sketch-a-day/2019/sketch_190531a/sketch_190531a.pyde

# Alexandre B A Villares - https://abav.lugaralgum.com/sketch-a-day
# More explorations of lines in grids

from random import shuffle
from itertools import product, combinations, permutations, combinations_with_replacement
from gif_exporter import gif_export
add_library('GifAnimation')

space, border = 20, 20
position = 0  # initial position


def setup():
    global line_combos, W, H, position, num
    size(800, 660)
    frameRate(1)
    rectMode(CENTER)
    strokeWeight(1.5)
    grid = product(range(-1, 2), repeat=2)  # 3X3
    # all line permutations on a grid
    possible_lines = list(combinations(grid, 3))
    # allow only some lines
    # possible_lines = []
    # for l in lines:
    #     (x0, y0), (x1, y1) = l[0], l[1]
    #     if dist(x0, y0, x1, y1) < 2:  # rule defined here...
    #         possible_lines.append(l)
    num_possible_lines = len(possible_lines)
    println("Number of possible lines: {}".format(num_possible_lines))
    # main stuff
    line_combos = list(combinations(possible_lines, 2))
    # shuffle(line_combos) # ucomment to shuffle!
    num = len(line_combos)
    println("Number of permutations: {}".format(num))
    W = (width - border * 2) // space
    H = (height - border * 2) // space
    println("Cols: {} Rows: {} Visible grid: {}".format(W, H, W * H))


def draw():
    global position
    background(240)
    i = position
    for y in range(H):
        for x in range(W):
            if i < len(line_combos):
                pushMatrix()
                translate(border / 2 + space + space * x,
                          border / 2 + space + space * y)
                # translate(border + space + space * x,
                #           border + space + space * y)
                draw_combo(i)
                popMatrix()
                i += 1
    if i < len(line_combos):
        # gif_export(GifMaker, SKETCH_NAME)
        # gif_export(GifMaker, SKETCH_NAME[:-1] + "b") # B option
        position += H * W
    else:
        # gif_export(GifMaker, finish=True)

def draw_combo(n):
    colorMode(RGB)
    siz = space/2
    for i, sl in enumerate(line_combos[n]):
        colorMode(HSB)
        stroke(i * 128, 128, 128)
        (x0, y0), (x1, y1) = sl[0], sl[1]
        noFill()
        var_bar(x0 * siz, y0 * siz, x1 * siz, y1 * siz, siz / 8, siz / 4)

def keyPressed():
    global W, H
    if key == "s":
        saveFrame("####.png")

def settings():
    from os import path
    global SKETCH_NAME
    SKETCH_NAME = path.basename(sketchPath())
    OUTPUT = ".png"
    println(
        """
![{0}]({2}/{0}/{0}{1})

[{0}](https://github.com/villares/sketch-a-day/tree/master/{2}/{0}) [[Py.Processing](https://villares.github.io/como-instalar-o-processing-modo-python/index-EN)]
""".format(SKETCH_NAME, OUTPUT, year())
    )

def var_bar(p1x, p1y, p2x, p2y, r1, r2=None):
    """
    Tangent/tangent shape on 2 circles of arbitrary radius
    """
    if r2 is None:
        r2 = r1
    #line(p1x, p1y, p2x, p2y)
    d = dist(p1x, p1y, p2x, p2y)
    ri = r1 - r2
    if d > abs(ri):
        rid = (r1 - r2) / d
        if rid > 1:
            rid = 1
        if rid < -1:
            rid = -1
        beta = asin(rid) + HALF_PI
        with pushMatrix():
            translate(p1x, p1y)
            angle = atan2(p1x - p2x, p2y - p1y)
            rotate(angle + HALF_PI)
            x1 = cos(beta) * r1
            y1 = sin(beta) * r1
            x2 = cos(beta) * r2
            y2 = sin(beta) * r2
            #print((d, beta, ri, x1, y1, x2, y2))
            with pushStyle():
                noStroke()
                beginShape()
                vertex(-x1, -y1)
                vertex(d - x2, -y2)
                vertex(d, 0)
                vertex(d - x2, +y2)
                vertex(-x1, +y1)
                vertex(0, 0)
                endShape(CLOSE)
            line(-x1, -y1, d - x2, -y2)
            line(-x1, +y1, d - x2, +y2)
            arc(0, 0, r1 * 2, r1 * 2,
                -beta - PI, beta - PI)
            arc(d, 0, r2 * 2, r2 * 2,
                beta - PI, PI - beta)
    else:
        ellipse(p1x, p1y, r1 * 2, r1 * 2)
        ellipse(p2x, p2y, r2 * 2, r2 * 2)