added twister.py

generators/twister.py

@@ -0,0 +1,124 @@
+#!/usr/bin/env python3
+
+import sys
+import random
+import math
+import argparse
+import collections
+import blup.frame
+import blup.output
+import blup.animation
+import blup.writebml
+import colorsys
+
+
+WIDTH = 22
+HEIGHT = 16
+DEPTH = 256
+
+
+class Point(collections.namedtuple('Point', ['x', 'y'])):
+    def __add__(self, other):
+        return Point(self.x + other.x, self.y + other.y)
+    def __sub__(self, other):
+        return Point(self.x - other.x, self.y - other.y)
+    def __mul__(self, other):
+        if isinstance(other, Point):
+            raise Exception('not implemented')
+        else:
+            return Point(self.x * other, self.y * other)
+    def __truediv__(self, other):
+        if isinstance(other, Point):
+            raise ValueError()
+        else:
+            return self * (1/other)
+    @property
+    def len(self):
+        return math.sqrt(self.x**2 + self.y**2)
+    @property
+    def n(self):
+        n = Point(self.y, -self.x)
+        return n / n.len
+    @property
+    def intp(self):
+        return Point(int(round(self.x)), int(round(self.y)))
+
+
+def convert_color(c):
+    return list(map(lambda x: int(round(x*(DEPTH-1))), c))
+
+
+def get_random_color():
+    return colorsys.hsv_to_rgb(random.random(), 0.5 + random.random() / 2, 1)
+
+
+class Twister:
+    def __init__(self, worldsize):
+        self.worldsize = worldsize
+        self.cycletime = 1.3
+        self.sat = 0.5 + random.random() / 2
+        self.hues = [random.random()]
+        self.hues += [ self.hues[0] + (i+1) * 0.25 for i in range(3) ]
+        random.shuffle(self.hues)
+        self.width = worldsize.x // 2.9
+
+    def update(self, t, dt):
+        # inspired by https://www.lexaloffle.com/bbs/?tid=3050
+
+        self.rows = []
+        a0 = t * math.pi / self.cycletime
+        while len(self.rows) < self.worldsize.y:
+            y = len(self.rows)
+            a = a0 - y * math.pi / self.worldsize.y \
+                * (math.sin(t * math.pi / 10) * 0.7)
+            ot1 = t * math.pi / 5
+            ot2 = y * math.pi / (self.worldsize.y * 2)
+            offs = self.worldsize.x / 2 + math.sin(ot1 + ot2) * self.width / 2
+            x1 = int(round(offs + self.width * math.sin(a)))
+            x2 = int(round(offs + self.width * math.sin(a+0.5*math.pi)))
+            x3 = int(round(offs + self.width * math.sin(a+math.pi)))
+            x4 = int(round(offs + self.width * math.sin(a+1.5*math.pi)))
+            row = []
+            for i, (start, end) in enumerate([(x1, x2), (x2, x3),
+                                              (x3, x4), (x4, x1)]):
+                if start < end:
+                    row += [(x, i, (x - start) / (end - start - 1)) 
+                            for x in range(start, end - 1)]
+            self.rows.append(row)
+
+    def draw(self, frame):
+        for y, line in enumerate(self.rows):
+            for point in line:
+                x, i, j = point
+                val = 1 - math.sin(j * math.pi) / 2.3
+                color = colorsys.hsv_to_rgb(self.hues[i], self.sat, val)
+                try:
+                    frame.setPixel(x, y, convert_color(color))
+                except ValueError:
+                    pass
+
+
+if __name__ == '__main__':
+    parser = argparse.ArgumentParser(description='Generate animations')
+    parser.add_argument('-d', '--delay', type=int, default=50)
+    parser.add_argument('-t', '--time', type=int, default=15)
+    parser.add_argument('output_file')
+    args = parser.parse_args()
+
+    dim = blup.frame.FrameDimension(WIDTH, HEIGHT, DEPTH, 3)
+    anim = blup.animation.Animation(dim)
+    anim.tags['description'] = ' '.join(sys.argv)
+
+    twister = Twister(Point(WIDTH, HEIGHT))
+    t = 0
+    dt = args.delay / 1000
+    while t < args.time:
+        t += dt
+        frame = blup.animation.AnimationFrame(dim, args.delay)
+
+        twister.update(t, dt)
+        twister.draw(frame)
+
+        anim.addFrame(frame)
+
+    blup.writebml.writeBml(anim, args.output_file)