Question

asteroid size estimator code in java​

Answer 1

Asteroids developed by Atari and self published in the year 1979 is a video game classic. The gameplay consists of the player steering a triangular spaceship, with the goal of destroying asteroids by shooting them.

What follows is a larger scale example, where we create a part of the Asteroids game. The game is also an exercise in the course — write the game into the provided template (at the end of the example) by following the example.

The game is constructed in multiple parts, which are the following:

Creating the game window

Creating the ship

Turning the ship

Moving the ship

Creating an asteroid

The collision between the ship and an asteroid

Multiple asteroids

Staying within the window

Projectiles

Adding points

Continuous adding of asteroids

Let's begin making the application by creating the game window

Creating the game window

We will build the application such that the game window may contain an arbitrary amount of elements, the positions of which will be ignored by the layout used. This task fits the Pane class. The Pane class contains a list of type ObservableList containing child elements. The list can be accessed using the getChildren method of the Pane class.

The program shown below creates a window that is 300 pixels wide and 200 pixels tall. At the point 30, 50 in the window is a circle with a radius of 10 pixels. In computer programs it is typical for the origin of the coordinate system is placed at the top left corner of the window. Additionally the value of the y-coordinate increases when moving down.

import javafx.application.Application;

import javafx.scene.Scene;

import javafx.scene.layout.Pane;

import javafx.scene.shape.Circle;

import javafx.stage.Stage;

public class PaneExample extends Application {

   @Override

   public void start(Stage stage) throws Exception {

       Pane pane = new Pane();

       pane.setPrefSize(300, 200);

       pane.getChildren().add(new Circle(30, 50, 10));

       Scene scene = new Scene(pane);

       stage.setScene(scene);

       stage.show();

   }

   public static void main(String[] args) {

       launch(args);

   }

}