.HP.COM>
Date: 8 May 91 16:35:24 GMT
References: <1991May6.075137.10947@ugle.unit.no>
Organization: Hewlett Packard, Vancouver, WA
Lines: 60

th@gpu.utcs.utoronto.ca writes:
> This brings up two questions...
> The original post indicated that he had gotten some WfW stuff in colour
> from his Epson.  I presume that this would have to have been not bitmap
> stuff then, and if so, what exactly is non bitmap? Text? Is ATM text not
> bitmaps? Is Windows text not bitmaps? Maybe only the printers builtin
> fonts will print in colour. I will experiment at home cause I have a
> colour epson. I have to admit that as soon as I found that paintbrush
> wouldn't do colour on the printer I sort of stopped trying, but
> Corel Draw did colour on it... hmmmm... more experiments.

This is a broad generalization that covers most (but not all) Windows
printer drivers:

Data can come to the printer in any of several forms:
Text: The driver then either sends a command to the printer to print the
	text or creates a bitmap of the text and sends that to the
        printer. (note that this is for printer fonts only, not ATM)
Bitmaps: Although Windows "defines" bitmaps as very general, in practice
        they are implemented as only having one plane/one bit per pixel
        (in other words, it is a monochrome bit map).  This can have a
        color attached to it and this is how ATM works - it passes a 
        monochrome bitmap and says "print this in Red".
Output: This is a command that handles general graphics - lines, pixels,
        arcs, etc. (although, for most printers, only pixels and scanlines
        are supported - GDI breaks all other objects down for these devices)
        Each of these objects can be drawn with a color pen or brush, so
        Color is no problem here (e.g., CorelDraw).
DIBs:   DIBs were new for Windows 3.0, so many printer drivers haven't added
        support for them.  If the driver doesn't support them, the image
        is sent down as a standard monochrome bitmap.

> The next question is, is it that hard to impiment DIBS that these major
> players can't add the support to the drivers?

It isn't trivial to add DIB support, but it isn't a huge effort, either.  The
problem is that most printer mfgr.s don't write their own drivers - HP does,
but Microsoft writes the drivers for most other printers, so the manufacturer
may not have that much control.

> Does anybody know of ANY other printer drivers for WIndows that support
> colour DIBS?

Most of the HP drivers (current revisions, anyway) do, as does the Postscript
driver and any drivers based on Microsofts generic driver (e.g. Canon BJ-10e).
Most dot matrix drivers and SuperPrint (at least version 1.0) do not.

> thanks.
>
> Bob, the first few lines look like an attack on what you said, they
> aren't, I just want to know the differences etc. Sorry it sounds that way.

no offense taken - I know how frustrating and confusing printing in Windows
can be.

p.s. - the above characterization of Windows printing is !extremely!
trivialized in order to answer the question at hand.

bob taylor
HP Vancouver