option explicit
declare sub plotArray( byval addr as single ptr, byval siz as integer, byval xscale as integer, byval yscale as integer, byval col as integer )
type fp as function ( byval x as single ) as single
declare function makeArray( byval f as fp ) as single ptr
declare sub plotFunc( byval f as fp, byval xscale as integer, byval yscale as integer, byval col as integer )
declare function square( byval x as single ) as single
declare function linear( byval x as single ) as single

screen 13

plotFunc(@linear, 20, 20, 12)

sleep
end

sub plotArray( byval addr as single ptr, byval siz as integer, byval xscale as integer, byval yscale as integer, byval col as integer )
	for i as integer = 0 to 199
		pset (0, i*yscale), col
	next i
	for i = 0 to 319
		pset (i*xscale, 199), col
	next i
	for i = 0 to siz
		line (i*xscale, cint(199-(*(addr + i))*yscale))-((i+1)*xscale, cint(200-(*(addr + i + 1))*yscale)), col
	next i
end sub

function makeArray( byval f as fp ) as single ptr
	dim arr(319) as single
	for i as integer = 0 to ubound(arr)
		arr(i) = f(i)
	next i
	makeArray = @arr(0)
end function

sub plotFunc( byval f as fp, byval xscale as integer, byval yscale as integer, byval col as integer )
	plotArray(makeArray(f), 319, xscale, yscale, col)
end sub
4
function square( byval x as single ) as single
	square = x^2
end function

function linear( byval x as single ) as single
	linear = x
end function