Update relative luminance sRGB threshold (#783)

Use the corrected value being included in WCAG 2.2 spec - Reference: w3c/wcag#1780 As stated in the update that there should be "no practical effect on the calculations" - as can be seen by the minor adjustments in precision
cast-org · Nov 4, 2021 · a05b068 · a05b068
1 parent aaf3005
commit a05b068
Showing 1 changed file with 36 additions and 33 deletions.
diff --git a/scss/functions/_color-util.scss b/scss/functions/_color-util.scss
@@ -156,10 +156,13 @@
 // Lookup table for channel color values in sRGB space
 // Needed since SASS does not have exponentiation or `pow`.
 //
+// Updated threshold (0.03928 --> 0.04045) based on WCAG 2.2 spec:
+// https://github.com/w3c/wcag/pull/1780
+//
 // Generated via the following JavaScript:
 // for (var i = 0; i < 256; i++) {
 //     var c = i / 255;
-//     var v =  (c < 0.03928) ? (c / 12.92) : Math.pow((c + 0.055) / 1.055, 2.4);
+//     var v =  (c < 0.04045) ? (c / 12.92) : Math.pow((c + 0.055) / 1.055, 2.4);
 //     console.log(v);
 // }
 // stylelint-disable-next-line scss/dollar-variable-default, scss/dollar-variable-colon-space-after
@@ -182,17 +185,17 @@ $color-channel-lookup:
     .004776953480693729
     .005181516702338386
     .005605391624202723
-    .006048833022857054
-    .006512090792594475
+    .006048833022857055
+    .006512090792594474
     .006995410187265387
     .007499032043226175
     .008023192985384994
     .008568125618069307
     .009134058702220787
     .009721217320237847
-    .010329823029626936
+    .010329823029626938
     .010960094006488246
-    .011612245179743885
+    .011612245179743887
     .012286488356915872
     .012983032342173012
     .013702083047289686
@@ -203,30 +206,30 @@ $color-channel-lookup:
     .017641954488384078
     .018500220128379697
     .019382360956935723
-    .020288563056652397
-    .021219010376003555
+    .0202885630566524
+    .021219010376003558
     .02217388479338738
     .02315336617811041
     .024157632448504756
-    .02518685962736163
+    .025186859627361627
     .026241221894849898
     .027320891639074897
     .028426039504420793
-    .029556834437808804
+    .0295568344378088
     .030713443732993635
     .03189603307301153
     .033104766570885055
     .03433980680868217
     .03560131487502034
     .03688945040110004
     .0382043715953465
-    .03954623527673284
+    .03954623527673283
     .04091519690685319
     .042311410620809675
     .043735029256973465
     .04518620438567554
-    .046665086336880095
-    .04817182422688942
+    .0466650863368801
+    .048171824226889426
     .04970656598412723
     .05126945837404324
     .052860647023180246
@@ -239,24 +242,24 @@ $color-channel-lookup:
     .06480326669290577
     .06662593864377289
     .06847816984440017
-    .07036009569659589
+    .07036009569659588
     .07227185068231748
     .07421356838014963
-    .07618538148130784
+    .07618538148130785
     .07818742180518633
-    .08021982031446832
+    .08021982031446831
     .0822827071298148
     .08437621154414882
     .08650046203654976
     .08865558628577294
-    .09084171118340768
-    .09305896284668745
+    .09084171118340767
+    .09305896284668747
     .0953074666309647
     .09758734714186246
     .09989872824711389
-    .10224173308810132
+    .1022417330881013
     .10461648409110419
-    .10702310297826763
+    .10702310297826761
     .10946171077829933
     .1119324278369056
     .11443537382697373
@@ -276,27 +279,27 @@ $color-channel-lookup:
     .15292615199615017
     .1559264637078274
     .1589608350608804
-    .162029375639111
+    .16202937563911096
     .1651321945016676
     .16826940018969075
     .1714411007328226
     .17464740365558504
-    .17788841598362912
+    .17788841598362914
     .18116424424986022
     .184474994500441
     .18782077230067787
-    .19120168274079138
-    .1946178304415758
+    .1912016827407914
+    .19461783044157582
     .19806931955994886
     .20155625379439707
     .20507873639031693
     .20863687014525575
     .21223075741405523
     .21586050011389923
-    .2195261997292692
+    .21952619972926923
     .2232279573168085
     .22696587351009836
-    .23074004852434912
+    .23074004852434915
     .23455058216100522
     .238397573812271
     .24228112246555486
@@ -322,7 +325,7 @@ $color-channel-lookup:
     .3277780980565422
     .33245153634617935
     .33716361504833037
-    .3419144249086609
+    .341914424908661
     .3467040563550296
     .35153259950043936
     .3564001441459435
@@ -340,9 +343,9 @@ $color-channel-lookup:
     .4178850708481375
     .4232676699860717
     .4286904966139067
-    .43415363617474895
+    .4341536361747489
     .4396571738409188
-    .4452011945162279
+    .44520119451622786
     .45078578283822346
     .45641102318040466
     .4620769996544071
@@ -376,22 +379,22 @@ $color-channel-lookup:
     .6375968739940326
     .6444796819705821
     .6514056374198242
-    .6583748172794485
+    .6583748172794486
     .665387298282272
     .6724431569576875
     .6795424696330938
-    .6866853124353135
+    .6866853124353134
     .6938717612919899
     .7011018919329731
-    .7083757798916869
+    .7083757798916868
     .7156935005064807
     .7230551289219693
     .7304607400903537
     .7379104087727308
     .7454042095403874
     .7529422167760779
     .7605245046752924
-    .768151147247507
+    .7681511472475071
     .7758222183174236
     .7835377915261935
     .7912979403326302
@@ -404,7 +407,7 @@ $color-channel-lookup:
     .846873231509858
     .8549926081242338
     .8631572134541023
-    .8713671191987972
+    .8713671191987973
     .8796223968878317
     .8879231178819663
     .8962693533742664