Add terminal constraint support to IPDDP

[astomodynamics]

Summary

Add terminal constraint support to the IPDDP solver and factor duplicated CDDP/interior-point utility logic into shared helpers.

Changes

• extend IPDDP to handle terminal equality and terminal inequality constraints in its single-shooting interior-point formulation
• expose the terminal constraint types through the public aggregate header and update terminal constraint overrides to match the indexed constraint interface
• add IPDDP options and solver bookkeeping needed for terminal constraint residuals, filter metrics, barrier merit evaluation, and step-size control
• extract shared line-search, warm-start trajectory repair, constraint bookkeeping, filter maintenance, iteration printing, and max-violation logic into cddp_context_utils and interior_point_utils
• add regression coverage for stale warm-start trajectory dimensions and terminal-inequality-only IPDDP solves

Test Plan

• cmake --build build --target test_cddp_core
• ctest --test-dir build -R "CDDPCoreTest\\.SolveReinitializesStaleTrajectoryDimensions" --output-on-failure

Related Issues

• None referenced in this branch.

How to Test

• configure a CDDP problem with solve("IPDDP")
• add a TerminalEqualityConstraint or TerminalInequalityConstraint via addTerminalConstraint(...)
• verify the returned solution status is acceptable and the terminal state satisfies the configured bound or equality residual
• run cmake --build build --target test_cddp_core test_ipddp_solver
• run ctest --test-dir build -R "CDDPCoreTest\\.SolveReinitializesStaleTrajectoryDimensions|IPDDPTest\\.SolveWithTerminalInequalityOnly" --output-on-failure

Screenshots/Videos

• None.

Additional Notes

• The branch also includes the shared helper extraction commit that removes duplicated CDDP and interior-point utility logic introduced during the terminal-constraint work.

[chatgpt-codex-connector]

💡 Codex Review

Here are some automated review suggestions for this pull request.

Reviewed commit: 9c9242f2d9

ℹ️ About Codex in GitHub

Your team has set up Codex to review pull requests in this repo. Reviews are triggered when you

• Open a pull request for review
• Mark a draft as ready
• Comment "@codex review".

If Codex has suggestions, it will comment; otherwise it will react with 👍.

Codex can also answer questions or update the PR. Try commenting "@codex address that feedback".

[Copilot]

Pull request overview

This PR extends the CDDP interior-point solver stack by adding terminal constraint support to IPDDP (terminal equalities + terminal inequalities) and refactors duplicated CDDP/interior-point utilities into shared helper modules.

Changes:

• Add terminal equality/inequality constraint handling to IPDDPSolver, including new bookkeeping for residuals, filter metrics, merit evaluation, and step-size control.
• Extract shared CDDP context utilities (line-search alphas, warm-start trajectory shaping, constraint add/remove) and shared interior-point filter/printing helpers.
• Add regression tests for stale warm-start trajectory dimensions and terminal-inequality-only IPDDP solves, plus tighten an existing IPDDP regression assertion.

Reviewed changes

Copilot reviewed 14 out of 15 changed files in this pull request and generated 5 comments.

Show a summary per file

File	Description
src/cddp_core/ipddp_solver.cpp	Major solver changes: terminal constraint support + refactor to shared interior-point helpers
include/cddp-cpp/cddp_core/ipddp_solver.hpp	New solver state for terminal constraints, filter metrics, and forward-pass failure handling
include/cddp-cpp/cddp_core/options.hpp	Expands IPDDP options surface (new knobs for filter/barrier/warmstart, etc.)
include/cddp-cpp/cddp_core/terminal_constraint.hpp	Updates terminal constraint overrides to match indexed constraint interface
src/cddp_core/msipddp_solver.cpp	Refactor to shared interior-point utils (filter, printing, max-violation)
src/cddp_core/interior_point_utils.hpp/.cpp	New shared interior-point helper implementations
src/cddp_core/cddp_core.cpp	Refactor duplicated logic to cddp_context_utils helpers
src/cddp_core/cddp_context_utils.hpp/.cpp	New shared helpers for line-search alphas, trajectory shaping, and constraint bookkeeping
tests/cddp_core/test_ipddp_solver.cpp	Adds terminal-inequality-only regression test + strengthens an existing SolveCar check
tests/cddp_core/test_cddp_core.cpp	Adds regression test ensuring stale trajectory dimensions are repaired on solve
include/cddp-cpp/cddp.hpp	Exposes terminal constraints via aggregate public header
CMakeLists.txt	Adds new helper .cpp files to the core library sources

---

💡 Add Copilot custom instructions for smarter, more guided reviews. Learn how to get started.