diff options
Diffstat (limited to 'Drivers/CMSIS/DSP/Source/FastMathFunctions/arm_atan2_q15.c')
| -rw-r--r-- | Drivers/CMSIS/DSP/Source/FastMathFunctions/arm_atan2_q15.c | 201 |
1 files changed, 201 insertions, 0 deletions
diff --git a/Drivers/CMSIS/DSP/Source/FastMathFunctions/arm_atan2_q15.c b/Drivers/CMSIS/DSP/Source/FastMathFunctions/arm_atan2_q15.c new file mode 100644 index 0000000..ddf98d8 --- /dev/null +++ b/Drivers/CMSIS/DSP/Source/FastMathFunctions/arm_atan2_q15.c @@ -0,0 +1,201 @@ +/* ---------------------------------------------------------------------- + * Project: CMSIS DSP Library + * Title: arm_atan2_q15.c + * Description: float32 Arc tangent of y/x + * + * $Date: 22 April 2022 + * $Revision: V1.10.0 + * + * Target Processor: Cortex-M and Cortex-A cores + * -------------------------------------------------------------------- */ +/* + * Copyright (C) 2010-2022 ARM Limited or its affiliates. All rights reserved. + * + * SPDX-License-Identifier: Apache-2.0 + * + * Licensed under the Apache License, Version 2.0 (the License); you may + * not use this file except in compliance with the License. + * You may obtain a copy of the License at + * + * www.apache.org/licenses/LICENSE-2.0 + * + * Unless required by applicable law or agreed to in writing, software + * distributed under the License is distributed on an AS IS BASIS, WITHOUT + * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. + * See the License for the specific language governing permissions and + * limitations under the License. + */ + +#include "dsp/fast_math_functions.h" +#include "dsp/utils.h" + +/* + +atan for argument between in [0, 1.0] + +*/ + + +/* Q2.13 */ +#define ATANHALFQ13 0xed6 +#define PIHALFQ13 0x3244 +#define PIQ13 0x6488 + +#define ATAN2_NB_COEFS_Q15 10 + +static const q15_t atan2_coefs_q15[ATAN2_NB_COEFS_Q15]={0x0000 +,0x7fff +,0xffff +,0xd567 +,0xff70 +,0x1bad +,0xfd58 +,0xe9a9 +,0x1129 +,0xfbdb +}; + +__STATIC_FORCEINLINE q15_t arm_atan_limited_q15(q15_t x) +{ + q31_t res=(q31_t)atan2_coefs_q15[ATAN2_NB_COEFS_Q15-1]; + int i=1; + for(i=1;i<ATAN2_NB_COEFS_Q15;i++) + { + res = ((q31_t) x * res) >> 15U; + res = res + ((q31_t) atan2_coefs_q15[ATAN2_NB_COEFS_Q15-1-i]) ; + } + + res = __SSAT(res>>2,16); + + + return(res); +} + + +__STATIC_FORCEINLINE q15_t arm_atan_q15(q15_t y,q15_t x) +{ + int sign=0; + q15_t res=0; + + if (y<0) + { + arm_negate_q15(&y,&y,1); + sign=1-sign; + } + + if (x < 0) + { + sign=1 - sign; + arm_negate_q15(&x,&x,1); + } + + if (y > x) + { + q15_t ratio; + int16_t shift; + + arm_divide_q15(x,y,&ratio,&shift); + + arm_shift_q15(&ratio,shift,&ratio,1); + + res = PIHALFQ13 - arm_atan_limited_q15(ratio); + + } + else + { + q15_t ratio; + int16_t shift; + + arm_divide_q15(y,x,&ratio,&shift); + + arm_shift_q15(&ratio,shift,&ratio,1); + + res = arm_atan_limited_q15(ratio); + + } + + + if (sign) + { + arm_negate_q15(&res,&res,1); + } + + return(res); +} + + +/** + @ingroup groupFastMath + */ + + +/** + @addtogroup atan2 + @{ + */ + +/** + @brief Arc Tangent of y/x using sign of y and x to get right quadrant + @param[in] y y coordinate + @param[in] x x coordinate + @param[out] result Result in Q2.13 + @return error status. + + @par Compute the Arc tangent of y/x: + The sign of y and x are used to determine the right quadrant + and compute the right angle. +*/ + + +arm_status arm_atan2_q15(q15_t y,q15_t x,q15_t *result) +{ + if (x > 0) + { + *result=arm_atan_q15(y,x); + return(ARM_MATH_SUCCESS); + } + if (x < 0) + { + if (y > 0) + { + *result=arm_atan_q15(y,x) + PIQ13; + } + else if (y < 0) + { + *result=arm_atan_q15(y,x) - PIQ13; + } + else + { + if (y<0) + { + *result= -PIQ13; + } + else + { + *result= PIQ13; + } + } + return(ARM_MATH_SUCCESS); + } + if (x == 0) + { + if (y > 0) + { + *result=PIHALFQ13; + return(ARM_MATH_SUCCESS); + } + if (y < 0) + { + *result=-PIHALFQ13; + return(ARM_MATH_SUCCESS); + } + } + + + return(ARM_MATH_NANINF); + +} + +/** + @} end of atan2 group + */ |