test(rtx-fsi): RTX_FSI{2,3}_UMEAN inflow override for the TWIN-1 parameter sweep

case_from_env applies the knob over the case's benchmark inflow; unset, the same f64 flows and both committed defaults are verified digit-identical in vivo (physics lines diff-clean vs same-day baselines; only wall-split timing percentages moved). Physics bands in both tests are guarded to benchmark inflow — an off-benchmark march (the sweep) asserts machinery invariants only; its bands live in the TWIN-1 composition harness (omni-cortex docs/twin_composition_campaign.md). The override prints loudly so sweep logs are self-describing. Co-Authored-By: Claude Fable 5 <[email protected]> Claude-Session: https://claude.ai/code/session_01X2GmJXeQ2njUecEKiJZ1G2
2026-08-31 21:25:30 -07:00
parent 4aec4e589d
commit c08abbdc4f
3 changed files with 42 additions and 7 deletions
@@ -79,6 +79,26 @@ pub const FSI3: BenchmarkCase = BenchmarkCase {
    rigid_drag_reference: 439.45,
 };

+/// `RTX_{prefix}_UMEAN` over the case's benchmark inflow — TWIN-1's
+/// sweep parameter (`docs/twin_composition_campaign.md` in omni-cortex).
+/// Unset, the case comes back unchanged: the same f64 flows and the
+/// march is digit-identical by construction (and verified in vivo on
+/// both committed defaults). When set, the march's printed rigid-drag
+/// reference still names the BENCHMARK value, which only applies at the
+/// case's own inflow — the override line below keeps logs honest.
+pub fn case_from_env(prefix: &str, case: BenchmarkCase) -> BenchmarkCase {
+    let u_mean = env_or(&format!("RTX_{prefix}_UMEAN"), case.u_mean);
+    if u_mean.to_bits() != case.u_mean.to_bits() {
+        println!(
+            "  {} u_mean OVERRIDDEN to {u_mean} (benchmark {}; Re = {:.0})",
+            case.name,
+            case.u_mean,
+            100.0 * u_mean
+        );
+    }
+    BenchmarkCase { u_mean, ..case }
+}
+
 pub fn circle_sdf(x: f64, y: f64) -> f64 {
    ((x - 0.2).powi(2) + (y - 0.2).powi(2)).sqrt() - 0.05
 }