hslToRgb.js 917 B

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  1. exports = function(hsl) {
  2. var h = hsl[0] / 360;
  3. var s = hsl[1] / 100;
  4. var l = hsl[2] / 100;
  5. var ret = [];
  6. var t2;
  7. var t3;
  8. var val;
  9. if (hsl[3]) ret[3] = hsl[3];
  10. if (s === 0) {
  11. val = round(l * 255);
  12. ret[0] = ret[1] = ret[2] = val;
  13. return ret;
  14. }
  15. if (l < 0.5) {
  16. t2 = l * (1 + s);
  17. } else {
  18. t2 = l + s - l * s;
  19. }
  20. var t1 = 2 * l - t2;
  21. for (var i = 0; i < 3; i++) {
  22. t3 = h + (1 / 3) * -(i - 1);
  23. if (t3 < 0) t3++;
  24. if (t3 > 1) t3--;
  25. if (6 * t3 < 1) {
  26. val = t1 + (t2 - t1) * 6 * t3;
  27. } else if (2 * t3 < 1) {
  28. val = t2;
  29. } else if (3 * t3 < 2) {
  30. val = t1 + (t2 - t1) * (2 / 3 - t3) * 6;
  31. } else {
  32. val = t1;
  33. }
  34. ret[i] = round(val * 255);
  35. }
  36. return ret;
  37. };
  38. var round = Math.round;
  39. module.exports = exports;