Fix tests after the community merges: GPU Pixel Motion Blur without a host, timeline footage kind, effects doc

- GPU Pixel Motion Blur (#695) declined without a host; it now averages the shutter's
  frames like the CPU effect (tests_fx_time::without_a_host).
- add_item_keeps_footage_longer_than_the_comp_at_full_length (#798) built footage with
  the default kind (Still), which adds at comp length; it is a movie.
- docs/effects.md regenerated.

Co-Authored-By: Claude Opus 5.5 <[email protected]>

crates/engine/src/tests_timeline.rs

@@ -973,6 +973,7 @@ fn add_item_keeps_footage_longer_than_the_comp_at_full_length() {
     let f = effectcraft_project::Footage {
         width: 100,
         height: 100,
+        kind: effectcraft_project::FootageKind::Video,
         has_video: true,
         duration: effectcraft_time::Tick::from_seconds_f64(10.0),
         ..Default::default()

crates/gpu/src/fx_time.rs

@@ -45,11 +45,17 @@ pub(crate) fn apply(e: &mut Enc, id: &str, ctx: &EffectCtx, b: GBuf) -> Option<G
             let fd = 1.0 / ctx.fps();
             mean_of(e, ctx, b, &(-back..=fwd).map(|k| ctx.time + k as f64 * fd).collect::<Vec<_>>())
         }
-        // Pixel Motion Blur synthesizes along measured motion vectors (#535); a plan that
-        // cannot be built (no host) declines to the CPU effect.
+        // Pixel Motion Blur synthesizes along measured motion vectors (#535); without a plan (no
+        // host to read neighbouring frames) it averages the shutter's frames, as the CPU effect does.
         "ec.time.pixelmotionblur" => match effectcraft_effects::pmb_plan(ctx) {
             Some(plan) => render_plan(e, &plan),
-            None => None,
+            None => {
+                let angle = if ctx.params.e("shutterControl") == 1 { ctx.params.f("shutterAngle") } else { 180.0 };
+                let n = ctx.params.f("shutterSamples").round().clamp(1.0, 64.0) as usize;
+                let span = angle.clamp(0.0, 720.0) / 360.0 / ctx.fps();
+                let times: Vec<f64> = (0..n).map(|i| ctx.time - span * 0.5 + if n > 1 { span * i as f64 / (n - 1) as f64 } else { span * 0.5 }).collect();
+                mean_of(e, ctx, b, &times)
+            }
         },
         "ec.time.timewarp" => timewarp(e, ctx, b),
         _ => None,

docs/effects.md

@@ -3,7 +3,7 @@
 <!-- Generated from the effect registry (crates/effects/src/catalog.rs); do not edit by hand.
      Regenerate: UPDATE_DOCS=1 cargo test -p effectcraft-effects --lib effects_doc_is_current -->
 
-EffectCraft ships 306 effects with 3014 parameters in total, grouped into the same categories as the Effects & Presets panel. Every effect is our own implementation, written from public behaviour descriptions and standard image-processing literature. Parameter names, order, popup options, units, defaults and ranges follow the reference application so that projects, expressions and muscle memory carry over.
+EffectCraft ships 306 effects with 3017 parameters in total, grouped into the same categories as the Effects & Presets panel. Every effect is our own implementation, written from public behaviour descriptions and standard image-processing literature. Parameter names, order, popup options, units, defaults and ranges follow the reference application so that projects, expressions and muscle memory carry over.
 
 - **GPU**: 280 effects also run on the GPU compositor with identical results.
 - **32**: 306 effects process 32-bit float (HDR, overbright) pixels without clamping.