TurtleGraphics: Turtle Graphics

##    TurtleGraphics package for R
##    Copyright (C) 2014-2017 A.Cena, M.Gagolewski, B.Zogala-Siudem, and others
##
##    This program is free software: you can redistribute it and/or modify
##    it under the terms of the GNU General Public License as published by
##    the Free Software Foundation, either version 3 of the License, or
##    (at your option) any later version.
##
##    This program is distributed in the hope that it will be useful,
##    but WITHOUT ANY WARRANTY; without even the implied warranty of
##    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
##    GNU General Public License for more details.
##
##    You should have received a copy of the GNU General Public License
##    along with this program.  If not, see <http://www.gnu.org/licenses/>.


#' @title Turtle Graphics in R
#'
#' @description
#' Learn computer programming while having a jolly time
#'
#' @details
#' Move the Turtle with commands that are relative
#' to its own position, e.g., "move forward 100 pixels" or
#' "turn right 30 degrees". From these building blocks you can build
#' more complex shapes like circles, fractals, etc.
#' Combined with R control flow, functions, and recursion,
#' the idea of Turtle graphics allows students to get familiar with
#' computer programming in a very accessible and pleasant way.
#'
#' @author
#' Anna Cena [aut]\cr
#' Marek Gagolewski [aut]\cr
#' Marcin Kosinski [aut]\cr
#' Natalia Potocka [aut]
#' Barbara Zogala-Siudem [aut, cre]
#'
#'
#' @family TurtleGraphics
#' @name TurtleGraphics-package
#' @docType package
#' @importFrom grid grid.newpage
#' @importFrom grid grid.remove
#' @importFrom grid pushViewport
#' @importFrom grid viewport
#' @importFrom grid gpar
#' @importFrom grid unit
#' @importFrom grid grid.circle
#' @importFrom grid grid.rect
#' @importFrom grid grid.lines
#' @importFrom grDevices col2rgb
invisible(NULL)