export function createMat4(): Float32Array {
    const out = new Float32Array( 16 );

    out[0] = 1;
    out[1] = 0;
    out[2] = 0;
    out[3] = 0;
    out[4] = 0;
    out[5] = 1;
    out[6] = 0;
    out[7] = 0;
    out[8] = 0;
    out[9] = 0;
    out[10] = 1;
    out[11] = 0;
    out[12] = 0;
    out[13] = 0;
    out[14] = 0;
    out[15] = 1;

    return out;
  }


export function orthoMat4( out: Float32Array, left: number, right: number, bottom: number, top: number, near: number, far: number ): Float32Array {
    const lr = 1 / (left - right);
    const bt = 1 / (bottom - top);
    const nf = 1 / (near - far);

    out[0] = -2 * lr;
    out[1] = 0;
    out[2] = 0;
    out[3] = 0;
    out[4] = 0;
    out[5] = -2 * bt;
    out[6] = 0;
    out[7] = 0;
    out[8] = 0;
    out[9] = 0;
    out[10] = 2 * nf;
    out[11] = 0;
    out[12] = (left + right) * lr;
    out[13] = (top + bottom) * bt;
    out[14] = (far + near) * nf;
    out[15] = 1;

    return out;
}


export function scaleMat4( out: Float32Array, a: Float32Array, v: number[] ): Float32Array {
    const x = v[0];
    const y = v[1];
    const z = v[2];

    out[0] = a[0] * x;
    out[1] = a[1] * x;
    out[2] = a[2] * x;
    out[3] = a[3] * x;
    out[4] = a[4] * y;
    out[5] = a[5] * y;
    out[6] = a[6] * y;
    out[7] = a[7] * y;
    out[8] = a[8] * z;
    out[9] = a[9] * z;
    out[10] = a[10] * z;
    out[11] = a[11] * z;
    out[12] = a[12];
    out[13] = a[13];
    out[14] = a[14];
    out[15] = a[15];

    return out;
}