fast_normalize
fast_normalize
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3
fast_normalize Normal vector length 1.

##

floatn `fast_normalize` floatn p

## Description

Returns a vector in the same direction as `p` but with a length of 1. `fast_normalize` is computed as:

              p * half_sqrt(p.x2 + p.y2 +...)

The result shall be within 8192 ulps error from the infinitely precise result of:

              if ( all(p == 0.0f))
                        result = p;
              else
                        result = p /  sqrt(p.x2 + p.y2 +...);

with the following exceptions:

1. If the sum of squares is greater than `FLT_MAX` then the value of the floating-point values in the result vector are undefined.

2. If the sum of squares is less than `FLT_MIN` then the implementation may return back `p`.

3. If the device is in 'denorms are flushed to zero' mode, individual operand elements with magnitude less than sqrt(`FLT_MIN`) may be flushed to zero before proceeding with the calculation.

## Notes

&geometricFunctionsInc;

## Specification

OpenCL Specification

## Also see

Geometric Functions

##