Checkers 0.1.1

"""
    This program is checkers. That is all.
"""

import pygame as py
import random
from pygame import *

py.init()

# Screen size, if you change this the board will scale with the width.
width = 600
height = 650

# create the screen and set the caption
screen = py.display.set_mode((width, height))
py.display.set_caption("Checkers")

fps = 75

clock = py.time.Clock()

white = (255,255,255)
dark_gray = (100,100,100)

black = (0,0,0)

brown = (101,67,33)
beige = (222, 184, 135)

redwood = (165, 91, 83)

# Configurable size of the board, and the size of the squares changes with it.
board_size = 8
square_size = width / board_size

# Groups to make my life easier
squares = py.sprite.Group()
checkers = py.sprite.Group()
all_sprites = py.sprite.Group()

# variable to figure out whos turn it is
turn = white

# Sets up the board logic. because of not enough planning it is [y, x]
board = [[None for i in range(board_size)] for j in range(board_size)]

# Checker sprite
class Checker(py.sprite.Sprite):
    def __init__(self, location, color):
        super(Checker, self).__init__()

        # create a circle of the color
        self.surf = py.Surface((square_size-10,square_size-10))
        self.surf.fill(black)
        self.surf.set_colorkey(black)

        py.draw.circle(self.surf, color, [(square_size-10)//2,(square_size-10)//2], (square_size-10)//2)

        # set starting position based on arguments.
        self.rect = self.surf.get_rect(topleft=(location[0]+5,location[1]+5))

        # set important variables
        self.isCrown = False
        self.isSelected = False
        self.coords = [int(location[0]//square_size), int(location[1]//square_size)]
        self.location = [float(location[0]+5),float(location[1]+5)]
        self.color = color

    # sets the position of the checker somewhere and also you can determine what becomes the center.
    # I made this function to make it easier to move it.
    def set_pos(self, location, reference):
        if reference == 'topleft':
            self.rect = self.surf.get_rect(topleft=location)
        elif reference == 'center':
            self.rect = self.surf.get_rect(center=location)

    # returns all valid moves. for a move to be valid it must be a jump,
    # be empty, and be across the diagonal.
    def valid_moves(self):
        valid_moves = []

        # figure out which direction it is coming from.
        if self.color == white:
            direction = -1
        else:
            direction = 1

        # variables to hold the location of the
        topright = [self.coords[0]-direction, self.coords[1]+direction]
        topleft = [self.coords[0]+direction, self.coords[1]+direction]


        # forward right
        if topright[0] < 7 and topright[1] > 0:
            if board[topright[1]][topright[0]] == None:
                valid_moves.append(topright)
            elif board[topright[1]][topright[0]] != None and board[topright[1]+direction][topright[0]-direction] == None and board[topright[1]][topright[0]].color != self.color:
                valid_moves.append([topright[0]-direction, topright[1]+direction])

        # forward left
        if topleft[0] > 0 and topleft[1] > 0:
            if board[topleft[1]][topleft[0]] == None:
                valid_moves.append(topleft)
            elif board[topleft[1]][topleft[0]] != None and board[topleft[1]+direction][topleft[0]+direction] == None and board[topleft[1]][topleft[0]].color != self.color:
                valid_moves.append([topleft[0]+direction, topleft[1]+direction])

        if self.isCrown:
            print("is a crown")

            """
                TO DO
            """

        return valid_moves

    # Determine if move is valid, and if so snap to the grid
    # and tell the game logic that there is a checker there
    def snap_to_grid(self):
        global turn
        x, y = self.rect.topleft

        coord_x = round(x / square_size)
        coord_y = round(y / square_size)

        new_x = coord_x * square_size + 5
        new_y = coord_y * square_size + 5

        # get all valid moves from the starting position
        valid_moves = self.valid_moves()

        # check if it is valid, or if it is going back to the same spot. If either is true,
        # then reset. If not, move to that spot.
        if [new_x, new_y] == self.location or not [coord_x, coord_y] in valid_moves:
            self.set_pos(self.location, 'topleft')
        else:
            # move to new position
            self.set_pos((new_x, new_y), 'topleft')

            # tell game data that the checker moved from the old square
            board[self.coords[1]][self.coords[0]] = None

            # the next few lines are to determine if the checker jumped or not
            old_x, old_y = self.coords

            self.location = [new_x, new_y]
            self.coords = [int(self.location[0]//square_size), int(self.location[1]//square_size)]

            distance = (old_x - self.coords[0])^2 + (old_y - self.coords[1])*2

            # check if checker jumped top right
            if distance == -8:
                board[self.coords[1]+1][self.coords[0]-1].kill()
            # check if checker jumped top left
            elif distance == 4:
                board[self.coords[1]+1][self.coords[0]+1].kill()
            # check if checker jumped bottom right
            elif distance == 0:
                board[self.coords[1]-1][self.coords[0]-1].kill()
            # check if checker jumped bottom left
            elif distance == -4:
                board[self.coords[1]-1][self.coords[0]+1].kill()


            # tell game data the checker moved to the new square
            board[self.coords[1]][self.coords[0]] = self

            # set to be the next turn
            if self.color == white:
                turn = dark_gray
            else:
                turn = white

    # if it is selected, move it with the cursor, if not then snap to the grid
    def update(self):
        mouse = py.mouse.get_pos()
        clicked = py.mouse.get_pressed()

        if clicked[0] and self.isSelected and self.color == turn:
            self.set_pos(mouse, 'center')
        elif not clicked[0] and self.isSelected:
            self.isSelected = False
            self.snap_to_grid()

# each square on the board, technically didnt have to be a sprite but this was easiest.
class Square(py.sprite.Sprite):
    def __init__(self, location, color):
        super(Square, self).__init__()
        self.surf = py.Surface((square_size, square_size))
        self.surf.fill(color)
        self.rect = self.surf.get_rect(topleft=location)

        self.location = location
        self.color = color

# Point used to determine what checker the user clicks.
class Point(py.sprite.Sprite):
    def __init__(self, location):
        super(Point, self).__init__()
        x = location[0]
        y = location[1]
        self.rect = py.Rect(x, y, 1, 1)

# function to quit the game
def quit_game():
    py.quit()
    quit()


# Function to set up the board and the starting position of the checkers.
def set_up():
    screen.fill(black)

    for i in range(board_size):
        for j in range(board_size):
            location = [i*square_size, j*square_size]

            if (i+j) % 2 == 0:
                color = brown

                if j > board_size-4:
                    new_checker = Checker(location, white)
                    checkers.add(new_checker)
                elif j < 3:
                    new_checker = Checker(location, dark_gray)
                    checkers.add(new_checker)
            else:
                color = beige

            new_square = Square(location, color)
            squares.add(new_square)

    # add the checkers to the game logic
    for checker in checkers:
        board[checker.coords[1]][checker.coords[0]] = checker

# the main loop
def game_loop():
    set_up()

    while True:
        # whenever an event happens it runs through this
        for event in py.event.get():
            # when the player hits the x button or alt-f4
            if event.type == QUIT:
                quit_game()
                # when the player clicks, check if it clicked a checker.
            elif event.type == MOUSEBUTTONDOWN:
                mouse = py.mouse.get_pos()
                collision = py.sprite.spritecollideany(Point(mouse), checkers)

                if collision:
                    collision.isSelected = True

        screen.fill(redwood)

        # update position of the checkers
        checkers.update()

        # add all the squares to the screen first
        for entity in squares:
            screen.blit(entity.surf, entity.rect)

        # then add all the checkers so that they render in front of the squares
        for entity in checkers:
            screen.blit(entity.surf, entity.rect)

        # update the display and limit the while loop to run at the speed of the
        # set fps.
        py.display.update()
        clock.tick(fps)

game_loop()