# M01-FND-COORD-BOUNDARY-GATE-001 — Coordinate conversion boundary gate

<!-- OPENWC_CLAIM:M01-FND-COORD-BOUNDARY-GATE-001:sindo-main-codex:2026-07-15 -->

## Ownership

- Target: M01
- Program: FND/QAR
- Owner/Agent ID: sindo-main-codex
- Branch: `work/sindo-main-codex/m01-coordinate-boundary-gate`
- Lease expires UTC: 2026-07-15
- Integrator: M01 milestone integrator

## Outcome

Route remaining GDScript world/tile axis conversions through `CoordinateMapper`
and add a repository-wide gate that rejects new manual world-center, axis-swap
or world-to-ADT tile formulas outside explicit contract/native-oracle boundaries.

## Non-goals

- Rewriting model-local M2/WMO vertex or placement orientation transforms.
- Moving renderer distance/LOD geometry out of Godot space.
- Replacing the native parser boundary with GDScript calls from worker threads.
- Changing coordinate contract semantics, renderer radii or cache formats.

## Paths

- Exclusive: `src/tools/verify_coordinate_conversion_boundaries.gd`
- Shared/hotspots: `src/domain/coordinates/coordinate_mapper.gd`, coordinate
  tests/docs/ADR, streamer/player/sky/terrain-probe consumers,
  `docs/CODING_STANDARD.md`, this claim
- Generated/ignored: Godot import metadata, extracted assets and renderer caches

## Contracts and data

- Additive mapper methods: Godot position to ADT tile/local and ADT tile/local
  to Godot position
- Native exception: one formula definition in `src/native/src/wow_chunk_reader.h`;
  ADT/WDT loaders may call it but may not define copies
- Oracle exception: `verify_render_coordinate_calibration.gd` retains one
  independent M00 formula to detect common-mode mapper regressions
- Model-local transforms are outside the world-coordinate gate

## Dependencies

- Requires: coordinate contract v2 and M01 seams through `7c64e8d`
- Blocks: M01 coordinate-centralization exit criterion and milestone evidence audit
- External state: no dependency or proprietary input

## Verification

- Commands: conversion-boundary gate, mapper/golden fixtures, streaming focus,
  identities, renderer calibration/manifest and repository gates
- Fixtures: Godot/ADT tile center, local offsets and exact boundaries
- Fidelity evidence: existing build-12340 points and raw ADT/server fixture remain unchanged
- Performance budget: mapper allocations occur only at adapter/update boundaries;
  renderer distance/LOD math remains in Godot scalars

## Documentation deliverables

- Inline public API docs: new mapper methods
- Module specification/ADR: boundary APIs, allowed exceptions and gate behavior
- Coding standard: mandatory review rule for cross-space conversions
- Data-flow diagram: existing coordinate module diagram updated for direct adapters
- State/sequence diagrams: unchanged; pure synchronous mapping

## Simplicity and naming

- Important names introduced: `godot_to_adt_tile`, `godot_to_adt_tile_local`,
  `adt_tile_local_to_godot`, `verify_coordinate_conversion_boundaries`
- Simplest considered solution: extend the existing mapper and scan source text
  for narrow high-signal formula signatures
- Rejected complexity/abstractions: generic coordinate algebra framework,
  native-to-GDScript calls on parser workers and a broad numeric-literal ban
- Unavoidable complexity and justification: one native boundary and one
  independent test oracle must remain explicit to avoid worker coupling and common-mode tests
- Measured optimization evidence: existing renderer distance/LOD scalar math is unchanged

## Status

- State: active
- Done: repository audit and exception taxonomy
- Next: mapper extensions, consumer migration, enforcement gate and documentation
- Blocked by: