Merry Christmas Illusion

MCIllusion.R

graphics.off()

W <- 5.5
H <- 5.5

parts <- function(x0, y0, BLfin, Size) {
  Nfin <- 48
  BLfin <- c(BLfin, 1-BLfin)
  FSize <- 1

  color <- c("white",
             do.call("rgb", lapply(runif(3, 0, 0.25), I)),
             rgb(runif(1, 0.75, 1), runif(1, 0.75, 1), runif(1, 0.5, 1)))
  
  j <- 1
  ths <- seq(0, 2*pi, length=Nfin+1)[-1]
  for (t in 1:length(ths)) {
    rate <- BLfin[t%%2+1]
    ts <- seq(ths[t] - 2*pi/Nfin*rate, ths[t] + 2*pi/Nfin*rate, length = 2)
    r <- 0.5
    px <- c(x0, r * (cos(ts))/W + x0, x0)
    py <- c(y0, r * (sin(ts))/H + y0, y0)
    grid.polygon(px, py, gp = gpar(col=NA, fill=color[j]))
    j <- 3-j
  }

  r <- Size * FSize
  ts <- seq(0, 2*pi, length = 32)
  px <- c(x0, r * (cos(ts))/W + x0, x0)
  py <- c(y0, r * (sin(ts))/H + y0, y0)
  grid.polygon(px, py, gp = gpar(col=color[3], fill=color[3]))
}    

quartz(width = 6, height = 6)

grid.polygon(c(0.5, 0.2, 0.8), c(1, 0.2, 0.2), gp = gpar(col = NA, fill = "darkgreen"))
grid.rect(0.5, 0.1, 0.2, 0.2, gp = gpar(col = NA, fill = "brown"))

ps <- data.frame(Xs = c(0.5, 0.4, 0.6, 0.3, 0.5, 0.7, 0.2, 0.4, 0.6, 0.8),
                 Ys = c(0.9, 0.7, 0.7, 0.5, 0.5, 0.5, 0.3, 0.3, 0.3, 0.3))

with(ps, {
  for(i in 1:nrow(ps)) {
    parts(Xs[i], Ys[i], 0.5, 0.1)
  }
})