rome.py

#!/usr/bin/env python3
#
# Generates a gif image comparing Montreal metro map to its real geography.
# Based on Reddit post "Berlin Subway Map compared to it's real geography"
# https://www.reddit.com/r/dataisbeautiful/comments/6baefh/berlin_subway_map_compared_to_its_real_geography/
#
# Project at https://github.com/will8211/montreal
#
# Shared at https://www.reddit.com/r/dataisbeautiful/comments/6c8ukp/montreal_metro_map_distances_vs_geographic/
# and http://imgur.com/a/TuRT8
#
# Depends on pycairo and imageio modules
# Also depends on gifsicle
# Font ('Falling Sky') available at http://www.fontspace.com/kineticplasma-fonts/falling-sky
#
# ~WM

import glob
import os
import subprocess as sp

import cairo
import imageio as io

FRAME_COUNT = 100
FRAME_DURATION = 0.02

# Station coordinates (start_x, start_y, node_type, end_x, end_y)
# Node types: 0 -> Regular station (small dot)
#             1 -> Transfer station (big dot)
#             2 -> Bend in the tracks, no station
#            -1 -> Bend only in geographical map

metro_a = ((200, 240, 1, 118, 293),
(209, 249, -1, 136, 308),
(219, 259, -1, 160, 312),
(228, 268, 0, 166, 321),
(237, 277, -1, 171, 330),
(247, 287, -1, 182, 336),
(256, 296, 0, 194, 334),
(302, 296, 0, 230, 313),
(346, 296, 0, 259, 285),
(368, 296, -1, 271, 285),
(391, 296, 0, 305, 273),
(436, 296, 0, 339, 262),
(474, 296, 0, 384, 254),
(493, 315, 0, 412, 289),
(504, 326, -1, 427, 296),
(515, 337, 0, 438, 309),
(536, 358, 0, 470, 313),
(559, 381, 1, 485, 323),
(582, 404, 0, 503, 362),
(606, 428, 0, 513, 387),
(634, 456, 1, 525, 412),
(658, 480, 0, 550, 439),
(684, 506, 0, 570, 462),
(708, 530, 0, 589, 480),
(732, 554, 0, 621, 510),
(756, 578, 0, 648, 529),
(768, 590, -1, 676, 532),
(780, 602, 0, 700, 541),
(804, 626, 0, 723, 556),
(828, 650, 0, 741, 569),
(852, 674, 0, 766, 587),
(876, 694, 0, 787, 606),
(900, 718, 0, 814, 630),
(912, 730, -1, 831, 647),
(924, 742, 1, 855, 658))

metro_c = ((634, 456, 1, 525, 412),
(681, 456, 0, 563, 402),
(729, 456, 0, 603, 394),
(777, 456, 0, 656, 400),
(792, 456, -1, 679, 400),
(809, 456, -1, 696, 388),
(824, 456, 0, 710, 388),
(871, 456, 0, 750, 408),
(882, 467, -1, 763, 417),
(893, 478, 0, 768, 435),
(898, 483, -1, 777, 473),
(904, 489, -1, 787, 484),
(910, 495, -1, 804, 487),
(915, 500, 0, 824, 494),
(937, 522, 0, 869, 514),
(944, 529, -1, 906, 519),
(952, 537, -1, 922, 519),
(959, 544, 0, 952, 532),
(970, 555, -1, 967, 538),
(981, 566, 0, 988, 538),
(1003, 588, 0, 1023, 533),
(1025, 610, 0, 1066, 535),
(1047, 632, 0, 1110, 541),
(1054, 639, -1, 1124, 542),
(1062, 647, -1, 1155, 532),
(1069, 654, 0, 1172, 530),
(1091, 676, 0, 1200, 530),
(1098, 683, -1, 1251, 540),
(1106, 691, -1, 1275, 531),
(1113, 698, 0, 1287, 527),
(1135, 720, 0, 1327, 526),
(1146, 731, -1, 1354, 523),
(1157, 742, 1, 1375, 524))

metro_b_one = ((577, 698, 1, 402, 747),
(534, 698, 0, 345, 733),
(512, 698, -1, 328, 725),
(491, 698, 0, 317, 710),
(478, 685, -1, 314, 692),
(466, 673, 0, 327, 675),
(466, 654, -1, 376, 633),
(466, 636, 0, 380, 621),
(466, 597, 0, 391, 584),
(466, 556, 0, 411, 524),
(466, 536, -1, 416, 502),
(466, 517, 0, 409, 477),
(466, 503, -1, 405, 460),
(466, 489, -1, 414, 441),
(466, 475, 0, 433, 423),
(482, 459, -1, 442, 406),
(498, 443, 0, 448, 376),
(531, 410, 0, 460, 353),
(559, 381, 1, 485, 323),
(584, 357, 0, 509, 289),
(597, 343, -1, 525, 279),
(611, 330, 0, 543, 277),
(628, 313, -1, 565, 255),
(645, 296, 0, 575, 251),  ## BIVIO
(660, 296, -1, 595, 258),
(675, 296, -1, 600, 265),
(688, 296, 0, 625, 272),
(699, 296, -1, 640, 258),
(710, 296, -1, 650, 243),
(732, 296, 0, 672, 236),
(770, 296, 0, 702, 241),
(784, 296, -1, 718, 246),
(808, 296, 0, 736, 245),
(820, 284, -1, 745, 238),
(832, 272, 0, 753, 226),
(859, 245, 0, 774, 191),
(882, 222, 1, 795, 179))

metro_b_two = ((645, 296, 0, 575, 251),
(645, 274, -1, 579, 240),
(645, 253, 0, 576, 221),
(645, 231, -1, 556, 201),
(645, 210, 0, 554, 188),
(657, 198, -1, 554, 159),
(669, 185, 0, 568, 142),
(675, 179, -1, 595, 117),
(681, 173, -1, 609, 80),
(688, 167, -1, 603, 67),
(694, 161, 1, 603, 55))


metro_lines = ((metro_a, 0.921, 0.510, 0.122),
               (metro_c, 0.001, 0.529, 0.322),
               (metro_b_one, 0.001, 0.443, 0.737),
               (metro_b_two, 0.001, 0.443, 0.737))

frames_list = []
surface = cairo.ImageSurface(cairo.FORMAT_ARGB32, 1500, 900)
ctx = cairo.Context(surface)

#############
# Functions #
#############

def smoothstep(a, b, value):
    '''
    Based on javascript code found at <https://github.com/gre/smoothstep>
    Takes a start time (a), and end time (b), and the current time (value),
    and return what proportion (between 0 and 1.0) of the distance it should
    currently be at, using a smooth s-curve for displacement. Used by the
    transform() function.

    NOT USED: Swtiched to smootherstep()
    '''
    x = max(0, min(1, (value - a) / (b - a)))
    return x**2 * (3 - 2*x)

def smootherstep(a, b, value):
    '''
    A smoother version of smoothstep()
    https://en.wikipedia.org/wiki/Smoothstep#Variations
    '''
    x = max(0, min(1, (value - a) / (b - a)))
    return x**3 * (x * (x*6 - 15) + 10)

def transform(start, end, current_frame):
    '''
    Takes the starting and ending states of a value (an x or y coordinate or
    a size) and determines what that value should be at the current frame.
    '''
    #multiplier = current_frame / (FRAME_COUNT - 1) # Flat velocity
    multiplier = smootherstep(0, FRAME_COUNT, current_frame)
    return start + multiplier * (end - start)


###################################
# Draw metro lines for each frame #
###################################

for frame in range(FRAME_COUNT):

    # Background

    ctx.set_source_rgb(1.000, 1.000, 1.000) # white
    ctx.rectangle(0, 0, 1500, 900)
    ctx.fill()

    for metro_line, r, g, b in metro_lines:

        # Draw tracks

        ctx.set_line_cap(cairo.LINE_CAP_ROUND)
        ctx.set_line_join(cairo.LINE_JOIN_ROUND)
        ctx.set_source_rgb(r, g, b)

        line_width = transform(15, 4, frame)
        ctx.set_line_width(line_width)

        for i, coord in enumerate(metro_line):

            x = transform(coord[0], coord[3], frame)
            y = transform(coord[1], coord[4], frame)

            if i == 0:
                ctx.move_to(x, y)

            # for frame 0, skip actual stations, following only track bends
            # this makes the lines straighter
            if frame > 0 or coord[2] > 0:
                ctx.line_to(x, y)

        ctx.stroke()

        # Draw logos

        logoA = cairo.ImageSurface.create_from_png('LOGO/A.png')

        a = transform(944, 875, frame)  ## X +20
        b = transform (722, 638, frame) ## Y -20

        ctx.set_source_surface(logoA, a, b)

        ctx.paint()

        logoB = cairo.ImageSurface.create_from_png('LOGO/B.png')

        a = transform(902, 815, frame)
        b = transform (202, 159, frame)

        ctx.set_source_surface(logoB, a, b)

        ctx.paint()

        logoC = cairo.ImageSurface.create_from_png('LOGO/C.png')

        a = transform(1177, 1395, frame)
        b = transform (722, 504, frame)

        ctx.set_source_surface(logoC, a, b)

        ctx.paint()

        # Draw stations

        ctx.set_source_rgb(1.000, 1.000, 1.000)

        for coord in metro_line:

            x = transform(coord[0], coord[3], frame)
            y = transform(coord[1], coord[4], frame)

            ctx.move_to(x, y)

            big_dot = transform(13, 3, frame)
            small_dot = transform(9, 3, frame)

            if coord[2] == 0:
                ctx.set_line_width(small_dot)
                ctx.line_to(x, y)

            elif coord[2] == 1:
                ctx.set_line_width(big_dot)
                ctx.line_to(x, y)

            ctx.stroke()

    # Write frame to file

    frame_name = 'frame_%d.png' % frame
    surface.write_to_png(frame_name)
    frames_list.append(frame_name)


################
# Generate gif #
################

images = []
for filename in frames_list:
    images.append(io.imread(filename))

io.imwrite('part_1.gif', images[0], duration = 1.00)
io.mimwrite('part_2.gif', images, duration = FRAME_DURATION)
io.imwrite('part_3.gif', images[-1], duration = 1.00)

# To transition back to the start
#io.mimwrite('part_4.gif', reversed(images), duration = FRAME_DURATION)

for f in glob.glob('frame_*.png'):
    os.remove(f)

result = sp.run(['gifsicle', '--colors', '256',
                 'part_1.gif', 'part_2.gif', 'part_3.gif'], # , 'part_4.gif'],
                 stdout=sp.PIPE)

with open('TEST.gif', 'wb') as f:
    f.write(result.stdout)

for f in glob.glob('part_*.gif'):
    os.remove(f)

sp.call(['xdg-open', 'TEST.gif'])