data mix up in composite track animations

[jrboyd]

Hi again,
I noticed this after stumbling on the merge() override to make Composite Tracks. (Nice feature but might be easier to discover with an explicit CompositeTrack constructor.)
This issue only effects Line and Area Tracks as far as I can tell. When moving or zooming, only data from the last track in the merge is displayed but oddly with the the first track's color. The static display is as expected.

library(TnT)
gen_signal = function(centers, widths = rep(2, length(centers)), heights = 100*widths, size = 100){
  signal = rep(0, size)
  if(length(heights) != length(centers) & length(heights) != 1){
    stop("length of heights must equal lenght of  centers or 1")
  }
  if(length(widths) != length(centers) & length(widths) != 1){
    stop("length of widths must equal lenght of  centers or 1")
  }
  if(length(heights) == 1){
    heights = rep(heights, length(centers))
  }
  if(length(widths) == 1){
    widths = rep(widths, length(centers))
  }
  
  for(i in 1:length(centers)){
    x = centers[i]
    h = heights[i]
    w = widths[i]
    toadd = table(factor(round(rnorm(h, mean = x, sd = w)), levels = 1:size))
    signal = signal + toadd
  }
  return(as.numeric(signal))
}

set.seed(0)
grs = lapply(c(40,50,60), function(x){
  signal = gen_signal(centers = x)
  gr = GRanges("a", IRanges(1:length(signal), 1:length(signal)), value = signal)
})
#for line tracks (and area), only the last track added animates but with the first track's color
lt1 = LineTrack(grs[[1]], label = "1", color = "red")
lt2 = LineTrack(grs[[2]], label = "2", color = "green")
lt3 = LineTrack(grs[[3]], label = "3", color = "blue")
TnTBoard(list(lt1, lt2, lt3, 
              merge(lt1, lt2), 
              merge(lt2, lt1), 
              merge(lt1, lt2, lt3),
              merge(lt3, lt2, lt1)), coord.range = c(-100, 200))

# #no problem with block tracks
# bt1 = BlockTrack(range(subset(grs[[1]], value > 0)), label = "1", color = "red")
# bt2 = BlockTrack(range(subset(grs[[2]], value > 0)), label = "2", color = "green")
# bt3 = BlockTrack(range(subset(grs[[3]], value > 0)), label = "3", color = "blue")
# TnTBoard(list(bt1, bt2, bt3, 
#               merge(bt1, bt2), 
#               merge(bt2, bt1), 
#               merge(bt1, bt2, bt3),
#               merge(bt3, bt2, bt1)), coord.range = c(-100, 200))

[Marlin-Na]

Thanks for reporting!

I can reproduce it, I haven't figure out the reason yet, but it might be a problem in upstream. I will check with that when I am free and fix it as soon as possible.

Best,