Gorilla Game

A Python re-implementation of the classic Basic Gorilla game.

Installation

Requires Python 3.6 or newer and the pillow imaging package. Install pillow using:

pip3 install pillow

How to Play

Run gorilla_name.py in a Python 3.6 or newer interpretter:

python3 gorilla_game.py

Goal: throw a banana that hits the other gorilla.

Use the Up & Down arrow keys to change the angle of banana toss; +/- keys to change the speed of banana toss. Press SPACE key to toss a banana. Alternatively, press buttons at the bottom of window for these actions.

The game remembers each player's previously selected banana speed and angle.

Customize the Game

You can customize the game by changing the values of some constants. Comments in the files describe the meaning of each constant.

• Change canvas size or gravity. Edit game_constants.py.
• Modify building colors, sizes, or heights. Edit the constants in building.py.

Changes to Starter Code

In gamelib.GameApp:

• create_canvas() returns the canvas reference instead of setting self.canvas.
• add methods add_element(element) and remove_element(element) so subclasses don't need to directly modify the elements attribute
• contains(x, y) returns True if a game element contains point (x,y). This method is used to detect collision between banana and a game element.
• start() sets a reference to the timer id returned by after so animation can be stopped.
• stop() new method to stop animation using the timer id
• running() test if the animation loop is running
• self.timer_id new attribute to keep track of timer id

In gamelib.GameCanvasElement

• change constructor params to __init__(self, canvas, x=0, y=0, **kwargs), where **kwargs is passed to init_canvas_object. This enables passing additional named parameters to Canvas widget constructors, such as text color or text alignment.
• init_canvas_object(**kwargs) method returns the object id (int) instead of setting it as a side-effect. This fixes warnings from VSCode about unknown symbol self.canvas_object_id.
• make canvas a property that returns self._canvas

In gamelib.Sprite

• add properties width and height to get the Sprite's image width and height

Source files

• Split the code in monkeys.py to separate files for each class.
• MonkeyGame class and the "main" block to start it moved to monkey_game.py.
• Move images to images subdirectory.
• Add game_constants.py for global constants.

Developer Notes on Images and Animation

The classes below are provided by the Python pillow package.

Pillow provids a better implementation of PhotoImage than tkinter. To use it:

from PIL import ImageTk, Image

image = ImageTk.PhotoImage(Image.open('myimage.png'))

documentation states that ImageTk.PhotoImage is a "Tkinter-compatible photo image." The ImageTk.PhotoImage constructor also accepts file= and data= parameters to initialize the photo image object.

PhotoImage also has a method we can use to change the image shown on a given PhotoImage object:

paste(image)
    Paste Image object into a PhotoImage. `image` must have the same dimensions
    as the original image.

The PIL.Image class has methods rotate or flip an image. We use this to create rotated bananas for animation:

image = Image.open("images/banana.png")
# an array to store images
self.images = [image]
# add rotated version of the original image
for angle in range(45,360,45):
     self.images.append( image.rotate(angle) )

While the banana is moving, the Banana update() method will "paste" the next image from the sequence into the banana PhotoImage object.
This makes the banana appear to spin as it moves.

Documentation for Pillow:

• Image https://pillow.readthedocs.io/en/stable/reference/Image.html
• ImageTk https://pillow.readthedocs.io/en/stable/reference/ImageTk.html

Dialog Box

The game shows a dialog box when a player wins. An easy way to do this is using tkinter.messagebox:

from tkinter import messagebox

message = "Play again?"
reply = messagebox.askyesno("Game Over", message)  # Returns true or false
if reply:
    print("play another game")
else:
    quit()