Name

smoothstep — perform Hermite interpolation between two values

Declaration

genType smoothstep(genType edge0,
 genType edge1,
 genType x);
 
genType smoothstep(float edge0,
 float edge1,
 genType x);
 

Parameters

edge0

Specifies the value of the lower edge of the Hermite function.

edge1

Specifies the value of the upper edge of the Hermite function.

x

Specifies the source value for interpolation.

Description

smoothstep performs smooth Hermite interpolation between 0 and 1 when edge0 < x < edge1. This is useful in cases where a threshold function with a smooth transition is desired. smoothstep is equivalent to: 

    genType t;  /* Or genDType t; */
    t = clamp((x - edge0) / (edge1 - edge0), 0.0, 1.0);
    return t * t * (3.0 - 2.0 * t);

smoothstep returns 0.0 if x ≤ edge0 and 1.0 if x ≥ edge1.

Results are undefined if edge0 ≥ edge1.

Version Support

OpenGL ES Shading Language Version
Function Name 1.00 3.00
smoothstep (genType)✔✔

See Also

mix, step

Copyright

Copyright © 2011-2013 Khronos Group. This material may be distributed subject to the terms and conditions set forth in the Open Publication License, v 1.0, 8 June 1999.