public float[] getColumn(int i, float[] store) {
        if (store == null) {
            store = new float[4];
        }
        switch (i) {
            case 0:
                store[0] = m00;
                store[1] = m10;
                store[2] = m20;
                store[3] = m30;
                break;
            case 1:
                store[0] = m01;
                store[1] = m11;
                store[2] = m21;
                store[3] = m31;
                break;
            case 2:
                store[0] = m02;
                store[1] = m12;
                store[2] = m22;
                store[3] = m32;
                break;
            case 3:
                store[0] = m03;
                store[1] = m13;
                store[2] = m23;
                store[3] = m33;
                break;
            default:
                logger.warning("Invalid column index.");
                throw new IllegalArgumentException("Invalid column index. " + i);
        }
        return store;
    }
Copy the specified column to a float array.

@param i the index of the column to copy (0, 1, 2, or 3)
@param store storage for the result (modified) or null to create a new
array
@return either store or a new array with length=4
jme3-core/src/main/java/com/jme3/math/Matrix4f.java