///move through different screens, some on timers
//pressing 'enter' or 'return' increments an int variable called 'scrn' which will define 
//which 'screen' we see, there is a timer, set to 20 seconds for some screens
//for those screens with a timer after 20 seconds the next screen is displayed

String info = "Press 'Enter' or 'Return' to advance to next screen";
int scrn = 0;
int scrnstart;
int scrntime = 20;
boolean scrnstarted = false;

PImage fibo;
PImage screen1;
PImage screen1a;//will capture screen
PImage screen2;
PImage screen2a;//will capture screen
PImage screen3;
PImage screen3a; //will capture screen
PImage screen4;
PImage screen4a;//will capture screen
PImage screen5;
PImage screen5a;//capture
PImage screen6;
PImage screen6a;//capture
PFont font;
PImage back; //first image, size of screen


void setup () {
  size (600,400);
  font = loadFont ("Garamond-48.vlw");
  textFont(font, 22);
  textAlign(CENTER);
  smooth();
  back=loadImage ("back.jpg"); //first image , first backgound image

    screen1 = createImage (width, height, RGB);  //createImage() Creates a new PImage (the datatype for storing images). 
  //This provides a fresh buffer of pixels 
  //we use it to get what is on screen, which we will display as thumbnails at the end
  fibo = loadImage("fibo.jpg"); 
  screen1 = loadImage("screen1.jpg");
  screen1a = createImage (width, height, RGB); //these 'a' images will be like thumbnail sketches
  screen2 = loadImage ("screen2.jpg");
  screen2a = createImage (width, height, RGB);
  screen3 = loadImage("screen3.jpg");
  screen3a = createImage (width, height, RGB); 
  screen4 = loadImage("screen4.jpg");
  screen4a = createImage (width, height, RGB);
  screen5 = loadImage("screen5.jpg");
  screen6 = loadImage("screen6.jpg");

}

void draw () {

  background (100);

  if (scrn == 0) { //screen is defined by the 'scrn' int variable which is incremented if the user presses 'enter' or 'return' key
    //scrn starts at 0
    image (back, 55, 10, 500, 350); //background image
    image(fibo, 40, 60, 40, 40);//mr fibbonacci
    fill(0);
    text ("PRESS ENTER TO SEE NEXT SCREEN", 340, 95);
    text ("screen o,  the program begins, look there's fibbonacci", width/2, 375);
  }
  else if (scrn == 1){
    image(screen1, 0, 0);
    image(fibo, 50, 50, 50, 50);
    text ("This is screen  1", width/2, 35);
    text ("This screen is not on a timer, but the next one is,  press \n 'Enter' to advance to the next screen", width/2, 160);
    screen1a = get(0,0,width,height); //capture this screen, would make more sense if interactive things were going on
  }
  else if (scrn == 2){
    if (scrnstarted == false){ //it will be false because pressing 'enter' sets it to false, we got here by 
   //pressing 'enter' 

      scrnstart= millis(); //Returns the number of milliseconds (thousandths of a second) since starting an applet. 
      //This information is often used for timing animation sequences.
      scrnstarted = true; //start timing
    }
    int scrn1current = millis(); //time at this point
    //calculate remaining time:
    int timeremaining = scrntime-(scrn1current-scrnstart)/1000;  //calculates how long this screen has been runing for
    //if you dont understand try printing the variables to the console so you can see what is what.
    //we gave scrntime the value of  20 (at top), but could change it to any length we want
    image(screen2, 0, 0);
    text ("You have 20 seconds at look at this screen", width/2, 85);
    text ("or press \n 'Enter' to advance to the next screen", width/2, 160);
    text ("This is screen 2", width/2, 35);
  
    fill(0);
    text (timeremaining, 25, 375); //print how much time is left
    if (timeremaining <= 0){ //and advance when we reach 0
      advscrn(); //move to next screen if time is up
    }
    screen2a = get(0,0,width,height);
  }
  else if (scrn == 3 ){


    image(screen3, 0, 0);
    text ("This is screen 3, it is not on  a timer, but could be", width/2, 35);
    screen3a=get(0,0, width, height);
  }
  else if (scrn == 4){

    if (scrnstarted == false){
      scrnstart= millis();
      scrnstarted = true;
    }
    int scrn2current = millis();
    int timeremaining = scrntime-(scrn2current-scrnstart)/1000;

    image(screen4, 0, 0);

    // text (advance, width/2, 375);
    text ("screen 4, this is on a timer", 220, 35);
    fill(0);
    text (timeremaining, 25, 375);
    if (timeremaining <= 0){
      advscrn();
    }
    screen4a = get(0,0,width,height);

  }
  else if (scrn == 5){

    image(screen5, 0, 0);
    fill(0, 0, 255);
    text ("This is screen  5, not timed", width/2, 35);
    screen5a=get(0,0, width, height);
  }
  else if (scrn == 6){

    if (scrnstarted == false){
      scrnstart= millis();
      scrnstarted = true;
    }
    int scrn6current = millis();
    int timeremaining = scrntime-(scrn6current-scrnstart)/1000; //remember int scrntime = 20 

      image(screen6, 0, 0);
    text (info, width/2, 375);
    text ("screen 6, timed", 90, 35);
    text (timeremaining, 25, 375);
    if (timeremaining <= 0){//we have run out of time
      advscrn(); //move to next screen
    }
    screen6a = get(0,0,width,height); //create a PImage from what is on screen
  }

  else if (scrn ==7){

    //display thumbnails
    image(screen1a, 5,5, 180, 120);
    image(screen2a, 5, 140, 180, 120);
    image(screen3a, 5, 275, 180, 120);
    image(screen4a, 200, 5, 180, 120);
    image(screen5a, 200, 140, 180, 120);
    image(screen6a, 200, 275, 180, 120);


    text ("Press 'Enter' \n to restart", 500, 330);

  }
}
void advscrn(){
  scrn++;
  scrnstarted = false;//stop timer from previous screen
}
void keyPressed() {
  if (key == ENTER || key == RETURN) {

    scrn++;
    scrnstarted = false; //stop timer 
    if (scrn>7){
      scrn =0; //go back to first screen
    }
  } 

}