Class: RGBCell

Inherits:
Object
  • Object
show all
Defined in:
lib/rgbcell.rb

Overview

An RGBCell object represents a single color in the red-green-blue color scheme, such as is used in HTML or CSS.

Constant Summary collapse

VERSION =

version

'0.5'
NAMES =

A hash of official named HTML colors. For the full list of names, see www.w3.org/wiki/CSS/Properties/color/keywords

{}

Instance Attribute Summary collapse

Class Method Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(*opts) ⇒ RGBCell

Initializes a new RGBCell object. The params can be in one of several forms.

  • three numbers

    RGBCell.new(127, 255, 0)

  • a named color

    RGBCell.new('orange')

  • a hexidecimal expression

    RGBCell.new('#7fff00')

  • a random color

    RGBCell.new('random')

  • no param returns black

    RGBCell.new



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# File 'lib/rgbcell.rb', line 34

def initialize(*opts)
	# $tm.hrm
	
	# no opts: set to black
	if opts.length == 0
		@red = 0.0
		@green = 0.0
		@blue = 0.0
		
	# 1 opt
	elsif opts.length == 1
		# array
		if opts[0].is_a?(Array)
			@red = opts[0][0].to_f
			@green = opts[0][1].to_f
			@blue = opts[0][2].to_f
		
		# random
		elsif opts[0] == 'random'
			randomize()
			
		# named
		elsif coords = NAMES[opts[0]]
			@red = coords[0].to_f
			@green = coords[1].to_f
			@blue = coords[2].to_f
			
		# hex
		elsif opts[0].match(/\A\#?[a-f0-9]{6,}\z/mu)
			rgbs = opts[0]
			rgbs = rgbs.sub(/\A\#/mu, '')
			@red = rgbs[0..1].hex
			@green = rgbs[2..3].hex
			@blue = rgbs[4..5].hex
		
		# else unknown opt
		else
			raise 'unknown-opt: ' + opts[0].to_s
		end
		
	# 3 opts
	elsif opts.length == 3
		@red = opts[0].to_f
		@green = opts[1].to_f
		@blue = opts[2].to_f
		
	# any other number of options is invalid
	else
		raise 'invalid-initialize-options-length: ' + opts.length.to_s
	end
end

Instance Attribute Details

#blue ⇒ Object

The value of the blue component.



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# File 'lib/rgbcell.rb', line 101

def blue
  @blue
end

#green ⇒ Object

The value of the green component.



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# File 'lib/rgbcell.rb', line 98

def green
  @green
end

#red ⇒ Object

The value of the red component.



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# File 'lib/rgbcell.rb', line 95

def red
  @red
end

Class Method Details

.average(*colors) ⇒ Object

Returns the midpoint of the given colors expressed as a color.



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# File 'lib/rgbcell.rb', line 218

def self.average(*colors)
	base = self.obj_or_new(colors.shift)
	return base.average(*colors)
end

.coord_to_hex(coord) ⇒ Object

Converts a color coordinate to hexidecimal.



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# File 'lib/rgbcell.rb', line 265

def self.coord_to_hex(coord)
	return coord.to_i.to_s(16).rjust(2, '0')
end

.method_missing(key) ⇒ Object

This method allows you to create colors by name as if the color names were methods. For example, RGBCell.red returns an object representing the color red.



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# File 'lib/rgbcell.rb', line 474

def self.method_missing(key)
	# $tm.hrm
	# puts key.class
	# puts NAMES[key.to_s]
	# $tm.devexit
	
	if name = NAMES[key.to_s]
		return self.new(name)
	else
		super(key)
	end
end

.obj_or_new(*positions) ⇒ Object

If the given object is an EGBCell object, then it is returned. Otherwise the object is used to create an RGBCell object.



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# File 'lib/rgbcell.rb', line 115

def self.obj_or_new(*positions)
	if positions[0].is_a?(RGBCell)
		return positions[0]
	else
		return self.new(*positions)
	end
end

Instance Method Details

#-(*other) ⇒ Object

Alias for RGBCell#distance.



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# File 'lib/rgbcell.rb', line 303

def -(*other)
	return distance(*other)
end

#average(*others) ⇒ Object

Returns a color representing the midpoint between the object’s color and the other given colors.



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# File 'lib/rgbcell.rb', line 187

def average(*others)
	# $tm.hrm
	r_sum = @red
	g_sum = @green
	b_sum = @blue
	
	# loop through others
	others.each do |other|
		other = self.class.obj_or_new(other)
		r_sum += other.red
		g_sum += other.green
		b_sum += other.blue
	end
	
	# total
	total = others.length + 1
	
	# return
	return self.class.new( r_sum/total, g_sum/total, b_sum/total )
end

#distance(*other) ⇒ Object

Returns the distance between the color and the given color. Always returns zero or a positive number.



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# File 'lib/rgbcell.rb', line 279

def distance(*other)
	# $tm.hrm
	
	# ensure object
	other = self.class.obj_or_new(*other)
	
	# individual distances
	red_d = (@red - other.red).abs2
	green_d = (@green - other.green).abs2
	blue_d = (@blue - other.blue).abs2
	
	# rv
	return Math.sqrt(red_d + green_d + blue_d).abs
end

#from_black ⇒ Object

Returns the distance from the color black.



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# File 'lib/rgbcell.rb', line 497

def from_black
	return distance(self.class.black)
end

#from_white ⇒ Object

Returns the distance from the color white.



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# File 'lib/rgbcell.rb', line 502

def from_white
	return distance(self.class.white)
end

#pivot ⇒ Object

Returns a new RGBCell object in which the component colors have been pivoted. Red becomes blue, green becomes red, blue becomes green.



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# File 'lib/rgbcell.rb', line 540

def pivot
	return self.class.new(@green, @blue, @red)
end

#pivot! ⇒ Object

Pivots the objects colors in place.



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# File 'lib/rgbcell.rb', line 545

def pivot!
	rgb = [@green, @blue, @red]
	@red = rgb[0]
	@green = rgb[1]
	@blue = rgb[2]
	return self
end

#positions ⇒ Object

Returns an array of the three component coordinates.



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# File 'lib/rgbcell.rb', line 157

def positions()
	return [@red, @green, @blue]
end

#randomize ⇒ Object

Sets the object to a random color.



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# File 'lib/rgbcell.rb', line 170

def randomize
	@red = self.class.rand_255().to_f
	@green = self.class.rand_255().to_f
	@blue = self.class.rand_255().to_f
end

#to_s ⇒ Object

Returns the hexidecimal representation of the color.



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# File 'lib/rgbcell.rb', line 233

def to_s
	return to_str()
end

#to_str ⇒ Object

Returns the hexidecimal representation of the color.



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# File 'lib/rgbcell.rb', line 238

def to_str
	rv = '#'
	
	# loop through coordinates
	positions.each do |pos|
		rv += self.class.coord_to_hex(pos)
	end
	
	# return
	return rv
end