CPSC 120A -- Assignment #3

More Fish (Sorry!!)
Due Thursday, November 20, 2003 by 2:50 p.m.(lab)

The Java Fish class should model a "Pac-man" style fish similar to the ones you drew in project 2 (without the bubbles!). The only requirements for the fish are that they have a body, with a mouth, and a tail. To model this your class needs the following instance data:

• an x coordinate for the position of the fish - it is up to you to decide exactly what the x represents (it could be where the tail starts or where the body starts, for example)
• a y coordinate for the position of the fish
• a "size" variable - I recommend just one size variable (so the body part of the fish is circular or if, you want fish that are not round you could make either the length or width proportional to the one size rather than generating two different numbers for size)
• a color
• a mouth size (this should be the number of degrees of the mouth opening)

The methods in the class should be the following:

• Two constructors
  • One with no parameters - this one should generate a random size between 30 and 100, a random x and y that guarantee the fish to be in the applet window (you should use the size to do this - do not use the loop technique from pre-lab 10 because it is inefficient), and a random shade of green for the color (to do this generate a random integer between 56 and 256 (not including 256) for the amount of green in the color, then use the constructor in the Color class that takes three parameters - the amount of red (use 0), the amount of green (use the value you generated), and the amount of blue (use 0). The constructor should set the mouth to 40 degrees.
  • One with 4 parameters - the x, y, size, and color. The constructor should initialize the object using the parameters and set the mouth size to 40 degrees.

• Three accessor methods - one to return the x coordinate of the position, one for the y and one for the size. Note: What you return may not be exactly what you store (for example, if your instance data for size stores the size of the body of the fish and if the tail is half that size then the size of the fish is 1.5 times what you store for size). You need to return position information so the program using the Fish class can use that information to place other fish in relation to the fish (without having to do unusual calculations).
• A method setColor to set the color to a color passed in as a parameter (so the method has one parameter - a Color object)
• A method to draw the fish
• A method openMouth that sets the mouth size to wide open (80 degrees). The method has no parameters.
• A method closeMouth that sets the mouth size to a partially closed mouth (16 degrees).

You need to create an applet to display the ocean full of fish. To avoid the problem of double images, use an init method in your applet. There is an example on page 257 but yours will be even simpler - it should set the background color and the applet size. Everything else is in the paint method as usual.

The applet should do the following:

• Draw at least 20 randomly sized and placed fish that are random shades of green.
• The largest fish among the 20 (or more) should be colored red.
• The smallest fish among the 20 should be colored yellow.
• A magenta fish, twice the size of the smallest fish, should be drawn just behind the smallest fish. The fish should have a wide open mouth.
• An orange fish, half the size of the largest fish, should be drawn just in front of the largest fish. This fish should have a partially closed mouth.
• A fish should be drawn in the lower left hand corner with your name in it. Make the fish big enough for your name to fit. You may choose the color.

You will need to construct an html file to display your applet.

Other Requirements

As usual, use good programming techniques. You should use good variable names, constants where appropriate, whitespace, and correct indentation and alignment of statements (emacs will do this for you if you let it!). Documentation must include a header with the file name, your name, the date, and a clear, complete description of what the program does. Both the Fish class and the class that draws the applet must be documented.

Hand In

Academic Integrity Reminder!!! Programming assignments are to be your own work. You may get help on the specifics of the assignment from no one except the instructor. You may not show your program to anyone or look at anyone else's program code (you may view each other's applets, just not the code that made the applet) or share ideas with anyone about how to write the program.