function projection(out, width, height) {
    out[0] = 2 / width;
    out[1] = 0;
    out[2] = 0;
    out[3] = 0;
    out[4] = -2 / height;
    out[5] = 0;
    out[6] = -1;
    out[7] = 1;
    out[8] = 1;
    return out;
  }
Generates a 2D projection matrix with the given bounds

@param {mat3} out mat3 frustum matrix will be written into
@param {number} width Width of your gl context
@param {number} height Height of gl context
@returns {mat3} out