Rechercher une page de manuel

trunc.3Cg

Langue: en

Version: 354760 (ubuntu - 24/10/10)

Section: 3 (Bibliothèques de fonctions)

trunc - returns largest integer not greater than a scalar or each vector component.

   float  trunc(float x);
   float1 trunc(float1 x);
   float2 trunc(float2 x);
   float3 trunc(float3 x);
   float4 trunc(float4 x);

   half   trunc(half x);
   half1  trunc(half1 x);
   half2  trunc(half2 x);
   half3  trunc(half3 x);
   half4  trunc(half4 x);

   fixed  trunc(fixed x);
   fixed1 trunc(fixed1 x);
   fixed2 trunc(fixed2 x);
   fixed3 trunc(fixed3 x);
   fixed4 trunc(fixed4 x);

Returns the integral value nearest to but no larger in magnitude than x.

trunc for a float3 vector could be implemented like this.

   float3 trunc(float3 v)
   {
     float3 rv;
     int i;

     for (i=0; i<3; i++) {
       float x = v[i];

       rv[i] = x < 0 ? -floor(-x) : floor(x);
     }
     return rv;
   }

trunc is supported in all profiles except fp20.