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.