A small example from a project of mine. Maybe you'll find things of
interest (the each method does that conversion, for instance).
class Grid
include Enumerable
attr_reader :width, :height, :depth
def initialize(width, height, depth)
@width = width
@height = height
@depth = depth
@tiles = Array.new(width * height * depth)
end
def include?(x, y, z)
(0..@width).include?(x) &&
(0..@height).include?(y) &&
(0..@depth).include?(z)
end
def (x, y, z)
if include? x, y, z
@tiles[z * @width * @height + y * @width + x]
else
raise "Tile out of bound : (#{x}, #{y}, #{z}) - #{self}"
end
end
def =(x, y, z, v)
if include? x, y, z
@tiles[z * @width * @height + y * @width + x] = v
else
raise "Tile out of bound : (#{x}, #{y}, #{z}) - #{self}"
end
end
def each
@tiles.each_with_index do |v, i|
yield v,
i % @width, # x
(i / @width) % @height, # y
i / (@height * @width) # z
end
end
def window(x, y, z, w, h, d)
z.upto(z + d - 1) do |sz|
y.upto(y + h - 1) do |sy|
x.upto(x + w - 1) do |sx|
yield self[sx, sy, sz], sx, sy, sz
end
end
end
end
end
Fred
···
Le 9 mai 2011 à 00:14, Paul A. a écrit :
But how can we do the opposite? I mean, a method looking like:
index_to_coordinates([3, 3], 3) # => [0, 1]
--
No will to wake for this morn
To see another black rose born
Deathbed is slowly covered with snow
(Nightwish, End of All Hope)
