Class: Pixelart::Palette8bit

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

Overview

or use Palette256 alias?

Constant Summary collapse

GRAYSCALE =

auto-add grayscale 0 to 255

e.g. rgb(0,0,0)
     rgb(1,1,1)
     rgb(2,2,2)
     ...
     rgb(255,255,255)

(0..255).map { |n| Color.rgb( n, n, n ) }
SEPIA_STOPS =

8x32 gradient color stops

see https://en.wikipedia.org/wiki/List_of_software_palettes#Color_gradient_palettes

[
  ['080400', '262117'],
  ['272218', '453E2F'],
  ['463F30', '645C48'],
  ['655D48', '837A60'],

  ['847A60', 'A29778'],
  ['A39878', 'C1B590'],
  ['C2B691', 'E0D2A8'],
  ['E1D3A9', 'FEEFBF'],
]
BLUE_STOPS = 
[
  ['000000', '001F3E'],
  ['002040', '003F7E'],
  ['004080', '005FBD'],
  ['0060BF', '007FFD'],

  ['0080FF', '009FFF'],
  ['00A0FF', '00BFFF'],
  ['00C0FF', '00DFFF'],
  ['00E0FF', '00FEFF'],
]
FALSE_STOPS = 
[
  ['FF00FF', '6400FF'],
  ['5F00FF', '003CFF'],
  ['0041FF', '00DCFF'],
  ['00E1FF', '00FF82'],

  ['00FF7D', '1EFF00'],
  ['23FF00', 'BEFF00'],
  ['C3FF00', 'FFA000'],
  ['FF9B00', 'FF0000'],
]
SEPIA = 
build_palette( SEPIA_STOPS )
BLUE = 
build_palette( BLUE_STOPS )
FALSE = 
build_palette( FALSE_STOPS )

Class Method Summary collapse

Class Method Details

.build_palette(gradients) ⇒ Object

Raises:

  • (ArgumentError) 


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# File 'lib/pixelart/palette.rb', line 56

def self.build_palette( gradients )
  colors_per_gradient, mod = 256.divmod( gradients.size )
  raise ArgumentError, "8bit palette - 256 must be divisible by # of gradients (#{gradients.size}; expected mod of 0 but got #{mod}"   if mod != 0

  colors = []
  gradients.each do |stops|
    colors += Gradient.new( *stops ).colors( colors_per_gradient )
  end
  colors
end