callbacks: User callbacks on mouse events

rgl.setMouseCallbacksR Documentation

User callbacks on mouse events


Set and get user callbacks on mouse events.


rgl.setMouseCallbacks(button, begin = NULL, update = NULL, end = NULL, 
                      dev = cur3d(), subscene = currentSubscene3d(dev))
                      dev = cur3d(), subscene = currentSubscene3d(dev))

                      dev = cur3d(), subscene = currentSubscene3d(dev))

rgl.getWheelCallback(dev = cur3d(), subscene = currentSubscene3d(dev))



Which button? Use 1 for left, 2 for right, 3 for middle, 4 for wheel. Use 0 to set an action when no button is pressed.


Called when mouse down event occurs


Called when mouse moves


Called when mouse is released


Called when mouse wheel is rotated

dev, subscene

The RGL device and subscene to work with


The set functions set event handlers on mouse events that occur within the current RGL window. The begin and update events should be functions taking two arguments; these will be the mouse coordinates when the event occurs. The end event handler takes no arguments. The rotate event takes a single argument, which will be equal to 1 if the user pushes the wheel away by one click, and 2 if the user pulls the wheel by one click.

Alternatively, the handlers may be set to NULL, the default value, in which case no action will occur.

If a subscene has multiple listeners, the user action will still only be called for the subscene that received the mouse event. It should consult par3d("listeners") if it makes sense to take action on the whole group of subscenes.

The get function retrieves the callbacks that are currently set.

The “no button” mouse handler may be set by specifying button = 0. The begin function will be called the first time the mouse moves within the subscene, and the update function will be called repeatedly as it moves. The end function will never be called.


The set functions are called for the side effect of setting the mouse event handlers.

The rgl.getMouseCallbacks function returns a list containing the callback functions or NULL if no user callback is set. The rgl.getWheelCallback returns the callback function or NULL.


Duncan Murdoch

See Also

par3d to set built-in handlers, setUserCallbacks to work with rglwidget.


 pan3d <- function(button, dev = cur3d(), subscene = currentSubscene3d(dev)) {
   start <- list()
   begin <- function(x, y) {
     activeSubscene <- par3d("activeSubscene", dev = dev)
     start$listeners <<- par3d("listeners", dev = dev, subscene = activeSubscene)
     for (sub in start$listeners) {
       init <- par3d(c("userProjection","viewport"), dev = dev, subscene = sub)
       init$pos <- c(x/init$viewport[3], 1 - y/init$viewport[4], 0.5)
       start[[as.character(sub)]] <<- init
   update <- function(x, y) {
     for (sub in start$listeners) {
       init <- start[[as.character(sub)]]
       xlat <- 2*(c(x/init$viewport[3], 1 - y/init$viewport[4], 0.5) - init$pos)
       mouseMatrix <- translationMatrix(xlat[1], xlat[2], xlat[3])
       par3d(userProjection = mouseMatrix %*% init$userProjection, dev = dev, subscene = sub )
   rgl.setMouseCallbacks(button, begin, update, dev = dev, subscene = subscene)
   cat("Callbacks set on button", button, "of RGL device", dev, "in subscene", subscene, "\n")
 shade3d(icosahedron3d(), col = "yellow")
 # This only works in the internal display...

rgl documentation built on June 10, 2022, 9:05 a.m.