drawing a circle-segment with gnomecanvas

[Joergen Scheibengruber <Joergen Scheibengruber informatik uni-ulm de>]

Hi!

I would like to know if there is a easy way to draw a circle/ecllipse
segment in gnome_canvas. As far as I see it is only possible to draw a
whole circle/ecllipse.

What I'm doing right now is drawing a polygon calcualting the points
with sin/cos (see below), but this doesn't look to good in my opinion
even in a antialiased canvas.

Is there a better way to do this?

Here is my code:

#define POINTS 100

void draw_circle_segment(GtkWidget* canvas,
                                                double x,
                                                double y,
                                                double radius,
                                                double percentage,
                                                gchar* color)
{
        double angel;
        int i, xi, yi, p;
        GnomeCanvasPoints *points;

        angel = (1.0f - percentage)*PI;
        
        if (percentage<1.0)
        {
                p = (int)(POINTS*percentage);
                points = gnome_canvas_points_new (p+2);
                points->coords[0] = (int)x;
                points->coords[1] = (int)y;
        }
        else
        {
                p = POINTS;
                points = gnome_canvas_points_new (p+2);
                points->coords[0] = (int)x;
                points->coords[1] = (int)y+radius;
        }
                        
        
        for (i=0;i<=p;i++)
        {
                xi = (int)(sin((double)i*3.14*2/POINTS+angel)*radius+x);
                points->coords[(i+1)*2] = xi;
                yi = (int)(cos((double)i*3.14*2/POINTS+angel)*radius+y);
                points->coords[(i+1)*2+1] = yi;
        }
        
        gnome_canvas_item_new(gnome_canvas_root(GNOME_CANVAS(canvas)),
                      gnome_canvas_polygon_get_type(),
                      "points", points,
                      "fill_color", color,
                      "outline_color", "black",
                      "width_units", (double)2,
                      NULL);

        gnome_canvas_points_free(points);
}


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