id: view_transform
order: 200
# A `rust:` node publishes its own descriptor; its attributes are on the type
# in `../src/ops/view_transform.rs`.
rust: ViewTransform

why_rust: |
  It is composed at its defaults — a photograph with no view transform is a
  scan, not a picture — which is `Stage::View`, and a declaration has no way to
  say it. Its three uniforms are also the solution of two equations rather than
  expressions over its parameters (`dr_pipeline::view::Sigmoid::new`).

placement: |
  Last, after every scene operation and, when there is one, after the detail
  stage (D19, FR-DEV-3j). It is the one stage allowed to map scene-linear colour
  to a display range, so anything after it would be working on a rendering.
  The order here only places it in the panel; the composer puts every
  `Stage::View` node at the end whatever its number says.