Add multi-tile entity support with tile_width/tile_height, closes #236

Entities can now span multiple grid cells via tile_width and tile_height
properties (default 1x1). Frustum culling accounts for entity footprint,
and spatial hash queries return multi-tile entities for all covered cells.

API: entity.tile_size = (2, 2) or entity.tile_width = 2; entity.tile_height = 3

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

tests/unit/multi_tile_entity_test.py

@@ -0,0 +1,104 @@
+"""Test multi-tile entity rendering and positioning (#236).
+
+Verifies that entities can span multiple grid cells using tile_width
+and tile_height properties, with correct frustum culling and spatial
+hash queries.
+"""
+import mcrfpy
+import sys
+
+def test_default_tile_size():
+    """New entities default to 1x1 tile size."""
+    entity = mcrfpy.Entity()
+    assert entity.tile_width == 1, f"Expected 1, got {entity.tile_width}"
+    assert entity.tile_height == 1, f"Expected 1, got {entity.tile_height}"
+    ts = entity.tile_size
+    assert ts.x == 1.0 and ts.y == 1.0, f"tile_size wrong: ({ts.x}, {ts.y})"
+    print("  PASS: default tile size")
+
+def test_set_tile_size_individual():
+    """tile_width and tile_height can be set individually."""
+    entity = mcrfpy.Entity()
+    entity.tile_width = 2
+    entity.tile_height = 3
+    assert entity.tile_width == 2, f"Expected 2, got {entity.tile_width}"
+    assert entity.tile_height == 3, f"Expected 3, got {entity.tile_height}"
+    print("  PASS: individual tile size setters")
+
+def test_set_tile_size_tuple():
+    """tile_size can be set as a tuple."""
+    entity = mcrfpy.Entity()
+    entity.tile_size = (4, 2)
+    assert entity.tile_width == 4, f"Expected 4, got {entity.tile_width}"
+    assert entity.tile_height == 2, f"Expected 2, got {entity.tile_height}"
+    print("  PASS: tile_size tuple setter")
+
+def test_tile_size_validation():
+    """tile_width/height must be >= 1."""
+    entity = mcrfpy.Entity()
+    try:
+        entity.tile_width = 0
+        assert False, "Should have raised ValueError"
+    except ValueError:
+        pass
+
+    try:
+        entity.tile_height = -1
+        assert False, "Should have raised ValueError"
+    except ValueError:
+        pass
+
+    try:
+        entity.tile_size = (0, 1)
+        assert False, "Should have raised ValueError"
+    except ValueError:
+        pass
+
+    print("  PASS: tile size validation")
+
+def test_multi_tile_in_grid():
+    """Multi-tile entities work correctly in grids."""
+    grid = mcrfpy.Grid(grid_size=(20, 20))
+    entity = mcrfpy.Entity(grid_pos=(5, 5), grid=grid)
+    entity.tile_width = 2
+    entity.tile_height = 2
+
+    assert entity.tile_width == 2
+    assert entity.tile_height == 2
+    assert entity.cell_pos.x == 5
+    assert entity.cell_pos.y == 5
+    print("  PASS: multi-tile entity in grid")
+
+def test_spatial_hash_multi_tile():
+    """Spatial hash queries find multi-tile entities at covered cells."""
+    grid = mcrfpy.Grid(grid_size=(20, 20))
+    entity = mcrfpy.Entity(grid_pos=(5, 5), grid=grid)
+    entity.tile_width = 2
+    entity.tile_height = 2
+
+    at_origin = grid.at(5, 5).entities
+    assert len(at_origin) >= 1, f"Entity not found at origin (5,5): {len(at_origin)}"
+
+    at_right = grid.at(6, 5).entities
+    assert len(at_right) >= 1, f"Entity not found at covered cell (6,5): {len(at_right)}"
+
+    at_below = grid.at(5, 6).entities
+    assert len(at_below) >= 1, f"Entity not found at covered cell (5,6): {len(at_below)}"
+
+    at_corner = grid.at(6, 6).entities
+    assert len(at_corner) >= 1, f"Entity not found at covered cell (6,6): {len(at_corner)}"
+
+    at_outside = grid.at(7, 5).entities
+    assert len(at_outside) == 0, f"Entity found outside footprint (7,5): {len(at_outside)}"
+
+    print("  PASS: spatial hash multi-tile queries")
+
+print("Testing #236: Multi-tile entities...")
+test_default_tile_size()
+test_set_tile_size_individual()
+test_set_tile_size_tuple()
+test_tile_size_validation()
+test_multi_tile_in_grid()
+test_spatial_hash_multi_tile()
+print("All #236 tests passed.")
+sys.exit(0)