import TempNode from '../core/TempNode.js';
import { vectorComponents } from '../core/constants.js';
/**
* This module is part of the TSL core and usually not used in app level code.
* It represents a flip operation during the shader generation process
* meaning it flips normalized values with the following formula:
* ```
* x = 1 - x;
* ```
* `FlipNode` is internally used to implement any `flipXYZW()`, `flipRGBA()` and
* `flipSTPQ()` method invocations on node objects. For example:
* ```js
* uvNode = uvNode.flipY();
* ```
*
* @augments TempNode
*/
class FlipNode extends TempNode {
static get type() {
return 'FlipNode';
}
/**
* Constructs a new flip node.
*
* @param {Node} sourceNode - The node which component(s) should be flipped.
* @param {String} components - The components that should be flipped e.g. `'x'` or `'xy'`.
*/
constructor( sourceNode, components ) {
super();
/**
* The node which component(s) should be flipped.
*
* @type {Node}
*/
this.sourceNode = sourceNode;
/**
* The components that should be flipped e.g. `'x'` or `'xy'`.
*
* @type {String}
*/
this.components = components;
}
/**
* This method is overwritten since the node type is inferred from the source node.
*
* @param {NodeBuilder} builder - The current node builder.
* @return {String} The node type.
*/
getNodeType( builder ) {
return this.sourceNode.getNodeType( builder );
}
generate( builder ) {
const { components, sourceNode } = this;
const sourceType = this.getNodeType( builder );
const sourceSnippet = sourceNode.build( builder );
const sourceCache = builder.getVarFromNode( this );
const sourceProperty = builder.getPropertyName( sourceCache );
builder.addLineFlowCode( sourceProperty + ' = ' + sourceSnippet, this );
const length = builder.getTypeLength( sourceType );
const snippetValues = [];
let componentIndex = 0;
for ( let i = 0; i < length; i ++ ) {
const component = vectorComponents[ i ];
if ( component === components[ componentIndex ] ) {
snippetValues.push( '1.0 - ' + ( sourceProperty + '.' + component ) );
componentIndex ++;
} else {
snippetValues.push( sourceProperty + '.' + component );
}
}
return `${ builder.getType( sourceType ) }( ${ snippetValues.join( ', ' ) } )`;
}
}
export default FlipNode;