Martin McBride, 2020-08-26
Tags geometry square
Categories generativepy generative art

The Square class draws a square.

There is also a square function that just creates a square as a new path.

Square class methods

The Square class inherits add, fill, stroke, fill_stroke, path, clip and other methods from Shape.

It has an additional method:

  • of_corner_size


Creates a square based on the position and size.

of_corner_size(corner, width)
Parameter Type Description
corner (number, number) A tuple of two numbers, giving the (x, y) position of the top left corner.
width number The side of the square.

square function

Adds a square as a new path, without the need to create a Square object in code.

square(ctx, corner, width, height)
Parameter Type Description
ctx Context The Pycairo Context to draw to
corner (number, number) A tuple of two numbers, giving the (x, y) position of the top left corner.
width number The side of the square.


Here is some example code that draws squares using the class and the utility function. The full code can be found on github.

from generativepy.drawing import make_image, setup
from generativepy.color import Color
from generativepy.geometry import Square, square

Create squares using the geometry module.

def draw(ctx, width, height, frame_no, frame_count):
    setup(ctx, width, height, width=5, background=Color(0.8))

    # The square function is a convenience function that adds a square as a new the path.
    # You can fill or stroke it as you wish.
    square(ctx, (1, 1), 1)
    ctx.set_source_rgba(*Color(1, 0, 0))

    # Square objects can be filled, stroked, filled and stroked.
    Square(ctx).of_corner_size((3, 1), 1).fill(Color(0, .5, 0))
    Square(ctx).of_corner_size((1, 3), 1).stroke(Color(0, .5, 0), 0.1)
    Square(ctx).of_corner_size((3, 3), 1).fill_stroke(Color(0, 0, 1), Color(0), 0.2)

make_image("/tmp/geometry-squares.png", draw, 500, 500)
If you found this article useful, you might be interested in the book Computer Graphics in Python or other books by the same author.


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