Silent Night

silentnight.R

# https://aschinchon.wordpress.com/2014/03/13/the-lonely-acacia-is-rocked-by-the-wind-of-the-african-night/
depth <- 9
angle<-30 #Between branches division
L <- 0.90 #Decreasing rate of branches by depth
nstars <- 300 #Number of stars to draw
mstars <- matrix(runif(2*nstars), ncol=2)
branches <- rbind(c(1,0,0,abs(jitter(0)),1,jitter(5, amount = 5)), data.frame())
colnames(branches) <- c("depth", "x1", "y1", "x2", "y2", "inertia")
for(i in 1:depth)
{
  df <- branches[branches$depth==i,]
  for(j in 1:nrow(df))
  {
    branches <- rbind(branches, c(df[j,1]+1, df[j,4], df[j,5], df[j,4]+L^(2*i+1)*sin(pi*(df[j,6]+angle)/180), 
                                  df[j,5]+L^(2*i+1)*cos(pi*(df[j,6]+angle)/180), df[j,6]+angle+jitter(10, amount = 8)))
    branches <- rbind(branches, c(df[j,1]+1, df[j,4], df[j,5], df[j,4]+L^(2*i+1)*sin(pi*(df[j,6]-angle)/180), 
                                  df[j,5]+L^(2*i+1)*cos(pi*(df[j,6]-angle)/180), df[j,6]-angle+jitter(10, amount = 8)))
  }
}
nodes <- rbind(as.matrix(branches[,2:3]), as.matrix(branches[,4:5]))
png("image.png", width = 1200, height = 600)
plot.new()
par(mai = rep(0, 4), bg = "gray12")
plot(nodes, type="n", xlim=c(-7, 3), ylim=c(0, 5))
for (i in 1:nrow(mstars)) 
{
  points(x=10*mstars[i,1]-7, y=5*mstars[i,2], col = "blue4", cex=.7, pch=16)
  points(x=10*mstars[i,1]-7, y=5*mstars[i,2], col = "blue",  cex=.3, pch=16)
  points(x=10*mstars[i,1]-7, y=5*mstars[i,2], col = "white", cex=.1, pch=16)
}
# The moon
points(x=-5, y=3.5, cex=40, pch=16, col="lightyellow")
# The tree
for (i in 1:nrow(branches)) {
  lines(x=branches[i,c(2,4)], y=branches[i,c(3,5)], 
    col = paste("gray", as.character(sample(seq(from=50, to=round(50+5*branches[i,1]), by=1), 1)), sep = ""), 
    lwd=(65/(1+3*branches[i,1])))
}
rm(branches)
dev.off()