smoothBezier.js 1.9 KB

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  1. import { min as v2Min, max as v2Max, scale as v2Scale, distance as v2Distance, add as v2Add, clone as v2Clone, sub as v2Sub } from '../../core/vector.js';
  2. export default function smoothBezier(points, smooth, isLoop, constraint) {
  3. var cps = [];
  4. var v = [];
  5. var v1 = [];
  6. var v2 = [];
  7. var prevPoint;
  8. var nextPoint;
  9. var min;
  10. var max;
  11. if (constraint) {
  12. min = [Infinity, Infinity];
  13. max = [-Infinity, -Infinity];
  14. for (var i = 0, len = points.length; i < len; i++) {
  15. v2Min(min, min, points[i]);
  16. v2Max(max, max, points[i]);
  17. }
  18. v2Min(min, min, constraint[0]);
  19. v2Max(max, max, constraint[1]);
  20. }
  21. for (var i = 0, len = points.length; i < len; i++) {
  22. var point = points[i];
  23. if (isLoop) {
  24. prevPoint = points[i ? i - 1 : len - 1];
  25. nextPoint = points[(i + 1) % len];
  26. }
  27. else {
  28. if (i === 0 || i === len - 1) {
  29. cps.push(v2Clone(points[i]));
  30. continue;
  31. }
  32. else {
  33. prevPoint = points[i - 1];
  34. nextPoint = points[i + 1];
  35. }
  36. }
  37. v2Sub(v, nextPoint, prevPoint);
  38. v2Scale(v, v, smooth);
  39. var d0 = v2Distance(point, prevPoint);
  40. var d1 = v2Distance(point, nextPoint);
  41. var sum = d0 + d1;
  42. if (sum !== 0) {
  43. d0 /= sum;
  44. d1 /= sum;
  45. }
  46. v2Scale(v1, v, -d0);
  47. v2Scale(v2, v, d1);
  48. var cp0 = v2Add([], point, v1);
  49. var cp1 = v2Add([], point, v2);
  50. if (constraint) {
  51. v2Max(cp0, cp0, min);
  52. v2Min(cp0, cp0, max);
  53. v2Max(cp1, cp1, min);
  54. v2Min(cp1, cp1, max);
  55. }
  56. cps.push(cp0);
  57. cps.push(cp1);
  58. }
  59. if (isLoop) {
  60. cps.push(cps.shift());
  61. }
  62. return cps;
  63. }