Accueil / npm / three@0.186.1 / src / nodes / core / StructNode.js
StructNode.js
import Node from './Node.js';
import StructTypeNode from './StructTypeNode.js';
import { nodeObject, nodeProxyConstructor } from '../tsl/TSLCore.js';
import { isArrayAsParameter } from './NodeUtils.js';
/**
* StructNode allows to create custom structures with multiple members.
* This can also be used to define structures in attribute and uniform data.
*
* ```js
* // Define a custom struct
* const BoundingBox = struct( { min: 'vec3', max: 'vec3' } );
*
* // Create a new instance of the struct
* const bb = BoundingBox( vec3( 0 ), vec3( 1 ) ); // style 1
* const bb = BoundingBox( { min: vec3( 0 ), max: vec3( 1 ) } ); // style 2
*
* // Access the struct members
* const min = bb.get( 'min' );
*
* // Assign a new value to a member
* min.assign( vec3() );
* ```
* @augments Node
*/
class StructNode extends Node {
static get type() {
return 'StructNode';
}
constructor( structTypeNode, values ) {
super( 'vec3' );
this.structTypeNode = structTypeNode;
this.values = values;
this.isStructNode = true;
}
generateNodeType( builder ) {
return this.structTypeNode.getNodeType( builder );
}
getMemberType( builder, name ) {
return this.structTypeNode.getMemberType( builder, name );
}
_getChildren() {
// Ensure struct type is the last child for correct code generation order
const children = super._getChildren();
const structTypeProperty = children.find( child => child.childNode === this.structTypeNode );
children.splice( children.indexOf( structTypeProperty ), 1 );
children.push( structTypeProperty );
return children;
}
generate( builder ) {
const nodeVar = builder.getVarFromNode( this );
const structType = nodeVar.type;
const propertyName = builder.getPropertyName( nodeVar );
builder.addLineFlowCode( `${ propertyName } = ${ builder.generateStruct( structType, this.structTypeNode.membersLayout, this.values ) }`, this );
return nodeVar.name;
}
}
export default StructNode;
/**
* TSL function for creating a struct node.
*
* @tsl
* @function
* @param {Object} membersLayout - The layout of the struct members.
* @param {?string} [name=null] - The name of the struct.
* @returns {Function} The struct function.
*/
export const struct = ( membersLayout, name = null ) => {
const structType = new StructTypeNode( membersLayout, name );
const struct = ( ...params ) => {
let values = null;
if ( params.length > 0 ) {
if ( isArrayAsParameter( params ) ) {
values = {};
const names = Object.keys( membersLayout );
for ( let i = 0; i < params.length; i ++ ) {
values[ names[ i ] ] = nodeObject( params[ i ] );
}
} else {
values = params[ 0 ];
}
}
return new StructNode( structType, values );
};
return nodeProxyConstructor( struct, structType );
};