HandmadeHero/project/platform/intrinsics.hpp

#pragma once

#if INTELLISENSE_DIRECTIVES
#include <math.h>
#include "grime.hpp"
#endif

// TODO(Ed) : Convert all of these to platform-efficient versions

//inline
//s32 abs( s32 value )
//{
//	return ;
//}

inline
s32 floor( f32 value )
{
	s32 result = scast(s32, floorf( value ));
	return result;
}

inline
s32 round( f32 value )
{
	s32 result = scast(s32, roundf( value ));
	return result;
}

inline
s32 truncate( f32 value )
{
	s32 result = scast(s32, value);
	return result;
}

inline
f32 sine( f32 angle )
{
	f32 result = sinf( angle );
	return result;
}

inline
f32 cosine( f32 angle )
{
	f32 result = cosf( angle );
	return result;
}

inline
f32 arc_tangent( f32 Y, f32 X )
{
	f32 result = atan2f( Y, X );
	return result;
}

inline
b32 bitscan_forward( u32* index, u32 value )
{
	b32 found = false;

	// TODO(Ed) : This file can technically be generated with a metaprogram or via the preprocessor..
	// We can keep The definitions for each of these based on the platform and
	// Choose which one gets added to te project that way (keeps the runtime definition clean)
#if Compiler_MSVC
	found = _BitScanForward( rcast(unsigned long*, index), value );
#elif Compiler_Clang
	*index = __builtin_ctz( value );
	found  = index;
#else
	for ( u32 test = 0; test < 32; ++ test )
	{
		if ( value & (1 << test ))
		{
			*index = test;
			found = true;
			break;
		}
	}
#endif
	return found;
}