CS 101 - Intro to Computing, Fall 2010

Lab 3

For this lab assignment, we will write a simple program in the DrJava environment that will do simple turtle drawings.

Running Dr.Java in the ACCC Labs

Dr.Java can be found on the machines in the ACCC labs by
  1. clicking on START
  2. then clicking on ALL Programs
  3. then clicking on Programming
  4. then clicking on the Dr.Java

Lab Assignment

Due: Thursday 9/16/2010 by 11:59 pm

For this lab assignment, complete the following:

  1. Write a java program that uses a single turtle write out your initials on an image/world and display that image/world. Each letter needs to drawn in a different color. This lab is assuming your initials have 3 letters. If you don't have three letters for your initials, add another letter or number to get it to at least three initials.

    The key to this lab is to write the letters using very "blocky" upper case letters. For example:

    I made letters that were 100 pixels high and 50 pixels wide. I also put a space of 25 pixels between each letter and left a space of 25 pixels around the border. You don't need to follow my plan exactly, but I think it works fairly well. I also set the width of the pen to be a little thicker than the default size of 1 pixel wide. Remember to keep the pen up between letters. This is done by using the penUp() and penDown() methods of the Turtle class. Refer to the JavaDocs for the bookClasses page to more information.

    Also, remember to change the color of the pen. To use color, you will need to add an import statement at the top of you program. This statement will add in the Java Color class from the Java-AWT library:

    import java.awt.Color;
    AWT stands for the "Abstract Windowing Toolkit". You could import the entire AWT library if you wished without causing any undo harm to the program but it is not really needed in this case. To do this, you would replace the word "Color" with an asterisk "*".

    Once you have added the import statement, you specify the color of the pen using the setPenColor() method from the Turtle class. The parameter will be the color you wish to use. The parameter will be given as: Color.xxx where xxx is the name of the color you wish to use. Note: the color names need to be defined in the library first. To find the defined color names check out the Java Sun Web Page on Color. The values is listed in the "Field Summary" section.

    For example, set have the turtle "turtle1" draw with the color red you would use the code:

    turtle1.setPenColor ( Color.red );
    Also you can check out the code we did in class that draw shapes in different colors. That code is Lect99d.java .

  2. Be sure to include a comment at the top of your java file that contains the following:

Submission of the Lab

The lab must be submitted electronically to the Assignment Link for Lab 3 inside of Blackboard. You will only need to submit the java source code file (the ".java" file).