clone function
Creates a new mat4 initialized with values from an existing matrix
@param {ReadonlyMat4} a matrix to clone @returns {mat4} a new 4x4 matrix
Implementation
List<double> clone(List<double> a) {
final out = <double>[];
out[0] = a[0];
out[1] = a[1];
out[2] = a[2];
out[3] = a[3];
out[4] = a[4];
out[5] = a[5];
out[6] = a[6];
out[7] = a[7];
out[8] = a[8];
out[9] = a[9];
out[10] = a[10];
out[11] = a[11];
out[12] = a[12];
out[13] = a[13];
out[14] = a[14];
out[15] = a[15];
return out;
}