foxmath.c

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/**
 *
 * @copyright © 2010 - 2021, Fraunhofer-Gesellschaft zur Foerderung der angewandten Forschung e.V.
 * All rights reserved.
 *
 * SPDX-License-Identifier: BSD-3-Clause
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/**
 * @file    foxmath.c
 * @author  foxBMS Team
 * @date    2018-01-18 (date of creation)
 * @updated 2021-08-06 (date of last update)
 * @ingroup DRIVERS
 * @prefix  MATH
 *
 * @brief   mathlib function implementations
 *
 */
 
/*========== Includes =======================================================*/
#include "foxmath.h"
 
/*========== Macros and Definitions =========================================*/
/** shift one byte (8 positions) */
#define SHIFT_ONE_BYTE (8u)
 
/** shift two bytes (16 positions) */
#define SHIFT_TWO_BYTES (16u)
 
/** shift four bytes (32 positions) */
#define SHIFT_FOUR_BYTES (32u)
 
/*========== Static Constant and Variable Definitions =======================*/
 
/*========== Extern Constant and Variable Definitions =======================*/
 
/*========== Static Function Prototypes =====================================*/
 
/*========== Static Function Implementations ================================*/
 
/*========== Extern Function Implementations ================================*/
 
/* AXIVION Disable Style Generic-MissingParameterAssert: If not specified otherwise, functions in this lib are designed to take full range input. No assert needed. */
 
extern void MATH_StartupSelfTest(void) {
    FAS_ASSERT(MATH_AbsInt64_t(INT64_MIN) == INT64_MAX);
    FAS_ASSERT(MATH_AbsInt32_t(INT32_MIN) == INT32_MAX);
}
 
extern float MATH_LinearInterpolation(
    const float x1,
    const float y1,
    const float x2,
    const float y2,
    const float x_interpolate) {
    float slope = 0.0f;
 
    if (fabsf(x1 - x2) >= FLT_EPSILON) {
        /* Calculate slope */
        slope = (y2 - y1) / (x2 - x1);
    }
    /* In the case that the if clause is not entered (x values are identical)
     * -> no interpolation possible: return y1 value
     * -> slope takes initialization value of 0.0f
     */
 
    /* Interpolate starting from x1/y1 */
    float y_interpolate = y1 + (slope * (x_interpolate - x1));
 
    return y_interpolate;
}
 
extern uint16_t MATH_SwapBytesUint16_t(const uint16_t val) {
    return (val << SHIFT_ONE_BYTE) | (val >> SHIFT_ONE_BYTE);
}
 
extern uint32_t MATH_SwapBytesUint32_t(const uint32_t val) {
    const uint32_t alternating2PatternStartFF = 0xFF00FF00u;
    const uint32_t alternating2PatternStart00 = 0x00FF00FFu;
    const uint32_t intermediate               = ((val << SHIFT_ONE_BYTE) & alternating2PatternStartFF) |
                                  ((val >> SHIFT_ONE_BYTE) & alternating2PatternStart00);
    return (intermediate << SHIFT_TWO_BYTES) | (intermediate >> SHIFT_TWO_BYTES);
}
 
extern uint64_t MATH_SwapBytesUint64_t(const uint64_t val) {
    const uint64_t alternating2PatternStartFF   = 0xFF00FF00FF00FF00uLL;
    const uint64_t alternating2PatternStart00   = 0x00FF00FF00FF00FFuLL;
    const uint64_t alternating4PatternStartFFFF = 0xFFFF0000FFFF0000uLL;
    const uint64_t alternating4PatternStart0000 = 0x0000FFFF0000FFFFuLL;
 
    uint64_t intermediate = ((val << SHIFT_ONE_BYTE) & alternating2PatternStartFF) |
                            ((val >> SHIFT_ONE_BYTE) & alternating2PatternStart00);
    intermediate = ((intermediate << SHIFT_TWO_BYTES) & alternating4PatternStartFFFF) |
                   ((intermediate >> SHIFT_TWO_BYTES) & alternating4PatternStart0000);
    return (intermediate << SHIFT_FOUR_BYTES) | (intermediate >> SHIFT_FOUR_BYTES);
}
 
extern float MATH_MinimumOfTwoFloats(const float value1, const float value2) {
    return fminf(value1, value2);
}
 
extern uint8_t MATH_MinimumOfTwoUint8_t(const uint8_t value1, const uint8_t value2) {
    uint8_t returnvalue = value1;
    if (returnvalue > value2) {
        returnvalue = value2;
    }
    return returnvalue;
}
 
extern uint16_t MATH_MinimumOfTwoUint16_t(const uint16_t value1, const uint16_t value2) {
    uint16_t returnvalue = value1;
    if (returnvalue > value2) {
        returnvalue = value2;
    }
    return returnvalue;
}
 
extern int32_t MATH_AbsInt32_t(const int32_t value) {
    int32_t absValue = INT32_MAX;
    if (value != INT32_MIN) {
        absValue = labs(value);
    }
    return absValue;
}
 
extern int64_t MATH_AbsInt64_t(const int64_t value) {
    int64_t absValue = INT64_MAX;
    if (value != INT64_MIN) {
        absValue = llabs(value);
    }
    return absValue;
}
 
/* AXIVION Enable Style Generic-MissingParameterAssert: */
 
/*========== Externalized Static Function Implementations (Unit Test) =======*/