Method updateCircle

src/tools/draw_circle_tool.cpp:244–290

}

void DrawCircleTool::updateCircle()
{
	MapCoordF first_pos_map;
	if (start_from_center)
		first_pos_map = circle_start_pos_map + (circle_start_pos_map - opposite_pos_map);
	else
		first_pos_map = circle_start_pos_map;
	
	float radius = 0.5f * first_pos_map.distanceTo(opposite_pos_map);
	float kappa = BEZIER_KAPPA;
	float m_kappa = 1 - BEZIER_KAPPA;
	
	MapCoordF across = opposite_pos_map - first_pos_map;
	across.setLength(radius);
	MapCoordF right = across.perpRight();
	
	float right_radius = radius;
	if (second_point_set && dragging)
	{
		if (right.length() < 1e-8)
			right_radius = 0;
		else
		{
			MapCoordF to_cursor = cur_pos_map - first_pos_map;
			right_radius = MapCoordF::dotProduct(to_cursor, right) / right.length();
		}
	}
	right.setLength(right_radius);
	
	preview_path->clearCoordinates();
	preview_path->addCoordinate(MapCoord(first_pos_map, MapCoord::CurveStart));
	preview_path->addCoordinate(MapCoord(first_pos_map + kappa * right));
	preview_path->addCoordinate(MapCoord(first_pos_map + right + m_kappa * across));
	preview_path->addCoordinate(MapCoord(first_pos_map + right + across, MapCoord::CurveStart));
	preview_path->addCoordinate(MapCoord(first_pos_map + right + (1 + kappa) * across));
	preview_path->addCoordinate(MapCoord(first_pos_map + kappa * right + 2 * across));
	preview_path->addCoordinate(MapCoord(first_pos_map + 2 * across, MapCoord::CurveStart));
	preview_path->addCoordinate(MapCoord(first_pos_map - kappa * right + 2 * across));
	preview_path->addCoordinate(MapCoord(first_pos_map - right + (1 + kappa) * across));
	preview_path->addCoordinate(MapCoord(first_pos_map - right + across, MapCoord::CurveStart));
	preview_path->addCoordinate(MapCoord(first_pos_map - right + m_kappa * across));
	preview_path->addCoordinate(MapCoord(first_pos_map - kappa * right));
	preview_path->parts().front().setClosed(true, false);
	
	updatePreviewPath();
	setDirtyRect();
}

void DrawCircleTool::setDirtyRect()
{