public class Main extends Application {

    private final Canvas canvas = new Canvas(770, 800);

    @Override
    public void start(Stage primaryStage) throws Exception {
        FXMLLoader loader = new FXMLLoader(getClass().getResource("/nawa.fxml"));
        Controller c = new Controller(canvas.getGraphicsContext2D());
        loader.setController(c);
        AnchorPane root = loader.load();

        primaryStage.setTitle("Waypoints");
        primaryStage.setScene(new Scene(root));

        Stage field = new Stage();
        FlowPane pane = new FlowPane();
        pane.getChildren().add(canvas);
        field.setScene(new Scene(pane));
        field.show();
        primaryStage.show();
    }

    public static void main(String[] args) {
        launch(args);
    }
}

aypoint;
    @FXML
    private TextField XPos;
    @FXML
    private TextField YPos;

    private double input_x = 15;
    private double input_y = 15;
    private int x = 0;
    private int y = 0;
    private int index = 0;
    private final int radius = 20;

    private HashMap<Integer, String> waypoints = new HashMap<>();
    private GraphicsContext gc;

    public Controller(GraphicsContext gc) {
        this.gc = gc;
    }

    @FXML
    public void Handler(ActionEvent event) {
        if (event.getSource() == addWaypoint) {
            try {
                input_x = Integer.parseInt(XPos.getText());
                input_y = Integer.parseInt(YPos.getText());
                System.out.println(input_x + " - " + input_y);
            } catch (NumberFormatException e) {
                input_x = 0;
                input_y = 0;
            }

            calculatePositions();
            drawWaypoints(x, y, gc);
//            drawField(gc);
//            waypoints.put(index, x + ";" + y);
//            index++;
        }
    }

    // and all the rest
}