Homework #4: Simple Swing event handling

For this homework, you will demonstrate your mastery of mouse, keyboard, and window events by creating the skeleton of a 2-dimensional "Lunar Lander" game. The application will draw a simple spaceship, animate its thrusters in response to keyboard events, and move it around the window in response to mouse clicks. (We aren't going to simulate the physics yet.)

The requirements for the application are as follows:

• The application class must be named 'EventTest04' and be a member of a package named cis370.hw04.
• The window's height and width must be 3/4 of the corresponding screen dimensions. The window must be centered on the display, and have a black background.
• The spaceship should be drawn (not filled) with white lines, pointed toward the top of the screen.
• Lay out the spaceship geometry and perform any calculations using doubles, but draw on the screen using the drawLine() method of the Graphics class.
• The spaceship has a main rocket thruster located at its base. It also has two reaction control thrusters, one on either side, which are used to rotate the ship clockwise and counterclockwise. All three thrusters can fire simultaneously.
• Choose three control keys to activate the thrusters. The application must draw the 'flames' from each thruster when the corresponding key is pressed, and un-draw them when the key is released. (A good choice for these keys is 'j', 'k', and 'l' for the clockwise, main, and counterclockwise thrusters respectively. Another good choice might be right arrow, down arrow, and left arrow.)
• Clicking the mouse anywhere in the window should redraw the spaceship, with the correct thruster animation, at the location of the click.
• The 'flames' from each thruster should be drawn in red, and should be at least 20 pixels long.
• The approximate height of the spaceship should be 150 pixels.
• The application must keep track of fuel consumption. The main thrusters burns 50 kg of fuel per second; each reaction control thruster burns 5 kg per second. Show the total fuel consumed, to the nearest 1/100 kg, at the bottom left of the window in a monospaced 10-point font. The total should update continuously when the thrusters are firing, except when the window is minimized or deactivated.
• Have fun and be creative with the graphics, but don't make the shape too fancy. Here are a couple of sample spaceships, with their counterclockwise reaction control thrusters and main thrusters firing:
   
• Extra credit: Animate the rotation of the spaceship. Whenever a reaction control thruster is firing, make the spaceship spin in the correct direction at 18 degrees per second. (If both reaction control thrusters are firing, the ship shouldn't rotate.)

Hint 1: Give a lot of thought to how you store and draw the 'shapes' of the rocket and the flames. You will be drawing lines, rather than Shape2Ds; ragged 2-dimensional arrays are worth considering. If you find yourself drawing the spaceship with a bunch of statements like

g.drawLine(x+ 7.0,y+ 3.0,x+21.0,y-17.0);
g.drawLine(x+21.0,y-17.0,x+25.0,y-19.0);
g.drawLine(x+25.0,y-19.0,x+10.0,y-12.0);
...

you are definitely doing something wrong.

Hint 2: This is a course in object-oriented programming. Your solution should involve more classes than just a subclass of JFrame. A couple of questions to ask yourself are, "How hard would it be to change the design of my spaceship?" and "How hard would it be to display multiple spaceships in the same window?"

Hint 3: You should be able to implement the entire application in fewer than 300 lines of code. Some of them might even be amazingly similar to the code from homework #3!

Hint 4: The javax.swing.Timer class described in Chapter 6 could be useful in animating the fuel consumption display.

Hint 5: If you decide to tackle the extra-credit part of the assignment, you will probably be interested in the java.awt.geom.AffineTransform class.

Due date: The homework is due at the beginning of class on 7 October.

Turn in: (1) A listing of the source file(s) for the application. (2) A screen dump of the application, with at least one rocket motor firing if possible. (Color output is not necessary.)

E-mail: A Zip or tar archive file containing all of your source files (including package.html) to grading@bozoid.com. The subject of the e-mail should be "EventTest04", and the archive name should be hw04.zip or hw04.tar.gz. In addition to your source files, the archive file should include a text file named readme.txt containing your name and any other identifying information you think is appropriate. Do not include .class files, javadoc files, or screen dumps in the e-mail.

Note: Staple all the pages of your submission together, and make sure you put your name on your homework!