Window size discrepancy on HighDPI monitor

Running the same sketch on a HighDPI monitor appears to create a larger window than necessary.

4K HighDPI monitor

1080p monitor

Version: mewnala 0.0.7

Code

"""
Redraw. 
  
The redraw() function makes draw() execute once.    
In this example, draw() is executed once every time 
the mouse is clicked. 
"""
from mewnala import *

y = 180

def setup():
    """ 
    The statements in the setup() function 
    execute once when the program begins.
    """
    size(640, 360)    # Size should be the first statement
    stroke(255)         # Set line drawing color to white
    no_loop()


def draw():
    """
    The statements in draw() are executed until the
    program is stopped. Each statement is executed in
    sequence and after the last line is read, the first
    line is executed again.
    """
    global y
    background(0)     # Set the background to black
    y = y - 4
    if (y < 0):
        y = height
    line(0, y, width, y)


def mouse_pressed():
    redraw()

run()

Start with the size(640, 360) call in the provided sketch and compare the window-creation and HighDPI behavior on the two monitor types. Trace the window sizing entry point in the implementation; done means the same sketch produces the intended, consistent window size on HighDPI and standard displays.