table of contents
fast_normalize - Normal vector length 1.
floatn fast_normalize(floatn p);
Returns a vector in the same direction as p but with a length of 1. fast_normalize is computed as:
p * sqrt(3clc)(p.x2 + p.y2 +...)
The result shall be within 8192 ulps error from the infinitely precise result of:
if ( any(3clc)(p == 0.0f)) result = p; else result = p / sqrt(3clc)(p.x2 + p.y2 +...);
with the following exceptions:
Built-in geometric functions operate component-wise. The description is per-component. floatn is float, float2, float3, or float4 and doublen is double, double2, double3, or double4. The built-in geometric functions are implemented using the round to nearest even rounding mode.
The geometric functions can be implemented using contractions such as mad(3clc) or fma(3clc).
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- OpenCL Specification
|01/14/2021||The Khronos Group|