forked from Mirror/GodMode9
1b04ca4fa1
- added very simple 12-bit precision fixed point arithmetic code as a fast float replacement
38 lines
889 B
C
Executable File
38 lines
889 B
C
Executable File
#pragma once
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// Fixed point math operations
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#include <types.h>
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#include <limits.h>
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typedef int32_t fixp_t;
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// 12 bit precision was chosen because
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// that's the touchscreen's ADC resolution
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#define FIXP_PRECISION (12)
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#define INT_TO_FIXP(i) ((fixp_t)((i) * (1 << FIXP_PRECISION)))
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#define FIXP_TO_INT(f) ((fixp_t)((f) / (1 << FIXP_PRECISION)))
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#define FIXP_WHOLE_UNIT INT_TO_FIXP(1)
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#define FIXP_HALF_UNIT (FIXP_WHOLE_UNIT / 2)
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#define FIXP_ZERO_UNIT (0)
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#define FIXP_FRAC_MASK (FIXP_WHOLE_UNIT - 1)
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#define FIXP_UNIT_MASK (~0 & ~FIXP_FRAC_MASK)
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static inline fixp_t fixp_product(fixp_t a, fixp_t b)
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{
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return (((s64)a * (s64)b) >> FIXP_PRECISION);
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}
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static inline fixp_t fixp_quotient(fixp_t a, fixp_t b)
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{
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return ((s64)a << FIXP_PRECISION) / b;
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}
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static inline fixp_t fixp_round(fixp_t n)
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{
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return (n + FIXP_HALF_UNIT) & FIXP_UNIT_MASK;
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}
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