[GRASS-dev] Cairo monitor driver

Glynn Clements glynn at gclements.plus.com
Thu Oct 18 01:26:39 EDT 2007


Lars Ahlzen wrote:

> >> Does complete documentation for these areas exist?
> > 
> > Nope.
> > 
> > Although, the PS driver is probably the best reference for the cairo
> > driver, as cairo was heavily modelled on PostScript, and the PS driver
> > is the closest to how it "should" work (as it doesn't have to deal
> > with pixel-grid issues).
> 
> Ok. That will of course make it more difficult to implement functions 
> like draw_text that are neither documented nor implemented by other 
> drivers (as far as I can tell).

Actually, I've just realised that it can't be implemented at present. 
Although the R_text() function can be handed off to individual
drivers, the R_text_size() and R_text_rotation() functions can't, nor
can R_font(), so the driver doesn't have enough information to
actually draw text.

[The reason that R_text() can be handed off is because the HTMLMAP
driver uses it to label areas.]

-- 
Glynn Clements <glynn at gclements.plus.com>




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