Борислава обнови решението на 19.12.2013 19:11 (преди над 10 години)
+module Graphics
+ module Renderers
+ class Ascii
+ def self.visualize(canvas)
+ (canvas.send :canvas).map(&:join).join "\n"
+ end
+ end
+
+ class Html
+ HTML_BEGINNING = "<!DOCTYPE html>
+ <html>
+ <head>
+ <title>Rendered Canvas</title>
+ <style type=\"text/css\">
+ .canvas {
+ font-size: 1px;
+ line-height: 1px;
+ }
+ .canvas * {
+ display: inline-block;
+ width: 10px;
+ height: 10px;
+ border-radius: 5px;
+ }
+ .canvas i {
+ background-color: #eee;
+ }
+ .canvas b {
+ background-color: #333;
+ }
+ </style>
+ </head>
+ <body>
+ <div class=\"canvas\">\n"
+ HTML_ENDING = " </div>
+ </body>
+ </html>"
+
+ def self.visualize(canvas)
+ html = (canvas.send :canvas).map(&:join).join "<br>\n"
+ html.gsub!('@', "<b></b>").gsub!('-', "<i></i>")
+ html.insert(0, HTML_BEGINNING).concat('\n' + HTML_ENDING)
+ end
+ end
+ end
+
+ class Canvas
+ include Renderers
+ attr_reader :width, :height
+
+ def initialize(width, height)
+ @width = width
+ @height = height
+ @canvas = Array.new(width) { Array.new(height, '-') }
+ end
+
+ def set_pixel(width, height)
+ @canvas[height][width] = '@'
+ end
+
+ def pixel_at?(width, height)
+ @canvas[height][width] == '@'
+ end
+
+ def draw(figure)
+ figure.draw self
+ end
+
+ def render_as(renderer)
+ renderer.visualize self
+ end
+
+ private
+ attr_reader :canvas
+ end
+
+ class Point
+ include Comparable
+ attr_reader :x, :y
+
+ def initialize(x, y)
+ @x = x
+ @y = y
+ end
+
+ def ==(other)
+ @x == other.x and @y == other.y
+ end
+
+ def eql?(other)
+ self == other
+ end
+
+ def hash
+ (@x.to_s + @y.to_s).hash
+ end
+
+ def <(other)
+ if @x == other.x
+ @y < other.y
+ elsif @x < other.x
+ true
+ else
+ false
+ end
+ end
+
+ def <=>(other)
+ if @x == other.x
+ @y <=> other.y
+ else
+ @x <=> other.x
+ end
+ end
+
+ def draw(canvas)
+ puts "in Point#draw"
+ canvas.set_pixel x, y
+ end
+ end
+
+ module BresenhamAlgorithm
+ def bresenham(left, right)
+ left, right, slope = adjust_points left, right
+
+ characteristics = set_characteristics left, right
+
+ compute_points left, right, slope, characteristics
+ end
+
+ private
+
+ def adjust_points(left, right)
+ slope = (left.y - right.y).abs > (left.x - right.x).abs
+
+ if slope
+ [Point.new(left.y, left.x), Point.new(right.y, right.x), slope]
+ else
+ [left, right, slope]
+ end
+ end
+
+ def set_characteristics(left, right, characteristics = {})
+ characteristics[:dx] = right.x - left.x
+ characteristics[:dy] = (left.y - right.y).abs
+
+ characteristics[:error] = (characteristics[:dx] / 2).to_i
+
+ characteristics[:y_step] = left.y < right.y ? 1 : -1
+ characteristics[:y] = left.y
+
+ characteristics
+ end
+
+ def compute_points(left, right, slope, characteristics)
+ points = []
+
+ left.x.upto right.x do |x|
+ y = characteristics[:y]
+ slope ? points << Point.new(y, x) : points << Point.new(x, y)
+
+ compute_error characteristics
+ end
+
+ points
+ end
+
+ def compute_error(characteristics)
+ characteristics[:error] -= characteristics[:dy]
+
+ if characteristics[:error] < 0
+ characteristics[:y] += characteristics[:y_step]
+ characteristics[:error] += characteristics[:dx]
+ end
+ end
+ end
+
+ class Line
+ include BresenhamAlgorithm
+ attr_reader :from, :to
+
+ def initialize(from, to)
+ @from, @to = from < to ? [from, to] : [to, from]
+ end
+
+ def ==(other)
+ @from == other.from and @to == other.to
+ end
+
+ def eql?(other)
+ self == other
+ end
+
+ def hash
+ (@from.to_s + @to.to_s).hash
+ end
+
+ def draw(canvas)
+ points = bresenham @from, @to
+ points.map { |point| canvas.set_pixel point.x, point.y }
+ end
+ end
+
+ class Rectangle
+ attr_reader :left, :right
+
+ def initialize(left, right)
+ @left, @right = left < right ? [left, right] : [right, left]
+ end
+
+ def top_left
+ if @left.y > @right.y
+ Point.new @left.x, @right.y
+ else
+ @left
+ end
+ end
+
+ def top_right
+ if @left.y < @right.y
+ Point.new @right.x, @left.y
+ else
+ @right
+ end
+ end
+
+ def bottom_left
+ if @left.y < @right.y
+ Point.new @left.x, @right.y
+ else
+ @left
+ end
+ end
+
+ def bottom_right
+ if @left.y > @right.y
+ Point.new @right.x, @left.y
+ else
+ @right
+ end
+ end
+
+ def ==(other)
+ get_points.sort == (other.send :get_points).sort
+ end
+
+ def eql?(other)
+ self == other
+ end
+
+ def hash
+ (@left.to_s + @right.to_s).hash
+ end
+
+ def draw(canvas)
+ puts "in Rectangle#draw"
+ sides = get_sides
+ sides.map { |line| canvas.draw line }
+ end
+
+ private
+
+ def get_points
+ [] << top_right << top_left << bottom_right << bottom_left
+ end
+
+ def get_sides
+ sides = []
+
+ sides << Line.new(top_left, top_right)
+ sides << Line.new(bottom_left, bottom_right)
+ sides << Line.new(top_left, bottom_left)
+ sides << Line.new(top_right, bottom_right)
+
+ sides
+ end
+ end
+end