Lua Shader Common Functions

Function	Syntax	Description
abs	abs(x)	Returns the absolute of x.
sign	sign(x)	Returns the sign of x (-1, 0 or 1).
floor	floor(x)	Returns a value equal to the nearest integer that is less than or equal to x.
trunc	trunc(x)	Returns a value equal to the nearest integer to x whose absolute value is not larger than the absolute value of x.
round	round(x)	Returns a value equal to the nearest integer to x.
eround	round(x)	Returns a value equal to the nearest even integer to x.
ceil	round(x)	Returns a value equal to the nearest integer that is greater than or equal to x.
fract	round(x)	Returns 1/floor(x).
mod	mod(x,y)	Modulus, returns x-y*floor(x/y).
modf	modf(x,y)	Returns the fractional part of x and sets i to the integer part (as a whole number floating point value).
min	mod(x,y)	Returns the lower of x or y.
max	mod(x,y)	Returns the greater of x or y.
clamp	clamp(x,minV,maxV)	Returns min(max(x,minV),maxV).
mix	mix(x,y,a)	Returns the linear blend of x and y. i.e x*(1−a)+y*a
step	step(edge,x)	Returns 0.0 if x<edge, otherwise it returns 1.0.
smoothstep	smoothstep(edge0,edge1,x)	Returns 0.0 if x <= edge0 and 1.0 if x >= edge1 and performs smooth Hermite interpolation between 0 and 1 when edge0<x<edge1.
isnan	mix(x)	Returns true if x holds a NaN (not a number).
isinf	mix(x)	Returns true if x holds a positive infinity or negative infinity.