Java Program to Count Integral Points Inside a Triangle

public class Main 
{
    public static void main(String [] args)
    {
         Point p = new Point(0, 0);
         Point q = new Point(25, 0);
         Point r = new Point(0, 20);
        int x = interiorPoint(p, q, r);
        System.out.println("Number of total interior integral points " + x );
    }
    static int interiorPoint(Point p, Point q, Point r)
     {
        // total boundary points of 3 sides + 3 extra integral points for the vertices of triangle
        int BoundaryPoints = boundaryPoint(p, q) + boundaryPoint(p, r) + boundaryPoint(q, r) + 3;
        // Calculate 2 times of area of the triangle
        int Area = Math.abs(p.x * (q.y - r.y) + q.x * (r.y - p.y) + r.x * (p.y - q.y));
         // Using Pick's theorem to calculate the no. of total Interior points
        int i = (Area - BoundaryPoints + 2) / 2;
        return i;
    }
     // Finds the no. of boundary integral points between 2 given points.
    static int boundaryPoint(Point p, Point q)
    {
        // Check if line parallel to x-axes
        if (p.x == q.x)
        return Math.abs(p.y - q.y) - 1;
        // Check if line parallel to x-axes
        if (p.y == q.y)
        return Math.abs(p.x - q.x) - 1;
        int gcd = gcd(Math.abs(p.x - q.x),Math.abs(p.y - q.y)) - 1;
        return gcd;
    }
    // GCD of 2 numbers
    static int gcd(int p, int q)
    {
        int gcd = 1;
        for (int i = 1; i<=p && i<=q; i++)
        {
            if(p%i==0 && q%i==0)
            gcd = i;
        }
        return gcd;
    }
}
class Point
{
    int x, y;
    public Point(int a, int b)
    {
        x = a;
        y = b;
    }
} 

Output:

Number of total interior integral points 226