Coordinates

All shapes drawn to the screen have a position that is specified as a coordinate. All coordinates are measured as the distance from the origin in units of pixels. The origin [0, 0] is the coordinate is in the upper left of the window and the coordinate in the lower right is [width-1, height-1].

from p5 import *

def draw():
    # Sets the screen to be 640 pixels wide and 360 pixels high
    size(640, 360)

    # Set the background to black and turn off the fill color
    background(0)
    no_fill()

    # The two parameters of the point() method each specify coordinates.
    # The first parameter is the x-coordinate and the second is the Y
    stroke(255)
    point(width * 0.5, height * 0.1)
    point(width * 0.5, height * 0.9)

    # Coordinates are used for drawing all shapes, not just points.
    # Parameters for different functions are used for different purposes.
    # For example, the first parameter to line() specify
    # the coordinates of the first endpoint and the second parameter
    # specify the second endpoint
    stroke(0, 153, 255)
    line((0, height*0.33), (width, height*0.33))

    # By default, the first parameter to rect() is the
    # coordinates of the upper-left corner and the second and third
    # parameter is the width and height
    stroke(255, 153, 0)
    rect((width*0.25, height*0.1), width * 0.5, height * 0.8)

if __name__ == '__main__':
    run()