Data commit

Task/Bitmap/Ruby/bitmap.rb

@@ -0,0 +1,49 @@
+class RGBColour
+  def initialize(red, green, blue)
+    unless red.between?(0,255) and green.between?(0,255) and blue.between?(0,255)
+      raise ArgumentError, "invalid RGB parameters: #{[red, green, blue].inspect}"
+    end
+    @red, @green, @blue = red, green, blue
+  end
+  attr_reader :red, :green, :blue
+  alias_method :r, :red
+  alias_method :g, :green
+  alias_method :b, :blue
+
+  RED   = RGBColour.new(255,0,0)
+  GREEN = RGBColour.new(0,255,0)
+  BLUE  = RGBColour.new(0,0,255)
+  BLACK = RGBColour.new(0,0,0)
+  WHITE = RGBColour.new(255,255,255)
+end
+
+class Pixmap
+  def initialize(width, height)
+    @width = width
+    @height = height
+    @data = fill(RGBColour::WHITE)
+  end
+  attr_reader :width, :height
+
+  def fill(colour)
+    @data = Array.new(@width) {Array.new(@height, colour)}
+  end
+
+  def validate_pixel(x,y)
+    unless x.between?(0, @width-1) and y.between?(0, @height-1)
+      raise ArgumentError, "requested pixel (#{x}, #{y}) is outside dimensions of this bitmap"
+    end
+  end
+
+  def [](x,y)
+    validate_pixel(x,y)
+    @data[x][y]
+  end
+  alias_method :get_pixel, :[]
+
+  def []=(x,y,colour)
+    validate_pixel(x,y)
+    @data[x][y] = colour
+  end
+  alias_method :set_pixel, :[]=
+end