Re: avoiding drawing tiny objects in foocanvas

[Jody Goldberg <jody gnome org>]

On Wed, May 12, 2004 at 04:26:00PM +0100, Rob Clack wrote:
> I'm drawing tens of thousands of rectangles, using foocanvas to 
> (successfully - thanks Jody!) speed things up, but when zooming out I 
> would like there to come a time when rectangles too small to be 
> correctly rendered are not drawn at all.
>
> At present there seems to be a minimum size beyond which they don't 
> shrink, so eventually they all merge into each other.  It's as though 
> the code says "OK, this is as small as this one gets" and keeps drawing 
> it that size, whatever the zoom factor.  I want it to say "This one's 
> too small to bother with, so I won't draw it at all"
>
> I accept I'm going to have to hack the foocanvas source code, but so far 
> can't find where it is that this decision is being made.
>
> Anyone know where I should be looking?

libfoocanvas/foo-canvas-rect-ellipse.c : foo_canvas_rect_draw 

Throw in some tests to see whether it is useful to draw something
small, or even if it is useful to draw the inside of something
overlapped by it's outline