EarthBound/Map Data/Tile Animation Properties Table

Map Data: Tile Animation Properties Table
Game	EarthBound
Start Address	0x2F146B
End Address	0x2F153E
# of Entries	20
Entry Length	Varies
Total Length	211 bytes (0xD3)
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The Tile Animation Properties Table contains metadata properties controlling the animation of map tiles for a given tileset. The entry for a given tileset is found using a lookup to the Tile Animation Properties Pointer Table.

Format

Num Subentries

• Length: 1 byte
• Offset within entry: 0x00
• Range of values: 0-8 (0x00-0x08)

Each entry begins with a single byte to specify the number of subentries to follow, representing different tile animations that will run concurrently for the tileset. EarthBound allocates space to load up to 8 concurrent animations to RAM (in the Map Tile Animation Data), but no tileset seems to use more than 6.

Subentry Format

Num Animation Cycles

• Length: 1 byte
• Offset within entry: 0x00
• Range of values: 1-255 (0x01-0xFF)

The number of different animation frames that the animation will cycle through.

Frame Delay

• Length: 1 byte
• Offset within entry: 0x01
• Range of values: 0x01-0xFF (~0.017s to ~4.25s)

Number of game frames to hold each animation frame before cycling to the next. As an NTSC SNES runs at approximately 60 FPS, this means the time delay can be calculated as delay_in_seconds = frame_delay / 60.

Transfer Size

• Length: 2 bytes
• Offset within entry: 0x02
• Range of values: 0x0000-0x2000 (0-256 tile characters)

Size in bytes of the tile characters to be replaced on each animation cycle. As EarthBound allocates space for up to 256 decompressed tile characters for animation, each 32 bytes, that gives a maximum transfer size of 0x2000 bytes in the silly scenario where the animation consists of a single animation cycle using all available tile characters.

Initial Transfer Source Offset

• Length: 2 bytes
• Offset within entry: 0x04
• Range of values: 0x0000-0x1FE0

Byte offset into the decompressed map animation tile characters stored at $7EC000-$7EDFFF to use for the transfer source for the first animation cycle. On each cycle, the source offset will be incremented by Transfer Size (and reset after cycling through all animation frames).

Transfer Destination Address

• Length: 2 bytes
• Offset within entry: 0x06
• Range of values: 0x0000-0x37F0

VRAM word address of the first tile character to be replaced on each animation cycle. Map tile characters occupy addresses $0000-$37FF (word addresses) of VRAM.

Note: Technically, the destination address could point outside the tile characters portion of VRAM to allow replacing/animating anything stored in VRAM. Nothing checks that tile animation is only used to replace/animate tile character data. But it would be difficult to make work for anything else because nothing else stays loaded into a dedicated portion of VRAM for the entire time the tileset is loaded with its animations running. E.g., it would be difficult to animate a certain place on the tilemap because tilemap entries are loaded and replaced as the player moves around the map.

Entries

Entry start	Tileset name	Tileset index	Num animation subentries
0x2F146B	Lost Underworld	00	5
0x2F1494	Onett	01	2
0x2F14A5	Twoson	02	0
0x2F14A6	Threed	03	0
0x2F14A7	Fourside	04	0
0x2F14A8	Magicant	05	1
0x2F14B1	Outdoors	06	2
0x2F14C2	Summers	07	2
0x2F14D3	Dusty Dunes Desert	08	1
0x2F14DC	Dalaam	09	0
0x2F14DD	Indoors 1	10	0
0x2F14DE	Indoors 2	11	0
0x2F14DF	Stores 1	12	1
0x2F14E8	Caves 1	13	1
0x2F14F1	Indoors 3	14	0
0x2F14F2	Stores 2	15	0
0x2F14F3	Indoors 4	16	6
0x2F1524	Winters	17	1
0x2F152D	Scaraba	18	1
0x2F1536	Caves 2	19	1

Note: All entries are in order by tileset index, but because EarthBound always accesses the entries by pointer, there is no known reason why they would need to be in any particular order.

External Links

• Tile Animation Properties Table Documentation
• IRC Log of a Tile Animation-related Discovery
• Dump of this Table