vec_step

Takes a built-in scalar or vector data type argument and returns an integer value representing the number of elements in the scalar or vector.

 ``` int vec_step (``` gentypen a`)`
 ``` int vec_step (``` char3 a`)`
 ``` int vec_step (``` uchar3 a`)`
 ``` int vec_step (``` short3 a`)`
 ``` int vec_step (``` ushort3 a`)`
 ``` int vec_step (``` half3 a`)`
 ``` int vec_step (``` int3 a`)`
 ``` int vec_step (``` uint3 a`)`
 ``` int vec_step (``` long3 a`)`
 ``` int vec_step (``` ulong3 a`)`
 ``` int vec_step (``` float3 a`)`
 ``` int vec_step (``` double3 a`)`
 ``` int vec_step (``` type`)`

Description

The `vec_step` built-in function takes a built-in scalar or vector data type argument and returns an integer value representing the number of elements in the scalar or vector.

For all scalar types, `vec_step` returns 1.

The `vec_step` built-in functions that take a 3-component vector return 4.

`vec_step` may also take a pure type as an argument, e.g. `vec_step`(float2)

We use the generic type name gentype`n` (or gentype`m`) to indicate the built-in data types char{2|4|8|16}, uchar{2|4|8|16}, short{2|4|8|16}, ushort{2|4|8|16}, int{2|4|8|16}, uint{2|4|8|16}, long{2|4|8|16}, ulong{2|4|8|16}, or float{2|4|8|16} as the type for the arguments unless otherwise stated. We use the generic name ugentype`n` to indicate the built-in unsigned integer data types.

The generic type name gentype`n` (or gentype`m`) may indicate the data type half{2|4|8|16} if the cl_khr_fp16 extension is supported, and may indicate the data type double{2|4|8|16} if the cl_khr_fp64 extension is supported.

Example

 uint4 mask = (uint4)(3, 2, 1, 0); float4 a; float4 r = shuffle(a, mask); // r.s0123 = a.wzyx uint8 mask = (uint8)(0, 1, 2, 3, 4, 5, 6, 7); float4 a, b; float8 r = shuffle2(a, b, mask); // r.s0123 = a.xyzw // r.s4567 = b.xyzw uint4 mask; float8 a; float4 b; b = shuffle(a, mask);

Also see

Copyright © 2007-2010 The Khronos Group Inc. Permission is hereby granted, free of charge, to any person obtaining a copy of this software and/or associated documentation files (the "Materials"), to deal in the Materials without restriction, including without limitation the rights to use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the Materials, and to permit persons to whom the Materials are furnished to do so, subject to the condition that this copyright notice and permission notice shall be included in all copies or substantial portions of the Materials.