Cg 3.1 Toolkit Documentation Cg / Standard Library / exp

Name

exp - returns the base-e exponential of scalars and vectors

Synopsis

```float  exp(float a);
float1 exp(float1 a);
float2 exp(float2 a);
float3 exp(float3 a);
float4 exp(float4 a);

half   exp(half a);
half1  exp(half1 a);
half2  exp(half2 a);
half3  exp(half3 a);
half4  exp(half4 a);

fixed  exp(fixed a);
fixed1 exp(fixed1 a);
fixed2 exp(fixed2 a);
fixed3 exp(fixed3 a);
fixed4 exp(fixed4 a);
```

Parameters

a
Vector or scalar of which to determine the base-e exponential. The value e is approximately 2.71828182845904523536.

Description

Returns the base-e exponential a.

For vectors, the returned vector contains the base-e exponential of each element of the input vector.

Reference Implementation

```float3 exp(float3 a)
{
float3 rv;
int i;

for (i=0; i<3; i++) {
rv[i] = exp(a[i]);  // this is the ANSI C standard library exp()
}
return rv;
}
```

exp is typically implemented with either a native base-2 exponentional instruction or pow.

Profile Support

exp is fully supported in all profiles unless otherwise specified.

Support in the fp20 is limited to constant compile-time evaluation.