Python Pen Control

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But before we get started, let me just say this: if you’ve ever tried using a mouse or trackpad to create digital art, you know it can be frustrating as hell. The cursor jumps around like a hyperactive squirrel on caffeine overdose, and your lines look more like scribbles than masterpieces. But don’t freak out, my friend! With Python pen control, we’re going to make drawing with a computer feel just as natural as using an actual pen or pencil.

So what exactly is Python pen control? It’s the ability to use your computer’s graphics tablet (or even a regular mouse) to draw lines and shapes on screen by writing code in Python. And let me tell you, it’s freaking awesome!

Here’s how it works: first, we need to install some software that allows us to connect our drawing device to the computer and send signals to Python. There are a few different options out there, but for this tutorial, we’re going to use PySimpleGUI (PSG) a popular library for creating graphical user interfaces in Python.

To set the stage: let’s install PSG using pip. Open up your terminal or command prompt and type the following: 

# This script installs the PySimpleGUI library using pip

# The following line uses the "pip" command to install the "pysimplegui" library
pip install pysimplegui

Once that’s done, we can start writing some code! Here’s a basic example of how to use Python pen control with PSG:

# Import necessary libraries
import time
import random
from pysimplegui import *

# Define a function to draw a line between two points
def draw_line(x1, y1, x2, y2):
    # Calculate the distance between the two points
    dx = abs(x2 - x1) # Corrected syntax error, added missing subtraction operator
    dy = abs(y2 - y1) # Corrected syntax error, added missing subtraction operator
    
    # Choose a random color for our line
    r = random.randint(0, 255)
    g = random.randint(0, 255)
    b = random.randint(0, 255)
    
    # Calculate the slope and y-intercept of our line
    if dy == 0:
        m = float('inf') # Set slope to infinity if dy is 0 to avoid division by 0 error
    else:
        m = (y2 - y1) / dx # Calculate slope using the two points
    
    b = y1 - m * x1 # Calculate y-intercept using slope and one of the points
    
    # Draw our line using PSG's Canvas element
    layout = [
        [Canvas(key='canvas', size=(800, 600), background_color='white')]
    ]
    window = Window('Python Pen Control', layout)
    while True:
        event, values = window.read()
        
        if event == 'Exit':
            break
        
        # Check for pen input and draw our line accordingly
        x, y = values['canvas'].get_mouse_position(button='left')
        if len(values['canvas'].get_drawing_list()) > 0:
            x1, y1 = values['canvas'].get_last_point()
            window['canvas'].delete_line([x1, y1], [x, y])
            draw_line(x1, y1, x, y)
        else:
            x1 = x
            y1 = y
            
    # Close the window and exit Python pen control mode
    window.close()
    
# Define a function to draw a line using the slope-intercept form
def draw_line(x1, y1, x2, y2):
    if (y2 - y1) == 0:
        for x in range(min(x1, x2), max(x1, x2)+1):
            window['canvas'].draw_point((x, y1), color=(r, g, b)) # Draw a point at each x coordinate with the same y coordinate
    else:
        m = (y2 - y1) / (x2 - x1) # Calculate slope using the two points
        b = y1 - m * x1 # Calculate y-intercept using slope and one of the points
        
        for x in range(min(x1, x2), max(x1, x2)+1):
            window['canvas'].draw_point((x, int(m*x+b)), color=(r, g, b)) # Draw a point at each x coordinate with the corresponding y coordinate calculated using the slope-intercept form
    
# Run our Python pen control program!
if __name__ == '__main__':
    layout = [
        [Canvas(key='canvas', size=(800, 600), background_color='white')]
    ]
    window = Window('Python Pen Control', layout)
    while True:
        event, values = window.read()
        
        if event == 'Exit':
            break
        
        # Check for pen input and draw our line accordingly
        x, y = values['canvas'].get_mouse_position(button='left')
        if len(values['canvas'].get_drawing_list()) > 0:
            x1, y1 = values['canvas'].get_last_point()
            window['canvas'].delete_line([x1, y1], [x, y])
            draw_line(x1, y1, x, y)
        else:
            x1 = x
            y1 = y
            
    # Close the window and exit Python pen control mode
    window.close()

With this code, we’ve created a basic Python pen control program that allows us to draw lines on screen using our computer’s graphics tablet (or mouse). Of course, this is just the tip of the iceberg with some creativity and experimentation, you can create all sorts of amazing digital art using Python pen control.

So go ahead, grab your favorite drawing device, fire up PySimpleGUI, and let your imagination run wild! And remember: when it comes to Python pen control, there’s no such thing as a bad line only opportunities for improvement and creativity.

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