plotting in the simplex in Maple

I would like routines programmed for Maple 11 (or earlier) to do the following: - accept as input a function f: R -> R, and a set of points in the 2-simplex, P = {**x**1,...,**x**n} - return a plot of the 2-simplex (triangle), including - the points (1,0,0), (1/2,1/2,0), and their permutations, - the set of points, P - D(**x**) for each of the points above, where D(**x**) = { (y1,y2,y3) in Delta2 | g(W,y) > g(L,y)}; W = { i in {1,2,3} | xi > yi}; L = { i in {1,2,3} | yi > xi}; and g(C,y) = sumi in C f(yi) (Distinction should be made between open and closed boundaries.) - interactive features for ease of visualisation (e.g. an ability to render invisible some of the **x**, D(**x**)) are desirable