format-path.js 4.5 KB

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  1. /*
  2. * 抽取pathSegment中的关键点
  3. * M,L,A,Q,H,V一个端点
  4. * Q, S抽取一个端点,一个控制点
  5. * C抽取一个端点,两个控制点
  6. */
  7. function _getSegmentPoints(segment) {
  8. var points = [];
  9. switch (segment[0]) {
  10. case 'M':
  11. points.push([segment[1], segment[2]]);
  12. break;
  13. case 'L':
  14. points.push([segment[1], segment[2]]);
  15. break;
  16. case 'A':
  17. points.push([segment[6], segment[7]]);
  18. break;
  19. case 'Q':
  20. points.push([segment[3], segment[4]]);
  21. points.push([segment[1], segment[2]]);
  22. break;
  23. case 'T':
  24. points.push([segment[1], segment[2]]);
  25. break;
  26. case 'C':
  27. points.push([segment[5], segment[6]]);
  28. points.push([segment[1], segment[2]]);
  29. points.push([segment[3], segment[4]]);
  30. break;
  31. case 'S':
  32. points.push([segment[3], segment[4]]);
  33. points.push([segment[1], segment[2]]);
  34. break;
  35. case 'H':
  36. points.push([segment[1], segment[1]]);
  37. break;
  38. case 'V':
  39. points.push([segment[1], segment[1]]);
  40. break;
  41. default:
  42. }
  43. return points;
  44. }
  45. // 将两个点均分成count个点
  46. function _splitPoints(points, former, count) {
  47. var result = [].concat(points);
  48. var index;
  49. var t = 1 / (count + 1);
  50. var formerEnd = _getSegmentPoints(former)[0];
  51. for (var i = 1; i <= count; i++) {
  52. t *= i;
  53. index = Math.floor(points.length * t);
  54. if (index === 0) {
  55. result.unshift([formerEnd[0] * t + points[index][0] * (1 - t), formerEnd[1] * t + points[index][1] * (1 - t)]);
  56. }
  57. else {
  58. result.splice(index, 0, [formerEnd[0] * t + points[index][0] * (1 - t), formerEnd[1] * t + points[index][1] * (1 - t)]);
  59. }
  60. }
  61. return result;
  62. }
  63. export default function formatPath(fromPath, toPath) {
  64. if (fromPath.length <= 1) {
  65. return fromPath;
  66. }
  67. var points;
  68. for (var i = 0; i < toPath.length; i++) {
  69. if (fromPath[i][0] !== toPath[i][0]) {
  70. // 获取fromPath的pathSegment的端点,根据toPath的指令对其改造
  71. points = _getSegmentPoints(fromPath[i]);
  72. switch (toPath[i][0]) {
  73. case 'M':
  74. fromPath[i] = ['M'].concat(points[0]);
  75. break;
  76. case 'L':
  77. fromPath[i] = ['L'].concat(points[0]);
  78. break;
  79. case 'A':
  80. fromPath[i] = [].concat(toPath[i]);
  81. fromPath[i][6] = points[0][0];
  82. fromPath[i][7] = points[0][1];
  83. break;
  84. case 'Q':
  85. if (points.length < 2) {
  86. if (i > 0) {
  87. points = _splitPoints(points, fromPath[i - 1], 1);
  88. }
  89. else {
  90. fromPath[i] = toPath[i];
  91. break;
  92. }
  93. }
  94. fromPath[i] = ['Q'].concat(points.reduce(function (arr, i) { return arr.concat(i); }, []));
  95. break;
  96. case 'T':
  97. fromPath[i] = ['T'].concat(points[0]);
  98. break;
  99. case 'C':
  100. if (points.length < 3) {
  101. if (i > 0) {
  102. points = _splitPoints(points, fromPath[i - 1], 2);
  103. }
  104. else {
  105. fromPath[i] = toPath[i];
  106. break;
  107. }
  108. }
  109. fromPath[i] = ['C'].concat(points.reduce(function (arr, i) { return arr.concat(i); }, []));
  110. break;
  111. case 'S':
  112. if (points.length < 2) {
  113. if (i > 0) {
  114. points = _splitPoints(points, fromPath[i - 1], 1);
  115. }
  116. else {
  117. fromPath[i] = toPath[i];
  118. break;
  119. }
  120. }
  121. fromPath[i] = ['S'].concat(points.reduce(function (arr, i) { return arr.concat(i); }, []));
  122. break;
  123. default:
  124. fromPath[i] = toPath[i];
  125. }
  126. }
  127. }
  128. return fromPath;
  129. }
  130. //# sourceMappingURL=format-path.js.map