Mark Erbaugh wrote:
When run under GTK (Ubuntu Dapper) with
the same hardware (computer and printer), it returns (72,72).
It's probably using PostScript, which is scalable, but uses points as it's coordinates, 72pt = 1".
Howver, printed output from GTK appears smooth and is at a resolution
higher than 72 DPI.
Right, 'cause the rendering happens at the native printer resolution.
I am running Gnome 2.14.3 so it doesn't have libgnomeprint support.
Does this mean that the printer's device context only has a resolution
of 72 dpi, but that at least text is rendered at full printer
resolution? Would this mean that text can be positioned only to the
nearest 1/72"?
It looks that way. The way its "should" work is that you can define coords in floating point (or fixed point fractions), which is what Postscript does. I thought that the PostScriptDC was hard-coded to default to 720 ppi (which then got translated at output to points), so that you'd at least have 1/10th point resolution.
If you're getting a PostScriptDC, you may be able to set that. Here's the doc:
wxPostScriptDC::SetResolution
static void SetResolution(int ppi)
Set resolution (in pixels per inch) that will be used in PostScript output. Default is 720ppi
So something is odd, but I'd try SetResolution, and see what happens.
-Chris
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Christopher Barker, Ph.D.
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