TileData.get_terrain_peering_bit() returns error

[andreas-volz]

Tested versions

v4.2.1.stable.official [b09f793]

System information

Godot v4.2.1.stable - Linux Mint 21 (Vanessa) - X11 - GLES3 (Compatibility) - NVIDIA GeForce RTX 3060 (nvidia; 535.161.07) - AMD Ryzen 5 2600X Six-Core Processor (12 Threads)

Issue description

My gdscript calls TileData.get_terrain_peering_bit() for all tiles in the tile atlas. The reason is to use the peering information for procedural generation.
https://docs.godotengine.org/en/stable/classes/class_tiledata.html#class-tiledata-method-get-terrain-peering-bit

The problem is that I get this error for all tiles which have no peering bits:

E 0:00:00:0861   SuperPosition.gd:116 @ print_tile_bits(): Condition "!is_valid_terrain_peering_bit(p_peering_bit)" is true. Returning: -1
  <C++-Quelle>   scene/resources/tile_set.cpp:5547 @ get_terrain_peering_bit()
  <Stacktrace>   SuperPosition.gd:116 @ print_tile_bits()
                 SuperPosition.gd:70 @ read_superposition_connectors_from_tileset()
                 World.gd:26 @ _ready()

This might be the "problem":
https://github.com/godotengine/godot/blob/master/scene/resources/2d/tile_set.cpp#L6434

solution ideas:

1. export a gdscript function has_terrain_peering_bit() returning information if any bits are set before asking for it
2. write a GdNative in my local project and direct access the native API before calling

Steps to reproduce

call get_terrain_peering_bit() on a cell with no peering bit.

Minimal reproduction project (MRP)

this test prints the error:

# works only in Tile Shape "Square"
const TERRAIN_MODE_MATCH_SIDES_DIRECTION := [
	TileSet.CellNeighbor.CELL_NEIGHBOR_TOP_SIDE, # N
	TileSet.CellNeighbor.CELL_NEIGHBOR_RIGHT_SIDE, # E
	TileSet.CellNeighbor.CELL_NEIGHBOR_BOTTOM_SIDE, # S
	TileSet.CellNeighbor.CELL_NEIGHBOR_LEFT_SIDE # W
]

func print_tile_bits(tile_set :TileSet):
	var atlas_source:TileSetAtlasSource = tile_set.get_source(tile_set.get_source_id(0))
	
	print("get_source_count: ", tile_set.get_source_count())
		
	var terrain_set = 0
	
	var terrain_mode := tile_set.get_terrain_set_mode(terrain_set)
	print("terrain_mode: ", terrain_mode)
	
	if terrain_mode == TileSet.TerrainMode.TERRAIN_MODE_MATCH_SIDES:
		for atlas_count in atlas_source.get_tiles_count():
			var tile_id = atlas_source.get_tile_id(atlas_count)
			for i in TERRAIN_MODE_MATCH_SIDES_DIRECTION.size():
				var peering_bit: int = TERRAIN_MODE_MATCH_SIDES_DIRECTION[i]
				var tile_data:TileData = atlas_source.get_tile_data(tile_id, 0)
				var terrain_bit := tile_data.get_terrain_peering_bit(peering_bit)
				#print("valid: ", tile_data.is_valid_terrain_peering_bit)
				if terrain_bit != -1:
					print("tile_id: ", tile_id)
		
		for tile in _data:
			var sockets: Array[int] = []
			sockets.resize(TERRAIN_MODE_MATCH_SIDES_DIRECTION.size())
			tile["sockets"] = sockets
		
			for i in TERRAIN_MODE_MATCH_SIDES_DIRECTION.size():
				var peering_bit: int = TERRAIN_MODE_MATCH_SIDES_DIRECTION[i]
				var tile_data:TileData = atlas_source.get_tile_data(tile.atlas, 0)
				var terrain_bit := tile_data.get_terrain_peering_bit(peering_bit)
				tile["sockets"][i] = terrain_bit
				print("SIDE terrain_bit: ", terrain_bit)

[AThousandShips]

Yes, the mode only works with square, it need other directions in other modes, this should be documented more clearly, but there's no bug here, see here for the valid neighbors:

godot/scene/resources/2d/tile_set.cpp

Lines 864 to 945 in 7d151c8

	bool TileSet::is_valid_terrain_peering_bit_for_mode(TileSet::TerrainMode p_terrain_mode, TileSet::CellNeighbor p_peering_bit) const {
	if (tile_shape == TileSet::TILE_SHAPE_SQUARE) {
	if (p_terrain_mode == TileSet::TERRAIN_MODE_MATCH_CORNERS_AND_SIDES || p_terrain_mode == TileSet::TERRAIN_MODE_MATCH_SIDES) {
	if (p_peering_bit == TileSet::CELL_NEIGHBOR_RIGHT_SIDE ||
	p_peering_bit == TileSet::CELL_NEIGHBOR_BOTTOM_SIDE ||
	p_peering_bit == TileSet::CELL_NEIGHBOR_LEFT_SIDE ||
	p_peering_bit == TileSet::CELL_NEIGHBOR_TOP_SIDE) {
	return true;
	}
	}
	if (p_terrain_mode == TileSet::TERRAIN_MODE_MATCH_CORNERS_AND_SIDES || p_terrain_mode == TileSet::TERRAIN_MODE_MATCH_CORNERS) {
	if (p_peering_bit == TileSet::CELL_NEIGHBOR_BOTTOM_RIGHT_CORNER ||
	p_peering_bit == TileSet::CELL_NEIGHBOR_BOTTOM_LEFT_CORNER ||
	p_peering_bit == TileSet::CELL_NEIGHBOR_TOP_LEFT_CORNER ||
	p_peering_bit == TileSet::CELL_NEIGHBOR_TOP_RIGHT_CORNER) {
	return true;
	}
	}
	} else if (tile_shape == TileSet::TILE_SHAPE_ISOMETRIC) {
	if (p_terrain_mode == TileSet::TERRAIN_MODE_MATCH_CORNERS_AND_SIDES || p_terrain_mode == TileSet::TERRAIN_MODE_MATCH_SIDES) {
	if (p_peering_bit == TileSet::CELL_NEIGHBOR_BOTTOM_RIGHT_SIDE ||
	p_peering_bit == TileSet::CELL_NEIGHBOR_BOTTOM_LEFT_SIDE ||
	p_peering_bit == TileSet::CELL_NEIGHBOR_TOP_LEFT_SIDE ||
	p_peering_bit == TileSet::CELL_NEIGHBOR_TOP_RIGHT_SIDE) {
	return true;
	}
	}
	if (p_terrain_mode == TileSet::TERRAIN_MODE_MATCH_CORNERS_AND_SIDES || p_terrain_mode == TileSet::TERRAIN_MODE_MATCH_CORNERS) {
	if (p_peering_bit == TileSet::CELL_NEIGHBOR_RIGHT_CORNER ||
	p_peering_bit == TileSet::CELL_NEIGHBOR_BOTTOM_CORNER ||
	p_peering_bit == TileSet::CELL_NEIGHBOR_LEFT_CORNER ||
	p_peering_bit == TileSet::CELL_NEIGHBOR_TOP_CORNER) {
	return true;
	}
	}
	} else {
	if (get_tile_offset_axis() == TileSet::TILE_OFFSET_AXIS_HORIZONTAL) {
	if (p_terrain_mode == TileSet::TERRAIN_MODE_MATCH_CORNERS_AND_SIDES || p_terrain_mode == TileSet::TERRAIN_MODE_MATCH_SIDES) {
	if (p_peering_bit == TileSet::CELL_NEIGHBOR_RIGHT_SIDE ||
	p_peering_bit == TileSet::CELL_NEIGHBOR_BOTTOM_RIGHT_SIDE ||
	p_peering_bit == TileSet::CELL_NEIGHBOR_BOTTOM_LEFT_SIDE ||
	p_peering_bit == TileSet::CELL_NEIGHBOR_LEFT_SIDE ||
	p_peering_bit == TileSet::CELL_NEIGHBOR_TOP_LEFT_SIDE ||
	p_peering_bit == TileSet::CELL_NEIGHBOR_TOP_RIGHT_SIDE) {
	return true;
	}
	}
	if (p_terrain_mode == TileSet::TERRAIN_MODE_MATCH_CORNERS_AND_SIDES || p_terrain_mode == TileSet::TERRAIN_MODE_MATCH_CORNERS) {
	if (p_peering_bit == TileSet::CELL_NEIGHBOR_BOTTOM_RIGHT_CORNER ||
	p_peering_bit == TileSet::CELL_NEIGHBOR_BOTTOM_CORNER ||
	p_peering_bit == TileSet::CELL_NEIGHBOR_BOTTOM_LEFT_CORNER ||
	p_peering_bit == TileSet::CELL_NEIGHBOR_TOP_LEFT_CORNER ||
	p_peering_bit == TileSet::CELL_NEIGHBOR_TOP_CORNER ||
	p_peering_bit == TileSet::CELL_NEIGHBOR_TOP_RIGHT_CORNER) {
	return true;
	}
	}
	} else {
	if (p_terrain_mode == TileSet::TERRAIN_MODE_MATCH_CORNERS_AND_SIDES || p_terrain_mode == TileSet::TERRAIN_MODE_MATCH_SIDES) {
	if (p_peering_bit == TileSet::CELL_NEIGHBOR_BOTTOM_RIGHT_SIDE ||
	p_peering_bit == TileSet::CELL_NEIGHBOR_BOTTOM_SIDE ||
	p_peering_bit == TileSet::CELL_NEIGHBOR_BOTTOM_LEFT_SIDE ||
	p_peering_bit == TileSet::CELL_NEIGHBOR_TOP_LEFT_SIDE ||
	p_peering_bit == TileSet::CELL_NEIGHBOR_TOP_SIDE ||
	p_peering_bit == TileSet::CELL_NEIGHBOR_TOP_RIGHT_SIDE) {
	return true;
	}
	}
	if (p_terrain_mode == TileSet::TERRAIN_MODE_MATCH_CORNERS_AND_SIDES || p_terrain_mode == TileSet::TERRAIN_MODE_MATCH_CORNERS) {
	if (p_peering_bit == TileSet::CELL_NEIGHBOR_RIGHT_CORNER ||
	p_peering_bit == TileSet::CELL_NEIGHBOR_BOTTOM_RIGHT_CORNER ||
	p_peering_bit == TileSet::CELL_NEIGHBOR_BOTTOM_LEFT_CORNER ||
	p_peering_bit == TileSet::CELL_NEIGHBOR_LEFT_CORNER ||
	p_peering_bit == TileSet::CELL_NEIGHBOR_TOP_LEFT_CORNER ||
	p_peering_bit == TileSet::CELL_NEIGHBOR_TOP_RIGHT_CORNER) {
	return true;
	}
	}
	}
	}
	return false;
	}

We should probably expose this helper method to help with using this properly

[AThousandShips]

Making a PR to expose this on TileData