- pi.pain.line(x + 1, y - o - h/2, x + dim.wid - 2, y - o - h/2,
- Line_color, Painter::line_solid, float(h));
+ // the horizontal dimension must be corrected with the heigth because
+ // of left and right border of the painted line for big heigth.
+ pi.pain.line(x + height_/2 + 1,
+ y - offset_ - height_/2,
+ x + dim.wid - height_/2 - 2,
+ y - offset_ - height_/2,
+ Line_color, Painter::line_solid, float(height_));