85 lines
2.6 KiB
JavaScript
85 lines
2.6 KiB
JavaScript
import { arraySize, squeeze } from '../../utils/array.js';
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import { factory } from '../../utils/factory.js';
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var name = 'cross';
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var dependencies = ['typed', 'matrix', 'subtract', 'multiply'];
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export var createCross = /* #__PURE__ */factory(name, dependencies, _ref => {
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var {
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typed,
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matrix,
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subtract,
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multiply
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} = _ref;
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/**
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* Calculate the cross product for two vectors in three dimensional space.
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* The cross product of `A = [a1, a2, a3]` and `B = [b1, b2, b3]` is defined
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* as:
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*
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* cross(A, B) = [
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* a2 * b3 - a3 * b2,
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* a3 * b1 - a1 * b3,
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* a1 * b2 - a2 * b1
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* ]
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*
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* If one of the input vectors has a dimension greater than 1, the output
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* vector will be a 1x3 (2-dimensional) matrix.
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*
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* Syntax:
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*
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* math.cross(x, y)
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*
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* Examples:
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*
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* math.cross([1, 1, 0], [0, 1, 1]) // Returns [1, -1, 1]
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* math.cross([3, -3, 1], [4, 9, 2]) // Returns [-15, -2, 39]
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* math.cross([2, 3, 4], [5, 6, 7]) // Returns [-3, 6, -3]
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* math.cross([[1, 2, 3]], [[4], [5], [6]]) // Returns [[-3, 6, -3]]
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*
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* See also:
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*
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* dot, multiply
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*
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* @param {Array | Matrix} x First vector
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* @param {Array | Matrix} y Second vector
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* @return {Array | Matrix} Returns the cross product of `x` and `y`
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*/
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return typed(name, {
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'Matrix, Matrix': function MatrixMatrix(x, y) {
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return matrix(_cross(x.toArray(), y.toArray()));
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},
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'Matrix, Array': function MatrixArray(x, y) {
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return matrix(_cross(x.toArray(), y));
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},
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'Array, Matrix': function ArrayMatrix(x, y) {
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return matrix(_cross(x, y.toArray()));
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},
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'Array, Array': _cross
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});
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/**
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* Calculate the cross product for two arrays
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* @param {Array} x First vector
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* @param {Array} y Second vector
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* @returns {Array} Returns the cross product of x and y
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* @private
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*/
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function _cross(x, y) {
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var highestDimension = Math.max(arraySize(x).length, arraySize(y).length);
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x = squeeze(x);
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y = squeeze(y);
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var xSize = arraySize(x);
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var ySize = arraySize(y);
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if (xSize.length !== 1 || ySize.length !== 1 || xSize[0] !== 3 || ySize[0] !== 3) {
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throw new RangeError('Vectors with length 3 expected ' + '(Size A = [' + xSize.join(', ') + '], B = [' + ySize.join(', ') + '])');
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}
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var product = [subtract(multiply(x[1], y[2]), multiply(x[2], y[1])), subtract(multiply(x[2], y[0]), multiply(x[0], y[2])), subtract(multiply(x[0], y[1]), multiply(x[1], y[0]))];
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if (highestDimension > 1) {
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return [product];
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} else {
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return product;
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}
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}
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}); |