conway/conway.py

from enum import Enum
from collections import namedtuple
from math import floor
import pygame
from dataclasses import dataclass

CellStates = Enum("CellStates", ("ALIVE", "DEAD")) #using enum for possible iterations on cellular automata
XYPair = namedtuple("XYPair", "x y")

class Colors(Enum):
    RED = (255, 0, 0)
    GREEN = (0, 255, 0)
    BLUE = (0, 0, 255)
    WHITE = (255, 255, 255)
    BLACK = (0, 0, 0)
    GRAY = (112, 128, 160) #slate gray

@dataclass
class Render_Info:
    screen_dimensions: XYPair = XYPair(1000,1000)
    padding: XYPair = XYPair(1, 1)
    background_color = Colors.BLACK.value
    
class Cell:

    PALETTE_MAP = {
        CellStates.ALIVE: Colors.GREEN.value,
        CellStates.DEAD: Colors.GRAY.value,
    }

    def calculate_screen_position(self, render_info: Render_Info) -> XYPair:

        def calculate_spacing(i, w, p):
            return i * (w + 2*p) + p
        
        padding = render_info.padding
        return XYPair(calculate_spacing(self.position.x, self.dimensions.x, padding.x), 
                      calculate_spacing(self.position.y, self.dimensions.y, padding.y))

    def __init__(self, position: XYPair, dimensions: XYPair, render_info: Render_Info, state: CellStates=CellStates.DEAD) -> None:
        self.crowding_number = 0
      
        self.position = position
        self.dimensions = dimensions
        self.state = state
        self.click_state = None
        self.screen_position = self.calculate_screen_position(render_info)
        self.image = pygame.Surface(self.dimensions)
        self.image.fill(Colors.GRAY.value)
        self.rect = pygame.Rect(self.screen_position.x, 
                                self.screen_position.y, 
                                self.dimensions.x, 
                                self.dimensions.y)

    def set_state(self, state: CellStates):
        self.state = state
        self.image.fill(self.PALETTE_MAP[self.state])

    def set_crowding_number(self, n: int):
        self.crowding_number = n

    def update_state(self):
        if self.crowding_number < 2 or self.crowding_number >= 4:
            self.set_state(CellStates.DEAD)
        if self.crowding_number == 3:
            self.set_state(CellStates.ALIVE)

    def draw(self, screen):
        screen.blit(self.image, self.rect)

class Board:

    def __init__(self, dimensions: XYPair, evolution_time, render_info: Render_Info):
        screen_dimenions = render_info.screen_dimensions
        self.evolution_time = evolution_time
        self.clock = 0
        padding = render_info.padding
        #calculate cell dimensions once instead of x*y times
        cell_dimensions = XYPair(screen_dimenions.x/dimensions.x - 2*padding.x, 
                                 screen_dimenions.y/dimensions.y - 2*padding.y)
        self.dimensions = dimensions
        self.matrix = [[Cell(XYPair(x,y), cell_dimensions, render_info) for x in range(dimensions.x)] for y in range(dimensions.y)]

    def normalize_submatrix_point(self, p: XYPair) -> XYPair:

        def normalize(x: int, cap: int) -> int:
            if x < 0:
                return 0
            if x >= cap:
                return cap-1
            return x
        
        return XYPair(normalize(p.x, self.dimensions.x), normalize(p.y, self.dimensions.y))

    def get_submatrix(self, center: XYPair, extents: XYPair):
        start_point = self.normalize_submatrix_point(XYPair(center.x - extents.x, center.y - extents.y))
        end_point = self.normalize_submatrix_point(XYPair(center.x + extents.x, center.y + extents.y))
        return [row[start_point.x:end_point.x+1] for row in self.matrix[start_point.y:end_point.y+1]]

    def calculate_crowding_number(self, center: XYPair, extents: XYPair):
        submatrix = self.get_submatrix(center, extents)
        #flattened_submatrix removes the center point because it does not contribute to the crowding number
        #if syntax is confusing, it just unrolls the 2d list and removes the cell in the center
        flattened_submatrix = [cell for row in submatrix for cell in row if cell.position != center]
        living_cells = map(lambda cell: cell.state == CellStates.ALIVE, flattened_submatrix)
        return sum(living_cells)
    
    def fill_crowding(self):
        for row in self.matrix:
            for cell in row:
                cell.set_crowding_number(
                    self.calculate_crowding_number(cell.position, XYPair(1,1))
                )
    
    def evolve_state(self):
        #calculate crowding numbers before updating any state, otherwise you'll be unhappy
        self.fill_crowding()
        for row in self.matrix:
            for cell in row:
                cell.update_state()

    def set_state(self, p: XYPair, state: CellStates):
        self.matrix[p.y][p.x].set_state(state)

    def draw(self, screen):
        for row in self.matrix:
            for cell in row:
                cell.draw(screen)

    def tick_clock(self, dt):
        self.clock += dt
        if self.clock >= self.evolution_time:
            self.evolve_state()
            self.clock = 0

    def handle_click(self, mouse_pos, render_info):

        def pixel_to_index(x, w, p):
            return floor((x - p)/(w + 2*p))
        
        #calculating the board index position is wayyy easier than point colliding
        #with every cell sprite
        dimensions = self.matrix[0][0].dimensions 
        x = pixel_to_index(mouse_pos[0], dimensions.x, render_info.padding.x)
        y = pixel_to_index(mouse_pos[1], dimensions.y, render_info.padding.y)

        try:
            cell = self.matrix[y][x]
        except IndexError:
            return #this exception corresponds to the case of the mouse being held down outside the game window

        if not self.click_state:
            if cell.state == CellStates.ALIVE:
                self.click_state = CellStates.DEAD
            else:
                self.click_state = CellStates.ALIVE
        
        self.matrix[y][x].set_state(self.click_state)


    def reset_click(self):
        self.click_state = None

    def reset(self):
        for row in self.matrix:
            for cell in row:
                cell.set_state(CellStates.DEAD)

    def __repr__(self):
        lines = []
        str_buffer = ''
        lines.append('-'*(self.dimensions.x+2))
        for row in self.matrix:
            str_buffer += '|'
            for cell in row:
                str_buffer += '#' if cell.state == CellStates.ALIVE else ' '
            str_buffer += '|'
            lines.append(str_buffer)
            str_buffer = ''
        lines.append('-'*(self.dimensions.x+2))
        return '\n'.join(lines)

def main():
    render_info: Render_Info = Render_Info()
    screen = pygame.display.set_mode(render_info.screen_dimensions)
    board = Board(XYPair(50, 50), 100, render_info)
    pygame.display.set_caption("Conway's Game of Life")

    clock = pygame.time.Clock()

    paused = True
    running = True

    while running:

        dt = clock.tick(144)
        board.draw(screen)
        pygame.display.flip()

        if not paused:
            board.tick_clock(dt)

        if pygame.mouse.get_pressed()[0]:
            board.handle_click(pygame.mouse.get_pos(), render_info)
        else:
            board.reset_click()

        for event in pygame.event.get():

            if event.type == pygame.KEYDOWN:
                if event.key == pygame.K_SPACE:
                    paused = not paused

                if event.key == pygame.K_ESCAPE:
                    board.reset()

            if event.type == pygame.QUIT:
                running = False


if __name__ == '__main__':
    main()