Implements ColorLayer and TileLayer classes with z_index ordering:
- ColorLayer: stores RGBA color per cell for overlays, fog of war, etc.
- TileLayer: stores sprite index per cell with optional texture
- z_index < 0: renders below entities
- z_index >= 0: renders above entities
Python API:
- grid.add_layer(type, z_index, texture) - create layer
- grid.remove_layer(layer) - remove layer
- grid.layers - list of layers sorted by z_index
- grid.layer(z_index) - get layer by z_index
- layer.at(x,y) / layer.set(x,y,value) - cell access
- layer.fill(value) - fill entire layer
Layers are allocated separately from UIGridPoint, reducing memory
for grids that don't need all features. Base grid retains walkable/
transparent arrays for TCOD pathfinding.
🤖 Generated with [Claude Code](https://claude.com/claude-code)
Co-Authored-By: Claude <noreply@anthropic.com>
