matrix.js 3.3 KB

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  1. /**
  2. * 3x2矩阵操作类
  3. * @exports zrender/tool/matrix
  4. */
  5. var ArrayCtor = typeof Float32Array === 'undefined' ? Array : Float32Array;
  6. /**
  7. * 创建一个单位矩阵
  8. * @return {Float32Array|Array.<number>}
  9. */
  10. function create() {
  11. var out = new ArrayCtor(6);
  12. identity(out);
  13. return out;
  14. }
  15. /**
  16. * 设置矩阵为单位矩阵
  17. * @param {Float32Array|Array.<number>} out
  18. */
  19. function identity(out) {
  20. out[0] = 1;
  21. out[1] = 0;
  22. out[2] = 0;
  23. out[3] = 1;
  24. out[4] = 0;
  25. out[5] = 0;
  26. return out;
  27. }
  28. /**
  29. * 复制矩阵
  30. * @param {Float32Array|Array.<number>} out
  31. * @param {Float32Array|Array.<number>} m
  32. */
  33. function copy(out, m) {
  34. out[0] = m[0];
  35. out[1] = m[1];
  36. out[2] = m[2];
  37. out[3] = m[3];
  38. out[4] = m[4];
  39. out[5] = m[5];
  40. return out;
  41. }
  42. /**
  43. * 矩阵相乘
  44. * @param {Float32Array|Array.<number>} out
  45. * @param {Float32Array|Array.<number>} m1
  46. * @param {Float32Array|Array.<number>} m2
  47. */
  48. function mul(out, m1, m2) {
  49. // Consider matrix.mul(m, m2, m);
  50. // where out is the same as m2.
  51. // So use temp variable to escape error.
  52. var out0 = m1[0] * m2[0] + m1[2] * m2[1];
  53. var out1 = m1[1] * m2[0] + m1[3] * m2[1];
  54. var out2 = m1[0] * m2[2] + m1[2] * m2[3];
  55. var out3 = m1[1] * m2[2] + m1[3] * m2[3];
  56. var out4 = m1[0] * m2[4] + m1[2] * m2[5] + m1[4];
  57. var out5 = m1[1] * m2[4] + m1[3] * m2[5] + m1[5];
  58. out[0] = out0;
  59. out[1] = out1;
  60. out[2] = out2;
  61. out[3] = out3;
  62. out[4] = out4;
  63. out[5] = out5;
  64. return out;
  65. }
  66. /**
  67. * 平移变换
  68. * @param {Float32Array|Array.<number>} out
  69. * @param {Float32Array|Array.<number>} a
  70. * @param {Float32Array|Array.<number>} v
  71. */
  72. function translate(out, a, v) {
  73. out[0] = a[0];
  74. out[1] = a[1];
  75. out[2] = a[2];
  76. out[3] = a[3];
  77. out[4] = a[4] + v[0];
  78. out[5] = a[5] + v[1];
  79. return out;
  80. }
  81. /**
  82. * 旋转变换
  83. * @param {Float32Array|Array.<number>} out
  84. * @param {Float32Array|Array.<number>} a
  85. * @param {number} rad
  86. */
  87. function rotate(out, a, rad) {
  88. var aa = a[0];
  89. var ac = a[2];
  90. var atx = a[4];
  91. var ab = a[1];
  92. var ad = a[3];
  93. var aty = a[5];
  94. var st = Math.sin(rad);
  95. var ct = Math.cos(rad);
  96. out[0] = aa * ct + ab * st;
  97. out[1] = -aa * st + ab * ct;
  98. out[2] = ac * ct + ad * st;
  99. out[3] = -ac * st + ct * ad;
  100. out[4] = ct * atx + st * aty;
  101. out[5] = ct * aty - st * atx;
  102. return out;
  103. }
  104. /**
  105. * 缩放变换
  106. * @param {Float32Array|Array.<number>} out
  107. * @param {Float32Array|Array.<number>} a
  108. * @param {Float32Array|Array.<number>} v
  109. */
  110. function scale(out, a, v) {
  111. var vx = v[0];
  112. var vy = v[1];
  113. out[0] = a[0] * vx;
  114. out[1] = a[1] * vy;
  115. out[2] = a[2] * vx;
  116. out[3] = a[3] * vy;
  117. out[4] = a[4] * vx;
  118. out[5] = a[5] * vy;
  119. return out;
  120. }
  121. /**
  122. * 求逆矩阵
  123. * @param {Float32Array|Array.<number>} out
  124. * @param {Float32Array|Array.<number>} a
  125. */
  126. function invert(out, a) {
  127. var aa = a[0];
  128. var ac = a[2];
  129. var atx = a[4];
  130. var ab = a[1];
  131. var ad = a[3];
  132. var aty = a[5];
  133. var det = aa * ad - ab * ac;
  134. if (!det) {
  135. return null;
  136. }
  137. det = 1.0 / det;
  138. out[0] = ad * det;
  139. out[1] = -ab * det;
  140. out[2] = -ac * det;
  141. out[3] = aa * det;
  142. out[4] = (ac * aty - ad * atx) * det;
  143. out[5] = (ab * atx - aa * aty) * det;
  144. return out;
  145. }
  146. exports.create = create;
  147. exports.identity = identity;
  148. exports.copy = copy;
  149. exports.mul = mul;
  150. exports.translate = translate;
  151. exports.rotate = rotate;
  152. exports.scale = scale;
  153. exports.invert = invert;