three.js/examples/jsm/nodes/inputs/TextureNode.js

import { InputNode } from '../core/InputNode.js';
import { UVNode } from '../accessors/UVNode.js';
import { ColorSpaceNode } from '../utils/ColorSpaceNode.js';
import { ExpressionNode } from '../core/ExpressionNode.js';

function TextureNode( value, uv, bias, project ) {

	InputNode.call( this, 'v4', { shared: true } );

	this.value = value;
	this.uv = uv || new UVNode();
	this.bias = bias;
	this.project = project !== undefined ? project : false;

}

TextureNode.prototype = Object.create( InputNode.prototype );
TextureNode.prototype.constructor = TextureNode;
TextureNode.prototype.nodeType = 'Texture';

TextureNode.prototype.getTexture = function ( builder, output ) {

	return InputNode.prototype.generate.call( this, builder, output, this.value.uuid, 't' );

};

TextureNode.prototype.generate = function ( builder, output ) {

	if ( output === 'sampler2D' ) {

		return this.getTexture( builder, output );

	}

	var tex = this.getTexture( builder, output ),
		uv = this.uv.build( builder, this.project ? 'v4' : 'v2' ),
		bias = this.bias ? this.bias.build( builder, 'f' ) : undefined;

	if ( bias === undefined && builder.context.bias ) {

		bias = builder.context.bias.setTexture( this ).build( builder, 'f' );

	}

	var method, code;

	if ( this.project ) method = 'texture2DProj';
	else method = bias ? 'tex2DBias' : 'tex2D';

	if ( bias ) code = method + '( ' + tex + ', ' + uv + ', ' + bias + ' )';
	else code = method + '( ' + tex + ', ' + uv + ' )';

	// add a custom context for fix incompatibility with the core
	// include ColorSpace function only for vertex shader (in fragment shader color space functions is added automatically by core)
	// this should be removed in the future
	// context.include is used to include or not functions if used FunctionNode
	// context.ignoreCache =: not create temp variables nodeT0..9 to optimize the code
	var context = { include: builder.isShader( 'vertex' ), ignoreCache: true };
	var outputType = this.getType( builder );

	builder.addContext( context );

	this.colorSpace = this.colorSpace || new ColorSpaceNode( new ExpressionNode( '', outputType ) );
	this.colorSpace.fromDecoding( builder.getTextureEncodingFromMap( this.value ) );
	this.colorSpace.input.parse( code );

	code = this.colorSpace.build( builder, outputType );

	// end custom context

	builder.removeContext();

	return builder.format( code, outputType, output );

};

TextureNode.prototype.copy = function ( source ) {

	InputNode.prototype.copy.call( this, source );

	if ( source.value ) this.value = source.value;

	this.uv = source.uv;

	if ( source.bias ) this.bias = source.bias;
	if ( source.project !== undefined ) this.project = source.project;

	return this;

};

TextureNode.prototype.toJSON = function ( meta ) {

	var data = this.getJSONNode( meta );

	if ( ! data ) {

		data = this.createJSONNode( meta );

		if ( this.value ) data.value = this.value.uuid;

		data.uv = this.uv.toJSON( meta ).uuid;
		data.project = this.project;

		if ( this.bias ) data.bias = this.bias.toJSON( meta ).uuid;

	}

	return data;

};

export { TextureNode };