LayerAttributes

Struct

Source: Renderer.h

Description

All tiles with attributes in a single tilemap layer.

LayerAttributes organizes all tile metadata for a single layer, providing efficient lookup of attributes by tile position. Only tiles with non-empty attributes are included, using a sparse representation to minimize memory.

Layer Organization:

• Each layer in a scene has its own LayerAttributes structure
• Layers are typically organized as: Background, Midground, Foreground, etc.
• Layer name matches the name defined in the Tilemap Editor

Memory Efficiency:

• Sparse representation: only tiles with attributes are stored
• All data stored in PROGMEM (flash memory) on ESP32
• No RAM overhead for attribute storage
• Typical size: ~40 bytes per tile with attributes (depends on key/value lengths)

Query Workflow:

1. Identify layer by index or name
2. Search tiles array for matching (x, y) position
3. If found, iterate through tile's attributes array
4. Compare keys using strcmp_P() for PROGMEM strings

Example Usage:

// Query attribute for tile at (10, 5) in layer 0
const char* value = get_tile_attribute(0, 10, 5, "solid");
if (value && strcmp_P(value, "true") == 0) {
    // Tile is solid
}

Layer name is a PROGMEM string (use strcmp_P() for comparison) Tiles array is sorted by position for potential binary search optimization Maximum 65535 tiles with attributes per layer (uint16_t limit)

TileAttributeEntry for individual tile attributes TileAttribute for key-value pairs Generated scene headers for query helper functions

TIP

Layer name is a PROGMEM string (use strcmp_P() for comparison)

TIP

Tiles array is sorted by position for potential binary search optimization

TIP

Maximum 65535 tiles with attributes per layer (uint16_t limit)

Properties

Name	Type	Description
char	const	Layer name (PROGMEM string, e.g., "Background")
num_tiles_with_attributes	uint16_t	Number of tiles with attributes in this layer
TileAttributeEntry	const	PROGMEM array of tiles with attributes (sparse)