Put the whole layout tuning surface on a reusable panel

[matt-edmondson]

Why

The simulation has eighteen settings and no consuming application could reach them without writing its own sliders. The demo had written some — covering fifteen of the eighteen, leaving StabilityThreshold, OverlapMargin and MaxOverlapCorrection unreachable — and every other application would have had to write the same thing again and drift from it.

What

PhysicsSettingsPanel.Draw(ref PhysicsSettings) draws all eighteen, grouped by the force each belongs to and captioned on hover with what moving it does:

Group	Settings
Repulsion	strength, minimum distance
Link springs	spring strength, rest length, left-to-right bias
Link shaping	flattening, flattening margin, untwisting
Gravity	strength, origin anchor
Overlap	clearance, maximum correction
Motion and limits	damping, max force, max speed, substep rate, settled-below

plus the run toggle and a reset that restores the defaults while leaving the run flag alone.

PhysicsSettingsPanel.DrawDiagnostics(engine) reports energy, whether the graph has settled, and the substep count and rate. That readout is what says whether a change helped: a graph that will not settle shows it in the energy long before the eye catches the drift, and one that settles instantly was probably damped into stillness before it finished arranging itself.

Exposing the whole record rather than a chosen subset is deliberate. The forces interact and none can be judged alone — raising repulsion changes what the spring's rest length means, and levelling links only works in the room repulsion made. A setting left off the panel is a setting nobody can reach without recompiling.

Every control marks itself with ktsu.ImGui.Probes, the way the ktsu widgets do rather than the Hexa-backed ones, so a UI test addresses it by the label the user sees instead of by geometry. That is what lets the demo's suite drive all seventeen sliders through the library's own panel — so what is covered is the control a consuming application gets, not a copy of it.

Demo

CleanImNodesDemo now draws that panel instead of its own, losing 203 lines, and keeps only its two presets, which are demo content rather than library surface. Two settings that had been narrowed by float sliders (ImGui edits floats; these are all doubles) now round-trip: a setting the user never touches keeps its full precision rather than being rounded by being looked at.

Verification

• ImGuiAppDemo.UITests Clean ImNodes 4/4 — including a new test that expands each of the six groups and drags every slider in it, and one that checks all five diagnostics readouts render.
• ImGui.NodeEditor.Tests 71/71.
• Solution builds clean in Release.

Two slider labels were made unique along the way (Repulsion strength, Gravity strength): both had been plain "Strength", which is ambiguous to the probe and to a reader following a tooltip.

Not verified visually — this environment is headless. The panel's layout is ordinary ImGui collapsing headers and sliders, but how it reads at the demo's pane width is not something I can check from here.

🤖 Generated with Claude Code

https://claude.ai/code/session_01D2KNUKr1xJPTEdDmeF2tQN

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Generated by Claude Code

[sonarqubecloud]

Quality Gate passed

Issues
0 New issues
0 Accepted issues

Measures
0 Security Hotspots
0.0% Coverage on New Code
0.0% Duplication on New Code

See analysis details on SonarQube Cloud