# [cairo] How can I draw the ellipse without a portion of it, defined by two angles?

Arjen Nienhuis a.g.nienhuis at gmail.com
Tue Oct 11 09:33:01 PDT 2011

```On Tue, Oct 11, 2011 at 17:26, Carlo <defrag1986 at gmail.com> wrote:

>  Hi ! How can I draw an ellipse without a portion of it (without a slice)??
> I have a start angle and end angle of the ellipse refered to the centre,
> but if I try with:
>
> *	*cairo_save(cr)
> 	cairo_translate(cr,x + width / 2., y + height / 2.);
>         cairo_scale(cr,1. * (width / 2.), 1. * (height / 2.));
> 	cairo_arc(cr,0., 0., 1., S_ANGLE, E_ANGLE);
> 	cairo_restore(cr);
> 	cairo_stroke(cr);*
> *
> the ellipse drawn isn't correct, because in scaling the coords. I scale the angles.
> How can I draw the ellipse without a correct portion of it, defined by two angles?
>
>
You can try to use a larger circle with the correct angles as clip path and
then draw the complete ellipse.

...
cairo_translate(...)
cairo_arc(cr, 0, 0, larger_than_ellipse_size_plus_pen_width, S_ANGLE,
E_ANGLE)
cairo_clip(cr)
cairo_scale(...)
cairo_arc(cr, 0, 0, 1, 0, 2 * pi)
...

I didn't try this...

> Thank you,
> Carlo
>
> P.S: Sorry for the double post.
>
>
> --
> cairo mailing list
> cairo at cairographics.org
> http://lists.cairographics.org/mailman/listinfo/cairo
>
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