@tbela99/css-parser
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CSS parser, minifier and validator for node and the browser
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JavaScript
// from https://www.w3.org/TR/css-color-4/multiply-matrices.js
/**
* Simple matrix (and vector) multiplication
* Warning: No error handling for incompatible dimensions!
* @author Lea Verou 2020 MIT License
*/
// A is m x n. B is n x p. product is m x p.
function multiplyMatrices(A, B) {
// if (!Array.isArray(A[0])) {
// // A is vector, convert to [[a, b, c, ...]]
// A = <number[][]>[A];
// }
if (!Array.isArray(B[0])) {
// B is vector, convert to [[a], [b], [c], ...]]
B = B.map((x) => [x]);
}
let p = B[0].length;
let B_cols = B[0].map((_, i) => B.map((x) => x[i])); // transpose B
// @ts-expect-error
let product = A.map((row) => B_cols.map((col) => {
// if (!Array.isArray(row)) {
// return col.reduce((a: number, c: number) => a + c * row, 0);
// }
return row.reduce((a, c, i) => a + c * (col[i] || 0), 0);
}));
// if (m === 1) {
// product = <number[]>product[0]; // Avoid [[a, b, c, ...]]
// }
if (p === 1) {
// @ts-expect-error
return product.map((x) => x[0]); // Avoid [[a], [b], [c], ...]]
}
return product;
}
export { multiplyMatrices };