From: Morton Goldberg Date: 2007-09-03T23:24:02+09:00 Subject: Re: Filling individual cells in a grid On Sep 3, 2007, at 8:40 AM, Joop Van den tillaart wrote: > Is there no one else who can help me out a bit? OK, I'll make some suggestions. 1. I think you could make your life a lot easier if you gave your cell objects more info about where they live. 2. I suggest you fill @grid with cells during initialization. 3. I suggest you include Enumerable in your Grid class. Then you only have to define Grid#each to get map, collect, and whole more for free.


class Cell
    attr_accessor :type, :distance_road
    attr_reader :i
    def initialize(grid, i)
       @my_grid = grid
       @i = i
    end
    def xy
       @i.divmod(@my_grid.width).reverse
    end
    def inspect
       "Cell[#{@i}, #{xy.inspect}, #{type}, #{distance_road}]"
    end
end
class Grid
    include Enumerable
    attr :width, :heigh
    def initialize(width, height)
       @grid = Array.new(width * height) { |i| Cell.new(self, i) }
       @width = width
       @height = height
    end
    def [](x, y)
       raise IndexError.new("Index (#{x}, #{y}) out of range") \
          if x < 0 || y < 0 || x >= @width || y >= @width
       @grid[y * width + x]
    end
    def []=(x, y, value)
       raise IndexError.new("Index (#{x}, #{y}) out of range") \
          if x < 0 || y < 0 || x >= @width || y >= @width
       @grid[y * width + x] = value
    end
    def each
       @grid.each { |cell| yield cell }
    end
end

# Now you can do all kinds of neat things.

g = Grid.new(2, 2)
p g
g.map { |cell| cell.type = 0; cell.distance_road = cell.i % 2 }
p g
h = g.select { |cell| cell.distance_road == 1 }
h.each { |cell| cell.type = 42 }
p g
p g.any? { |cell| cell.type == 42 }
p g.all? { |cell| g[*cell.xy] == cell }

# # # true true Regards, Morton