Identifying a tie on tictactoe

im wondering if theres a way to identify a tie in this tic tac toe game using the method of the rest of the game.
here is my code <
Cell board; //Object
int cols=3; //Number of columns
int rows=3; //Number of rows
int player=0; //Player
int win=0; //Used for wins
int screen=0; //Game screens
int full=9; //Cells
PFont font;

void setup() {
size(500, 500); //Setting screen size
font = loadFont(“cutetext.vlw”);
textFont(font);
board = new Cell[cols][rows]; //Creating new object
for (int i=0; i<cols; i++) //Loop until false columns
{
for (int j=0; j<rows; j++)//Loop until false rows
{
board[i][j] = new Cell(width/3 * i, height/3 * j, width/3, height/3); //Drawing the board
}
}
}

void draw() {
background(#FCEDF3); //Setting the background colour to white
if (screen==0) //determining the screen
{
fill(#FAC5D9); //Setting fill colour to black
textSize(20); //Setting text size
text(“press enter to start”, width/3.7, height/2); //Text
textSize(40);
text(“TIC TAC TOE”,100,140);
fill(#FAC5D9);
textSize(10);
text(“by adelynne and nicole <3”,10,490);
} else if (screen==1) //Determining the screen
{
checkGame(); //Checking for winners
for (int i = 0; i < cols; i++) //Loop until false for columns
{
for (int j = 0; j < rows; j++) //Loop until false for rows
{
board[i][j].display(); //Calling display function
}
}
}
}

void mousePressed() {
if (screen==1) //Play screen
{
if (win==0) //No winner yet
{
for (int i=0; i<cols; i++) //Loop until false for columns
{
for (int j=0; j<rows; j++) //Loop until false for rows
{
board[i][j].click(mouseX, mouseY); //Calling click function at mouse point
}
}
}
}
}

void keyPressed() {
if (screen==0) //Starting screen
{
if (key==ENTER) //User presses enter key
{
screen=1;//Play Screen
full=9; //Cells are full
}
} else if (screen==1 && win==0 && full==0) //Checking for play screen, no winners and empty cells
{
if (key==ENTER)//User presses enter key
{
screen=0; //Start Again Screen
for (int i=0; i<cols; i++) //Loop until false for columns
{
for (int j=0; j<rows; j++) //Loop until false for rows
{
board[i][j].clean(); //Calling clean function
win=0; //Ressetting winner
full=9; //Cells are full
}
}
}
} else if (screen==1&&(win==1||win==2)) //Checking for play screen and winner
{
if (key==ENTER) //User presses enter key
{
screen=0; //Start Again Screen
for (int i=0; i<cols; i++) //Adding 1 to i til its greater or equal to cols
{
for (int j=0; j<rows; j++) //Adding 1 to j til its greater or equal to rows
{
board[i][j].clean(); //Calling clean function
win=0; //Resetting winner
full=9; //Cells are full
}
}
}
}
}

void checkGame() { //Checking for winners
int row=0;
//Checking for vertical and horizontal condition
for (int col=0; col<cols; col++)
{
if (board[col][row].checkState()==1&&board[col][row+1].checkState()==1&&board[col][row+2].checkState()==1) {
win=1; //Vertical 0 win
} else if (board[row][col].checkState()==1&&board[row+1][col].checkState()==1&&board[row+2][col].checkState()==1) {
win = 1; //Horizontal 0 win
}
if (board[col][row].checkState()==2&&board[col][row+1].checkState()==2&&board[col][row+2].checkState()==2) {
win=2; //Vertical X win
} else if (board[row][col].checkState()==2&&board[row+1][col].checkState()==2&&board[row+2][col].checkState()==2) {
win = 2; //Horizontal X win
}
}

//Checking the diagonal conditions
if (board[row][row].checkState()==1&&board[row+1][row+1].checkState()==1&&board[row+2][row+2].checkState()==1) {
win=1; //Diagonal 0 win
} else if (board[row][row].checkState()==2&&board[row+1][row+1].checkState()==2&&board[row+2][row+2].checkState()==2) {
win=2; //Diagonal X win
} else if (board[0][row+2].checkState()==1&&board[1][row+1].checkState()==1&& board[2][row].checkState()==1) {
win=1; //0 win
} else if (board[0][row+2].checkState()==2&&board[1][row+1].checkState()==2&& board[2][row].checkState()==2) {
win=2; //X win
}

//Printing the winner
textSize(20); //Setting text size
if (win==1) { //Player 2 wins
fill(#F0BFD2); //Fill in pink
text(“player 2 \n won!”, board[1][1].checkX()+40, board[1][1].checkY()+70);//Text
} else if (win==2) { //Player 1 wins
fill(#F0BFD2); //Fill in pink
text(“player 1 \n won!”, board[1][1].checkX()+40, board[1][1].checkY()+70); //Text
}
if (win==1||win==2) { //Either players wins
fill(#F0BFD2);
textSize(20); //Setting text size
text(“press enter to restart”, 130, 90);//Text

}
if (win==0&& full==0) { //No winners and empty cells
text(“press enter to restart”, 130, 90);//Text
}
}

class Cell { //Class

//Declaring variables
int x;
int y;
int w;
int h;
int state;

//Constructor
Cell(int tx, int ty, int tw, int th) {
x=tx;
y=ty;
w=tw;
h=th;
}

void click(int tx, int ty) { //User clicks function
int mx=tx; //Declaring equality
int my=ty; //Declaring equality
if (mx > x && mx < x + w && my > y && my < y + h) {
if (player == 0 && state==0) //First players turn
{
//New values
state=1;
full=-1;
player= 1;
} else if (player == 1 && state ==0) { //Secon players turn
//New values
state=2;
full=-1;
player= 0;
}
}
}

void clean() { //Reset function
state=0; //Assignning value
}
int checkState() { //Retains the state
return state; //Returning to original state value
}
int checkX() { //Retains X
return x; //Returning to original X value
}
int checkY() { //Retains Y
return y; //Returning to original Y value
}

void display() { //Board and looks function
noFill(); //Removing fill
strokeWeight(3); //Setting stroke thickness
stroke(#FAC5D9);
rect(x, y, w, h); //Rectangle for board
if (state==1) { //Checking state value is equal to 1
ellipseMode(CORNER); //Enabling corner mode
ellipse(x, y, w, h); //Ellipse for zero
} else if (state==2) { //Checking state value is equal to 2
line(x, y, x+w, y+h); //Diagonal lines for x
line(x+w, y, x, y+h); //Diagonal lines for x
}
}
}

pls help

Count the fields with state = x or = o (count the full fields)

  • When no one wins and the count == 9 we have a tie

Correction

Ah, I just saw: you have the counter with variable full going from 9 to 0

Alas, you have a spelling mistake:

full=-1;

must be

full -= 1; (minus in front of = sign)

which is the same as full = full - 1; !!!

Or full--;

You use screen variable in draw().

You can add further screens in draw for a win and for a tie

This is a better code than to hide it in other functions

Only in draw() you have the text() command then. Good.