Framebuffer

A texture-backed WebGL framebuffer that is both a render destination and a texture source.

Draw into it by passing it as the destination of a ShaderPass.draw (or any consumer of Framebuffer.glFramebuffer), sample from it by passing it as a source (or reading Framebuffer.texture). There is no implicit bind/unbind protocol to sequence.

Contents are premultiplied alpha, matching the rest of the Excalibur WebGL pipeline.

Hierarchy

• Framebuffer
  • MultisampleFramebuffer

Index

Constructors

• constructor

Properties

• bufferFormat
• filtering
• transparency
• wrapping

Accessors

• glFramebuffer
• height
• texelSize
• texture
• width

Methods

• blitToScreen
• clear
• copyToTexture
• dispose
• resize

Constructors

constructor

• Framebuffer(options: FramebufferOptions): Framebuffer

• Parameters

  • options: FramebufferOptions

  Returns Framebuffer

Properties

publicreadonlybufferFormat

bufferFormat: number

Format compatible with the canvas drawing buffer, needed for Framebuffer.blitToScreen

publicreadonlyfiltering

filtering: ImageFiltering

publicreadonlytransparency

transparency: boolean

publicreadonlywrapping

wrapping: ImageWrapConfiguration

Accessors

publicglFramebuffer

• get glFramebuffer(): WebGLFramebuffer

• The framebuffer to bind when drawing into this framebuffer.

  On a MultisampleFramebuffer this is the multisampled renderbuffer framebuffer.

  ---

  Returns WebGLFramebuffer

publicheight

• get height(): number

• Returns number

publictexelSize

• get texelSize(): [texelWidth: number, texelHeight: number]

• [1 / width, 1 / height], useful for passing to shaders that sample neighboring texels (blurs etc.)

  ---

  Returns [texelWidth: number, texelHeight: number]

publictexture

• get texture(): WebGLTexture

• The color texture backing this framebuffer, for sampling as a source.

  On a MultisampleFramebuffer reading this resolves the MSAA renderbuffer first.

  ---

  Returns WebGLTexture

publicwidth

• get width(): number

• Returns number

Methods

publicblitToScreen

• blitToScreen(): void

• Blits the (resolved) contents 1:1 to the canvas drawing buffer

  ---

  Returns void

publicclear

• clear(color?: Color): void

• Clears the framebuffer to the provided color (transparent black by default)

  Leaves this framebuffer bound

  ---

  Parameters

  • optionalcolor: Color

  Returns void

publiccopyToTexture

• copyToTexture(texture: WebGLTexture): void

• Copies the current (resolved) contents into the provided texture, which is reallocated at this framebuffer's dimensions

  ---

  Parameters

  • texture: WebGLTexture

  Returns void

publicdispose

• dispose(): void

• Deletes the GL resources owned by this framebuffer, it cannot be used afterwards

  ---

  Returns void

publicresize

• resize(width: number, height: number): void

• Resize the framebuffer, contents are discarded

  ---

  Parameters

  • width: number

  • height: number

  Returns void