README.md

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Pyxel is a retro game engine for Python.

With simple specifications inspired by retro gaming consoles, such as displaying only 16 colors and playing back only 4 sounds simultaneously, you can enjoy making pixel-art-style games with ease.

The development of Pyxel is driven by user feedback. Please give Pyxel a star on GitHub!

Pyxel's specifications and APIs are inspired by PICO-8 and TIC-80.

Pyxel is open source under the MIT License and free to use. Let's start making a retro game with Pyxel!

Specifications

• Runs on Windows, Mac, Linux, and Web
• Programming in Python
• 16-color palette
• 256x256-sized 3 image banks
• 256x256-sized 8 tilemaps
• 4 channels with 64 definable sounds
• 8 music tracks that can combine any sounds
• Keyboard, mouse, and gamepad inputs
• Image and sound editing tools
• User expansion of colors, channels, and banks

Color Palette

How to Install

Windows

After installing Python3 (version 3.8 or higher), run the following command:

pip install -U pyxel

If you install Python using the official installer, make sure to check the Add Python 3.x to PATH option to enable the pyxel command.

Mac

After installing Homebrew, run the following commands:

brew install pipx
pipx ensurepath
pipx install pyxel

To update Pyxel after installation, run pipx upgrade pyxel.

Linux

After installing the SDL2 package (libsdl2-dev for Ubuntu), Python3 (version 3.8 or higher), and python3-pip, run the following command:

sudo pip3 install -U pyxel

If the above command doesn't work, try building Pyxel from source by following the instructions in the Makefile.

Web

The web version of Pyxel does not require Python or Pyxel installation and runs on PCs, smartphones, and tablets with supported web browsers.

For specific instructions, please refer to this page.

Try Pyxel Examples

After installing Pyxel, you can copy the examples to the current directory with the following command:

pyxel copy_examples

The following examples will be copied to your current directory:

01_hello_pyxel.py	Simplest application	Demo	Code
02_jump_game.py	Jump game with Pyxel resource file	Demo	Code
03_draw_api.py	Demonstration of drawing APIs	Demo	Code
04_sound_api.py	Demonstration of sound APIs	Demo	Code
05_color_palette.py	Color palette list	Demo	Code
06_click_game.py	Mouse click game	Demo	Code
07_snake.py	Snake game with BGM	Demo	Code
08_triangle_api.py	Demonstration of triangle drawing APIs	Demo	Code
09_shooter.py	Shoot'em up game with screen transition	Demo	Code
10_platformer.py	Side-scrolling platform game with map	Demo	Code
11_offscreen.py	Offscreen rendering with Image class	Demo	Code
12_perlin_noise.py	Perlin noise animation	Demo	Code
13_bitmap_font.py	Drawing a bitmap font	Demo	Code
14_synthesizer.py	Synthesizer utilizing audio expantion features	Demo	Code
15_tiled_map_file.py	Loading and drawing a Tile Map File (.tmx)	Demo	Code
16_transform.py	Image rotation and scaling	Demo	Code
99_flip_animation.py	Animation with flip function (non-web platforms only)	Demo	Code
30sec_of_daylight.pyxapp	1st Pyxel Jam winning game by Adam	Demo	Code
megaball.pyxapp	Arcade ball physics game by Adam	Demo	Code
8bit-bgm-gen.pyxapp	Background music generator by frenchbread	Demo	Code

The examples can be executed with the following commands:

cd pyxel_examples
pyxel run 01_hello_pyxel.py
pyxel play 30sec_of_daylight.pyxapp

How to Use

Create Pyxel Application

In your Python script, import the Pyxel module, specify the window size with the init function, and then start the Pyxel application with the run function.

import pyxel

pyxel.init(160, 120)

def update():
    if pyxel.btnp(pyxel.KEY_Q):
        pyxel.quit()

def draw():
    pyxel.cls(0)
    pyxel.rect(10, 10, 20, 20, 11)

pyxel.run(update, draw)

The arguments of the run function are the update function, which processes frame updates, and the draw function, which handles screen drawing.

In an actual application, it is recommended to wrap Pyxel code in a class, as shown below:

import pyxel

class App:
    def __init__(self):
        pyxel.init(160, 120)
        self.x = 0
        pyxel.run(self.update, self.draw)

    def update(self):
        self.x = (self.x + 1) % pyxel.width

    def draw(self):
        pyxel.cls(0)
        pyxel.rect(self.x, 0, 8, 8, 9)

App()

To create simple graphics without animation, use the show function to make the code more concise.

import pyxel

pyxel.init(120, 120)
pyxel.cls(1)
pyxel.circb(60, 60, 40, 7)
pyxel.show()

Run Pyxel Application

A created script can be executed using the python command:

python PYTHON_SCRIPT_FILE

It can also be run with the pyxel run command:

pyxel run PYTHON_SCRIPT_FILE

Additionally, the pyxel watch command monitors changes in a specified directory and automatically re-runs the program when changes are detected:

pyxel watch WATCH_DIR PYTHON_SCRIPT_FILE

Directory monitoring can be stopped by pressing Ctrl(Command)+C.

Special Controls

The following special controls are available while a Pyxel application is running:

• Esc
  Quit the application
• Alt(Option)+1
  Save the screenshot to the desktop
• Alt(Option)+2
  Reset the recording start time of the screen capture video
• Alt(Option)+3
  Save a screen capture video to the desktop (up to 10 seconds)
• Alt(Option)+9
  Switch between screen modes (Crisp/Smooth/Retro)
• Alt(Option)+0
  Toggle the performance monitor (fps, update time, and draw time)
• Alt(Option)+Enter
  Toggle full screen
• Shift+Alt(Option)+1/2/3
  Save the corresponding image bank to the desktop
• Shift+Alt(Option)+0
  Save the current color palette to the desktop

How to Create Resources

Pyxel Editor can create images and sounds used in a Pyxel application.

It starts with the following command:

pyxel edit PYXEL_RESOURCE_FILE

If the specified Pyxel resource file (.pyxres) exists, it will be loaded. If it does not exist, a new file will be created with the specified name. If the resource file is omitted, the name is my_resource.pyxres.

After starting Pyxel Editor, you can switch between resource files by dragging and dropping another resource file.

The created resource file can be loaded with the load function.

Pyxel Editor has the following editing modes.

Image Editor

The mode to edit the image banks.

Drag and drop an image file (PNG/GIF/JPEG) onto the Image Editor to load the image into the currently selected image bank.

Tilemap Editor

The mode to edit tilemaps in which images of the image banks are arranged in a tile pattern.

Drag and drop a TMX file (Tiled Map File) onto the Tilemap Editor to load its layer in the drawing order that corresponds to the currently selected tilemap number.

Sound Editor

The mode to edit sounds.

Music Editor

The mode to edit musics in which the sounds are arranged in order of playback.

Other Resource Creation Methods

Pyxel images and tilemaps can also be created using the following methods:

• Create an image from a list of strings using the Image.set function or the Tilemap.set function
• Load an image file (PNG/GIF/JPEG) in Pyxel palette with Image.load function

Pyxel sounds can also be created using the following method:

• Create a sound from strings with Sound.set function or Music.set function

Refer to the API reference for usage of these functions.

How to Distribute Applications

Pyxel supports a dedicated application distribution file format (Pyxel application file) that is cross-platform.

A Pyxel application file (.pyxapp) is created using the pyxel package command:

pyxel package APP_DIR STARTUP_SCRIPT_FILE

If you need to includes resources or additional modules, place them in the application directory.

Metadata can be displayed at runtime by specifying it in the following format within the startup script. Fields other than title and author are optional.

# title: Pyxel Platformer
# author: Takashi Kitao
# desc: A Pyxel platformer example
# site: https://github.com/kitao/pyxel
# license: MIT
# version: 1.0

The created application file can be run using the pyxel play command:

pyxel play PYXEL_APP_FILE

A Pyxel application file can also be converted to an executable or an HTML file using the pyxel app2exe or pyxel app2html commands.

API Reference

System

• width, height
  The width and height of the screen

• frame_count
  The number of the elapsed frames

• init(width, height, [title], [fps], [quit_key], [display_scale], [capture_scale], [capture_sec])
  Initialize the Pyxel application with the screen size (width, height). The following options can be specified: the window title with title, the frame rate with fps, the key to quit the application with quit_key, the display scale with display_scale, the screen capture scale with capture_scale, and the maximum recording time of the screen capture video with capture_sec.
  Example: pyxel.init(160, 120, title="My Pyxel App", fps=60, quit_key=pyxel.KEY_NONE, capture_scale=3, capture_sec=0)

• run(update, draw)
  Start the Pyxel application and call the update function for frame update and the draw function for drawing.

• show()
  Show the screen and wait until the Esc key is pressed.

• flip()
  Refresh the screen by one frame. The application exits when the Esc key is pressed. This function is not available in the web version.

• quit()
  Quit the Pyxel application.

Resource

• load(filename, [excl_images], [excl_tilemaps], [excl_sounds], [excl_musics])
  Load the resource file (.pyxres). If an option is set to True, the corresponding resource will not be loaded. If a palette file (.pyxpal) with the same name exists in the same location as the resource file, the palette display colors will also be updated. The palette file contains hexadecimal entries for the display colors (e.g. 1100FF), separated by newlines. The palette file can also be used to change the colors displayed in Pyxel Editor.

Input

• mouse_x, mouse_y
  The current position of the mouse cursor

• mouse_wheel
  The current value of the mouse wheel

• btn(key)
  Return True if the key is pressed, otherwise return False. (Key definition list)

• btnp(key, [hold], [repeat])
  Return True if the key is pressed in that frame, otherwise return False. When hold and repeat are specified, True is returned at the repeat frame interval when the key is held down for more than hold frames.

• btnr(key)
  Return True if the key is released in that frame, otherwise return False.

• mouse(visible)
  If visible is True, show the mouse cursor. If False, hide it. Even if the mouse cursor is not displayed, its position is still updated.

Graphics

• colors
  List of the palette display colors. The display color is specified by a 24-bit numerical value. Use colors.from_list and colors.to_list to directly assign and retrieve Python lists.
  Example: old_colors = pyxel.colors.to_list(); pyxel.colors.from_list([0x111111, 0x222222, 0x333333]); pyxel.colors[15] = 0x112233

• images
  List of the image banks (0-2). (See the Image class)
  Example: pyxel.images[0].load(0, 0, "title.png")

• tilemaps
  List of the tilemaps (0-7). (See the Tilemap class)

• clip(x, y, w, h)
  Set the drawing area of the screen from (x, y) with a width of w and a height of h. Reset the drawing area to full screen by calling clip().

• camera(x, y)
  Change the upper-left corner coordinates of the screen to (x, y). Reset the upper-left corner coordinates to (0, 0) by calling camera().

• pal(col1, col2)
  Replace color col1 with col2 when drawing. Call pal() to reset to the initial palette.

• dither(alpha)
  Apply dithering (pseudo-transparency) when drawing. Set alpha in the range 0.0-1.0, where 0.0 is transparent and 1.0 is opaque.

• cls(col)
  Clear screen with color col.

• pget(x, y)
  Get the color of the pixel at (x, y).

• pset(x, y, col)
  Draw a pixel of color col at (x, y).

• line(x1, y1, x2, y2, col)
  Draw a line of color col from (x1, y1) to (x2, y2).

• rect(x, y, w, h, col)
  Draw a rectangle of width w, height h and color col from (x, y).

• rectb(x, y, w, h, col)
  Draw the outline of a rectangle of width w, height h and color col from (x, y).

• circ(x, y, r, col)
  Draw a circle of radius r and color col at (x, y).

• circb(x, y, r, col)
  Draw the outline of a circle of radius r and color col at (x, y).

• elli(x, y, w, h, col)
  Draw an ellipse of width w, height h and color col from (x, y).

• ellib(x, y, w, h, col)
  Draw the outline of an ellipse of width w, height h and color col from (x, y).

• tri(x1, y1, x2, y2, x3, y3, col)
  Draw a triangle with vertices (x1, y1), (x2, y2), (x3, y3) and color col.

• trib(x1, y1, x2, y2, x3, y3, col)
  Draw the outline of a triangle with vertices (x1, y1), (x2, y2), (x3, y3) and color col.

• fill(x, y, col)
  Fill the area connected with the same color as (x, y) with color col.

• blt(x, y, img, u, v, w, h, [colkey], [rotate], [scale])
  Copy the region of size (w, h) from (u, v) of the image bank img(0-2) to (x, y). If a negative value is assigned to w and/or h, the region will be flipped horizontally and/or vertically. If colkey is specified, it will be treated as a transparent color. If rotate(in degrees), scale(1.0 = 100%), or both are specified, the corresponding transformations will be applied.

• bltm(x, y, tm, u, v, w, h, [colkey], [rotate], [scale])
  Copy the region of size (w, h) from (u, v) of the tilemap tm(0-7) to (x, y). If a negative value is assigned to w and/or h, the region will be flipped horizontally and/or vertically. If colkey is specified, it will be treated as a transparent color. If rotate(in degrees), scale(1.0 = 100%), or both are specified, the corresponding transformations will be applied. The size of a tile is 8x8 pixels and is stored in a tilemap as a tuple of (tile_x, tile_y).

• text(x, y, s, col)
  Draw a string s of color col at (x, y).

Audio

• sounds
  List of the sounds (0-63). (See the Sound class)
  Example: pyxel.sounds[0].speed = 60

• musics
  List of the musics (0-7). (See the Music class)

• play(ch, snd, [tick], [loop], [resume])
  Play the sound snd(0-63) on channel ch(0-3). If snd is a list, the sounds will be played in order. The playback start position can be specified by tick(1 tick = 1/120 seconds). If loop is set to True, loop playback is performed. To resume the previous sound after playback ends, set resume to True.

• playm(msc, [tick], [loop])
  Play the music msc(0-7). The playback start position can be specified by tick(1 tick = 1/120 seconds). If loop is set to True, loop playback is performed.

• stop([ch])
  Stop playback of the specified channel ch(0-3). Call stop() to stop all channels.

• play_pos(ch)
  Get the sound playback position of channel ch(0-3) as a tuple of (sound_no, note_no). Return None when playback is stopped.

Math

• ceil(x)
  Return the smallest integer greater than or equal to x.

• floor(x)
  Return the largest integer less than or equal to x.

• sgn(x)
  Return 1 when x is positive, 0 when it is 0, and -1 when it is negative.

• sqrt(x)
  Return the square root of x.

• sin(deg)
  Return the sine of deg degrees.

• cos(deg)
  Return the cosine of deg degrees.

• atan2(y, x)
  Return the arctangent of y/x in degrees.

• rseed(seed)
  Sets the seed of the random number generator.

• rndi(a, b)
  Return a random integer greater than or equal to a and less than or equal to b.

• rndf(a, b)
  Return a random floating-point number greater than or equal to a and less than or equal to b.

• nseed(seed)
  Set the seed of Perlin noise.

• noise(x, [y], [z])
  Return the Perlin noise value for the specified coordinates.

Image Class

• width, height
  The width and height of the image

• set(x, y, data)
  Set the image at (x, y) using a list of strings.
  Example: pyxel.images[0].set(10, 10, ["0123", "4567", "89ab", "cdef"])

• load(x, y, filename)
  Load an image file (PNG/GIF/JPEG) at (x, y).

• pget(x, y)
  Get the color of the pixel color at (x, y).

• pset(x, y, col)
  Draw a pixel with the color col at (x, y).

Tilemap Class

• width, height
  The width and height of the tilemap

• imgsrc
  The image bank (0-2) referenced by the tilemap

• set(x, y, data)
  Set the tilemap at (x, y) using a list of strings.
  Example: pyxel.tilemap(0).set(0, 0, ["0000 0100 a0b0", "0001 0101 a1b1"])

• load(x, y, filename, layer)
  Load the layer in the drawing order layer(0-) from the TMX file (Tiled Map File) at (x, y).

• pget(x, y)
  Get the tile at (x, y). A tile is represented as a tuple of (tile_x, tile_y).

• pset(x, y, tile)
  Draw a tile at (x, y). A tile is represented as a tuple of (tile_x, tile_y).

Sound Class

• notes
  List of notes (0-127). The higher the number, the higher the pitch. Note 33 corresponds to 'A2'(440Hz). Rest notes are represented by -1.

• tones
  List of tones (0:Triangle / 1:Square / 2:Pulse / 3:Noise)

• volumes
  List of volumes (0-7)

• effects
  List of effects (0:None / 1:Slide / 2:Vibrato / 3:FadeOut / 4:Half-FadeOut / 5:Quarter-FadeOut)

• speed
  Playback speed. 1 is the fastest, and the larger the number, the slower the playback speed. At 120, the length of one note becomes 1 second.

• set(notes, tones, volumes, effects, speed)
  Set notes, tones, volumes, and effects using a string. If the length of tones, volumes, or effects are shorter than the notes, they will be repeated from the beginning.

• set_notes(notes)
  Set the notes using a string made of 'CDEFGAB'+'#-'+'01234' or 'R'. It is case-insensitive, and whitespace is ignored.
  Example: pyxel.sounds[0].set_notes("G2B-2D3R RF3F3F3")

• set_tones(tones)
  Set the tones with a string made of 'TSPN'. Case-insensitive and whitespace is ignored.
  Example: pyxel.sounds[0].set_tones("TTSS PPPN")

• set_volumes(volumes)
  Set the volumes with a string made of '01234567'. Case-insensitive and whitespace is ignored.
  Example: pyxel.sounds[0].set_volumes("7777 7531")

• set_effects(effects)
  Set the effects with a string made of 'NSVFHQ'. Case-insensitive and whitespace is ignored.
  Example: pyxel.sounds[0].set_effects("NFNF NVVS")

Music Class

• seqs
  A two-dimensional list of sounds (0-63) across multiple channels

• set(seq0, seq1, seq2, ...)
  Set the lists of sound (0-63) for each channel. If an empty list is specified, that channel is not used for playback.
  Example: pyxel.musics[0].set([0, 1], [], [3])

Advanced APIs

Pyxel includes "advanced APIs" that are not mentioned in this reference because they "may confuse users" or "require specialized knowledge to use".

If you are confident in your skills, try creating amazing works using this as a guide!

How to Contribute

Submitting Issues

Use the Issue Tracker to submit bug reports and feature or enhancement requests. Before submitting a new issue, make sure there are no similar open issue.

Manual Testing

Anyone who manually tests the code and reports bugs or suggestions for enhancements in the Issue Tracker is very welcome!

Submitting Pull Requests

Patches and fixes are accepted in the form of pull requests (PRs). Make sure that the issue the pull request addresses is open in the Issue Tracker.

By submitting a pull request, you agree to publish your contribution under the MIT License.

Other Information

• FAQ
• User Examples
• Developer X account

License

Pyxel is licensed under the MIT License. It can be reused in proprietary software, provided that all copies of the software or its substantial portions include a copy of the MIT License terms and a copyright notice.

Recruiting Sponsors

Pyxel is looking for sponsors on GitHub Sponsors. Please consider sponsoring Pyxel to support its continued maintenance and feature development. As a benefit, sponsors can consult directly with the Pyxel developer. For more details, please visit this page.