bernhard: thuban/Extensions/svgexport/test test_svgmapwriter.py, 1.9, 1.10

[Bernhard Reiter]

On Tue, Dec 07, 2004 at 12:37:52PM +0100, Bernhard Herzog wrote:
> cvs at intevation.de writes:
> 
> > +    def test_drawbezier(self):
> > +        '''Test DrawSpline (which actually draws bezier curves).'''
> > +        data = ('<path style="stroke-linejoin:round; stroke:#ff00ff; '
> > +                'stroke-width:3; stroke-linecap:round; fill:none" ' 
> > +                'meta="Object:test; Label:nothing" d="M 10 10 '
> > +                'C 15 12 15 8.0 20 10"/>')
> > +        file = StringIO.StringIO()
> > +        dc = VirtualDC(file)
> > +        dc.SetPen(self.solid_pen)
> > +        dc.SetMeta(self.meta)
> > +        dc.SetBrush(self.trans_brush)
> > +        dc.DrawSpline([ Point(10, 10),
> > +                        Point(15, 12),
> > +                        Point(15,  8.0),
> > +                        Point(20, 10) ])
> 
> Looking at the DrawSpline code in wxWidgets, it seems that the
> coordinates of the spline do not translate directly to the coordinates
> of the control points of a cubic bezier curve as you assume here.

Ah, thanks for noticing this.
So it is broken until I understand this better and can fix it.

> Rather a cubic bezier curve derived in some other fashion from the
> parameters to DrawSpline.  The docs say that the algorithm was taken
> from XFig, so I'd assume it's what XFig <= 3.1 calls interpolated
> splines.  I have no time to analyse this further, though.

Thanks for the hints.
-------------- next part --------------
A non-text attachment was scrubbed...
Name: not available
Type: application/pgp-signature
Size: 189 bytes
Desc: not available
Url : http://www.intevation.de/pipermail/thuban-devel/attachments/20041207/33576112/attachment.bin