Add refactoring plan for removing Visuals classes

Documents the 12-step plan to remove Visuals1D/Visuals2D and pass
overlay objects directly to matplotlib plot functions.

https://claude.ai/code/session_01B9sVEV54XWCa2LJw1C8gvv

Author: claude

PLAN.md

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+# Plan: Remove Visuals Classes and Pass Overlays Directly
+
+## Current State
+
+The codebase is in a *partial* refactoring state. Standalone `plot_array`, `plot_grid`,
+`plot_yx`, `plot_inversion_reconstruction` functions already exist in
+`autoarray/plot/plots/` and are called by the new-style plotters. However:
+
+- `Visuals1D` and `Visuals2D` wrapper classes still exist
+- Every plotter still accepts `visuals_2d` / `visuals_1d` constructor args and stores them
+- Helper functions (`_lines_from_visuals`, `_positions_from_visuals`, `_mask_edge_from`,
+  `_grid_from_visuals`) bridge old Visuals → new standalone functions
+- `MatPlot2D.plot_array/plot_grid/plot_mapper` and `MatPlot1D.plot_yx` still exist and
+  `InterferometerPlotter` still calls them directly
+- `InversionPlotter.subplot_of_mapper` directly mutates `self.visuals_2d`
+
+## Goal
+
+Remove `Visuals1D`, `Visuals2D`, and `AbstractVisuals` entirely. Each plotter holds its
+overlay data as plain attributes and passes them straight to the `plot_*` standalone
+functions. Default overlays (e.g. mask derived from `array.mask`) are computed inline.
+
+---
+
+## Steps
+
+### 1. Update `AbstractPlotter` (`abstract_plotters.py`)
+- Remove `visuals_1d: Visuals1D` and `visuals_2d: Visuals2D` constructor parameters and
+  their default instantiation (`self.visuals_1d = visuals_1d or Visuals1D()`, etc.)
+- Remove the imports of `Visuals1D` and `Visuals2D`
+
+### 2. Update each Plotter constructor to accept individual overlay objects
+
+Replace `visuals_2d: Visuals2D = None` with explicit per-overlay kwargs. Plotters store
+each overlay as a plain instance attribute (defaulting to `None`).
+
+**`Array2DPlotter`** (`structures/plot/structure_plotters.py`):
+```python
+def __init__(self, array, mat_plot_2d=None,
+             mask=None, origin=None, border=None, grid=None,
+             positions=None, lines=None, vectors=None,
+             patches=None, fill_region=None, array_overlay=None):
+```
+
+**`Grid2DPlotter`**:
+```python
+def __init__(self, grid, mat_plot_2d=None, lines=None, positions=None):
+```
+
+**`YX1DPlotter`**:
+```python
+def __init__(self, y, x=None, mat_plot_1d=None,
+             shaded_region=None, vertical_line=None, points=None, ...):
+```
+
+**`MapperPlotter`** (`inversion/plot/mapper_plotters.py`):
+```python
+def __init__(self, mapper, mat_plot_2d=None,
+             lines=None, grid=None, positions=None):
+```
+
+**`InversionPlotter`** (`inversion/plot/inversion_plotters.py`):
+```python
+def __init__(self, inversion, mat_plot_2d=None,
+             lines=None, grid=None, positions=None,
+             residuals_symmetric_cmap=True):
+```
+
+**`ImagingPlotterMeta` / `ImagingPlotter`** (`dataset/plot/imaging_plotters.py`):
+```python
+def __init__(self, dataset, mat_plot_2d=None,
+             mask=None, grid=None, positions=None, lines=None):
+```
+
+**`FitImagingPlotterMeta` / `FitImagingPlotter`** (`fit/plot/fit_imaging_plotters.py`):
+```python
+def __init__(self, fit, mat_plot_2d=None,
+             mask=None, grid=None, positions=None, lines=None,
+             residuals_symmetric_cmap=True):
+```
+
+**`InterferometerPlotter`** (`dataset/plot/interferometer_plotters.py`):
+```python
+def __init__(self, dataset, mat_plot_1d=None, mat_plot_2d=None, lines=None):
+```
+
+### 3. Inline overlay logic inside each plotter's `_plot_*` / `figure_*` methods
+
+Each plotter's internal plot helpers already call the standalone functions. Replace
+calls like:
+```python
+mask=_mask_edge_from(array, self.visuals_2d),
+lines=_lines_from_visuals(self.visuals_2d),
+```
+with direct access to the plotter's own attributes plus inline auto-extraction:
+```python
+mask=self.mask if self.mask is not None else _auto_mask_edge(array),
+lines=self.lines,
+```
+
+Where `_auto_mask_edge(array)` is a tiny module-level helper (no Visuals dependency):
+```python
+def _auto_mask_edge(array):
+    """Return edge-pixel (y,x) coords from array.mask, or None."""
+    try:
+        if not array.mask.is_all_false:
+            return np.array(array.mask.derive_grid.edge.array)
+    except AttributeError:
+        pass
+    return None
+```
+
+### 4. Fix `InversionPlotter.subplot_of_mapper` — drop the `visuals_2d` mutation
+
+Currently this method does:
+```python
+self.visuals_2d += Visuals2D(mesh_grid=mapper.image_plane_mesh_grid)
+```
+Replace by passing `mesh_grid` directly to the specific `figures_2d_of_pixelization`
+call that needs it, or by temporarily storing `self.mesh_grid` on the plotter and
+checking it in `_plot_array`. The mutation and the `Visuals2D(...)` construction are
+both removed.
+
+Similarly remove `self.visuals_2d.indexes = indexes` in `subplot_mappings` — store as
+`self._indexes` and pass through.
+
+### 5. Update `InterferometerPlotter.figures_2d` — replace old MatPlot calls
+
+`InterferometerPlotter` still calls `self.mat_plot_2d.plot_array(...)`,
+`self.mat_plot_2d.plot_grid(...)`, and `self.mat_plot_1d.plot_yx(...)`.
+
+Replace each with the equivalent standalone function call, deriving `ax`, `output_path`,
+`filename`, `fmt` via `_output_for_mat_plot` (which already exists and has no Visuals
+dependency).
+
+### 6. Remove `MatPlot2D.plot_array`, `plot_grid`, `plot_mapper` (and private helpers)
+
+Once no caller uses them, delete these methods from `mat_plot/two_d.py`:
+- `plot_array`
+- `plot_grid`
+- `plot_mapper`
+- `_plot_rectangular_mapper`
+- `_plot_delaunay_mapper`
+
+Remove the `from autoarray.plot.visuals.two_d import Visuals2D` import.
+
+### 7. Remove `MatPlot1D.plot_yx`
+
+Delete the method from `mat_plot/one_d.py` and remove the `Visuals1D` import.
+
+### 8. Remove helper extraction functions from `structure_plotters.py`
+
+Delete (no longer needed):
+- `_lines_from_visuals`
+- `_positions_from_visuals`
+- `_mask_edge_from`
+- `_grid_from_visuals`
+
+Keep: `_zoom_array`, `_output_for_mat_plot` (neither depends on Visuals).
+
+### 9. Delete `autoarray/plot/visuals/`
+
+Remove:
+- `autoarray/plot/visuals/__init__.py`
+- `autoarray/plot/visuals/abstract.py`
+- `autoarray/plot/visuals/one_d.py`
+- `autoarray/plot/visuals/two_d.py`
+
+### 10. Update `autoarray/plot/__init__.py`
+
+Remove `Visuals1D` and `Visuals2D` exports (lines 45–46).
+
+### 11. Check and update remaining plotters
+
+Read and update:
+- `fit/plot/fit_interferometer_plotters.py`
+- `fit/plot/fit_vector_yx_plotters.py`
+
+Both import `Visuals1D`/`Visuals2D`; apply the same pattern as above.
+
+### 12. Run full test suite
+
+```bash
+python -m pytest test_autoarray/ -q --tb=short
+```
+
+Fix any failures before committing.
+
+---
+
+## Summary of files changed
+
+| File | Change |
+|------|--------|
+| `autoarray/plot/abstract_plotters.py` | Remove `visuals_1d`, `visuals_2d` |
+| `autoarray/plot/mat_plot/one_d.py` | Remove `plot_yx`, remove Visuals1D import |
+| `autoarray/plot/mat_plot/two_d.py` | Remove `plot_array/grid/mapper` methods, remove Visuals2D import |
+| `autoarray/plot/visuals/` | **Delete entire directory** |
+| `autoarray/plot/__init__.py` | Remove Visuals exports |
+| `autoarray/structures/plot/structure_plotters.py` | Replace visuals args with individual kwargs; remove helper functions |
+| `autoarray/inversion/plot/mapper_plotters.py` | Replace visuals args with individual kwargs |
+| `autoarray/inversion/plot/inversion_plotters.py` | Replace visuals args; fix subplot_of_mapper mutation |
+| `autoarray/dataset/plot/imaging_plotters.py` | Replace visuals args with individual kwargs |
+| `autoarray/dataset/plot/interferometer_plotters.py` | Replace visuals args; replace old MatPlot calls |
+| `autoarray/fit/plot/fit_imaging_plotters.py` | Replace visuals args with individual kwargs |
+| `autoarray/fit/plot/fit_interferometer_plotters.py` | Replace visuals args |
+| `autoarray/fit/plot/fit_vector_yx_plotters.py` | Replace visuals args |