Beam justification

[oleandor]

I will look into a fix for this.

[oleandor]

Justification Refactor & Flush Handling -- Implementation Plan

Goal

Unify how Ada handles beam justification and numeric eccentricities
(e1, e2) so that:

• Ada COG calculation
• Ada viewer / GLB export
• IFC export
• Genie XML export/import roundtrip

are all consistent and deterministic.

We will:

• Introduce FLUSH_TOP and FLUSH_BOTTOM
• Keep Justification.FLUSH_OFFSET temporarily for verification and
  migration
• Materialize numeric offsets (e1, e2) inside Ada when needed
• Keep OffsetHelper unchanged for now
• Ensure "top" direction matches Genie interpretation exactly

---

Core Design Principles

1. Separation of Concerns

Semantic Intent

beam.justification expresses placement intent: - NA - TOS -
CUSTOM - UNSET - FLUSH_OFFSET (legacy, temporary) - FLUSH_TOP
(new) - FLUSH_BOTTOM (new)

Resolved Geometry

beam.e1 and beam.e2 represent numeric eccentricities and are the
source of truth for: - Geometry - COG - GLB - IFC - Viewer

All geometry systems must rely on numeric offsets --- never directly on
flush semantics.

---

Direction Convention

"Top" direction must match Genie interpretation.

Definition: - beam.up is the local beam Z-axis. - FLUSH_TOP means
offset in +beam.up direction. - FLUSH_BOTTOM means offset in -beam.up
direction.

This convention must remain identical to Genie behavior to avoid
confusion.

---

Implementation Phases

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Phase 0 -- Lock Down Flush Definitions

Create a reference table defining:

• For each section type:
  • What FLUSH_TOP means
  • What FLUSH_BOTTOM means
  • Whether special handling is required (ANGULAR, TPROFILE,
    unsymmetric I)

This table becomes the single source of truth.

---

Phase 1 -- Extend Justification Enum

Add:

• FLUSH_TOP
• FLUSH_BOTTOM

Keep: - FLUSH_OFFSET temporarily for validation and comparison.

Update from_str() to accept: - "flush top" - "flush bottom" - keep
"flush offset" mapped to legacy value

---

Phase 2 -- Introduce resolve_justification()

Rename get_offset_from_justification() to:

resolve_justification(beam)

Responsibilities:

• Convert semantic justification → numeric local offset
• Use beam local Z-axis (beam.up)
• Handle special section types (ANGULAR, TPROFILE, unsymm I)
• Do NOT use face normals
• Do NOT modify OffsetHelper

This function becomes the canonical justification resolver.

---

Phase 3 -- Materialize Numeric Offsets

When a beam has:

• Justification in {FLUSH_TOP, FLUSH_BOTTOM, TOS}
• And e1/e2 are not already defined

Then:

• Compute numeric offset using resolve_justification()
• Assign beam.e1 and beam.e2
• Preserve justification value for roundtrip export

This must happen during:

• Beam construction (Para model)
• Genie XML import

After this phase:

All Ada beams used for geometry must have numeric e1/e2 defined.

---

Phase 4 -- Genie XML Import Update

When reading:

<aligned_curve_offset alignment="flush_top|flush_bottom">

Do:

1. Map to Justification.FLUSH_TOP or FLUSH_BOTTOM
2. Immediately materialize numeric offsets
3. Store justification on beam
4. Do NOT rely on OffsetHelper for resolving flush

This fixes second-pass COG mismatch.

---

Phase 5 -- Verify All Consumers

Ensure the following rely only on numeric offsets:

• GLB export
• IFC export
• Ada viewer
• COG calculation

Remove any logic that tries to interpret flush semantics directly.

---

Phase 6 -- Keep Genie Export Compatible

For now:

• If justification is FLUSH_TOP or FLUSH_BOTTOM
• Write <aligned_curve_offset> in Genie XML
• Do not write constant offsets

Keep current exporter logic temporarily.

Later cleanup can simplify this.

---

Phase 7 -- Regression Testing Matrix

Test all section types:

• IPROFILE (symmetric)
• IPROFILE (unsymmetric / T-as-I)
• TPROFILE
• ANGULAR (HP)
• BOX
• TUBULAR
• CHANNEL
• FLATBAR

Test scenarios:

• Para model creation
• Genie import (aligned flush)
• Genie import (constant offsets)
• Ada → Genie → Ada roundtrip

Validate:

• COG matches Genie
• GLB matches Ada viewer
• IFC consistent
• Numeric e1/e2 correct after import

---

Temporary Migration Strategy

Justification.FLUSH_OFFSET remains temporarily to:

• Compare legacy vs new behavior
• Validate numeric resolution
• Ensure no regression before removing legacy mode

Once verified:

• Remove FLUSH_OFFSET
• Remove legacy exporter mapping
• Unify justification logic fully

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Final Target State

Ada Beam:

• Holds semantic justification (FLUSH_TOP / FLUSH_BOTTOM / etc.)
• Always has numeric e1/e2 resolved for geometry
• No ambiguity between semantic and numeric states
• All viewers and exports behave consistently
• Genie roundtrip is stable and predictable

---

End of Plan

[oleandor]

created PR with fix