New thickness to chord constraint implementation

[A-CGray]

Purpose

The current thickness to chord constraint implementations has a few limitations:

1. You could only compute thickness to chord along a 1D line.
2. The constraint didn't actually compute an accurate chord length, it just used two points spaced slightly apart in the chordwise direction. This meant you could only use the thickness to chord constraint in the scaled sense (relative to the baseline).

This PR adds a completely new implementation of t/c constraints in DVConstraints. The new implementation basically uses two sets of thickness constraints, one to compute the thicknesses and another to compute the chord lengths.

This new implementation has the following advantages:

1. You can compute thickness to chord over a 1D line or a 2D grid
2. The constraints use leading and trailing edge points to actually compute an accurate chord length and therefore accurate (non-scaled) t/c values
3. The 2D version can compute the max t/c value for each chordwise section using KS aggregation

Technically these changes are backward incompatible because defining the 1D thickness to chord constraints now requires a set of leading and trailing edge coordinates instead of a projection direction and a chord direction. I don't think this is a big issue because these constraints weren't used by many people.

Expected time until merged

Type of change

• Bugfix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Breaking change (non-backwards-compatible fix or feature)
• Code style update (formatting, renaming)
• Refactoring (no functional changes, no API changes)
• Documentation update
• Maintenance update
• Other (please describe)

Testing

I've expanded the existing thickness to chord constraint test to test the new capabilities (2D, section max)

Checklist

• I have run ruff check and ruff format to make sure the Python code adheres to PEP-8 and is consistently formatted
• I have formatted the Fortran code with fprettify or C/C++ code with clang-format as applicable
• I have run unit and regression tests which pass locally with my changes
• I have added new tests that prove my fix is effective or that my feature works
• I have added necessary documentation

[codecov]

Codecov Report

❌ Patch coverage is 91.73554% with 20 lines in your changes missing coverage. Please review.
✅ Project coverage is 69.02%. Comparing base (ee331a6) to head (00aa366).

Files with missing lines	Patch %	Lines
pygeo/constraints/DVCon.py	89.36%	15 Missing ⚠️
pygeo/mphys/mphys_dvgeo.py	33.33%	4 Missing ⚠️
pygeo/constraints/thicknessConstraint.py	98.93%	1 Missing ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##             main     #280      +/-   ##
==========================================
+ Coverage   67.10%   69.02%   +1.92%     
==========================================
  Files          48       48              
  Lines       12378    12492     +114     
==========================================
+ Hits         8306     8623     +317     
+ Misses       4072     3869     -203     

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[Copilot]

Pull Request Overview

This PR adds a new implementation of thickness-to-chord constraints in DVConstraints, providing more accurate chord length computations and 2D grid support. The new implementation uses separate thickness constraints for measuring thickness and chord lengths based on leading/trailing edge points.

• Replaces the previous thickness-to-chord constraint implementation with a more accurate one that computes actual chord lengths
• Adds support for 2D thickness-to-chord constraints with optional section maximum values using KS aggregation
• Updates existing constraint methods to return constraint objects and improves surface projection utilities

Reviewed Changes

Copilot reviewed 6 out of 7 changed files in this pull request and generated 6 comments.

Show a summary per file

File	Description
tests/reg_tests/test_DVConstraints.py	Expands tests to cover new 1D/2D thickness-to-chord constraint variants and adds writeTecplot testing
pygeo/mphys/mphys_dvgeo.py	Adds wrapper methods for new thickness-to-chord constraint functions
pygeo/geo_utils/ffd_generation.py	Updates method name from _generateIntersections to _generateGridIntersections
pygeo/constraints/thicknessConstraint.py	Complete rewrite of ThicknessToChordConstraint class with new architecture
pygeo/constraints/baseConstraint.py	Adds documentation to GeometricConstraint.init method
pygeo/constraints/DVCon.py	Major refactoring with new constraint methods, improved surface projection, and return values

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[Copilot]

Pull Request Overview

Copilot reviewed 6 out of 7 changed files in this pull request and generated 2 comments.

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