303

s303/line_geometry.py

@@ -0,0 +1,140 @@
+
+def create_points(non_intersecting=True):
+    background(200)
+    done = False
+    while not done:
+        poly_points = [PVector(random(BORDER, width - BORDER),
+                               random(BORDER, height - BORDER)
+                               )
+                       for _ in range(NUM)]
+        ed = edges(poly_points)
+        done = True
+        if non_intersecting:
+            for p1, p2 in ed[::-1]:
+                for p3, p4 in ed[2::]:
+                    # test only non consecutive edges
+                    if (p1 != p3) and (p2 != p3) and (p1 != p4):
+                        if line_instersect(Line(p1, p2), Line(p3, p4)):
+                            done = False
+                            break
+    return poly_points
+     
+def is_inside(x, y, poly_points):   
+    min_, max_ = min_max(poly_points)
+    if x < min_.x or y < min_.y or x > max_.x or y > max_.y:
+        return False
+    
+    a = PVector(x, min_.y)
+    b = PVector(x, max_.y)
+    v_lines = inter_lines(Line(a, b), poly_points)
+    if not v_lines:
+        return False
+        
+    a = PVector(min_.x, y)
+    b = PVector(max_.x, y)
+    h_lines = inter_lines(Line(a, b), poly_points)
+    if not h_lines:
+        return False
+                
+    for v in v_lines:
+        for h in h_lines:
+            if line_instersect(v, h):
+                return True   
+                         
+    return False
+
+
+def inter_lines(L, poly_points):
+    inter_points = []
+    for p1, p2 in edges(poly_points):
+        inter = line_instersect(Line(p1, p2), L)
+        if inter:
+            inter_points.append(inter)
+    if  not inter_points:
+        return []
+    inter_lines = []
+    if len(inter_points) > 1:
+        inter_points.sort()
+        pairs = zip(inter_points[::2], inter_points[1::2])
+        for p1, p2 in pairs:
+            if p2:
+                inter_lines.append(Line(PVector(p1.x, p1.y),
+                                        PVector(p2.x, p2.y))) 
+    return inter_lines
+
+        
+class Line():
+    """ I should change this to a named tuple... """
+    def __init__(self, p1, p2):
+        self.p1 = p1
+        self.p2 = p2
+        
+    def plot(self):
+        line(self.p1.x, self.p1.y, self.p2.x, self.p2.y)
+    
+def line_instersect(line_a, line_b):     
+    """
+    code adapted from Bernardo Fontes 
+    https://github.com/berinhard/sketches/
+    """
+       
+    x1, y1 = line_a.p1.x, line_a.p1.y
+    x2, y2 = line_a.p2.x, line_a.p2.y
+    x3, y3 = line_b.p1.x, line_b.p1.y
+    x4, y4 = line_b.p2.x, line_b.p2.y
+        
+    try:
+        uA = ((x4-x3)*(y1-y3) - (y4-y3)*(x1-x3)) / ((y4-y3)*(x2-x1) - (x4-x3)*(y2-y1));
+        uB = ((x2-x1)*(y1-y3) - (y2-y1)*(x1-x3)) / ((y4-y3)*(x2-x1) - (x4-x3)*(y2-y1));
+    except ZeroDivisionError:
+        return
+        
+    if not(0 <= uA <= 1 and 0 <= uB <= 1):
+        return
+        
+    x = line_a.p1.x + uA * (line_a.p2.x - line_a.p1.x)
+    y = line_a.p1.y + uA * (line_a.p2.y - line_a.p1.y)
+        
+    return PVector(x, y)
+
+
+def edges(poly_points):
+    return pairwise(poly_points) + [(poly_points[-1], poly_points[0])]   
+
+def pairwise(iterable):
+    import itertools
+    "s -> (s0,s1), (s1,s2), (s2, s3), ..."
+    a, b = itertools.tee(iterable)
+    next(b, None)
+    return zip(a, b) 
+
+def min_max(points):
+        points = iter(points)
+        try:
+            p = points.next()
+            min_x, min_y = max_x, max_y = p.x, p.y
+        except StopIteration:
+            raise ValueError, "min_max requires at least one point"
+        for p in points:
+            if p.x < min_x:
+                min_x = p.x
+            elif p.x > max_x:
+                max_x = p.x
+            if p.y < min_y:
+                min_y = p.y
+            elif p.y > max_y:
+                max_y = p.y
+        return (PVector(min_x, min_y),
+                PVector(max_x, max_y))
+        
+def par_hatch(points, divisions, *sides):
+        lines = []
+        if not sides: sides = [0]
+        for s in sides:
+            a, b = points[-1 + s].v, points[+0 + s].v
+            d, c = points[-2 + s].v, points[-3 + s].v
+            for i in range(1, divisions):
+                s0 = PVector.lerp(a, b, i/float(divisions))
+                s1 = PVector.lerp(d, c, i/float(divisions))
+                lines.append(Line(s0, s1)) 
+        return lines

s303/s303.pyde

@@ -0,0 +1,123 @@
+# Alexandre B A Villares - https://abav.lugaralgum.com/sketch-a-day
+SKETCH_NAME = "s303"  # 20181028
+OUTPUT = ".png"
+GRID_SIZE = 24
+
+from line_geometry import Line
+from line_geometry import par_hatch
+
+rule = lambda x, y: (x - y) % 3 == 0
+
+def setup():
+    global xo, yo
+    size(500, 500)
+    smooth(8)
+    init_grid(GRID_SIZE)
+    
+def draw():
+    background(0)
+    stroke(255)
+    for c in Cell.cells:
+        c.plot()
+
+def init_grid(grid_size):
+    Cell.border = 50.
+    Cell.spacing = (width - Cell.border *2) / grid_size
+    Cell.cells = []
+
+    for x in range(0, grid_size, 2):
+        for y in range(0, grid_size, 2):
+                new_cell = Cell(x, y)
+                Cell.cells.append(new_cell)
+                Cell.grid[x, y] = new_cell
+
+    Node.nodes = []
+    for x in range(-1, grid_size+1, 2):
+        for y in range(-1, grid_size+1, 2):
+                new_node = Node(x, y)
+                #Cell.cells.append(new_node)  # mudar!
+                Cell.grid[x, y] = new_node   # extrarir do dict
+
+    for c in Cell.cells:
+        c.update_vers()
+   
+class Node():
+    nodes = []
+    grid = dict()
+
+    def __init__(self, x, y):
+        self.ix = x
+        self.iy = y
+        self.px = Cell.border + Cell.spacing + x * Cell.spacing 
+        self.py = Cell.border + Cell.spacing + y * Cell.spacing 
+        if rule(x, y):
+           self.px += random(-10, 10)
+           self.py += random(-10, 10)
+        self.x = self.px
+        self.y = self.py
+        self.v = PVector(self.x, self.y)
+
+class Cell():
+    cells = []
+    grid = dict()
+    vers = []
+
+    def __init__(self, x, y):
+        self.ix = x
+        self.iy = y
+        self.px = Cell.border + Cell.spacing  + x * Cell.spacing 
+        self.py = Cell.border + Cell.spacing  + y * Cell.spacing 
+        self.vers = []        
+      
+    def plot(self):
+        strokeWeight(1)
+        for l in self.lines:
+            l.plot()
+        beginShape()
+        noFill()
+        for p in self.vers:
+          if rule(p.ix, p.iy):
+            ellipse(p.x, p.y, 10, 10)
+        strokeWeight(2)
+        for p in self.vers:
+            vertex(p.x, p.y)
+        endShape(CLOSE)
+        
+    def update_vers(self):
+        self.v0 = Cell.grid.get((self.ix-1, self.iy-1))
+        self.v1 = Cell.grid.get((self.ix-1, self.iy+1))
+        self.v3 = Cell.grid.get((self.ix+1, self.iy-1))
+        self.v2 = Cell.grid.get((self.ix+1, self.iy+1))
+        # if random(10) > 2:
+        self.vers = [self.v0, self.v1, self.v2, self.v3]
+        # elif random(2) > 1:
+        #     self.vers = [self.v0, self.v1, self.v1, self.v3]
+        # else:
+        #      self.vers = [self.v0, self.v2, self.v2, self.v3]
+        self.hatch()
+        
+    def hatch(self):
+        poly_points = self.vers
+        # min_, max_ = min_max(poly_points)
+        self.lines = []
+        n = int(random(5, 12))
+        r = random(10)
+        if r > 5:                        
+            self.lines.extend(par_hatch(poly_points, n, 0))
+        if r < 6:
+            self.lines.extend(par_hatch(poly_points, n, 1))
+        
+def keyPressed():
+    if key == "n":
+        init_grid(GRID_SIZE)
+    if key == "s": saveFrame("###.png")
+
+# print text to add to the project's README.md             
+def settings():
+    println(
+"""
+![{0}]({0}/{0}{2})
+
+{1}: [code](https://github.com/villares/sketch-a-day/tree/master/{0}) [[Py.Processing](https://villares.github.io/como-instalar-o-processing-modo-python/index-EN)]
+""".format(SKETCH_NAME, SKETCH_NAME[1:], OUTPUT)
+    )