def test_turtle():
#
# [<<< table of contents](index.html)
#
# ---
#
# Turtle graphics
# ===============
# Use a turtle to keep track of a path as you build it.
from huygens import canvas, style, color
from huygens.turtle import Turtle
cvs = canvas.canvas()
turtle = Turtle(cvs=cvs)
n = 8
angle = 360. / n
R = 3.0
for i in range(n):
turtle.fwd(1. * R)
turtle.left((1. / 3) * angle)
turtle.back(0.5 * R)
turtle.left((1. / 3) * angle)
turtle.back(0.7 * R)
turtle.left((1. / 3) * angle)
turtle.stroke()
cvs.writeSVGfile("output.svg")
yield cvs
# We can change the stroke style that the turtle uses
# to a thick green line.
attrs = [style.linewidth.THIck, color.rgb(0.2, 0.6, 0.2)]
cvs = canvas.canvas()
turtle = Turtle(cvs=cvs, attrs=attrs)
turtle.fwd(2.)
turtle.right(300, 1.)
turtle.fwd(2.)
turtle.arrow(0.4)
turtle.stroke()
yield cvs
cvs = canvas.canvas()
turtle = Turtle(cvs=cvs, attrs=attrs)
R = 1.0
for i in range(24 * 2):
turtle.left(320, 0.6 * R)
turtle.left(-60, 0.3 * R)
turtle.right(90, 0.6 * R)
turtle.stroke(attrs=attrs)
yield cvs
def test_canvas():
#
# [<<< table of contents](index.html)
#
# ---
#
# Canvas
# ======
#
# The canvas is a front-end drawing API
# modelled after the amazing
# [PyX](https://pyx-project.org/) package.
#
# The canvas coordinates are positive in the
# upper right quadrant.
from huygens import canvas, path, color
cvs = canvas.canvas()
cvs.stroke(path.line(0., 0., 3., 2.))
cvs.fill(path.circle(3., 2., 0.2), [color.rgb.red])
cvs.writeSVGfile("output.svg")
# This produces the following SVG image:
yield cvs
# The canvas also has a `writePDFfile` method.
#
# Unlike PyX, angles are specified in
# radians in calls to `path.arc` and `trafo.rotate`.
from math import pi
from huygens import style, trafo, linestyle
cvs = canvas.canvas()
cvs.stroke(path.circle(0., 0., 1.),
[style.linewidth.thick, color.rgb.blue, linestyle.dashed])
cvs.text(0., 0., "hey there!", [trafo.rotate(0.5 * pi)])
yield cvs
# Composite paths are built using the `path.path` constructor:
cvs = canvas.canvas()
p = path.path([
path.moveto(0., 0.),
path.arc(0., 0., 1., 0., 0.5 * pi),
path.lineto(-1., 1.),
path.arc(-1., 0., 1., 0.5 * pi, 1.0 * pi),
path.arc(-1.5, 0., 0.5, 1.0 * pi, 2.0 * pi),
path.closepath()
])
cvs.fill(p, [color.rgb.red, trafo.scale(1.2, 1.2)])
cvs.stroke(p, [color.rgb.black, style.linewidth.THick])
yield cvs
def XXXtest_braid():
from random import shuffle, seed, randint
from operator import matmul
from functools import reduce
seed(1)
scale = 0.5
w = 1.4 * scale
h = 1.8 * scale
Id = lambda: VWire(min_height=0.5, min_width=0.5)
Swap = lambda inverse: Braid(
inverse=inverse, min_width=w, min_height=h, space=0.7)
box = None
m, n = 4, 4
k = 2 * m + n
for count in range(6):
items = [Swap(randint(0, 1))
for k in range(m)] + [Id() for k in range(n)]
shuffle(items)
row = reduce(matmul, items)
if box is None:
box = row
else:
box = box * row
#box = Id() @ box
lhs = reduce(matmul, [Id() for i in range(k)])
box = lhs @ box
rels = [(i, 2 * k - i - 1) for i in range(k)]
#rels = [(i, i+k) for i in range(k)]
rel = Relation(0, 2 * k, botbot=rels, weight=200.0)
box = rel * box
rels = [(i, 2 * k - i - 1) for i in range(k)]
rel = Relation(2 * k, 0, toptop=rels, weight=200.0)
box = box * rel
#rect = RectBox(box, bg=color.rgb(0.9, 0.9, 0.3, 0.6))
Box.DEBUG = False
cvs = canvas.canvas()
#cvs.append(trafo.rotate(pi/2))
system = box.layout(cvs)
def rectbox(box):
x = system[box.llx]
y = system[box.lly]
width = system[box.width]
height = system[box.height]
return x, y, width, height
def fillbox(box, st):
rect = rectbox(box)
p = path.rect(*rect)
cvs.fill(p, st)
#fillbox(box, [color.rgb(0.9, 0.8, 0.5)])
sub = box[0][1][1]
x = 0.5 * (system[box.llx] + system[box.urx])
y = system[sub.lly]
width = system[box.urx] - x
height = system[sub.ury] - y
p = path.rect(x, y, width, height)
cvs.fill(p, [color.rgb(0.9, 0.9, 0.6)])
cvs.stroke(p, [style.linewidth.thick])
cvs.append(style.linewidth.THICk)
#cvs.append(color.rgb(0.2,0.5,0.2))
box.render(cvs)
cvs.append(style.linewidth.thick)
cvs.append(color.rgb(0.9, 0.9, 0.9))
box.render(cvs)
#cvs.writePDFfile("test_diagram.pdf")
yield cvs
def test_braid():
from random import shuffle, seed, randint
from operator import matmul
from functools import reduce
from huygens import canvas, color, style, path
from huygens.box import Box, HBox
from huygens.diagram import VWire, Braid, Relation
seed(1)
scale = 0.3
w = 1.4 * scale
h = 1.8 * scale
Id = lambda: VWire(min_height=scale, min_width=scale)
Swap = lambda inverse: Braid(
inverse=inverse, min_width=w, min_height=h, space=0.5)
box = None
m, n = 3, 3
k = 2 * m + n
for count in range(3):
items = [Swap(randint(0, 1))
for k in range(m)] + [Id() for k in range(n)]
shuffle(items)
row = reduce(matmul, items)
if box is None:
box = row
else:
box = box * row
# This is what the `box` looks like now:
yield box, "braid-strands"
# Now we take the closure of this braid:
#box = Id() @ box
lhs = reduce(matmul, [Id() for i in range(k)])
box = lhs @ box
rels = [(i, 2 * k - i - 1) for i in range(k)]
#rels = [(i, i+k) for i in range(k)]
rel = Relation(0, 2 * k, botbot=rels, weight=200.0)
box = rel * box
rels = [(i, 2 * k - i - 1) for i in range(k)]
rel = Relation(2 * k, 0, toptop=rels, weight=200.0)
box = box * rel
yield box
# Draw this now with some more fancy tricks.
cvs = canvas.canvas()
system = box.layout(cvs)
sub = box[0][1][1]
x = 0.5 * (box.llx + box.urx)
y = sub.lly
width = box.urx - x
height = sub.ury - y
p = path.rect(x, y, width, height)
cvs.fill(p, [color.rgb(0.9, 0.9, 0.6)])
cvs.stroke(p, [style.linewidth.thick])
system.refresh() # refresh for a new render
cvs.append(style.linewidth.THICk)
#cvs.append(color.rgb(0.2,0.5,0.2))
box.render(cvs)
cvs.append(style.linewidth.thick)
cvs.append(color.rgb(0.9, 0.0, 0.0))
box.render(cvs)
#cvs.writePDFfile("test_diagram.pdf")
yield cvs