Java – Stream/IntRange on 2D coordinates?

I have the following classes:

public class Rectangle
{
   public int width, height;
   public Point start;

public Rectangle(Point start, int width, int height)
   {
      this.start = start;
      this.width = width;
      this.height = height;
   }
}

public class Point
{
   public int x, y;

public Point(int x, int y)
   {
      this.x = x;
      this.y = y;
   }
}

I want to create a method of the Rectangle class that returns a Java 8 Stream of type Point, which will stream the index position inside the rectangle. Predecessor.

// This is inside the rectangle class.
public Stream<Point> stream(int hstep, int vstep)
{
    if the rectangle started at 0,0
    and had a width and height of 100
    and hstep and vstep were both 1
    then the returned stream would be
    0,0 -> 1,0 -> 2,0 -> ... -> 100,0 -> 0,1 -> 1,1 -> ...

 If vstep was 5 and h step was 25 it would return
    0,0 -> 25,0 -> 50,0 -> 75,0 -> 100,0 -> 0,5 -> 25,5 -> ...

return ...
}

I

use IntStream, map, filter, etc. a lot, but this is much more complicated than anything I’ve tried. I don’t know how I would do something like that. Can someone guide me in the right direction?

You can use nested IntStreams to generate each Point, and then flatten the resulting stream:

public Stream<Point> stream(int hstep, int vstep) {
    return IntStream.range(0, height / vstep)
            .mapToObj(y -> IntStream.range(0, width / hstep)
                    .mapToObj(x -> new Point(start.x + x * hstep, start.y + y * vstep)))
            .flatMap(Function.identity());
}