sketch-a-day/2019/sketch_190630a/s190630web/target/s190630web.py

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2.4 KiB
Python

# Alexandre B A Villares - https://abav.lugaralgum.com/sketch-a-day
# More combinatorics of triangles in grids based on sketch_190629a
# Lerp to make intermediary triangles
from pyp5js import *
border = 100
two_triangle_combos = []
space = None
from itertools import product, combinations
def setup():
global two_triangle_combos, space, border
createCanvas(500, 500, WEBGL)
space = width - 2 * border
smooth(8)
blendMode(MULTIPLY)
# strokeJoin(ROUND)
# points on a 3x3 grid
grid = product((-1, 0, 1), repeat=2)
# all 3-point combinations on the grid
points = combinations(grid, 3)
# identify triangles (discard colinear point triples)
triangles = []
for p in points:
area = (p[1][0] * (p[2][1] - p[0][1]) +
p[2][0] * (p[0][1] - p[1][1]) +
p[0][0] * (p[1][1] - p[2][1]))
if area != 0:
triangles.append(p)
print("Number of possible triangles: {}"
.format(len(triangles)))
# calculate 2-triangle combinations
two_triangle_combos = list(combinations(triangles, 2))
print("Number of 2-triangle combinations: {}"
.format(len(two_triangle_combos)))
def draw():
background(240)
# ortho() # clipping issues in p5js
# translate(width / 2, height / 2) # WEBGL already centered
rotateY(radians(frameCount))
noFill()
i = (frameCount // 90) % len(two_triangle_combos)
draw_combo(two_triangle_combos[i])
def draw_combo(combo):
strokeWeight(border / 10)
noFill()
siz = space * .5 # .35
triangles = (combo[0],
lerp_poly(combo[0], combo[1], 0.33),
lerp_poly(combo[0], combo[1], 0.66),
combo[1])
for i, t in enumerate(triangles):
# colors for each of the triangles
colors = (color(200, 100, 0),
color(133, 100, 66),
color(66, 100, 133),
color(0, 100, 200))
stroke(colors[i])
draw_poly(scale_poly(t, siz))
def draw_poly(p_list):
beginShape()
for p in p_list:
vertex(p[0], p[1], p[0] * p[1] / space)
endShape(CLOSE)
def lerp_poly(p0, p1, t):
pt = []
for sp0, sp1 in zip(p0, p1):
pt.append((lerp(sp0[0], sp1[0], t),
lerp(sp0[1], sp1[1], t)))
return pt
def scale_poly(p_list, s):
return [(p[0] * s, p[1] * s) for p in p_list]