diff options
Diffstat (limited to 'node_modules/chroma-js/src/conversions/lab2rgb.coffee')
| -rw-r--r-- | node_modules/chroma-js/src/conversions/lab2rgb.coffee | 25 |
1 files changed, 25 insertions, 0 deletions
diff --git a/node_modules/chroma-js/src/conversions/lab2rgb.coffee b/node_modules/chroma-js/src/conversions/lab2rgb.coffee new file mode 100644 index 0000000000..049f382ce5 --- /dev/null +++ b/node_modules/chroma-js/src/conversions/lab2rgb.coffee @@ -0,0 +1,25 @@ + +lab2rgb = (l,a,b) -> + ### + adapted to match d3 implementation + ### + if l != undefined and l.length == 3 + [l,a,b] = l + if l != undefined and l.length == 3 + [l,a,b] = l + y = (l + 16) / 116 + x = y + a / 500 + z = y - b / 200; + x = lab_xyz(x) * X + y = lab_xyz(y) * Y + z = lab_xyz(z) * Z + r = xyz_rgb( 3.2404542 * x - 1.5371385 * y - 0.4985314 * z) + g = xyz_rgb(-0.9692660 * x + 1.8760108 * y + 0.0415560 * z) + b = xyz_rgb( 0.0556434 * x - 0.2040259 * y + 1.0572252 * z) + [limit(r,0,255), limit(g,0,255), limit(b,0,255), 1] + +lab_xyz = (x) -> + if x > 0.206893034 then x * x * x else (x - 4 / 29) / 7.787037 + +xyz_rgb = (r) -> + Math.round(255 * (if r <= 0.00304 then 12.92 * r else 1.055 * Math.pow(r, 1 / 2.4) - 0.055)) |