Function rotateBetween

src/plots/geo/zoom.js:344–351

(a, b)

}

function rotateBetween(a, b) {
    if(!a || !b) return;
    var axis = cross(a, b);
    var norm = Math.sqrt(dot(axis, axis));
    var halfgamma = 0.5 * Math.acos(Math.max(-1, Math.min(1, dot(a, b))));
    var k = Math.sin(halfgamma) / norm;
    return norm && [Math.cos(halfgamma), axis[2] * k, -axis[1] * k, axis[0] * k];
}

// input:
//   rotateAngles: a calculated set of Euler angles