czuger/rhex

require_relative 'axial_hex'
require_relative 'modules/grid_to_pic'
require_relative 'modules/ascii_to_grid_flat'

# This class represents a grid of hexagons stored in an axial coordinate system.
#
# Please read http://www.redblobgames.com/grids/hexagons/#coordinates to understand what an axial coordinates system is.
#
# @author Cédric ZUGER
#
# @attr_reader [Float] hex_ray the ray of an hexagon
# @attr_reader [Float] hex_height the height of an hexagon
# @attr_reader [Float] hex_width the width of an hexagon
# @attr_reader [Float] quarter_height the quarter of the height of an hexagon
# @attr_reader [Float] half_height the half of the height of an hexagon
# @attr_reader [Float] half_width the half of the width of an hexagon
#
class AxialGrid

  include AsciiToGridFlat

  attr_reader :hex_ray, :hex_height, :hex_width, :quarter_height, :half_width

  # Create an axial hexagon grid
  #
  # @param hex_ray [Integer] the size of an hexagon. Please read : http://www.redblobgames.com/grids/hexagons/#basics for information about the size of an hexagon
  #
  def initialize( hex_ray: 16, element_to_color_hash: {} )
    @hexes={}
    @element_to_color_hash = element_to_color_hash
    @hex_ray = hex_ray
  end

  # Set the hex color to color conversion hash
  #
  # @param element_to_color_hash [Hash] see initialize
  #
  def set_element_to_color_hash( element_to_color_hash )
    @element_to_color_hash = element_to_color_hash
  end

  # Create an hexagon at a given position (q, r)
  #
  # @param q [Integer] the q coordinate of the hexagon
  # @param r [Integer] the r coordinate of the hexagon
  # @param color [String] a colorstring that can be used by ImageMagic
  # @param border [Boolean] is the hex on the border of the screen (not fully draw)
  # @param data [Unknown] some data associated with the hexagone. Everything you want, it is up to you.
  #
  # @return [AxialHex] an hexagon
  #
  def cset( q, r, color: nil, border: false, data: nil )
    @hexes[ [ q, r ] ] = AxialHex.new( q, r, color: color, border: border, data: data )
  end

  # Insert an hexagon into the grid
  #
  # @param hex [AxialHex] the hexagon you want to add into the grid
  #
  # @return [AxialHex] the hexagon you inserted
  #
  def hset( hex )
    @hexes[ [ hex.q, hex.r ] ] = hex
  end

  # Get the hexagon at a given position (q, r)
  #
  # @param q [Integer] the q coordinate of the hexagon
  # @param r [Integer] the r coordinate of the hexagon
  #
  # @return [AxialHex] the hexagon at the requested position. nil if nothing
  #
  def cget( q, r )
    @hexes[ [ q, r ] ]
  end

  # Get the hexagon at a given position (q, r)
  #
  # @param hex [AxialHex] the hexagon containing the position you want to read
  #
  # @return [AxialHex] the hexagon at the requested position. nil if nothing
  #
  def hget( hex )
    @hexes[ [ hex.q, hex.r ] ]
  end

  # Call the block for each Hex in the grid
  #
  # @example
  #   mygrid.each{ |h| p h }
  #
  def each
    @hexes.sort.each{ |h| yield h[1] }
  end

  # Return all surrounding hexes from grid
  #
  # @param h [AxialHex] the hexagon you want to get surronding hexes
  #
  # @return [Array<AxialHex>] all surrounding hexes
  def h_surrounding_hexes( h )
    h.surrounding_hexes.map{ |sh| hget( sh ) }.compact
  end

  # Return the grid as a json string
  #
  # @return [Array] the grid as a json string
  def to_json
    a = @hexes.map{ |e| { q: e[0][0], r: e[0][1], c: e[1].color, b: e[1].border } }
    a.to_json
  end

end