r_hasher.h

/* Copyright (c) 2021 Hans-Kristian Arntzen
 *
 * Permission is hereby granted, free of charge, to any person obtaining
 * a copy of this software and associated documentation files (the
 * "Software"), to deal in the Software without restriction, including
 * without limitation the rights to use, copy, modify, merge, publish,
 * distribute, sublicense, and/or sell copies of the Software, and to
 * permit persons to whom the Software is furnished to do so, subject to
 * the following conditions:
 *
 * The above copyright notice and this permission notice shall be
 * included in all copies or substantial portions of the Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
 * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
 * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.
 * IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY
 * CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT,
 * TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE
 * SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
 */
#ifndef R_HASHER_H
#define R_HASHER_H

#include "../gameshared/q_arch.h"

typedef uint64_t hash_t;
static hash_t const HASH_INITIAL_VALUE = 0xcbf29ce484222325ull;

static inline hash_t hash_u32( hash_t hash, uint32_t value )
{
	return ( hash * 0x100000001b3ull ) ^ value;
}

static inline hash_t hash_s32( hash_t hash, int32_t value )
{
	return hash_u32( hash, value );
}

static inline hash_t hash_u64( hash_t hash, uint64_t value )
{
	hash = hash_u32( hash, value & 0xffffffffu );
	hash = hash_u32( hash, value >> 32 );
	return hash;
}

static inline hash_t hash_f32( hash_t hash, float value )
{
	union {
		float f32;
		uint32_t u32;
	} u;
	u.f32 = value;
	return hash_u32( hash, u.u32 );
}

static inline hash_t hash_data( hash_t hash, const void *data, size_t size )
{
	for( size_t i = 0; i < size; i++ )
		hash = ( hash * 0x100000001b3ull ) ^ ( (uint8_t *)data )[i];
	return hash;
}

// inline void string( const std::string &str )
//{
//	u32( 0xff );
//	for( auto &c : str )
//		u32( uint8_t( c ) );
// }

#endif