On Tue, 25 Apr 2000, Alexander Larsson wrote:
> On Tue, 25 Apr 2000, James Henstridge wrote:
>
> > I am currently working on some of the view code, and am using one canvas
> > unit == one pixel, as the GnomeCanvas uses this by default. You can
> > change a view's zoom factor without too much trouble though. (I should
> > check this code in).
>
> Well. The question is where to do the conversion from "units" to
> pixels. I looked a bit at your view-code. It looks like the zoom factor
> specifies the conversion from canvas units to pixels. Does this mean that
> all dia-canvas-items should look at view->zoom_factor and draw in
> pixel-coordinates or should the view set the correct conversion-factor
> in the renderer so that items draw in canvas units?
>
> I think letting the items draw in canvas units is best (and that is how
> Dia does). This means we'll have to add support for setting the pixel/unit
> conversion for pixel-based renderers and the physical/dia-unit conversion
> for physically based renderers (like postscript printers). This can
> probably be a implementation-dependent call (i.e. dia_gdk_renderer_set_zoom()).
That was the idea. The DiaCanvasView would tell its renderer what the
canvas coordinates of its window were before calling the item's render
routine. I must have misunderstood what you said.
>
> > As far as an EPS/postscript renderer goes, you would probably want to tell
> > it how much to scale by no matter what units you choose.
>
> Yes.
>
> In dia-canvas.h i saw DiaRectangle and DiaPoint. I need at least DiaPoint
> in dia-renderer.h, in fact i define DiaRendererPoint there. I think maybe
> we should move these to a dia-geometry.h just like in Dia, then we can add
> all the little helper-functions that will be needed there. One thing
> though, I had this idea that we should be able to do s/Dia/Gtk/ (or
> something close to that) one day if we want to be included in Gtk+. This
> means we need to be carefull about name-spaces, and GtkPoint is already in
> Gtk+...I don't know if this is worth pursuing.
I don't know what is best to do here. It is probably a good idea to make
sure we don't clash namespaces if possible. In this case though, there is
no GtkPoint type -- just a GdkPoint.
>
> / Alex
>
James.
--
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