[NTG-context] Colors in lmt_surface and luametafun

[Otared Kavian]

Hi Hans,

On page 36 of luametafun.pdf there is the following example of using lmt_surface:

\startMPcode{doublefun}
	draw lmt_surface [
		preamble  = "local sin, cos = math.sin, math.cos",
		code = "sin(x*x) - cos(y*y)",
		color = "f, f/2, 1-f",
		color = "f, f, 0",
		xstep = .02,
		ystep = .02,
		xvector = {-0.4, -0.4},
		height = 10cm,
		lines = true,
	] xsized .TextWidth ;
\stopMPcode

What is the meaning of « f » in « color = "f, f/5, 1-f" »?
Is it possible to specify other colors and how can it be done?

Thanks for your attention: Otared