77 lines
1.5 KiB
C
77 lines
1.5 KiB
C
#ifndef HANDMADE_INTRINSICS_H_SENTRY
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#define HANDMADE_INTRINSICS_H_SENTRY
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/* TODO: Re-implement these functions so we do not have to rely on
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math.h. */
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#include <math.h>
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#include <string.h> // memset
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S32 RoundF32toS32(F32 Real32)
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{
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S32 Result = (S32)roundf(Real32);
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return Result;
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}
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S32 FloorF32toS32(F32 Real32)
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{
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S32 Result = (S32)floorf(Real32);
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return Result;
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}
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F32 Sin(F32 Angle)
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{
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F32 Result = sinf(Angle);
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return Result;
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}
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F32 Cos(F32 Angle)
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{
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F32 Result = cosf(Angle);
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return Result;
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}
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F32 ATan2(F32 Y, F32 X)
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{
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F32 Result = atan2f(Y, X);
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return Result;
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}
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typedef struct bit_scan_result {
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B32 Found;
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U32 Index;
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} bit_scan_result;
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static bit_scan_result FindLeastSignificantSetBit(U32 Value)
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{
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bit_scan_result Result;
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memset(&Result, 0, sizeof(Result));
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#if COMPILER_MSVC
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unsigned long Index;
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Result.Found = _BitScanForward(&Index, Value);
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Result.Index = (U32)Index;
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#elif COMPILER_CLANG
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Result.Index = __builtin_ffsll(Value); // NOTE: It is a GCC function, but is supported by clang compiler.
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// https://gcc.gnu.org/onlinedocs/gcc/Bit-Operation-Builtins.html
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if(Result.Index) {
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Result.Found = TRUE;
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if(Result.Index > 0)
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Result.Index--;
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}
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#else
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for(U32 Test = 0; Test < 32; Test++) {
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if(Value & (1 << Test)) {
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Result.Index = Test;
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Result.Found = TRUE;
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break;
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}
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}
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#endif
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return Result;
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}
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#endif
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