import pygame

import random

def play(model,draw, step, events, width=1280, height=720,background='Black',fps=60):
  pygame.init()
  screen = pygame.display.set_mode((width, height))
  clock = pygame.time.Clock()

  running = True
  while running:
    for event in pygame.event.get():
      if event.type == pygame.QUIT:
        running = False
      model = events(model)
    screen.fill(background)
    draw(screen,model)
    pygame.display.flip()
    model=step(model)
    clock.tick(fps) / 1000
  pygame.quit()
  
def  ball():
  play( (0.0,0.4,0),drawBall,stepBall, keyBall,500,800,'black',33)

def drawBall(screen,model):
  pygame.draw.circle(screen, "red", pygame.Vector2(245,model[0]), 10)

def keyBall(model):
  (h,v,t) = model
  keys = pygame.key.get_pressed()
  if keys[pygame.K_r]: return (10,-v*0.8,0)
  else: return model

def stepBall(model):
  (h,v0,t) = model
  v = v0 + 0.981 * t
  return (h-10,-v*0.8,0) if h>795 else (h+v,v0,t+1)

ball()