Animate through several closed b-splines

closed_spline_anim.r

library(ggforce) # need github version
library(tweenr)
library(animation)

# Define the different states
controls <- list(
    data.frame(
        x = runif(6),
        y = runif(6),
        col = 'steelblue',
        stringsAsFactors = FALSE
    ),
    data.frame(
        x = runif(6),
        y = runif(6),
        col = 'firebrick',
        stringsAsFactors = FALSE
    ),
    data.frame(
        x = runif(6),
        y = runif(6),
        col = 'forestgreen',
        stringsAsFactors = FALSE
    ),
    data.frame(
        x = runif(6),
        y = runif(6),
        col = 'goldenrod',
        stringsAsFactors = FALSE
    )
)

# Repeat first state so the animation loops
controls[[5]] <- controls[[1]]

# Create intermediary states
controls <- tween_states(controls, tweenlength = 2, statelength = 0, ease = 'cubic-in-out', nframes = 300)

# Create animation
saveGIF({
    for (i in seq_len(max(controls$.frame))) {
        p <- ggplot(controls[controls$.frame == i,], aes(x, y)) +
            geom_polygon(fill = NA, colour = 'grey', linetype = 'dashed') +
            geom_point(colour = 'black') +
            geom_bspline_closed(aes(fill = col)) + 
            scale_fill_identity() + 
            scale_x_continuous(limits = c(0, 1)) + 
            scale_y_continuous(limits = c(0, 1))
        plot(p)
    }
}, movie.name = 'closed_spline.gif', interval = 1/24)