[E-devel] [PATCH] non-filled polygon [Was: drawing lots of line segments]

[Chia-I Wu <ol...@op...>]

Sorry, I just realized that I mailed to the wrong list.

On Wed, Sep 17, 2008 at 09:44:15AM -0300, Gustavo Sverzut Barbieri wrote:
> > I am working on a map application and I would like to draw the GPS track
> > on the map.  The track is basically lots (thousands) of line segments,
> > with each segment begins at where the previous one ends.  Is it a good
> > idea to represent each line segment by a line object?
> No, since most algorithms we use are linear or exponential on the
> number of objects, so more objects, more slowdown.
> Also, Evas has no line width property, so you'll not be able to make
> it with lines. Use Polygons instead. Polygons are not the most
> optimized bit of Evas, however it is counted as just one object and
> it's processed using the scanline polygon fill mode.
I have made a simple patch to give polygon the option not to fill its
enclosed region.  It adds the following functions:

	void evas_object_polygon_fill_set  (Evas_Object *obj, int fill);
	int  evas_object_polygon_fill_get  (const Evas_Object *obj);
	void evas_object_polygon_close_set (Evas_Object *obj, int close);
	int  evas_object_polygon_close_get (const Evas_Object *obj);

By default, polygon has "fill" and "close" set to TRUE.  When "fill" is
FALSE, line_draw is called instead polygon_draw.  "close" makes sense
only when "fill" is FALSE.  It decides whether the polygon should close
the path, that is, draw a line from the last point to the first point.

-- 
Regards,
olv