Making the Rladies Sydney Bitmap Animation

bitmap.R

library(readbitmap)
library(gganimate)
library(dplyr)
library(ggplot2)
b1 <- read.bitmap("~/Documents/rladies.png")
b2 <- read.bitmap("~/Documents/sydney.png")
x1 <- 1 - b1[,,1]
x2 <- 1 - b2[,,1]
# plot(raster::raster(x1)) # check
# plot(raster::raster(x2)) # check
df_rladies <- data.frame(row=as.vector(col(x1)), 
                         col=8 - as.vector(row(x1)),
                         value=as.vector(x1)) %>% 
  filter(value==1)
#ggplot(df_rladies, aes(row, col)) + geom_tile() + coord_equal() + theme_minimal()
df_sydney <- data.frame(row=as.vector(col(x2)), 
                         col=8 - as.vector(row(x2)),
                         value=as.vector(x2)) %>% 
  filter(value==1) 
plot_df <- bind_rows(
  df_rladies %>% mutate(idx=1),
  df_sydney %>% mutate(idx=2)
)

p <- ggplot(plot_df, aes(row, col)) + geom_tile(fill="#88398a", width=0.9, height=0.9) + coord_equal() + xlab("") + ylab("")
#p + 
#  facet_wrap(~idx) + 
#  theme_bw() 

panim <- p +
  transition_states(
    states            = idx, # variable in data
    transition_length = 1,   # all states display for 1 time unit
    state_length      = 1    # all transitions take 1 time unit
  ) +
  enter_fade() +             # How new blocks appear
  exit_fade() +              # How blocks disappear
  ease_aes('sine-in-out')    # Tweening movement

save_animation(animate(panim, fps=20, nframes=50, width=1400, height=200), "rladies.gif")