/* ----------------------------------------------------------------------
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* Copyright (C) 2010-2014 ARM Limited. All rights reserved.
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*
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* $Date: 19. March 2015
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* $Revision: V.1.4.5
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*
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* Project: CMSIS DSP Library
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* Title: arm_sin_cos_q31.c
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*
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* Description: Cosine & Sine calculation for Q31 values.
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*
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* Target Processor: Cortex-M4/Cortex-M3/Cortex-M0
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*
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* Redistribution and use in source and binary forms, with or without
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* modification, are permitted provided that the following conditions
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* are met:
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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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* - Redistributions in binary form must reproduce the above copyright
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* notice, this list of conditions and the following disclaimer in
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* the documentation and/or other materials provided with the
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* distribution.
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* - Neither the name of ARM LIMITED nor the names of its contributors
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* may be used to endorse or promote products derived from this
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* software without specific prior written permission.
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*
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* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
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* "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
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* LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
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* FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
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* COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
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* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
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* BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
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* LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
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* CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
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* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
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* ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
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* POSSIBILITY OF SUCH DAMAGE.
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* -------------------------------------------------------------------- */
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#include "arm_math.h"
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#include "arm_common_tables.h"
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/**
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* @ingroup groupController
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*/
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/**
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* @addtogroup SinCos
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* @{
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*/
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/**
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* @brief Q31 sin_cos function.
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* @param[in] theta scaled input value in degrees
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* @param[out] *pSinVal points to the processed sine output.
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* @param[out] *pCosVal points to the processed cosine output.
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* @return none.
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*
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* The Q31 input value is in the range [-1 0.999999] and is mapped to a degree value in the range [-180 179].
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*
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*/
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void arm_sin_cos_q31(
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q31_t theta,
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q31_t * pSinVal,
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q31_t * pCosVal)
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{
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q31_t fract; /* Temporary variables for input, output */
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uint16_t indexS, indexC; /* Index variable */
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q31_t f1, f2, d1, d2; /* Two nearest output values */
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q31_t Dn, Df;
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q63_t temp;
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/* Calculate the nearest index */
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indexS = (uint32_t)theta >> CONTROLLER_Q31_SHIFT;
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indexC = (indexS + 128) & 0x1ff;
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/* Calculation of fractional value */
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fract = (theta - (indexS << CONTROLLER_Q31_SHIFT)) << 8;
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/* Read two nearest values of input value from the cos & sin tables */
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f1 = sinTable_q31[indexC+0];
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f2 = sinTable_q31[indexC+1];
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d1 = -sinTable_q31[indexS+0];
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d2 = -sinTable_q31[indexS+1];
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Dn = 0x1921FB5; // delta between the two points (fixed), in this case 2*pi/FAST_MATH_TABLE_SIZE
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Df = f2 - f1; // delta between the values of the functions
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temp = Dn*((q63_t)d1 + d2);
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temp = temp - ((q63_t)Df << 32);
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temp = (q63_t)fract*(temp >> 31);
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temp = temp + ((3*(q63_t)Df << 31) - (d2 + ((q63_t)d1 << 1))*Dn);
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temp = (q63_t)fract*(temp >> 31);
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temp = temp + (q63_t)d1*Dn;
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temp = (q63_t)fract*(temp >> 31);
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/* Calculation of cosine value */
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*pCosVal = clip_q63_to_q31((temp >> 31) + (q63_t)f1);
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/* Read two nearest values of input value from the cos & sin tables */
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f1 = sinTable_q31[indexS+0];
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f2 = sinTable_q31[indexS+1];
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d1 = sinTable_q31[indexC+0];
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d2 = sinTable_q31[indexC+1];
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Df = f2 - f1; // delta between the values of the functions
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temp = Dn*((q63_t)d1 + d2);
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temp = temp - ((q63_t)Df << 32);
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temp = (q63_t)fract*(temp >> 31);
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temp = temp + ((3*(q63_t)Df << 31) - (d2 + ((q63_t)d1 << 1))*Dn);
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temp = (q63_t)fract*(temp >> 31);
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temp = temp + (q63_t)d1*Dn;
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temp = (q63_t)fract*(temp >> 31);
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/* Calculation of sine value */
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*pSinVal = clip_q63_to_q31((temp >> 31) + (q63_t)f1);
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}
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/**
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* @} end of SinCos group
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*/
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