94 lines
1.5 KiB
C
94 lines
1.5 KiB
C
//---
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// fixed: 16:16 fixed-point arithmetic
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//---
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#pragma once
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#include <stdint.h>
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typedef int32_t fixed_t;
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#include "util.h"
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/* Type of map coordinates */
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typedef fixed_t map_coord_t;
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/* Standard arithmetic. */
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static inline fixed_t fmul(fixed_t left, fixed_t right)
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{
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/* Generally optimized by the compiler to use dmuls.l and xtrct */
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int64_t p = (int64_t)left * (int64_t)right;
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return (int32_t)(p >> 16);
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}
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static inline fixed_t fdiv(fixed_t left, fixed_t right)
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{
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/* Pretty slow */
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int64_t d = (int64_t)left << 16;
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return d / right;
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}
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#define fix(x) ((int)((x) * 65536))
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static inline fixed_t fixdouble(double constant)
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{
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return (fixed_t)(constant * 65536);
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}
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static inline fixed_t fdec(fixed_t f)
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{
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return f & 0xffff;
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}
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static inline fixed_t fsqrt(fixed_t f)
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{
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return sqrtll((int64_t)f << 16);
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}
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static inline int ffloor(fixed_t f)
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{
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return f >> 16;
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}
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static inline int fceil(fixed_t f)
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{
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return (f + 0xffff) >> 16;
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}
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static inline int fround(fixed_t f)
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{
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return (f + 0x8000) >> 16;
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}
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static inline float f2float(fixed_t f)
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{
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return (float)f / 65536;
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}
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static inline double f2double(fixed_t f)
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{
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return (double)f / 65536;
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}
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static inline fixed_t feasein(fixed_t x)
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{
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return fmul(x, x);
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}
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static inline fixed_t fease(fixed_t x)
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{
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if(x <= fix(0.5)) {
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return 2 * fmul(x, x);
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}
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else {
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x = fix(1) - x;
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return fix(1) - 2 * fmul(x, x);
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}
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}
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static inline fixed_t fclamp(fixed_t x, fixed_t min, fixed_t max)
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{
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return (x <= min) ? min : (x >= max) ? max : x;
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}
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