npgame makes it easy and fast to write simple games, powered by Numpy and PyGame. It's a lightweight API to quickly get something done and for learning rather than a solution full-blown feature-rich games.

Features include opening a window, showing graphics like colored rectangles and images, and detecting keyboard input. For additional features like mouse input and audio, check out PyGame, which can be combined freely.

pip install npgame

import npgame

# Initialize state
pos = 5.5

game = npgame.Game(grid=(20, 15), scale=40)
game.title('Quickstart')
while game.running:
  game.update()

  # Update state
  if game.pressed('escape'):
    game.close()
  if game.pressed('a'):
    pos -= game.delta * 2.0
  if game.pressed('d'):
    pos += game.delta * 2.0

  # Display
  game.draw(0, 0, 40, 30, (1, 1, 1))  # White background
  game.draw(pos, 3.4, 1.5, 1.5, (1, 0.7, 0))  # Yellow box

Coordinates mimic the convention for numeric charts. In other words, X is the horizontal axis and Y is the vertical axis and zero is in the lower left corner of the window. The size of the coordinate system is specified with Game(grid=(40, 30)).

Create a Game object that processes keyboard events and graphics for us. The grid determines the size of coordinate system for drawing. The scale sets the size of each grid tile in pixels. It also determines the window size. The fps set the maximum number of frames per second, beyond which update() will add a pause.

• running

  Boolean attribute that signals whether the game is still running. This should be used as condition in the main loop. Closing the game window or calling close() switches the flag to False.

• delta

  Float attribute that contains the time that has passed between the last two update() calls. When moving objects, this value should be used to multiply the velocities to ensure that objects move at constant speed regardless of how fast the computer is. Multiplying velocities by delta effectively gives them the unit of grid tiles per second.

• title(text)

  Set the title of the window. This can be called either once in the beginning or repeatedly later on, for example to display status information to the user.

• resize(grid=None, scale=None)

  Change the size of the grid that is displayed on the window. This changes the size of the window. The grid argument is a tuple of integers for the width and height of the grid. The scale is an integer indicating how many pixels big each grid tile is. If omitted, the values are not changed.

• update()

  This function should be called early inside the main loop. It displays the things that have been drawn and processes external events, such as key presses and checks whether the window has been closed.

• pressed(key)

  Returns a boolean indicating whether the given key is pressed. The requested key is passed in as a string, corresponding to the [pygame key name][keynames]. The function detects both keys that are currently held down and keys that were briefly pressed between the last two update() calls.

• draw(x, y, w, h, color=None, array=None, image=None)

  Draws a rectangle of a color given as RGB tuple, an Numpy array, or an image given as string path. The position of the area is specified with x and y and its size with w and h. Images are resized as needed and cached for efficiency. For the area to appear, update() must be called inside the main loop.

• text(x, y, message, font, color=(0.5, 0.5, 0.5, 1), size=1)

  Render text given the filename of a font in TTF format. An example file of the free DejaVu font can be found in the examples directory of the npgame repository. The color of the font can include the opacity as the last number. The position and size are relative to the grid of the Game object.

• close()

  Shuts down pygame, which closes the window, and sets running to False so that the main loop ends.