DiscreteMap now implements tp_as_buffer/bf_getbuffer, exposing its dense uint8
storage as a 2-D (height, width) C-contiguous writable view. memoryview(dmap)
and np.asarray(dmap) share memory with the map -- no copy -- so per-entity FOV
memory (#294 perspective_map) and other DiscreteMaps can be inspected/edited
with numpy at native speed.
The exporter owns the buffer via its shared_ptr<DiscreteMap>; getbuffer INCREFs
it for the view's lifetime (balanced by the default PyBuffer_Release DECREF, so
no bf_releasebuffer). shape/strides are stored on the object -- dimensions are
immutable after construction, so concurrent views safely share them.
Independent of the GridData SoA work (#332): DiscreteMap already owned a dense
contiguous uint8_t* with no libtcod coupling.
Regression test issue_334_discretemap_buffer_test.py: shape/format/strides,
row-major [x,y]->[y,x] mapping, zero-copy writeback both directions, optional
numpy aliasing (skipped when not bundled), and a buffer over a live entity
perspective_map. Suite 309/309.
Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
