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39 lines
1.3 KiB
Markdown
39 lines
1.3 KiB
Markdown
10 years ago
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## Smoothstep
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Perform Hermite interpolation between two values
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### Declaration
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```glsl
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float smoothstep(float edge0, float edge1, float x)
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vec2 smoothstep(vec2 edge0, vec2 edge1, vec2 x)
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vec3 smoothstep(vec3 edge0, vec3 edge1, vec3 x)
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vec4 smoothstep(vec4 edge0, vec4 edge1, vec4 x)
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vec2 smoothstep(float edge0, float edge1, vec2 x)
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vec3 smoothstep(float edge0, float edge1, vec3 x)
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vec4 smoothstep(float edge0, float edge1, vec4 x)
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```
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### Parameters
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```edge0``` specifies the value of the lower edge of the Hermite function.
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```edge1``` specifies the value of the upper edge of the Hermite function.
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```x``` specifies the source value for interpolation.
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### Description
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```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:
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```glsl
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genType t; /* Or genDType t; */
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t = clamp((x - edge0) / (edge1 - edge0), 0.0, 1.0);
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return t * t * (3.0 - 2.0 * t);
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```
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Results are undefined ```if edge0 ≥ edge1```.
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<div class="simpleFunction" data="y = smoothstep(0.0,1.0,x); "></div>
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<div class="codeAndCanvas" data="../05/smoothstep.frag"></div>
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### See Also
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9 years ago
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[mix](/glossary/?search=mix), [step](/glossary/?search=step), [Chapter 05: Shaping Functions](/05/)
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