game.py

import sys
import time

import pygame
from pygame import Surface, Rect
from pygame.font import Font
from pygame.math import Vector2

from body import Body


class Game:
    G = 6.674 * 10 ** -11

    def __init__(self):
        self.__scale: int = 1
        self.time_scale = 1
        pygame.init()
        pygame.display.set_caption("Orbit Simulator")
        self.screen: Surface = pygame.display.set_mode((1280, 720))
        self.clock = pygame.time.Clock()
        self.sun = Body(
            mass=400000000000,
            coordinates=Rect((self.screen.get_width() / 2),
                             (self.screen.get_height() / 2),
                             10,
                             10),
            velocity=Vector2(),
            game_instance=self,
            color=(200, 245, 25))
        self.planets = self.create_planets()
        self.paused = False
        self.alive = True
        self.font: Font = pygame.font.SysFont(pygame.font.get_default_font(), 24)

    def create_planets(self) -> [Body]:
        return [
            self.sun,
            Body(
                mass=10000,
                coordinates=Rect(420, 240, 9, 9),
                velocity=Vector2(0.08, -0.05),
                game_instance=self,
                color=(50, 220, 100)),
            Body(
                mass=10000000,
                coordinates=Rect(self.sun.coordinates.x, 140, 10, 10),
                velocity=Vector2(0.1, 0.05),
                game_instance=self),
            Body(
                mass=10000,
                coordinates=Rect(self.sun.coordinates.x, 190, 10, 10),
                velocity=Vector2(0.10, -0.01),
                game_instance=self)
        ]

    def tick(self):
        self.clock.tick(120)

        for event in pygame.event.get():
            if event.type == pygame.QUIT:
                sys.exit()
            elif event.type == pygame.KEYDOWN:
                pressed = pygame.key.get_pressed()
                if pressed[pygame.K_COMMA] and self.time_scale > 1 and not self.paused:
                    self.time_scale = int(self.time_scale / 2)
                elif pressed[pygame.K_PERIOD] and self.time_scale < 1000 and not self.paused:
                    self.time_scale = int(self.time_scale * 2)
                elif pressed[pygame.K_SPACE]:
                    self.paused = not self.paused
                elif pressed[pygame.K_q]:
                    self.alive = False

        if self.paused:
            return

        self.screen.fill((10, 10, 10))
        self.draw_time_scale()

        for i in range(self.time_scale):
            for body in self.planets:
                for other in self.planets:
                    if body == other:
                        continue

                    body.force_between(other)

                body.x += body.velocity.x
                body.y += body.velocity.y
                if i == self.time_scale - 1:
                    body.draw()

        # self.screen.blit(self.scaled_screen, (0, 0))
        pygame.display.flip()

    @property
    def scale(self):
        return self.__scale

    @scale.setter
    def scale(self, scale: int):
        if scale >= 1:
            # c, d = self.screen.get_width() / 2, self.screen.get_height() / 2,
            # factor = scale / self.__scale
            # for b in self.planets:
            #     b.coordinates.x = c + factor * (b.coordinates.x - c)
            #     b.coordinates.y = d + factor * (b.coordinates.y - d)

            self.__scale = int(scale)

    def draw_time_scale(self):
        ts = self.font.render("{}x".format(self.time_scale), True, (200, 200, 200))

        self.screen.blit(ts, (2, self.screen.get_height() - ts.get_height()))