three
Version:
JavaScript 3D library
208 lines (149 loc) • 4.27 kB
JavaScript
import Node from './Node.js';
import { addMethodChaining, nodeProxy } from '../tsl/TSLCore.js';
/**
* Class for representing shader variables as nodes. Variables are created from
* existing nodes like the following:
*
* ```js
* const depth = sampleDepth( uvNode ).toVar( 'depth' );
* ```
*
* @augments Node
*/
class VarNode extends Node {
static get type() {
return 'VarNode';
}
/**
* Constructs a new variable node.
*
* @param {Node} node - The node for which a variable should be created.
* @param {?string} [name=null] - The name of the variable in the shader.
* @param {boolean} [readOnly=false] - The read-only flag.
*/
constructor( node, name = null, readOnly = false ) {
super();
/**
* The node for which a variable should be created.
*
* @type {Node}
*/
this.node = node;
/**
* The name of the variable in the shader. If no name is defined,
* the node system auto-generates one.
*
* @type {?string}
* @default null
*/
this.name = name;
/**
* `VarNode` sets this property to `true` by default.
*
* @type {boolean}
* @default true
*/
this.global = true;
/**
* This flag can be used for type testing.
*
* @type {boolean}
* @readonly
* @default true
*/
this.isVarNode = true;
/**
*
* The read-only flag.
*
* @type {boolean}
* @default false
*/
this.readOnly = readOnly;
}
getMemberType( builder, name ) {
return this.node.getMemberType( builder, name );
}
getElementType( builder ) {
return this.node.getElementType( builder );
}
getNodeType( builder ) {
return this.node.getNodeType( builder );
}
generate( builder ) {
const { node, name, readOnly } = this;
const { renderer } = builder;
const isWebGPUBackend = renderer.backend.isWebGPUBackend === true;
let isDeterministic = false;
let shouldTreatAsReadOnly = false;
if ( readOnly ) {
isDeterministic = builder.isDeterministic( node );
shouldTreatAsReadOnly = isWebGPUBackend ? readOnly : isDeterministic;
}
const vectorType = builder.getVectorType( this.getNodeType( builder ) );
const snippet = node.build( builder, vectorType );
const nodeVar = builder.getVarFromNode( this, name, vectorType, undefined, shouldTreatAsReadOnly );
const propertyName = builder.getPropertyName( nodeVar );
let declarationPrefix = propertyName;
if ( shouldTreatAsReadOnly ) {
if ( isWebGPUBackend ) {
declarationPrefix = isDeterministic
? `const ${ propertyName }`
: `let ${ propertyName }`;
} else {
const count = builder.getArrayCount( node );
declarationPrefix = `const ${ builder.getVar( nodeVar.type, propertyName, count ) }`;
}
}
builder.addLineFlowCode( `${ declarationPrefix } = ${ snippet }`, this );
return propertyName;
}
}
export default VarNode;
/**
* TSL function for creating a var node.
*
* @tsl
* @function
* @param {Node} node - The node for which a variable should be created.
* @param {?string} name - The name of the variable in the shader.
* @returns {VarNode}
*/
const createVar = /*@__PURE__*/ nodeProxy( VarNode );
/**
* TSL function for creating a var node.
*
* @tsl
* @function
* @param {Node} node - The node for which a variable should be created.
* @param {?string} name - The name of the variable in the shader.
* @returns {VarNode}
*/
export const Var = ( node, name = null ) => createVar( node, name ).toStack();
/**
* TSL function for creating a const node.
*
* @tsl
* @function
* @param {Node} node - The node for which a constant should be created.
* @param {?string} name - The name of the constant in the shader.
* @returns {VarNode}
*/
export const Const = ( node, name = null ) => createVar( node, name, true ).toStack();
// Method chaining
addMethodChaining( 'toVar', Var );
addMethodChaining( 'toConst', Const );
// Deprecated
/**
* @tsl
* @function
* @deprecated since r170. Use `Var( node )` or `node.toVar()` instead.
*
* @param {any} node
* @returns {VarNode}
*/
export const temp = ( node ) => { // @deprecated, r170
console.warn( 'TSL: "temp( node )" is deprecated. Use "Var( node )" or "node.toVar()" instead.' );
return createVar( node );
};
addMethodChaining( 'temp', temp );