mirror of
https://github.com/autc04/Retro68.git
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95 lines
4.0 KiB
C
95 lines
4.0 KiB
C
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/* -------------------------------------------------------------- */
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/* (C)Copyright 2007,2008, */
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/* International Business Machines Corporation */
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/* All Rights Reserved. */
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/* */
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/* Redistribution and use in source and binary forms, with or */
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/* without modification, are permitted provided that the */
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/* following conditions are met: */
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/* */
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/* - Redistributions of source code must retain the above copyright*/
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/* notice, this list of conditions and the following disclaimer. */
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/* */
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/* - Redistributions in binary form must reproduce the above */
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/* copyright notice, this list of conditions and the following */
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/* disclaimer in the documentation and/or other materials */
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/* provided with the distribution. */
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/* */
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/* - Neither the name of IBM Corporation nor the names of its */
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/* contributors may be used to endorse or promote products */
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/* derived from this software without specific prior written */
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/* permission. */
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/* */
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/* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND */
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/* CONTRIBUTORS "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, */
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/* INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF */
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/* MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE */
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/* DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR */
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/* CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, */
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/* SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT */
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/* NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; */
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/* LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) */
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/* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN */
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/* CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR */
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/* OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, */
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/* EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. */
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/* -------------------------------------------------------------- */
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/* PROLOG END TAG zYx */
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#ifdef __SPU__
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#ifndef _ATAN2F4_H_
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#define _ATAN2F4_H_ 1
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#include <spu_intrinsics.h>
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#include "divf4.h"
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#include "atanf4.h"
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/*
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* FUNCTION
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* vector float _atan2f4(vector float y, vector float x)
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*
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* DESCRIPTION
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* The atan2f4 function returns a vector containing the angles
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* whose tangets are y/x for the corresponding elements of the
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* input vectors.
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*
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* The reason this function exists is to use the signs of the
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* arguments to determine the quadrant of the result. Consider
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* sin(x)/cos(x) on the domain (-pi, pi]. Four quadrants are
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* defined by the signs of sin and cos on this domain.
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*
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* Special Cases:
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* - If the corresponding elements of x and y are zero, the
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* resulting element is undefined.
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*
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*/
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static __inline vector float _atan2f4(vector float y, vector float x)
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{
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vector float pi = spu_splats((float)SM_PI);
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vector float zero = spu_splats(0.0f);
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vector unsigned int quad1;
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vector unsigned int quad4;
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vector float result;
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vector unsigned int xlt0;
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vector unsigned int yge0;
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vector unsigned int ylt0;
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xlt0 = (vec_uint4)spu_rlmaska((vec_int4)x, 31);
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ylt0 = (vec_uint4)spu_rlmaska((vec_int4)y, 31);
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yge0 = spu_cmpeq(ylt0, (vec_uint4)zero);
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quad1 = spu_and(ylt0, xlt0);
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quad4 = spu_and(yge0, xlt0);
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result = _atanf4(_divf4(y,x));
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result = spu_sel(result, spu_sub(result, pi), quad1);
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result = spu_sel(result, spu_add(result, pi), quad4);
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return result;
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}
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#endif /* _ATAN2F4_H_ */
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#endif /* __SPU__ */
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