Class: ShaderPlugin<ResultT>

@geenee/armature.ShaderPlugin

Generic shader plugin

ShaderPlugin is a specialization of a Plugin for ShaderRenderer. They apply complex computationally demanding post-processing effects to the input stream. For example, simple mono-chrome or sepia effects, or more complex face beatification and dynamic geometry filters. ShaderPlugin shares webgl context with the main renderer. Basic implementation uses ShaderProgram created for shaders provided to plugin's constructor. Plugins are organized in chain within ShaderRenderer, input of the next shader is output of the previous and initial input is original video image, output of the last plugin is rendered.

Type parameters

Name	Type	Description
ResultT	extends Object = {}	Type of processing results

Hierarchy

• Plugin<ResultT>

  ↳ ShaderPlugin

Constructors

constructor

• new ShaderPlugin<ResultT>(inputs?, uniforms?, fragSrc?, vertSrc?)

Constructor

Type parameters

Name	Type
ResultT	extends Object = {}

Parameters

Name	Type	Description
inputs?	string[]	Shader texture inputs (names of sampler uniforms)
uniforms?	Object	Shader uniforms as name-type map object
fragSrc?	string	Code of fragment shader (copy shader by default)
vertSrc?	string	Vertex shader source (copy shader by default)

Overrides

Plugin.constructor

Properties

fragSrc

• Protected Optional fragSrc: string

---

inputs

• Protected Optional inputs: string[]

---

loaded

• loaded: boolean = false

Loaded state

Inherited from

Plugin.loaded

---

renderer

• Protected Optional renderer: Renderer<ResultT>

Renderer loaded the plugin

Inherited from

Plugin.renderer

---

shader

• Protected Optional shader: ShaderProgram

Rendering shader

---

size

• Protected size: Size

Image size

---

uniforms

• Protected Optional uniforms: Object

Index signature

▪ [key: string]: UniformType

---

vertSrc

• Protected Optional vertSrc: string

Methods

dispose

▸ dispose(): void

Dispose video plugin

Returns

void

Inherited from

Plugin.dispose

---

load

▸ load(renderer): Promise<void>

Initialize plugin

Initializes resources required for shader effect. Acquires webgl context of the main webgl renderer. Basic implementation creates and compiles rendering program for shaders provided to plugin's constructor. Overridden by derived classes for particular effect.

Parameters

Name	Type	Description
renderer	Renderer<ResultT>	Renderer this plugin is attached to

Returns

Promise<void>

Promise resolving when initialization is finished

Overrides

Plugin.load

---

process

▸ process(result, input): boolean

Process the image

Main method implementing webgl shader effect or filter. It's called by update() and should be overridden to add custom logic. process() should return true if effect is successfully applied and false if it is skipped, for example, if effect applies only when result is not empty.

Parameters

Name	Type	Description
result	ResultT	Results of video processing
input	WebGLTexture	Current image texture

Returns

boolean

True on success, false otherwise

---

setupVideo

▸ setupVideo(size): void

Set video size

Adjusts shader and texture to a new size.

Parameters

Name	Type
size	Size

Returns

void

Overrides

Plugin.setupVideo

---

unload

▸ unload(): void

Reset plugin

Releases all resources and instances created in load(). Overridden by derived classes for particular effect.

Returns

void

Overrides

Plugin.unload

---

update

▸ update(result, stream): Promise<void>

Update the image

Main method implementing webgl shader effect or filter. ShaderRenderer has current image texture that will be rendered. ShaderPlugin uses current texture as input and writes results to ShaderPlugin#output. ShaderPlugin#output becomes new current texture of ShaderRenderer. This way all ShaderPlugins attached to renderer organize a chain of effects applied on top of each other. Method process() implements shader effect itself, it's intended to be overridden by effect authors.

Parameters

Name	Type	Description
result	ResultT	Results of video processing
stream	HTMLCanvasElement	Captured video frame

Returns

Promise<void>

Promise resolving when update is finished

Overrides

Plugin.update