Provided by: opencl-1.2-man-doc_1.0~svn22836-1.1_all

**NAME**

fast_normalize - Normal vector length 1.floatnfast_normalize(floatnp);

**DESCRIPTION**

Returns a vector in the same direction aspbut with a length of 1.fast_normalizeis 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; elseresult=p/sqrt(3clc)(p.x2 +p.y2 +...); with the following exceptions: 1. If the sum of squares is greater thanFLT_MAXthen the value of the floating-point values in the result vector are undefined. 2. If the sum of squares is less thanFLT_MINthen the implementation may return backp. 3. If the device is in 'denorms are flushed to zero' mode, individual operand elements with magnitude less thansqrt(3clc)(FLT_MIN) may be flushed to zero before proceeding with the calculation.

**NOTES**

Built-in geometric functions operate component-wise. The description is per-component.floatnisfloat,float2,float3, orfloat4anddoublenisdouble,double2,double3, ordouble4. The built-in geometric functions are implemented using the round to nearest even rounding mode. The geometric functions can be implemented using contractions such asmad(3clc) orfma(3clc).

**SPECIFICATION**

OpenCLSpecification[1]

**SEE** **ALSO**

geometricFunctions(3clc)

**AUTHORS**

TheKhronosGroup

**COPYRIGHT**

Copyright © 2007-2011 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.

**NOTES**

1. OpenCL Specification page 262, section 6.12.5 - Geometric Functions