   }
 }
 
-
 // TODO: Investigate performance of this shader and see
 //       if it's worthwhile splitting it / removing branches etc.
 void main(void) {

  return mix(white, circleColor, circleColor.a);
}

vec4 draw_double_edge(float pos, float len, float pixelsPerFragment) {
  float total_border_width = len;
  float one_third_width = total_border_width / 3.0;

  // Contribution of the outer border segment.
  float alpha = alpha_for_solid_border(pos,
                                       total_border_width - one_third_width,
                                       total_border_width,
                                       pixelsPerFragment);

  // Contribution of the inner border segment.
  alpha += alpha_for_solid_border(pos, 0, one_third_width, pixelsPerFragment);
  return get_fragment_color(vDistanceFromMixLine, pixelsPerFragment) * vec4(1, 1, 1, alpha);
}

vec4 draw_double_edge_vertical(float pixelsPerFragment) {
  // Get our position within this specific segment
  float position = vLocalPos.x - vLocalRect.x;
  return draw_double_edge(position, vLocalRect.z, pixelsPerFragment);
}

vec4 draw_double_edge_horizontal(float pixelsPerFragment) {
  // Get our position within this specific segment
  float position = vLocalPos.y - vLocalRect.y;
  return draw_double_edge(position, vLocalRect.w, pixelsPerFragment);
}

vec4 draw_double_edge_corner_with_radius(float pixelsPerFragment) {
  float total_border_width = vRadii.x - vRadii.z;
  float one_third_width = total_border_width / 3.0;

  // Contribution of the outer border segment.
  float alpha = alpha_for_solid_border_corner(vLocalPos,
                                              vRadii.x - one_third_width,
                                              vRadii.x,
                                              pixelsPerFragment);

  // Contribution of the inner border segment.
  alpha += alpha_for_solid_border_corner(vLocalPos,
                                         vRadii.z,
                                         vRadii.z + one_third_width,
                                         pixelsPerFragment);
  return get_fragment_color(vDistanceFromMixLine, pixelsPerFragment) * vec4(1, 1, 1, alpha);
}

vec4 draw_double_edge_corner(float pixelsPerFragment) {
  if (vRadii.x > 0) {
    return draw_double_edge_corner_with_radius(pixelsPerFragment);
  }

  bool is_vertical = (vBorderPart == PST_TOP_LEFT) ? vDistanceFromMixLine < 0 :
                                                     vDistanceFromMixLine >= 0;
  if (is_vertical) {
    return draw_double_edge_vertical(pixelsPerFragment);
  } else {
    return draw_double_edge_horizontal(pixelsPerFragment);
  }
}

// Our current edge calculation is based only on
// the size of the border-size, but we need to draw
// the dashes in the center of the segment we're drawing.

            draw_solid_border(vDistanceFromMixLine, local_pos);
            break;
        case BORDER_STYLE_DOUBLE:
            draw_double_border(vDistanceFromMixLine, local_pos);
            break;
        default:
            discard;
