XNA Game-Themed CS1 Examples ( XGC1 )

Release 2.0 (XNA V3.1)

Topic: Topic.5.RepetitionStructures
Example: Ex_13.ExampleWithFor

Repetition: Drawing A Sine Curve With A For Loop



1. Obtain the example code

Download and unzip the zip file and you will see an ExampleProgram folder. Open the ExampleProgram folder, the EXE folder contains the compiled program and you can double click on the .sln file to work with the source code.

When the game starts, you'll see a screen that looks similar to this:

The program for this tutorial is almost exactly identical to the program used in the drawing A Sine curve with a While Loop tutorial .   The difference is that for this tutorial, we're using a for loop.

2. Examining The Program:

Let's examine the C# source code that produces the behavior we see on-screen


  1. Start from a blank starter project (1000.201, if you need it), and re-do the code from memory as much as possible.  On your first try, do what you can, and keep the above code open so that when you get stuck, you can quickly look up what you forgot (and that after you finish a line, so that you can compare your line to the 'correct' line).  On the next try, do the same thing, but try to use the finished code less.  Repeat this until you can type everything, without refering the tutorial's code.
  2. Familiarizing Yourself With Loops: Modifying the program
    For this exercise, you should use the same project that was explained in the above tutorial.
    Go back to the previous tutorial about animating sinusoidal motion, and run that program.  Observe how the program moves the small basketball along the sine wave.  You should implement identical functionality here in this program, and you should do that from memory as much as possible.  To be clear: do not refer to the source code in that previous tutorial unless you absolutely have to - the more of this exercise that you can and figure out (and do) on your own, the more you'll learn from it.

Project home page : The Game-Themed Introductory Programming Project.
Kelvin Sung
Computing and Software Systems
University of Washington, Bothell
Michael Panitz
Business And Information Technology
Cascadia Community College

Microsoft Logo This work is supported in part by a grant from Microsoft Research under the Computer Gaming Curriculum in Computer Science RFP, Award Number 15871 and 16531.