From 8b709705ba31e7e9c7f46c7c8d60fc143bfdccb3 Mon Sep 17 00:00:00 2001
From: Jules Laplace <julescarbon@gmail.com>
Date: Wed, 21 Nov 2018 14:22:26 +0100
Subject: site

---
 docs/js/cielab.js | 70 +++++++++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 70 insertions(+)
 create mode 100644 docs/js/cielab.js

(limited to 'docs/js/cielab.js')

diff --git a/docs/js/cielab.js b/docs/js/cielab.js
new file mode 100644
index 0000000..2293f0d
--- /dev/null
+++ b/docs/js/cielab.js
@@ -0,0 +1,70 @@
+var cielab = (function(){
+  var cielab = {}
+  
+  var xyz = [0,0,0]
+  var rgb = [0,0,0]
+
+  L_range = [0, 100]
+  a_range = [-86.185, 98.254]
+  b_range = [-107.863, 94.482]
+  
+  cielab.gradient = function (n) {
+    n = n || 100
+    var k = 0
+    
+    var L, a, b
+    
+    var L0 = randrange(L_range[0] + 50, L_range[1])
+    var L1 = randrange(L_range[0]+ 50, L_range[1])
+    var a0 = randrange(a_range[0], a_range[1])
+    var a1 = randrange(a_range[0], a_range[1])
+    var b0 = randrange(b_range[0], b_range[1])
+    var b1 = randrange(b_range[0], b_range[1])
+    return function next (aa){
+      L = mix(k/n, L0, L1)
+      a = mix(k/n, a0, a1)
+      b = mix(k/n, b0, b1)
+      rgb = xyz2rgb(hunterlab2xyz(L, a, b))
+      k += 1
+      return rgba_string(rgb, aa)
+    }
+  }
+  function rgba_string (rgb, a) { return "rgb(" + rgb.map(Math.round).join(",")  + "," + a + ")" }
+  function hex_string (rgb) { return "#" + rgb.map(Math.round).map(function(n){ var s = n.toString(16); return s.length == 1 ? "0"+s : s }).join("") }
+
+  function mix(n,a,b){ return n*a + (1-n)*b }
+  function clamp(n,a,b){ return n<a?a:n<b?n:b }
+  function hunterlab2xyz (L,a,b) {
+    var_Y = L / 10
+    var_X = a / 17.5 * L / 10
+    var_Z = b / 7 * L / 10
+
+    Y = Math.pow(var_Y, 2)
+    X = ( var_X + Y ) / 1.02
+    Z = -( var_Z - Y ) / 0.847
+    xyz = [X,Y,Z]
+  }
+  function xyz2rgb(){
+    var var_X = xyz[0] / 100        //X from 0 to  95.047      (Observer = 2°, Illuminant = D65)
+    var var_Y = xyz[1] / 100        //Y from 0 to 100.000
+    var var_Z = xyz[2] / 100        //Z from 0 to 108.883
+
+    var_R = var_X *  3.2406 + var_Y * -1.5372 + var_Z * -0.4986
+    var_G = var_X * -0.9689 + var_Y *  1.8758 + var_Z *  0.0415
+    var_B = var_X *  0.0557 + var_Y * -0.2040 + var_Z *  1.0570
+
+    if ( var_R > 0.0031308 ) var_R = 1.055 * Math.pow( var_R, 1 / 2.4 ) - 0.055
+    else                     var_R = 12.92 * var_R
+    if ( var_G > 0.0031308 ) var_G = 1.055 * Math.pow( var_G, 1 / 2.4 ) - 0.055
+    else                     var_G = 12.92 * var_G
+    if ( var_B > 0.0031308 ) var_B = 1.055 * Math.pow( var_B, 1 / 2.4 ) - 0.055
+    else                     var_B = 12.92 * var_B
+
+    rgb[0] = clamp(var_R * 255, 0, 255)
+    rgb[1] = clamp(var_G * 255, 0, 255)
+    rgb[2] = clamp(var_B * 255, 0, 255)
+    return rgb
+  }
+
+  return cielab
+})()
\ No newline at end of file
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