Class: Ws2812::GammaCorrection

Inherits:
Object
  • Object
show all
Defined in:
lib/ws2812/gamma_correction.rb

Overview

This class implements (on Ruby level) the gamma correction that is internally used as part of the brightness setup.

It’s especially useful if you want to mess around with pixel brightness in direct mode. See the digiclock example for more info.

Constant Summary collapse

GAMMA_TABLE =

correction table thanks to rgb-123.com/ws2812-color-output/

[
	0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
	0, 0, 0, 0, 0, 0, 1, 1, 1, 1, 1, 1, 1, 2, 2, 2,
	2, 2, 2, 3, 3, 3, 3, 3, 4, 4, 4, 4, 5, 5, 5, 5,
	6, 6, 6, 7, 7, 7, 8, 8, 8, 9, 9, 9, 10, 10, 11, 11,
	11, 12, 12, 13, 13, 13, 14, 14, 15, 15, 16, 16, 17, 17, 18, 18,
	19, 19, 20, 21, 21, 22, 22, 23, 23, 24, 25, 25, 26, 27, 27, 28,
	29, 29, 30, 31, 31, 32, 33, 34, 34, 35, 36, 37, 37, 38, 39, 40,
	40, 41, 42, 43, 44, 45, 46, 46, 47, 48, 49, 50, 51, 52, 53, 54,
	55, 56, 57, 58, 59, 60, 61, 62, 63, 64, 65, 66, 67, 68, 69, 70,
	71, 72, 73, 74, 76, 77, 78, 79, 80, 81, 83, 84, 85, 86, 88, 89,
	90, 91, 93, 94, 95, 96, 98, 99,100,102,103,104,106,107,109,110,
	111,113,114,116,117,119,120,121,123,124,126,128,129,131,132,134,
	135,137,138,140,142,143,145,146,148,150,151,153,155,157,158,160,
	162,163,165,167,169,170,172,174,176,178,179,181,183,185,187,189,
	191,193,194,196,198,200,202,204,206,208,210,212,214,216,218,220,
	222,224,227,229,231,233,235,237,239,241,244,246,248,250,252,255
]

Instance Attribute Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(brightness) ⇒ GammaCorrection

Returns a new instance of GammaCorrection.



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# File 'lib/ws2812/gamma_correction.rb', line 29

def initialize(brightness)
	self.brightness = brightness
end

Instance Attribute Details

#brightness ⇒ Object

Returns the value of attribute brightness.



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# File 'lib/ws2812/gamma_correction.rb', line 37

def brightness
  @brightness
end

Instance Method Details

#correct(value) ⇒ Object 



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# File 'lib/ws2812/gamma_correction.rb', line 39

def correct(value)
	if value.kind_of?(Color)
		Color.new(
			self.correct(value.r),
			self.correct(value.g),
			self.correct(value.b))
	else
		raise ArgumentError, "value should be within (0..255)" unless (0..255).include?(value.to_i)
		(GAMMA_TABLE[value.to_i] * (@brightness + 1)) >> 8
	end
end

#correct_with_min_max(value, min = nil, max = nil) ⇒ Object 



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# File 'lib/ws2812/gamma_correction.rb', line 51

def correct_with_min_max(value, min = nil, max = nil)
	trim(correct(value), min, max)
end

#trim(value, min = nil, max = nil) ⇒ Object 



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# File 'lib/ws2812/gamma_correction.rb', line 55

def trim(value, min = nil, max = nil)
	if value.kind_of?(Color)
		Color.new(
			self.trim(value.r, min && min.r, max && max.r),
			self.trim(value.g, min && min.g, max && max.g),
			self.trim(value.b, min && min.b, max && max.b))
	else
		if min && value.to_i < min.to_i
			min.to_i
		elsif max && value.to_i > max.to_i
			max.to_i
		else
			value.to_i
		end
	end
end