High School level (years 9-10 in Australia, ages 14-16) introduction to programming course, based on the language Processing, includes class material, exercises, examples, and tests. Course ran for 2 terms in 2014. Feel free to use as is, borrow ideas, etc. 6th class.

1. Introduction to Programming
Class 6
Paul Brebner

2. Exercise
• Create a cannon trajectory game
– Place a cannon at lower left of screen, with a target on lower right.
– Set initial cannon angle (0-90 degrees, 0 is horizontal, 90 is vertical), and
velocity, and cannon ball location (x and y, same as cannon).
– Calculate velocity of the cannon ball, vx and vy, initially:
• float vx = velocity * cos(radians(angle));
• float vy = velocity * sin(radians(angle));
– Each frame, change x and y position (and draw ball) and vy as follows:
• x += vx; // add vx to get next cannon ball x position
• y -= vy; // subtract vy to get next cannon ball y position
• vy -= g; // g is gravity acting down, try 1
– Remember that in processing x increases from 0 to width, and y from 0 to
height (starting at top left, so increases as ball goes down!)
– Use frameRate(1) (or slower) to make debugging easier
– How will you change the angle and velocity? How will you fire? How will you
check if the ball hits the target? What happens when it hits?
– Can you put another cannon on the right and make the game 2 player?
– Can you work out how load images for the cannon, ball, target, explosion etc?
– Next page is a simple online example

3. Try this example
http://phet.colorado.edu/sims/projectile-motion/projectile-motion_en.html

4. Example program structure, add detail to TODOs
// global variables for cannon and cannon ball position and velocity go here ...
TODO
boolean cannonFired = false; // true after cannon fired until ball lands
void setup() // set size, background (sky colour), cannon position, and frame rate
{
TODO
}
void draw() // everything done once per frame
{
// draw cannon
TODO
if (cannonFired)
{
// move and draw the ball until it hits the ground again, then set cannonFired to false
TODO
}
else
{
// change angle and velocity and firing of cannon, set cannonFired to true and cannon ball x and y to cannon
location
TODO
}
}