Chapter 235: TextureNode

Core Idea

This type of uniform node represents a 2D texture.

Key Concepts

biasNode : Node.<float>: Represents the bias to be applied during level-of-detail computation.
compareNode : Node.<float>: Represents a reference value a texture sample is compared to.
depthNode : Node.<int>: When using texture arrays, the depth node defines the layer to select.
gatherNode : Node.<int>: Represents the optional index constant of the channel to gather. This must be in range [0, 3] and a compile-time constant.
gradNode : Array.<Node.<vec2>>: When defined, a texture is sampled using explicit gradients.
isTextureNode : boolean (readonly): This flag can be used for type testing.
levelNode : Node.<int>: Represents the mip level that should be selected.
offsetNode : Node.<(ivec2|ivec3)>: Represents the optional texel offset applied to the unnormalized texture coordinate before sampling the texture.
referenceNode : Node: The reference node.
sampler : boolean: Whether texture values should be sampled or fetched.

Reference Tables

Constructor

Signature
`new TextureNode( value : Texture, uvNode : Node.<(vec2

Properties

Property	Description
`.biasNode : Node.<float>`	Represents the bias to be applied during level-of-detail computation.
`.compareNode : Node.<float>`	Represents a reference value a texture sample is compared to.
`.depthNode : Node.<int>`	When using texture arrays, the depth node defines the layer to select.
`.gatherNode : Node.<int>`	Represents the optional index constant of the channel to gather. This must be in range [0, 3] and a compile-time constant.
`.gradNode : Array.<Node.<vec2>>`	When defined, a texture is sampled using explicit gradients.
`.isTextureNode : boolean (readonly)`	This flag can be used for type testing.
`.levelNode : Node.<int>`	Represents the mip level that should be selected.
`.offsetNode : Node.<(ivec2	ivec3)>`
`.referenceNode : Node`	The reference node.
`.sampler : boolean`	Whether texture values should be sampled or fetched.
`.updateMatrix : boolean`	Whether the uv transformation matrix should be automatically updated or not. Use `setUpdateMatrix()` if you want to change the value of the property.
`.updateType : string`	By default the `update()` method is not executed. Depending on whether a uv transformation matrix and/or flipY is applied, `update()` is executed per object.
`.uvNode : Node.<(vec2	vec3)>`
`.value : Texture`	The texture value.

Methods

Method	Description
`.bias( biasNode : Node.<float> ) : TextureNode`	Samples the texture with the given bias.
`.blur( amountNode : Node.<float> ) : TextureNode`	Samples a blurred version of the texture by defining an internal bias.
`.clone() : TextureNode`	Clones the texture node.
`.compare( compareNode : Node.<float> ) : TextureNode`	Samples the texture by executing a compare operation.
`.depth( depthNode : Node.<int> ) : TextureNode`	Samples the texture by defining a depth node.
`.gather( gatherNode : Node.<int> ) : TextureNode`	Gathers four texels from the texture.
`.generate( builder : NodeBuilder, output : string ) : string`	Generates the code snippet of the texture node.
`.generateNodeType( builder : NodeBuilder ) : string`	Overwritten since the node type is inferred from the texture type.
`.generateOffset( builder : NodeBuilder, offsetNode : Node ) : string`	Generates the offset code snippet.
`.generateSnippet( builder : NodeBuilder, textureProperty : string, uvSnippet : string, levelSnippet : string, biasSnippet : string, depthSnippet : string, compareSnippet : string, gradSnippet : Array.<string>, gatherSnippet : string, offsetSnippet : string, flipYSnippet : string ) : string`	Generates the snippet for the texture sampling.
`.generateUV( builder : NodeBuilder, uvNode : Node ) : string`	Generates the uv code snippet.
`.getBase() : TextureNode`	Returns the base texture of this node.
`.getDefaultUV() : AttributeNode.<vec2>`	Returns a default uvs based on the current texture's channel.
`.getInputType( builder : NodeBuilder ) : string`	Overwrites the default implementation to return a fixed value `'texture'`.
`.getSampler() : boolean`	Returns the sampler value.
`.getTransformedUV( uvNode : Node ) : Node`	Transforms the given uv node with the texture transformation matrix.
`.getUniformHash( builder : NodeBuilder ) : string`	Overwritten since the uniform hash is defined by the texture's UUID.
`.grad( gradNodeX : Node.<vec2>, gradNodeY : Node.<vec2> ) : TextureNode`	Samples the texture using an explicit gradient.
`.level( levelNode : Node.<int> ) : TextureNode`	Samples a specific mip of the texture.
`.load( uvNode : Node.<uvec2> ) : TextureNode`	TSL function for creating a texture node that fetches/loads texels without interpolation.
`.offset( offsetNode : Node.<ivec2> ) : TextureNode`	Samples the texture by defining an offset node.
`.sample( uvNode : Node ) : TextureNode`	Samples the texture with the given uv node.
`.setSampler( value : boolean ) : TextureNode`	Sets the sampler value.
`.setUpdateMatrix( value : boolean ) : TextureNode`	Defines whether the uv transformation matrix should automatically be updated or not.
`.setup( builder : NodeBuilder )`	Setups texture node by preparing the internal nodes for code generation.
`.setupUV( builder : NodeBuilder, uvNode : Node ) : Node`	Setups the uv node. Depending on the backend as well as texture's image and type, it might be necessary to modify the uv node for correct sampling.
`.size( levelNode : Node.<int> ) : TextureSizeNode`	Returns the texture size of the requested level.
`.update()`	The update is used to implement the update of the uv transformation matrix.
`.updateReference( state : any ) : Texture`	Overwritten to always return the texture reference of the node.

Key Takeaways

TextureNode extends: EventDispatcher → Node → InputNode → UniformNode
Most relevant properties: biasNode, compareNode, depthNode, gatherNode.
Key methods: bias, blur, clone, compare.

Connects To

EventDispatcher: parent class
Node: parent class
InputNode: parent class
UniformNode: parent class
Source: src/nodes/accessors/TextureNode.js