When functions are unprototyped, compund types will be passed byref, and strings will be passed by strptr, floating-pt numbers are passed as double.
Opengl uses both floats and doubles for many of its params, so prototypes are needed here. Also some array values have to be passed byref.
Here is a demo of what happens when a rectangle is passed to an unprototype function
type rectangle long left,top,right,bottom
function f(...)
indexbase 1
rectangle r at param[1]
print r.left " " r.top " " r.right " " r.bottom
end function
rectangle t={10,20,30,40}
f t 'auto pass byref
f @t 'explicit pass byref
