Damn thing is slow as a slug

wfc/generator.gd

@@ -5,32 +5,51 @@ extends Node
 func generate_chunk_at(_x: int, _y: int, _chunk_array: Array[Chunk], _samples: Array[PackedInt32Array]) -> Chunk:
 	#TODO: fix the chunk-edges
 	var chunk: Chunk = Chunk.new(_x, _y)
-
-	var latch: int = 1
-	while latch:
-		latch = 0 #if set to true, the generator needs another pass
-		#iterate over unset tiles with valid neighbours
-		for x in range(Chunk.CHUNK_WIDTH):
-			for y in range((Chunk.CHUNK_HEIGHT)):
-				if chunk.data[y * Chunk.CHUNK_HEIGHT + x] == 0: #direct access, to skip extra checks
-					#TODO: convert this to the low-entropy method
-					if _set_tile_from_samples(chunk, x, y, _samples) > 0:
-						latch += 1
-		print("latch: ", latch)
 	
-	print(chunk.data)
+	while _set_lowest_entropy_tile(chunk, _samples) > 0: pass
+	
 	_chunk_array.append(chunk)
 	return chunk
 
-## Returns the value set, or -1 if no options found
-func _set_tile_from_samples(chunk: Chunk, tile_x: int, tile_y: int, _samples: Array[PackedInt32Array]) -> int:
+## Returns the entropy of the selected tile
+func _set_lowest_entropy_tile(chunk: Chunk, _samples: Array[PackedInt32Array]) -> int:
+	var entropy: Array[Array] = []
+	entropy.resize(Chunk.CHUNK_WIDTH * Chunk.CHUNK_HEIGHT)
+	
+	#iterate over unset tiles with valid neighbours
+	for x in range(Chunk.CHUNK_WIDTH):
+		for y in range((Chunk.CHUNK_HEIGHT)):
+			if chunk.data[y * Chunk.CHUNK_HEIGHT + x] == 0: #direct access, to skip extra checks
+				entropy[y * Chunk.CHUNK_HEIGHT + x] = _find_valid_samples(chunk, x, y, _samples)
+	
+	#find the lowest-entropy tile
+	var lowest: int = -1
+	for i in range(Chunk.CHUNK_WIDTH * Chunk.CHUNK_HEIGHT):
+		if entropy[i].size() == 0: continue #no options
+		
+		if lowest < 0:
+			lowest = i
+			continue
+		if entropy[i].size() < entropy[lowest].size():
+			lowest = i
+	
+	#finished
+	if lowest < 0: return lowest
+	
+	#finally, set the tile from the sample
+	var s: PackedInt32Array = entropy[lowest].pick_random()
+	chunk.data[lowest] = s[4]
+	return entropy.size()
+
+## Returns the valid samples
+func _find_valid_samples(chunk: Chunk, tile_x: int, tile_y: int, _samples: Array[PackedInt32Array]) -> Array[PackedInt32Array]:
 	var valid: Array[PackedInt32Array] = []
 	
 	#use a lambda for easy reading below
 	var compare := func (tile_value: int, sample: int) -> bool:
 		return tile_value <= 0 or tile_value == sample
 	
-	#find all valid samples
+	#filter the samples
 	for sample in _samples:
 		if !compare.call(chunk.get_tile(tile_x -1, tile_y -1), sample[0]): continue
 		if !compare.call(chunk.get_tile(tile_x   , tile_y -1), sample[1]): continue
@@ -43,10 +62,5 @@ func _set_tile_from_samples(chunk: Chunk, tile_x: int, tile_y: int, _samples: Ar
 		if !compare.call(chunk.get_tile(tile_x +1, tile_y +1), sample[8]): continue
 		
 		valid.append(sample)
-	print("Valid samples: ", valid.size())
-	if valid.size() <= 0: return -1
-	var s = valid.pick_random()	
 	
-	#set the tile to the randomly selected value
-	chunk.set_tile(tile_x, tile_y, s[4])
-	return s[4]
+	return valid