// constantly re-orient the avatar's orientation such that UP points out from some center
var GRAVITATIONAL_CENTER = { x: 20.0, y: 20.0, z: 20.0 };
function updateAvatarGravity(dt) {
    var upOffset = Vec3.subtract(MyAvatar.position, GRAVITATIONAL_CENTER);
    var orientation = MyAvatar.orientation;
    var oldUp = Quat.getUp(orientation);
    var deltaRotation = Quat.rotationBetween(oldUp, upOffset);
    MyAvatar.orientation = Quat.multiply(deltaRotation, MyAvatar.orientation);
}
Script.update.connect(updateAvatarGravity);


// Create a spherical planet
var PLANET_RADIUS = 20.0;
var SKY_RADIUS = 25.0;
var MOON_RADIUS = 4.0;

var fortyTwoDirections = [
	{ x: 0.000000, y: -0.000000, z: -1.000000 },
	{ x: 0.723608, y: -0.525725, z: -0.447219 },
	{ x: -0.276388, y: -0.850649, z: -0.447219 },
	{ x: -0.894426, y: -0.000000, z: -0.447216 },
	{ x: -0.276388, y: 0.850649, z: -0.447220 },
	{ x: 0.723608, y: 0.525725, z: -0.447219 },
	{ x: 0.276388, y: -0.850649, z: 0.447220 },
	{ x: -0.723608, y: -0.525725, z: 0.447219 },
	{ x: -0.723608, y: 0.525725, z: 0.447219 },
	{ x: 0.276388, y: 0.850649, z: 0.447219 },
	{ x: 0.894426, y: 0.000000, z: 0.447216 },
	{ x: -0.000000, y: 0.000000, z: 1.000000 },
	{ x: 0.425323, y: -0.309011, z: -0.850654 },
	{ x: -0.162456, y: -0.499995, z: -0.850654 },
	{ x: 0.262869, y: -0.809012, z: -0.525738 },
	{ x: 0.425323, y: 0.309011, z: -0.850654 },
	{ x: 0.850648, y: -0.000000, z: -0.525736 },
	{ x: -0.525730, y: -0.000000, z: -0.850652 },
	{ x: -0.688190, y: -0.499997, z: -0.525736 },
	{ x: -0.162456, y: 0.499995, z: -0.850654 },
	{ x: -0.688190, y: 0.499997, z: -0.525736 },
	{ x: 0.262869, y: 0.809012, z: -0.525738 },
	{ x: 0.951058, y: 0.309013, z: 0.000000 },
	{ x: 0.951058, y: -0.309013, z: 0.000000 },
	{ x: 0.587786, y: -0.809017, z: 0.000000 },
	{ x: 0.000000, y: -1.000000, z: 0.000000 },
	{ x: -0.587786, y: -0.809017, z: 0.000000 },
	{ x: -0.951058, y: -0.309013, z: -0.000000 },
	{ x: -0.951058, y: 0.309013, z: -0.000000 },
	{ x: -0.587786, y: 0.809017, z: -0.000000 },
	{ x: -0.000000, y: 1.000000, z: -0.000000 },
	{ x: 0.587786, y: 0.809017, z: -0.000000 },
	{ x: 0.688190, y: -0.499997, z: 0.525736 },
	{ x: -0.262869, y: -0.809012, z: 0.525738 },
	{ x: -0.850648, y: 0.000000, z: 0.525736 },
	{ x: -0.262869, y: 0.809012, z: 0.525738 },
	{ x: 0.688190, y: 0.499997, z: 0.525736 },
	{ x: 0.525730, y: 0.000000, z: 0.850652 },
	{ x: 0.162456, y: -0.499995, z: 0.850654 },
	{ x: -0.425323, y: -0.309011, z: 0.850654 },
	{ x: -0.425323, y: 0.309011, z: 0.850654 },
	{ x: 0.162456, y: 0.499995, z: 0.85065 }
];

var MOON_ORBIT_RADIUS = SKY_RADIUS + MOON_RADIUS;
var LIFETIME = 600;

var planetProperties = {
    name: "planet",
    type : "Sphere",
    dimensions : { x: 2 * PLANET_RADIUS, y: 2 * PLANET_RADIUS, z: 2 * PLANET_RADIUS },
    position : GRAVITATIONAL_CENTER,
    lifetime : LIFETIME,
    color : { red: 180, green: 180, blue: 180 }
};
Entities.addEntity(planetProperties);

var numMoons = fortyTwoDirections.length;
for (var i = 0; i < numMoons; ++i) {
    var direction = fortyTwoDirections[i];
    print("adebug dir = < " + direction.x + ", " + direction.y + ", " + direction.z + " >");
    var moonPosition = {
        x: GRAVITATIONAL_CENTER.x + MOON_ORBIT_RADIUS * direction.x,
        y: GRAVITATIONAL_CENTER.y + MOON_ORBIT_RADIUS * direction.y,
        z: GRAVITATIONAL_CENTER.z + MOON_ORBIT_RADIUS * direction.z
    };

    var moonColor = {
        red: 255 * (direction.x + 1) / 2,
        green: 255 * (direction.y + 1) / 2,
        blue: 255 * (direction.z + 1) / 2
    };

    var moonProperties = {
        name: "moon",
        type: "Sphere",
        dimensions: { x: 2 * MOON_RADIUS, y: 2 * MOON_RADIUS, z: 2 * MOON_RADIUS },
        position: moonPosition,
        lifetime: LIFETIME,
        color : moonColor
    };
    Entities.addEntity(moonProperties);
}