@woosh/meep-engine/src/core/geom/mat2/m2_transpose.js

Pure JavaScript game engine. Fully featured and production ready.

/**
 * Transposes a 2x2 matrix, stored in a flattened array.
 *
 * @param {number[]} out Output: The transposed matrix. Can be the same array as `m`.
 * @param {number[]} m Input: The 2x2 matrix to transpose, stored as a flattened array [a, b, c, d], representing [[a, c], [b, d]].
 * @returns {number[]} The `out` parameter.
 */
export function m2_transpose(out, m) {
    const b = m[1]; // Cache m[1] (which becomes m[2] after the swap)

    out[0] = m[0];
    out[1] = m[2];
    out[2] = b; // Use the cached value
    out[3] = m[3];

    return out;
}