Instance Method

nextDrawable()

Waits until a Metal drawable is available, and then returns it.

Declaration

func nextDrawable() -> CAMetalDrawable?

Return Value

A Metal drawable. Use the drawable’s texture property to configure a MTLRenderPipelineColorAttachmentDescriptor object for rendering to the layer.

Discussion

A CAMetalLayer object maintains an internal pool of textures for displaying layer content, each wrapped in a CAMetalDrawable object. Use this method to retrieve the next available drawable from the pool. If all drawables are in use, the layer waits up to one second for one to become available, after which it returns nil. The allowsNextDrawableTimeout property affects this behavior.

This method returns nil if the layer’s pixelFormat or other properties are invalid.

See Also

Obtaining a Metal Drawable

var maximumDrawableCount: Int

The number of Metal drawables in the resource pool managed by Core Animation.

var allowsNextDrawableTimeout: Bool

A Boolean value that determines whether requests for a new buffer expire if the system can’t satisfy them.