Gustavo wrote: > On Wed, Sep 17, 2008 at 11:59 PM, Chia-I Wu <[EMAIL PROTECTED]> wrote: > >> 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. >> > > Ok, that could do. But I doubt you'll be able to use 1px lines on a > map application. When we did it, we had to draw thick lines and use > filled polygons for that :-) > > I don't have time to review this patch atm, but I guess it's simple. > Let's see if someone do it before me, otherwise wait until weekend. >
There are plans (and work already done) for a large overhaul of much of such 'vgfx' stuff in evas - this includes things like lines, rects, and polygons. Please wait a bit on this, it's not particularly trivial stuff and needs care.. for example, you can't just 'draw lines' from one vertex of the polygon to the next to 'stroke' the polygon as you've done, it's just not correct. See the "enesim" lib in svn for some work related to such vgfx notions. ____________________________________________________________ Fly cheap! Click here for great airfare deals. http://thirdpartyoffers.juno.com/TGL2141/fc/Ioyw6i3nMQl81KvR7KkASiDhaDykXboFt0cFOwts8KgtEysrId6t32/ ------------------------------------------------------------------------- This SF.Net email is sponsored by the Moblin Your Move Developer's challenge Build the coolest Linux based applications with Moblin SDK & win great prizes Grand prize is a trip for two to an Open Source event anywhere in the world http://moblin-contest.org/redirect.php?banner_id=100&url=/ _______________________________________________ enlightenment-devel mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/enlightenment-devel
