Teach Your Kids To Code: A Parent-friendly Guide to Python Programming

Game Programming: Coding for Fun 247

F1 key (pygame.K_F1). The code that follows this second if statement

will be our play again or new game code.

noTe You can get a full list of the Pygame keycodes, such as K_F1, at
http://www.pygame.org/docs/ref/key.html.

“Play again” means that we want to start over from the begin-

ning. For Smiley Pong, we started with 0 points, 5 lives, and the

ball coming at us at 5 pixels per frame from the top-left corner of

the screen, (0, 0). If we reset these variables, we should get the new

game effect:

points = 0

lives = 5

picx = 0

picy = 0

speedx = 5

speedy = 5

Add these lines to the if statement for the F1 key KEYDOWN

event, and you’ll be able to restart the game anytime. If you’d like

to allow restarting only when the game is already over, you can

include an additional condition that lives == 0, but we’ll leave the

if statements as they currently are in our version 2.0 so that the

user can restart anytime.

Faster and Faster

Our game lacks one final element

of game design: it doesn’t get more

challenging the longer it’s played,

so someone could play almost for-

ever, paying less and less attention.

Let’s add difficulty as the game

progresses to engage the player and

make the game more arcade-like.

We want to increase the speed

of the ball slightly as the game advances, but not too much, or the

player might get frustrated. We want to make the game just a bit

faster after each bounce. The natural place to do this is within the

code that checks for bounces. Increasing the speed means making

speedx and speedy greater so that the ball moves farther in each

direction each frame. Try changing our if statements for collision