pipeline.md

Pipe

• Composed of tapins
• A pipe has a set of methods to help configure the tapin workflow
  • addTapin(name, tapin)
  • addTapinBefore(before, name, tapin)
  • addTapinAfter(after, name, tapin)
  • replaceTapin(name, tapin)
  • removeTapin(name)
• A tri-pipe also contains methods to configure state and output
  • createState()
  • createOutput()

Tapin

• A tapin is a function that takes data as a parameter
• A tapin is registered in the pipeline with a name
• A tapin must return true/false. If false or nothing is returned, then pipeline will abort.
• A tapin may receive extra input parameters. Example: RenderPipe has ctx and region that are used for render pass context.

TriTapin

• A tritapin is a function that takes input, state, output as parameters
• A tritapin will receive the following 3 input parameters.
  • input
    • Pipeline input
    • Read-only (should not be mutated)
    • Because immutable, input coming from another pipeline don't need to be copied
  • state
    • Pipeline state parameters
    • Can be mutated by a tapin that is used in a latter tapin
    • Can also be used to reduce memory allocation/deallocation
  • output
    • Pipeline output
    • Write-only
    • For layout pipes, the Updater expects a certain set of outputs to be set upon pipeline completion
    • Can also be used to report layout errors