Merge remote-tracking branch 'origin/master' into worktree-spot-removal

# Conflicts:
#	docs/traceability.md

core/dr-pipeline/src/ops/film_sim.rs

@@ -37,6 +37,23 @@ pub const ID: OpId = OpId("film_sim");
 pub const EXPOSURE: ParamId = ParamId("exposure");
 pub const PRINT_EXPOSURE: ParamId = ParamId("print_exposure");
 pub const PUSH: ParamId = ParamId("push");
+pub const FORMAT: ParamId = ParamId("format");
+
+/// TRACES: FR-DEV-3f
+/// The frames a photograph can be simulated on, smallest first.
+///
+/// A genuinely fixed list, unlike the stocks: nobody invents a film format, so
+/// this is a declared `enum` parameter and gets its control, its place in the
+/// sidecar and its undo step for free. The *sizes* live in `dr_film::Format`;
+/// this crate carries only the names, in the same order.
+static FORMATS: [LocalizedKey; 6] = [
+    LocalizedKey("param.film_sim.format.35mm"),
+    LocalizedKey("param.film_sim.format.645"),
+    LocalizedKey("param.film_sim.format.6x6"),
+    LocalizedKey("param.film_sim.format.6x7"),
+    LocalizedKey("param.film_sim.format.4x5"),
+    LocalizedKey("param.film_sim.format.8x10"),
+];
 
 /// How many samples a characteristic curve carries.
 ///
@@ -70,6 +87,13 @@ static DESCRIPTOR: OpDescriptor = OpDescriptor {
         // actually published: Double-X's measured axis spans about -1 to +2,
         // and beyond a range like that a curve would have to be invented.
         ParamDescriptor::stops("push", "param.film_sim.push", -1.0, 3.0),
+        // TRACES: FR-DEV-3f
+        // Which frame this was taken on — the half of the enlargement a
+        // photograph cannot supply. A crystal is a fixed size in micrometres,
+        // so how grainy a picture looks is film size against output size, and
+        // the same emulsion on 4x5 renders about three times smoother than on
+        // 35mm at the same print.
+        ParamDescriptor::choice("format", "param.film_sim.format", &FORMATS),
     ],
 };
 
@@ -129,6 +153,8 @@ pub struct FilmSim {
     exposure: f32,
     print_exposure: f32,
     push: f32,
+    /// Index into `FORMATS`. Zero is 35 mm, which is the neutral choice.
+    format: f32,
     tables: Option<FilmTables>,
 }
 
@@ -173,6 +199,7 @@ impl Operation for FilmSim {
             EXPOSURE => self.exposure = value,
             PRINT_EXPOSURE => self.print_exposure = value,
             PUSH => self.push = value,
+            FORMAT => self.format = value,
             _ => log::warn!("film_sim: unknown parameter {id}"),
         }
     }
@@ -182,6 +209,7 @@ impl Operation for FilmSim {
             EXPOSURE => self.exposure,
             PRINT_EXPOSURE => self.print_exposure,
             PUSH => self.push,
+            FORMAT => self.format,
             _ => 0.0,
         }
     }