module Hsluv
Constants
- EPSILON
- KAPPA
- M
- M_INV
- REF_U
- REF_V
- REF_X
- REF_Y
- REF_Z
Public Instance Methods
degrees_to_radians(degrees)
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# File lib/hsluv.rb, line 192 def degrees_to_radians (degrees) degrees * Math::PI / 180.0 end
distance_from_pole(point)
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# File lib/hsluv.rb, line 247 def distance_from_pole (point) Math.sqrt(point[0] ** 2 + point[1] ** 2) end
dot_product(a, b)
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# File lib/hsluv.rb, line 267 def dot_product (a, b) a.zip(b).map { |i, j| i * j }.inject(:+) end
f(t)
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# File lib/hsluv.rb, line 251 def f (t) t > EPSILON ? 116 * ((t / REF_Y) ** (1.0 / 3.0)) - 16.0 : t / REF_Y * KAPPA end
f_inv(t)
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# File lib/hsluv.rb, line 255 def f_inv (t) t > 8 ? REF_Y * ((t + 16.0) / 116.0) ** 3.0 : REF_Y * t / KAPPA end
from_linear(c)
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# File lib/hsluv.rb, line 263 def from_linear (c) c <= 0.0031308 ? 12.92 * c : (1.055 * (c ** (1.0 / 2.4)) - 0.055) end
get_bounds(l)
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# File lib/hsluv.rb, line 219 def get_bounds (l) sub1 = ((l + 16.0) ** 3.0) / 1560896.0 sub2 = sub1 > EPSILON ? sub1 : l / KAPPA ret = [] M.each do |m1, m2, m3| [0, 1].each do |t| top1 = (284517.0 * m1 - 94839.0 * m3) * sub2 top2 = (838422.0 * m3 + 769860.0 * m2 + 731718.0 * m1) * l * sub2 - 769860.0 * t * l bottom = (632260.0 * m3 - 126452.0 * m2) * sub2 + 126452.0 * t ret << [top1 / bottom, top2 / bottom] end end ret end
hex_to_hpluv(hex)
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# File lib/hsluv.rb, line 38 def hex_to_hpluv (hex) rgb_to_hpluv(*hex_to_rgb(hex)) end
hex_to_hsluv(hex)
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# File lib/hsluv.rb, line 34 def hex_to_hsluv (hex) rgb_to_hsluv(*hex_to_rgb(hex)) end
hex_to_rgb(hex)
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# File lib/hsluv.rb, line 70 def hex_to_rgb (hex) hex = hex.tr('#', '') [].tap { |arr| hex.split('').each_slice(2) { |block| arr << block.join.to_i(16) / 255.0 } } end
hpluv_to_hex(h, s, l)
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# File lib/hsluv.rb, line 30 def hpluv_to_hex (h, s, l) rgb_to_hex(*hpluv_to_rgb(h, s, l)) end
hpluv_to_lch(arr)
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# File lib/hsluv.rb, line 174 def hpluv_to_lch (arr) h, s, l = arr return [100, 0.0, h] if l > 99.9999999 return [0.0, 0.0, h] if l < 0.00000001 mx = max_safe_chroma_for(l) c = mx / 100.0 * s [l, c, h] end
hpluv_to_rgb(h, s, l)
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# File lib/hsluv.rb, line 50 def hpluv_to_rgb (h, s, l) lch_to_rgb(*hpluv_to_lch([h, s, l])) end
hsluv_to_hex(h, s, l)
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# File lib/hsluv.rb, line 26 def hsluv_to_hex (h, s, l) rgb_to_hex(*hsluv_to_rgb(h, s, l)) end
hsluv_to_lch(arr)
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# File lib/hsluv.rb, line 162 def hsluv_to_lch (arr) h, s, l = arr return [100, 0.0, h] if l > 99.9999999 return [0.0, 0.0, h] if l < 0.00000001 mx = max_chroma_for(l, h) c = mx / 100.0 * s [l, c, h] end
hsluv_to_rgb(h, s, l)
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# File lib/hsluv.rb, line 42 def hsluv_to_rgb (h, s, l) xyz_to_rgb(luv_to_xyz(lch_to_luv(hsluv_to_lch([h, s, l])))) end
intersect_line_line(line1, line2)
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# File lib/hsluv.rb, line 243 def intersect_line_line (line1, line2) (line1[1] - line2[1]) / (line2[0] - line1[0]) end
lch_to_hpluv(arr)
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# File lib/hsluv.rb, line 116 def lch_to_hpluv (arr) l, c, h = arr return [h, 0.0, 100.0] if l > 99.9999999 return [h, 0.0, 0.0] if l < 0.00000001 mx = max_safe_chroma_for(l) s = c / mx * 100.0 [h, s, l] end
lch_to_hsluv(arr)
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# File lib/hsluv.rb, line 105 def lch_to_hsluv (arr) l, c, h = arr return [h, 0.0, 100.0] if l > 99.9999999 return [h, 0.0, 0.0] if l < 0.00000001 mx = max_chroma_for(l, h) s = c / mx * 100.0 [h, s, l] end
lch_to_luv(arr)
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# File lib/hsluv.rb, line 152 def lch_to_luv (arr) l, c, h = arr hrad = degrees_to_radians(h) u = Math.cos(hrad) * c v = Math.sin(hrad) * c [l, u, v] end
lch_to_rgb(l, c, h)
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# File lib/hsluv.rb, line 58 def lch_to_rgb (l, c, h) xyz_to_rgb(luv_to_xyz(lch_to_luv([l, c, h]))) end
length_of_ray_until_intersect(theta, line)
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# File lib/hsluv.rb, line 236 def length_of_ray_until_intersect (theta, line) m1, b1 = line length = b1 / (Math.sin(theta) - m1 * Math.cos(theta)) return nil if length < 0 length end
luv_to_lch(arr)
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# File lib/hsluv.rb, line 96 def luv_to_lch (arr) l, u, v = arr c = ((u ** 2) + (v ** 2)) ** (1 / 2.0) hrad = Math.atan2(v, u) h = radians_to_degrees(hrad) h += 360.0 if h < 0.0 [l, c, h] end
luv_to_xyz(arr)
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# File lib/hsluv.rb, line 135 def luv_to_xyz (arr) l, u, v = arr return [0.0, 0.0, 0.0] if l == 0 var_y = f_inv(l) var_u = u / (13.0 * l) + REF_U var_v = v / (13.0 * l) + REF_V y = var_y * REF_Y x = 0.0 - (9.0 * y * var_u) / ((var_u - 4.0) * var_v - var_u * var_v) z = (9.0 * y - (15.0 * var_v * y) - (var_v * x)) / (3.0 * var_v) [x, y, z] end
max_chroma_for(l, h)
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# File lib/hsluv.rb, line 196 def max_chroma_for (l, h) hrad = h / 360.0 * Math::PI * 2.0 lengths = [] get_bounds(l).each do |line| l = length_of_ray_until_intersect(hrad, line) lengths << l if l end lengths.min end
max_safe_chroma_for(l)
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# File lib/hsluv.rb, line 208 def max_safe_chroma_for (l) lengths = [] get_bounds(l).each do |m1, b1| x = intersect_line_line([m1, b1], [-1.0 / m1, 0.0]) lengths << distance_from_pole([x, b1 + x * m1]) end lengths.min end
radians_to_degrees(rad)
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# File lib/hsluv.rb, line 188 def radians_to_degrees (rad) rad * 180.0 / Math::PI end
rgb_prepare(arr)
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# File lib/hsluv.rb, line 271 def rgb_prepare (arr) arr.map! { |ch| ch = ch.round(3); ch = [0, ch].max; ch = [1, ch].min; (ch * 255).round } end
rgb_to_hex(r, g, b)
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# File lib/hsluv.rb, line 66 def rgb_to_hex (r, g, b) '#%02x%02x%02x' % rgb_prepare([r, g, b]) end
rgb_to_hpluv(r, g, b)
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# File lib/hsluv.rb, line 54 def rgb_to_hpluv (r, g, b) lch_to_hpluv(rgb_to_lch(r, g, b)) end
rgb_to_hsluv(r, g, b)
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# File lib/hsluv.rb, line 46 def rgb_to_hsluv (r, g, b) lch_to_hsluv(rgb_to_lch(r, g, b)) end
rgb_to_lch(r, g, b)
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# File lib/hsluv.rb, line 62 def rgb_to_lch (r, g, b) luv_to_lch(xyz_to_luv(rgb_to_xyz([r, g, b]))) end
rgb_to_xyz(arr)
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# File lib/hsluv.rb, line 77 def rgb_to_xyz (arr) rgbl = arr.map { |val| to_linear(val) } M_INV.map { |i| dot_product(i, rgbl) } end
to_linear(c)
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# File lib/hsluv.rb, line 259 def to_linear (c) c > 0.04045 ? ((c + 0.055) / 1.055) ** 2.4 : c / 12.92 end
xyz_to_luv(arr)
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# File lib/hsluv.rb, line 82 def xyz_to_luv (arr) x, y, z = arr l = f(y) return [0.0, 0.0, 0.0] if [x, y, z, 0.0].uniq.length == 1 || l == 0.0 var_u = (4.0 * x) / (x + (15.0 * y) + (3.0 * z)) var_v = (9.0 * y) / (x + (15.0 * y) + (3.0 * z)) u = 13.0 * l * (var_u - REF_U) v = 13.0 * l * (var_v - REF_V) [l, u, v] end
xyz_to_rgb(arr)
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# File lib/hsluv.rb, line 130 def xyz_to_rgb (arr) xyz = M.map { |i| dot_product(i, arr) } xyz.map { |i| from_linear(i) } end