54 lines
2.1 KiB
C
54 lines
2.1 KiB
C
#pragma once
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#include <stdint.h>
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/*
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* Generic fixed-point helpers.
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*
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* Example for Q4.12 using int16_t:
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* typedef int16_t q4_12_t;
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* #define Q4_12_FRAC_BITS 12
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* q4_12_t a = FIXED_FROM_INT(3, Q4_12_FRAC_BITS);
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* q4_12_t b = FIXED_FROM_RATIO_T(int16_t, 1, 2, Q4_12_FRAC_BITS);
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* q4_12_t c = FIXED_MUL_T(int16_t, a, b, Q4_12_FRAC_BITS);
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*
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* Example for Q16.16 using int32_t:
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* typedef int32_t q16_16_t;
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* #define Q16_16_FRAC_BITS 16
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*/
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#define FIXED_ONE(frac_bits) ((int32_t)1 << (frac_bits))
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#define FIXED_HALF(frac_bits) (FIXED_ONE(frac_bits) >> 1)
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#define FIXED_FRACTION_MASK(frac_bits) (FIXED_ONE(frac_bits) - 1)
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#define FIXED_FROM_INT(value, frac_bits) ((value) << (frac_bits))
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#define FIXED_TO_INT(value, frac_bits) ((value) >> (frac_bits))
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#define FIXED_FRACTION(value, frac_bits) ((value) & FIXED_FRACTION_MASK(frac_bits))
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#define FIXED_ABS(value) ((value) < 0 ? -(value) : (value))
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#define FIXED_MIN(a, b) ((a) < (b) ? (a) : (b))
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#define FIXED_MAX(a, b) ((a) > (b) ? (a) : (b))
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#define FIXED_CLAMP(value, min_value, max_value) \
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((value) < (min_value) ? (min_value) : ((value) > (max_value) ? (max_value) : (value)))
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#define FIXED_MUL(a, b, frac_bits) \
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((int32_t)(((int64_t)(a) * (int64_t)(b)) >> (frac_bits)))
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#define FIXED_DIV(numerator, denominator, frac_bits) \
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((denominator) == 0 ? 0 : (int32_t)(((int64_t)(numerator) << (frac_bits)) / (denominator)))
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#define FIXED_FROM_RATIO(numerator, denominator, frac_bits) \
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((denominator) == 0 ? 0 : (int32_t)(((int64_t)(numerator) << (frac_bits)) / (denominator)))
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#define FIXED_LERP(a, b, t, frac_bits) \
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((a) + FIXED_MUL((b) - (a), (t), (frac_bits)))
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#define FIXED_MUL_T(type, a, b, frac_bits) \
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((type)(((int64_t)(a) * (int64_t)(b)) >> (frac_bits)))
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#define FIXED_DIV_T(type, numerator, denominator, frac_bits) \
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((denominator) == 0 ? (type)0 : (type)(((int64_t)(numerator) << (frac_bits)) / (denominator)))
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#define FIXED_FROM_RATIO_T(type, numerator, denominator, frac_bits) \
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((denominator) == 0 ? (type)0 : (type)(((int64_t)(numerator) << (frac_bits)) / (denominator)))
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