buildFunctionCode( shaderNode ) {

		const layout = shaderNode.layout;
		const flowData = this.flowShaderNode( shaderNode );

		const parameters = [];

		for ( const input of layout.inputs ) {

			parameters.push( this.getType( input.type ) + ' ' + input.name );

		}

		//

		const code = `${ this.getType( layout.type ) } ${ layout.name }( ${ parameters.join( ', ' ) } ) {

	${ flowData.vars }

${ flowData.code }
	return ${ flowData.result };

}`;

		//

		return code;

	}
Builds the given shader node.

@param {ShaderNodeInternal} shaderNode - The shader node.
@return {string} The GLSL function code.