@openhps/core
Version:
Open Hybrid Positioning System - Core component
82 lines (77 loc) • 2.42 kB
JavaScript
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;