/*
           DO WHAT THE FUCK YOU WANT TO PUBLIC LICENSE
                 Version 2.71828, December 2014

Copyright (C) 2014 me <vomitme @g mail>

Everyone is permitted to copy and distribute verbatim or modified
copies of this license document, and changing it is allowed as long
as the name is changed.

           DO WHAT THE FUCK YOU WANT TO PUBLIC LICENSE
  TERMS AND CONDITIONS FOR COPYING, DISTRIBUTION AND MODIFICATION

 0. You just DO WHAT THE FUCK YOU WANT TO.
*/

#include <digitalIOPerformance.h>

#define PIN_PDIODE A0
#define PIN_BUTTON 2
#define BUTTON_PRESSED LOW

void setup()
{
  Mouse.begin();
  Serial.begin(9600); //somehow it can act as a mouse and a serial thing simultaneously
  pinModeFast(PIN_PDIODE, INPUT);
  pinModeFast(PIN_BUTTON, INPUT);
}

void loop()
{
  while (digitalReadFast(PIN_BUTTON) == BUTTON_PRESSED) {
    unsigned long i = 0, s, n;

    while (digitalReadFast(PIN_PDIODE) != LOW) {
      Serial.print(analogRead(PIN_PDIODE));
      Serial.println("starting position too bright :P");
    }

    //shake mouse before the twitchnot necessary
    for (i = 0; i < 12; i++) {
      Mouse.move(0,1,0);
      delayMicroseconds(2000);
      Mouse.move(0,-1,0);
      delayMicroseconds(2000);
    }

    //twitch
    i = 0;
    Mouse.move(0,-100,0);

    //measure time until screen change detected
    s = micros(); //~3us
    while (digitalReadFast(PIN_PDIODE) != HIGH) i++; //~0.6us per cycle when using digitalReadFast
    n = micros(); //~3us

    //print results
    //Serial.print("time (us):\t");
    Serial.println(n - s);
    //Serial.print("\tcycles:\t");
    //Serial.println(i);

    delay(10);
    Mouse.move(0,100,0);
    delay(random(14,62));
    //delay(100); //uncomment this if vsync
  }
}