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Diffstat (limited to 'Middlewares/Third_Party/ARM/ARM.CMSIS-DSP.1.17.1/Source/FastMathFunctions/arm_atan2_q15.c')
| -rwxr-xr-x | Middlewares/Third_Party/ARM/ARM.CMSIS-DSP.1.17.1/Source/FastMathFunctions/arm_atan2_q15.c | 232 |
1 files changed, 232 insertions, 0 deletions
diff --git a/Middlewares/Third_Party/ARM/ARM.CMSIS-DSP.1.17.1/Source/FastMathFunctions/arm_atan2_q15.c b/Middlewares/Third_Party/ARM/ARM.CMSIS-DSP.1.17.1/Source/FastMathFunctions/arm_atan2_q15.c new file mode 100755 index 0000000..c507f3d --- /dev/null +++ b/Middlewares/Third_Party/ARM/ARM.CMSIS-DSP.1.17.1/Source/FastMathFunctions/arm_atan2_q15.c @@ -0,0 +1,232 @@ +/* ---------------------------------------------------------------------- + * Project: CMSIS DSP Library + * Title: arm_atan2_q15.c + * Description: q15 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 "arm_compiler_specific.h" + + +#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]={ + 0, // 0x0000 + 32767, // 0x7fff + -1, // 0xffff +-10905, // 0xd567 + -144, // 0xff70 + 7085, // 0x1bad + -680, // 0xfd58 + -5719, // 0xe9a9 + 4393, // 0x1129 + -1061 // 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) + { + /* Negate y */ +#if defined (ARM_MATH_DSP) + y = __QSUB16(0, y); +#else + y = (y == (q15_t) 0x8000) ? (q15_t) 0x7fff : -y; +#endif + + sign=1-sign; + } + + if (x < 0) + { + sign=1 - sign; + + /* Negate x */ +#if defined (ARM_MATH_DSP) + x = __QSUB16(0, x); +#else + x = (x == (q15_t) 0x8000) ? (q15_t) 0x7fff : -x; +#endif + } + + if (y > x) + { + q15_t ratio; + int16_t shift; + + arm_divide_q15(x,y,&ratio,&shift); + + /* Shift ratio by shift */ + if (shift >=0) + { + ratio = __SSAT(((q31_t) ratio << shift), 16); + } + else + { + ratio = (ratio >> -shift); + } + + res = PIHALFQ13 - arm_atan_limited_q15(ratio); + + } + else + { + q15_t ratio; + int16_t shift; + + arm_divide_q15(y,x,&ratio,&shift); + + /* Shift ratio by shift */ + if (shift >=0) + { + ratio = __SSAT(((q31_t) ratio << shift), 16); + } + else + { + ratio = (ratio >> -shift); + } + + + res = arm_atan_limited_q15(ratio); + + } + + + if (sign) + { + /* Negate res */ +#if defined (ARM_MATH_DSP) + res = __QSUB16(0, res); +#else + res = (res == (q15_t) 0x8000) ? (q15_t) 0x7fff : -res; +#endif + } + + 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. Returned value is between -Pi and Pi. +*/ + + +ARM_DSP_ATTRIBUTE 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 + { + *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 + */ |