Deckgl Game Of Life#
import json
import numpy as np
import pandas as pd
import panel as pn
pn.extension('deckgl', template='fast', sizing_mode="stretch_width")
pn.state.template.param.update(
title="Deck.gl - Game of Life",
main_max_width="768px"
)
This demo was adapted from PyDeck’s Conway Game of Life example, full copyright lies with the original authors.
This modified example demonstrates how to display and update a DeckGL pane with a periodic callback by modifying the JSON representation and triggering an update.
Declare Game of Life logic#
import random
def new_board(x, y, num_live_cells=2, num_dead_cells=3):
"""Initializes a board for Conway's Game of Life"""
board = []
for i in range(0, y):
# Defaults to a 3:2 dead cell:live cell ratio
board.append([random.choice([0] * num_dead_cells + [1] * num_live_cells) for _ in range(0, x)])
return board
def get(board, x, y):
"""Return the value at location (x, y) on a board, wrapping around if out-of-bounds"""
return board[y % len(board)][x % len(board[0])]
def assign(board, x, y, value):
"""Assigns a value at location (x, y) on a board, wrapping around if out-of-bounds"""
board[y % len(board)][x % len(board[0])] = value
def count_neighbors(board, x, y):
"""Counts the number of living neighbors a cell at (x, y) on a board has"""
return sum([
get(board, x - 1, y),
get(board, x + 1, y),
get(board, x, y - 1),
get(board, x, y + 1),
get(board, x + 1, y + 1),
get(board, x + 1, y - 1),
get(board, x - 1, y + 1),
get(board, x - 1, y - 1)])
def process_life(board):
"""Creates the next iteration from a passed state of Conway's Game of Life"""
next_board = new_board(len(board[0]), len(board))
for y in range(0, len(board)):
for x in range(0, len(board[y])):
num_neighbors = count_neighbors(board, x, y)
is_alive = get(board, x, y) == 1
if num_neighbors < 2 and is_alive:
assign(next_board, x, y, 0)
elif 2 <= num_neighbors <= 3 and is_alive:
assign(next_board, x, y, 1)
elif num_neighbors > 3 and is_alive:
assign(next_board, x, y, 0)
elif num_neighbors == 3 and not is_alive:
assign(next_board, x, y, 1)
else:
assign(next_board, x, y, 0)
return next_board
Set up DeckGL JSON#
points = {
'@@type': 'PointCloudLayer',
'data': [],
'getColor': '@@=color',
'getPosition': '@@=position',
'getRadius': 40,
'id': '0558257e-1a5c-43d7-bd98-1fba69981c6c'
}
board_json = {
"initialViewState": {
"bearing": 44,
"latitude": 0.01,
"longitude": 0.01,
"pitch": 45,
"zoom": 13
},
"layers": [points],
"mapStyle": "",
"views": [
{
"@@type": "MapView",
"controller": True
}
]
}
Declare callbacks to periodically update the board#
PINK = [155, 155, 255, 245]
PURPLE = [255, 155, 255, 245]
SCALING_FACTOR = 1000.0
def convert_board_to_df(board):
"""Makes the board matrix into a list for easier processing"""
rows = []
for x in range(0, len(board[0])):
for y in range(0, len(board)):
rows.append([[x / SCALING_FACTOR, y / SCALING_FACTOR], PURPLE if board[y][x] else PINK])
return pd.DataFrame(rows, columns=['position', 'color'])
def run_gol(event=None):
global board
board = process_life(board)
records = convert_board_to_df(board)
points['data'] = records
gol.param.trigger('object')
def reset_board(event):
global board
board = new_board(30, 30)
run_gol()
def toggle_periodic_callback(event):
if event.new:
periodic_toggle.name = 'Stop'
periodic_toggle.button_type = 'warning'
periodic_cb.start()
else:
periodic_toggle.name = 'Run'
periodic_toggle.button_type = 'primary'
periodic_cb.stop()
def update_period(event):
periodic_cb.period = event.new
Set up Panel and callbacks#
board = new_board(30, 30)
gol = pn.pane.DeckGL(board_json, height=400)
run_gol()
periodic_toggle = pn.widgets.Toggle(
name='Run', value=False, button_type='primary', align='end', width=50
)
periodic_toggle.param.watch(toggle_periodic_callback, 'value')
period = pn.widgets.Spinner(name="Period (ms)", value=500, step=50, start=50,
align='end', width=100)
period.param.watch(update_period, 'value')
reset = pn.widgets.Button(name='Reset', button_type='warning', width=60, align='end')
reset.on_click(reset_board)
periodic_cb = pn.state.add_periodic_callback(run_gol, start=False, period=period.value)
settings = pn.Row(period, periodic_toggle, reset, width=400, sizing_mode="fixed")
description = """
**Conway's Game of Life** is a classic demonstration of *emergence*, where higher level patterns form from a few simple rules. Fantastic patterns emerge when the game is let to run long enough.
The **rules** here, to borrow from [Wikipedia](https://en.wikipedia.org/wiki/Conway%27s_Game_of_Life), are as follows:
- Any live cell with fewer than two live neighbours dies, as if by underpopulation.
- Any live cell with two or three live neighbours lives on to the next generation.
- Any live cell with more than three live neighbours dies, as if by overpopulation.
- Any dead cell with exactly three live neighbours becomes a live cell, as if by reproduction.
This demo was **adapted from [PyDeck's Conway Game of Life example](https://github.com/uber/deck.gl/blob/66c75051d5b385db31f0a4322dff054779824783/bindings/pydeck/examples/06%20-%20Conway's%20Game%20of%20Life.ipynb)**, full copyright lies with the original authors.
This modified example demonstrates **how to display and update a `DeckGL` pane with a periodic callback** by modifying the JSON representation and triggering an update."""
pn.Column(
'## Game of Life (using Deck.GL)',
pn.Column(
description,
gol,
settings
).servable()
)
