+#!/usr/bin/env python
+
+# Any copyright is dedicated to the Public Domain.
+# https://creativecommons.org/publicdomain/zero/1.0/
+
+# Written by Francois Fleuret <francois@fleuret.org>
+
+import math, sys, tqdm, os
+
+import torch, torchvision
+
+from torch import nn
+from torch.nn import functional as F
+
+######################################################################
+
+import problem
+
+
+class Physics(problem.Problem):
+ colors = torch.tensor(
+ [
+ [128, 128, 128],
+ [128, 128, 255],
+ [255, 0, 0],
+ [255, 255, 0],
+ ]
+ )
+
+ token_empty = 0
+ token_head = 1
+ token_tail = 2
+ token_conductor = 3
+ token_forward = 4
+ token_backward = 5
+
+ token2char = (
+ "_" + "".join([chr(ord("A") + n) for n in range(len(colors) - 1)]) + "><"
+ )
+
+ def __init__(
+ self, height=6, width=8, nb_objects=2, nb_walls=2, speed=1, nb_iterations=4
+ ):
+ self.height = height
+ self.width = width
+ self.nb_objects = nb_objects
+ self.nb_walls = nb_walls
+ self.speed = speed
+ self.nb_iterations = nb_iterations
+
+ def direction_tokens(self):
+ return self.token_forward, self.token_backward
+
+ def generate_frame_sequences(self, nb):
+ frame_sequences = []
+
+ result = torch.full(
+ (nb * 100, self.nb_iterations, self.height, self.width), self.token_empty
+ )
+
+ for n in range(result.size(0)):
+ while True:
+ i = torch.randint(self.height, (1,))
+ j = torch.randint(self.width, (1,))
+ v = torch.randint(2, (2,))
+ vi = v[0] * (v[1] * 2 - 1)
+ vj = (1 - v[0]) * (v[1] * 2 - 1)
+ while True:
+ if i < 0 or i >= self.height or j < 0 or j >= self.width:
+ break
+ result[n, 0, i, j] = self.token_conductor
+ i += vi
+ j += vj
+ if torch.rand(1) < 0.5:
+ break
+
+ weight = torch.full((1, 1, 3, 3), 1.0)
+
+ mask = (torch.rand(result[:, 0].size()) < 0.01).long()
+ rand = torch.randint(4, mask.size())
+ result[:, 0] = mask * rand + (1 - mask) * result[:, 0]
+
+ # empty->empty
+ # head->tail
+ # tail->conductor
+ # conductor->head if 1 or 2 head in the neighborhood, or remains conductor
+
+ for l in range(self.nb_iterations - 1):
+ nb_head_neighbors = (
+ F.conv2d(
+ input=(result[:, l] == self.token_head).float()[:, None, :, :],
+ weight=weight,
+ padding=1,
+ )
+ .long()
+ .squeeze(1)
+ )
+ mask_1_or_2_heads = (nb_head_neighbors == 1).long() + (
+ nb_head_neighbors == 2
+ ).long()
+ result[:, l + 1] = (
+ (result[:, l] == self.token_empty).long() * self.token_empty
+ + (result[:, l] == self.token_head).long() * self.token_tail
+ + (result[:, l] == self.token_tail).long() * self.token_conductor
+ + (result[:, l] == self.token_conductor).long()
+ * (
+ mask_1_or_2_heads * self.token_head
+ + (1 - mask_1_or_2_heads) * self.token_conductor
+ )
+ )
+
+ i = (result[:, -1] == self.token_head).flatten(1).max(dim=1).values > 0
+
+ result = result[i]
+
+ if result.size(0) < nb:
+ print(result.size(0))
+ result = torch.cat(
+ [result, self.generate_frame_sequences(nb - result.size(0))], dim=0
+ )
+
+ return result
+
+ def generate_token_sequences(self, nb):
+ frame_sequences = self.generate_frame_sequences(nb)
+
+ result = []
+
+ for frame_sequence in frame_sequences:
+ a = []
+ if torch.rand(1) < 0.5:
+ for frame in frame_sequence:
+ if len(a) > 0:
+ a.append(torch.tensor([self.token_forward]))
+ a.append(frame.flatten())
+ else:
+ for frame in reversed(frame_sequence):
+ if len(a) > 0:
+ a.append(torch.tensor([self.token_backward]))
+ a.append(frame.flatten())
+
+ result.append(torch.cat(a, dim=0)[None, :])
+
+ return torch.cat(result, dim=0)
+
+ ######################################################################
+
+ def frame2img(self, x, scale=15):
+ x = x.reshape(-1, self.height, self.width)
+ m = torch.logical_and(x >= 0, x < 4).long()
+
+ x = self.colors[x * m].permute(0, 3, 1, 2)
+ s = x.shape
+ x = x[:, :, :, None, :, None].expand(-1, -1, -1, scale, -1, scale)
+ x = x.reshape(s[0], s[1], s[2] * scale, s[3] * scale)
+
+ x[:, :, :, torch.arange(0, x.size(3), scale)] = 0
+ x[:, :, torch.arange(0, x.size(2), scale), :] = 0
+ x = x[:, :, 1:, 1:]
+
+ for n in range(m.size(0)):
+ for i in range(m.size(1)):
+ for j in range(m.size(2)):
+ if m[n, i, j] == 0:
+ for k in range(2, scale - 2):
+ for l in [0, 1]:
+ x[n, :, i * scale + k, j * scale + k - l] = 0
+ x[
+ n, :, i * scale + scale - 1 - k, j * scale + k - l
+ ] = 0
+
+ return x
+
+ def seq2img(self, seq, scale=15):
+ all = [
+ self.frame2img(
+ seq[:, : self.height * self.width].reshape(-1, self.height, self.width),
+ scale,
+ )
+ ]
+
+ separator = torch.full((seq.size(0), 3, self.height * scale - 1, 1), 0)
+
+ t = self.height * self.width
+
+ while t < seq.size(1):
+ direction_tokens = seq[:, t]
+ t += 1
+
+ direction_images = self.colors[
+ torch.full(
+ (direction_tokens.size(0), self.height * scale - 1, scale), 0
+ )
+ ].permute(0, 3, 1, 2)
+
+ for n in range(direction_tokens.size(0)):
+ if direction_tokens[n] == self.token_forward:
+ for k in range(scale):
+ for l in [0, 1]:
+ direction_images[
+ n,
+ :,
+ (self.height * scale) // 2 - scale // 2 + k - l,
+ 3 + scale // 2 - abs(k - scale // 2),
+ ] = 0
+ elif direction_tokens[n] == self.token_backward:
+ for k in range(scale):
+ for l in [0, 1]:
+ direction_images[
+ n,
+ :,
+ (self.height * scale) // 2 - scale // 2 + k - l,
+ 3 + abs(k - scale // 2),
+ ] = 0
+ else:
+ for k in range(2, scale - 2):
+ for l in [0, 1]:
+ direction_images[
+ n,
+ :,
+ (self.height * scale) // 2 - scale // 2 + k - l,
+ k,
+ ] = 0
+ direction_images[
+ n,
+ :,
+ (self.height * scale) // 2 - scale // 2 + k - l,
+ scale - 1 - k,
+ ] = 0
+
+ all += [
+ separator,
+ direction_images,
+ separator,
+ self.frame2img(
+ seq[:, t : t + self.height * self.width].reshape(
+ -1, self.height, self.width
+ ),
+ scale,
+ ),
+ ]
+
+ t += self.height * self.width
+
+ return torch.cat(all, dim=3)
+
+ def seq2str(self, seq):
+ result = []
+ for s in seq:
+ result.append("".join([self.token2char[v] for v in s]))
+ return result
+
+ def save_image(self, input, result_dir, filename):
+ img = self.seq2img(input.to("cpu"))
+ image_name = os.path.join(result_dir, filename)
+ torchvision.utils.save_image(img.float() / 255.0, image_name, nrow=6, padding=4)
+
+ def save_quizzes(self, input, result_dir, filename_prefix):
+ self.save_image(input, result_dir, filename_prefix + ".png")
+
+
+######################################################################
+
+if __name__ == "__main__":
+ import time
+
+ sky = Physics(height=10, width=15, speed=1, nb_iterations=100)
+
+ start_time = time.perf_counter()
+ frame_sequences = sky.generate_frame_sequences(nb=96)
+ delay = time.perf_counter() - start_time
+ print(f"{frame_sequences.size(0)/delay:02f} seq/s")
+
+ # print(sky.seq2str(seq[:4]))
+
+ for t in range(frame_sequences.size(1)):
+ img = sky.seq2img(frame_sequences[:, t])
+ torchvision.utils.save_image(
+ img.float() / 255.0,
+ f"/tmp/frame_{t:03d}.png",
+ nrow=8,
+ padding=6,
+ pad_value=0,
+ )
+
+ # m = (torch.rand(seq.size()) < 0.05).long()
+ # seq = (1 - m) * seq + m * 23
+
+ # img = sky.seq2img(frame_sequences[:60])
+
+ # torchvision.utils.save_image(
+ # img.float() / 255.0, "/tmp/world.png", nrow=6, padding=10, pad_value=0.1
+ # )