Pygame: Exercises

What does this code do? pygame.display.update()

• a. Nothing.

• b. Clears the screen.

• c. Displays everything that has been drawn so far.

• d. Flips the screen from left to right.

• e. Flips the screen from top to bottom.

Should the following line go inside, or outside, of the game loop?

• a. Outside the loop, because it isn’t a good idea to load the image from the disk 20 times per second.

• b. Inside the loop, because the background image needs to be redrawn every frame.

Changing the tick value from 20 to 30 will cause what to happen? clock.tick(20)

• a. Nothing.

• b. The game will run faster.

• c. The game will run slower.

What is a game loop?

• a. It processes user input, updates objects, and draws the screen in each frame of the game.

• b. It runs once for the entire game.

• c. It loops once for each life that the player has.

• d. It loops once for each level of the game.

Where does this code go? clock = pygame.time.Clock()

• a. The code is placed after the game loop.

• b. The code is placed inside the game loop.

• c. This code is placed before the game loop.

In the following code, what does the [0, 0] do?

• a. Sets the size of the image.

• b. Specifies the x and y of the top left coordinate of where to start drawing the bitmap on the screen.

• c. Draw the bitmap in the center of the screen.

What types of image file formats are lossless (i.e., they do not change the image)? Choose the best answer.

• d. jpg

• e. gif

• c. png

• b. png, gif

• a. png, jpg, gif

This code is supposed to draw a white rectangle. But when the program is run, no rectangle shows up. Why?

• c. The rectangle is the same color as the background.

• a. The rectangle dimensions are off-screen.

• b. There is no update function.

• d. The rectangle is drawn outside the game loop.

• e. The rectangle is too small to see.

Which of these bits of code will open up a window 400 pixels high and 800 pixels wide?

• d. size = 400,800 screen = pygame.display.set_mode(size)

• b. size = [400, 800] screen = pygame.display.set_mode(size)

• a. size = [800, 400] screen = pygame.display.set_mode(size)

• c. size = 800,400 screen = pygame.display.set_mode(size)

• e. screen = pygame.display.open_window(800, 400)

This code is supposed to draw a white rectangle, but when the program is run, no rectangle shows up. However, when the user hits the close button, a rectangle briefly appears before the program closes. Why?

• a. The rectangle dimensions are off-screen.

• e. The rectangle is too small to see.

• d. The rectangle is drawn outside the game loop.

• c. The rectangle is the same color as the background.

• b. The update is unindented and doesn’t show until after the program ends.