#
#Copyright (C) 2012 Mateus Valadas Preto Bravo Cordeiro
#Escola Secundária da Ramada
#
#This program is free software; you can redistribute it and/or modify it under 
#the terms of the GNU General Public License as published by the Free Software 
#Foundation; either version 2 of the License, or (at your option) any later 
#version.
#
#This program is distributed in the hope that it will be useful, but WITHOUT 
#ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS 
#FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details.
#
from visual import*
from visual.text import *
#scene.fullscreen=1
g=-9.8
cb=0
cor=''
v0y=0
v0x=0
x0=-25
a=0
y0=0


m=abs(float(input('Insira o valor da massa da bola (kg) ')))
d=0
while d<4:
    d=abs(float(input('Insira o valor da distancia entre as placas (m) ')))
    if d<4:
        print("Insira um valor superior a 4")
        
scene.range=(70,d+7,10)
p=m*g

print( "opções:\n 1- neutra \n 2- negativa \n 3- positiva")
while cb<=0 or cb>3:
    cb = int(input ("Escolha o sinal da carga da esfera: "))
    if cb==1:
        cor=color.white
        q=0
    if cb==2:
        cor=color.blue
        q=abs(float(input('Insira o modulo do valor da carga pontual: ')))
        q=-q
    if cb==3:
        cor=color.red
        q=abs(float(input('Insira o modulo do valor da carga pontual: ')))
        print('Para a forca eletrica anular o peso, a ddp entre as placas tera de ter um valor de ',9.8*m/(q*d),' V')
    if cb<=0 or cb>3:
        print(" Escolha entre as opções 1, 2 ou 3")

ddp=abs(float(input('Insira o valor da diferenca de potencial (V) ')))
E=ddp*d
    
while v0x<=0:
    v0x = float(input ("Velocidade Inicial (m/s)="))
    if v0x <=0:
        print(" A velocidade inicial tem de tomar valores positivos\n Insira um valor positivo")

CN= box(pos= (0,d/2,0), size=(50,2,30),color=color.blue)
CP= box(pos= (0,-d/2,0), size=(50,2,30),color=color.red)
positivo=text(pos=(0,d/2-0.5,15.1), axis=(1,0,0), width=1, height=1, string='PLACA NEGATIVA', color=color.white, justify='center')
positivo=text(pos=(0,-d/2-0.5,15.1), axis=(1,0,0), width=1, height=1, string='PLACA POSITIVA', color=color.white, justify='center')

ball= sphere(pos= (-25,0,0), radius=1, color=cor)
ball.trail=curve(radius=0.25)

dt=0.01

while true:
    rate (100)
    a=(E*q)/m+g
    x=x0+v0x*dt
    dx=x-x0
    vy=v0y+a*dt
    y=y0+vy*dt
    dy=y-y0
    x0=x
    y0=y
    v0y=vy
    ball.x=ball.x+dx
    ball.y=ball.y+dy
    ball.trail.append(ball.pos)
    if  ball.x>25:
        E=0
    if ball.y<-d/2+ball.radius+1 or ball.y>d/2-ball.radius-1:
        break