311 & 312

README.md

@@ -7,6 +7,18 @@ Hi! I'm [Alexandre Villares](https://abav.lugaralgum.com), let's see if I can ma
 If you enjoy this, be a [patreon](https://patreon.com/arteprog) or make a donation [here](https://www.paypal.com/cgi-bin/webscr?cmd=_s-xclick&hosted_button_id=HCGAKACDMVNV2) 
 
 
+---
+
+![s312](s312/s312.gif)
+
+312: [code](https://github.com/villares/sketch-a-day/tree/master/s312) [[Py.Processing](https://villares.github.io/como-instalar-o-processing-modo-python/index-EN)]
+
+---
+
+![s311](s311b/s311.gif)
+
+311: [code](https://github.com/villares/sketch-a-day/tree/master/s311) [[Py.Processing](https://villares.github.io/como-instalar-o-processing-modo-python/index-EN)]
+
 ---
 
 ![s310](s310/s310.gif)

s311/s311.pyde

@@ -1,12 +1,12 @@
 # Alexandre B A Villares - https://abav.lugaralgum.com/sketch-a-day
-SKETCH_NAME = "s311"  # 20181105
+SKETCH_NAME = "s311b"  # 20181105
 OUTPUT = ".gif"
 GRID_SIZE = 12
 
 from line_geometry import Line
 from line_geometry import par_hatch
-add_library('gifAnimation')
-from gif_exporter import gif_export
+# add_library('gifAnimation')
+# from gif_exporter import gif_export
 
 rule = lambda x, y: random(40) < 20
 
@@ -20,22 +20,23 @@ def draw():
     background(200)
     f = frameCount/10.
     t = 0.5 + sin(f)/2    
-    stroke(0, 0, 200)
+    stroke(0, 0, 200, 240)
     for c in Cell.cells:
         c.plot(-t)    
     stroke(0)
-    stroke(200, 0, 0)
+    stroke(200, 0, 0, 240)
     for c in Cell.cells:
         c.plot(+t)    
-    stroke(0)
 
+    # stroke(0)
     # for c in Cell.cells:
     #     c.plot(t)
 
-    if f < TWO_PI:
-        gif_export(GifMaker, SKETCH_NAME)
-    else:
-        exit()
+    # if f < TWO_PI:
+    #     pass
+    #     # gif_export(GifMaker, SKETCH_NAME)
+    # else:
+    #     exit()
 
 def init_grid(grid_size):
     Cell.border = 125.

s312/gif_exporter.py

@@ -0,0 +1,42 @@
+"""
+Alexandre B A Villares http://abav.lugaralgum.com - GPL v3 
+
+A helper for the Processing gifAnimation library https://github.com/extrapixel/gif-animation/tree/3.0
+Download from https://github.com/villares/processing-play/blob/master/export_GIF/unzip_and_move_to_libraries_GifAnimation.zip
+This helper was inspired by an example by Art Simon https://github.com/APCSPrinciples/AnimatedGIF/
+
+# add at the start of your sketch:
+  add_library('gifAnimation')
+  from gif_exporter import gif_export
+# add at the end of draw():
+  gif_export(GifMaker)
+"""
+
+def gif_export(GifMaker,             # gets a reference to the library
+               filename="exported",  # .gif will be added
+               repeat=0,             # 0 makes it an "endless" animation
+               quality=255,          # quality range 0 - 255
+               delay=200,            # this is quick
+               frames=0,             # 0 will stop on keyPressed or frameCount >= 100000
+               finish=False):        # force stop
+    global gifExporter
+    try:
+        gifExporter
+    except NameError:
+        gifExporter = GifMaker(this, filename + ".gif")
+        gifExporter.setRepeat(repeat)
+        gifExporter.setQuality(quality)
+        gifExporter.setDelay(delay)
+
+    gifExporter.addFrame()
+
+    if frames == 0:
+       if keyPressed or frameCount >= 100000:
+           finish = True
+    elif frameCount >= frames:
+        finish = True
+
+    if finish:
+        gifExporter.finish()
+        print("gif saved")
+        exit()

s312/line_geometry.py

@@ -0,0 +1,146 @@
+
+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 lerp(self, other, t):
+        p1 = PVector.lerp(self.p1, other.p1, t)
+        p2 = PVector.lerp(self.p2, other.p2, t)
+        return Line(p1, p2)
+
+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):
+        vectors = [PVector(p.x, p.y) for p in points]
+        lines = []
+        if not sides: sides = [0]
+        for s in sides:
+            a, b = vectors[-1 + s], vectors[+0 + s]
+            d, c = vectors[-2 + s], vectors[-3 + s]
+            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