Simple pong

# Pong - NumWorks
# Created by Alvar Laigna - https://alvarlaigna.com
# Up/Down:paddle OK:serve/restart Back:quit
from kandinsky import fill_rect as F,draw_string as D
from ion import keydown as K
from time import sleep as Z,monotonic as M
W,H=320,222
BK=(0,)*3;WH=(255,)*3
P1C=(80,160,255);P2C=(255,100,80)
BC=(0,255,100);DC=(30,)*3

okv=1 if K(4)or K(52) else 0

def okd():
 return K(4)or K(52)

def okp():
 global okv
 d=okd()
 if d and not okv:
  okv=1
  return True
 if not d:okv=0
 return False

def wup():
 while okd():Z(0.02)
 Z(0.12)

def title():
 F(0,0,W,H,BK)
 D("P O N G",112,30,(0,255,100),BK)
 D("- - - - - - - - - - -",50,55,DC,BK)
 D("You",20,80,P1C,BK);D("vs",150,80,WH,BK);D("CPU",260,80,P2C,BK)
 D("Up / Down",100,115,(180,)*3,BK)
 D("move paddle",95,135,(120,)*3,BK)
 D("OK = serve & restart",60,165,(180,)*3,BK)
 D("Back = quit",105,185,(120,)*3,BK)
 D("Press OK",125,206,(0,255,100),BK)
 while True:
  if okp():wup();return
  if K(17):return False
  Z(0.05)

def serve(s1,s2):
 # Draw center score big
 F(100,85,120,35,BK)
 D(str(s1),135,90,(80,160,255),BK)
 D("-",155,90,DC,BK)
 D(str(s2),170,90,(255,100,80),BK)
 Z(0.6)
 for c in("3","2","1"):
  F(155,115,10,18,BK)
  D(c,155,115,(0,255,100),BK)
  Z(0.5)
 F(100,85,120,65,BK)

def drawfield(s1,s2):
 F(0,0,W,H,BK)
 # Dashed center line
 for i in range(0,H,8):F(W//2,i,1,4,DC)
 # Score at top
 D(str(s1),W//2-25,2,P1C,BK)
 D(str(s2),W//2+15,2,P2C,BK)
 # Goal markers
 D("7",5,2,(50,)*3,BK)
 D("7",W-15,2,(50,)*3,BK)

def flash(px,py,c):
 F(px,py,5,30,WH)
 Z(0.03)
 F(px,py,5,30,c)

def pong():
 if title()==False:return
 p1=p2=H//2-15
 bx,by=float(W//2),float(H//2)
 vx,vy=0.0,0.0
 s1=s2=0;paused=True
 drawfield(s1,s2)
 while True:
  if K(17):return
  # Erase
  F(6,int(p1),5,30,BK);F(W-11,int(p2),5,30,BK)
  F(int(bx)-1,int(by)-1,7,7,BK)
  # P1 input
  if K(1)and p1>2:p1-=4
  if K(2)and p1<H-32:p1+=4
  if paused:
   F(6,int(p1),5,30,P1C);F(W-11,int(p2),5,30,P2C)
   F(int(bx),int(by),5,5,BC)
   if okp():
    serve(s1,s2)
    drawfield(s1,s2)
    bx,by=float(W//2),float(H//2)
    vx=3.5 if s1<=s2 else-3.5;vy=2.0
    paused=False
   Z(0.02);continue
  # AI
  sp=min(3.5,2.0+(s1+s2)*0.15)
  pred=by+vy*((W-20-bx)/max(abs(vx),0.1)if vx>0 else 99)
  t=max(0,min(H-30,pred-15))
  if p2<t-2:p2=min(p2+sp,H-30)
  elif p2>t+2:p2=max(p2-sp,0)
  # Ball
  bx+=vx;by+=vy
  if by<1:by=1.0;vy=abs(vy)
  if by>H-6:by=float(H-6);vy=-abs(vy)
  # Paddle hits
  hit=False
  if vx<0 and 6<bx<14 and p1-5<by<p1+30:
   vx=abs(vx)+0.15;vy+=(by-p1-13)/5
   hit=True;flash(6,int(p1),P1C)
  if vx>0 and W-16<bx<W-8 and p2-5<by<p2+30:
   vx=-(abs(vx)+0.15);vy+=(by-p2-13)/5
   hit=True;flash(W-11,int(p2),P2C)
  vy=max(-5.5,min(5.5,vy))
  vx=max(-7.0,min(7.0,vx))
  # Goal
  if bx<-5 or bx>W+5:
   if bx<-5:s2+=1
   else:s1+=1
   drawfield(s1,s2)
   p1=p2=H//2-15
   bx,by=float(W//2),float(H//2)
   vx=vy=0.0;paused=True
   if s1>=7 or s2>=7:
    F(0,0,W,H,BK)
    if s1>=7:
     D("YOU WIN!",105,70,(0,255,100),BK)
    else:
     D("CPU WINS",105,70,(255,80,60),BK)
    D(str(s1)+" - "+str(s2),130,100,WH,BK)
    D("OK = play again",80,145,(180,)*3,BK)
    D("Back = quit",105,170,(120,)*3,BK)
    while True:
     if K(17):return
     if okp():wup();break
     Z(0.05)
    s1=s2=0;drawfield(s1,s2)
   continue
  # Draw
  F(6,int(p1),5,30,P1C)
  F(W-11,int(p2),5,30,P2C)
  F(int(bx),int(by),5,5,BC)
  Z(0.018)

pong()