Curves: Added serialization/ deserialization

[Mugen87]

This PR adds serialization/ deserialization for all curve entities. It's now possible to store and load ShapeGeometry and ShapeBufferGeometry.

The implementation allows to perform serialization/ deserialization on all hierarchy levels (Curve, CurvePath, Path, Shape) with .toJSON() and .fromJSON() methods.

I'll consider ExtrudeGeometry in a separate PR.

Demo: https://jsfiddle.net/ht3zuzkr/2/

[Mugen87]

This PR directly addresses #8007 since ObjectLoader can now load ShapeGeometry and ShapeBufferGeometry.

[mrdoob]

Hmm... It's kind of tempting to move shapes to its own group (along geometries and materials in the JSON format. In order to support this we'll probably need to add a UUID to Shape too. Would that make things too complicated?

[Mugen87]

Okay, I've changed the code so shapes are stored in their own group. ShapeGeometry and ShapeBufferGeometry now refer with uuids to their shapes.

Updated Demo: https://jsfiddle.net/ht3zuzkr/2/

[Mugen87]

@mrdoob Is the PR now okay like this? 😊

[mrdoob]

Checking!

[mrdoob]

How about adding this in ShapeBufferGeometry's own toJSON()?

ShapeBufferGeometry.prototype.toJSON = function () {

	var data = BufferGeometry.prototype.toJSON.call( this );

	data.shapes = [];

	if ( Array.isArray( shapes ) ) {

		for ( var i = 0, l = shapes.length; i < l; i ++ ) {

			var shape = shapes[ i ];

			data.shapes.push( shape.uuid );

		}

	} else {

		data.shapes.push( shapes.uuid );

	}

	return data;

}

I think that should work?

[Mugen87]

Yes. Indeed, it's better to place this code not in Geometry or BufferGeometry but in ShapeGeometry.

[mrdoob]

Same here...

[mrdoob]

Apart from these two. It's looking good to me! 👌

[Mugen87]

Done! Updated Demo https://jsfiddle.net/ht3zuzkr/2/

The PR performs no changes to Geometry or BufferGeometry anymore 😊

[mrdoob]

What's this array for? 🤔

[Mugen87]

Oh, this is a remnant of a previous solution. I'll remove it...

[mrdoob]

Beautiful! 😊

[mrdoob]

Thanks!