Мария обнови решението на 02.12.2015 01:56 (преди над 8 години)
+module TurtleGraphics
+ class Canvas
+ def pixel_intensities(grid)
+ grid_max_value = grid.max
+
+ grid.map { |cell_value| Rational(cell_value, grid_max_value) }
+ end
+
+ class ASCII < Canvas
+ def initialize(symbols)
+ @symbols = symbols
+ @intensity_symbols = generate_intensities
+ end
+
+ def render_grid(grid)
+ pixel_intensities(grid).map { |intensity| to_symbol(intensity) }
+ .each_slice(grid.dimensions.last).map { |row| row.join }.join("\n")
+ end
+
+ private
+
+ def to_symbol(pixel_intensity)
+ @intensity_symbols.select do |intensity|
+ intensity === pixel_intensity
+ end.values.first
+ end
+
+ def generate_intensities
+ intensity_symbols = {0 => @symbols[0]}
+
+ (1...@symbols.size).each do |symbol_number|
+ intensity_range = Rational(symbol_number - 1, @symbols.size - 1)..
+ Rational(symbol_number, @symbols.size - 1)
+
+ intensity_symbols[intensity_range] = @symbols[symbol_number]
+ end
+
+ intensity_symbols
+ end
+ end
+
+ class HTML < Canvas
+ def initialize(pixel_size)
+ @pixel_size = pixel_size
+ end
+
+ def render_grid(grid)
+<<-EOS
+<!DOCTYPE html>
+<html>
+<head>
+ <title>Turtle graphics</title>
+
+ <style>
+ table {
+ border-spacing: 0;
+ }
+
+ tr {
+ padding: 0;
+ }
+
+ td {
+ width: #{@pixel_size}px;
+ height: #{@pixel_size}px;
+
+ background-color: black;
+ padding: 0;
+ }
+ </style>
+</head>
+<body>
+ <table>
+#{table(grid)}
+ </table>
+</body>
+</html>
+EOS
+ end
+
+ private
+
+ def pixel_opacity(intensity)
+ format('%.2f', intensity)
+ end
+
+ def table(grid)
+ pixel_intensities(grid).map { |intensity| " <td style=" \
+ "\"opacity: #{pixel_opacity(intensity)}\"></td>\n" }.to_a
+ .each_slice(grid.dimensions.last)
+ .map { |row| row.join.insert(0, " <tr>\n").insert(-1, " </tr>\n") }
+ .join
+ end
+ end
+
+ class Numerical
+ def initialize(grid)
+ @grid = grid
+ end
+
+ def render_grid(grid)
+ grid.cells
+ end
+ end
+
+ end
+
+ class Grid
+ include Enumerable
+
+ ORIGIN = [0, 0]
+ INITIAL_VALUE = 0
+
+ attr_reader :dimensions, :cells
+
+ def initialize(number_of_rows, number_of_columns)
+ @dimensions = [number_of_rows, number_of_columns]
+ @cells = Array.new(number_of_rows) do
+ Array.new(number_of_columns) { INITIAL_VALUE }
+ end
+ end
+
+ def reset_cell_value(row, column)
+ @cells[row][column] = INITIAL_VALUE
+ end
+
+ def increment_cell_value(row, column)
+ @cells[row][column] += 1
+ end
+
+ def each(&block)
+ @cells.each { |row| row.each { |cell_value| yield cell_value } }
+ end
+
+ def max
+ @cells.flatten.max
+ end
+ end
+
+ class Turtle
+ DIRECTIONS = {up: [-1, 0], right: [0, 1], down: [1, 0], left: [0, -1]}
+ INITIAL_POSITION = Grid::ORIGIN
+ INITIAL_DIRECTION = :right
+
+ attr_reader :grid
+
+ def initialize(number_of_rows, number_of_columns)
+ @grid = Grid.new(number_of_rows, number_of_columns)
+ spawn_at(*INITIAL_POSITION)
+ end
+
+ def draw(canvas = TurtleGraphics::Canvas::Numerical.new(grid), &block)
+ instance_eval &block
+ canvas.render_grid(@grid)
+ end
+
+ def turn_left
+ @direction = case @direction
+ when :right then :up
+ when :up then :left
+ when :left then :down
+ when :down then :right
+ end
+ end
+
+ def turn_right
+ @direction = case @direction
+ when :right then :down
+ when :down then :left
+ when :left then :up
+ when :up then :right
+ end
+ end
+
+ def spawn_at(row, column)
+ @grid.reset_cell_value(*INITIAL_POSITION)
+ look(INITIAL_DIRECTION)
+
+ step_on_position(row, column)
+ end
+
+ def look(orientation)
+ @direction = orientation
+ end
+
+ def move
+ step_on_position(*next_position)
+ end
+
+ private
+
+ def next_position
+ row = (@position[0] + DIRECTIONS[@direction][0]) % @grid.dimensions[0]
+ column = (@position[1] + DIRECTIONS[@direction][1]) % @grid.dimensions[1]
+
+ [row, column]
+ end
+
+ def step_on_position(row, column)
+ @position = [row, column]
+ @grid.increment_cell_value(row, column)
+ end
+ end
+end