utils.py

import re
import numpy as np
import tensorflow as tf

def preprocess_scores(scores):
    for i, score in enumerate(scores):
        score = str(score).encode('utf-8')
        score = score.decode('utf-8-sig')
        #print(f'i: {i} score: {score}, type: {type(score)}')
        
        if score[0:2] == '#+':
            score = 1501
        elif score[0:2] == '#-':
            score = -1501
        elif int(score) > 1500:
            score = 1500
        elif int(score) < -1500:
            score = -1500
        
        scores[i] = int(score)
    #scale between -15 and 15
    #scores += 16
    #scores /= 32

    #scaler = MinMaxScaler(feature_range=(-1, 1))
    #scores = scaler.fit_transform(scores.reshape(-1, 1))
    
    scores = scores.astype('float32')
    
    return scores

def vectorize(fen):
    data = re.split(" ", fen)
    rows= re.split("/", data[0])
    turn = data[1]
    can_castle = data[2]
    passant = data[3]
    half_moves = data[4]
    full_moves = data[5]
    
    bit_vector = np.zeros((13, 8, 8), dtype=np.float32)
    #print(bit_vector.shape)
    #what layer each piece is found on
    piece_to_layer = {
            'R': 1,
            'N': 2,
            'B': 3,
            'Q': 4,
            'K': 5,
            'P': 6,
            'p': 7,
            'k': 8,
            'q': 9,
            'b': 10,
            'n': 11,
            'r': 12
        }
    #find each piece based on type
    for r,value in enumerate(rows):
        colum = 0
        for piece in value:
            if piece in piece_to_layer:
                bit_vector[piece_to_layer[piece],r,colum] =1
                colum += 1
            else:
                colum += int(piece)
    
    if turn.lower() == 'w':
        bit_vector [0,7,4] =1
    else:
        bit_vector [0,0,4] =1
        
    #where each castle bit is located
    castle ={
        'k': (0,0),
        'q': (0,7),
        'K': (7,0),
        'Q': (7,7),
        }

    for value in can_castle:
        if value in castle:
            bit_vector[0,castle[value][0],castle[value][1]] = 1
    
    #put en-passant square in the vector
    if passant != '-':
        bit_vector[0,  5 if (int(passant[1])-1 == 3) else 2 , ord(passant[0]) - 97,] = 1
    
    return bit_vector