/******************************************************************************
	libx42 - skinned vertex animation library
	Copyright (C) 2007 HermitWorks Entertainment Corporation

	This program is free software; you can redistribute it and/or modify it
	under the terms of the GNU General Public License as published by the Free
	Software Foundation; either version 2 of the License, or (at your option)
	any later version.

	This program is distributed in the hope that it will be useful, but
	WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
	or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
	for more details.

	You should have received a copy of the GNU General Public License along
	with this program; if not, write to the
	
		Free Software Foundation, Inc.
		51 Franklin Street, Fifth Floor
		Boston, MA  02110-1301, USA.
******************************************************************************/

#include "local.h"

#ifndef LIBX42_MINIMIZE_CRT

#include <malloc.h>

typedef struct tmpMemInt_t
{
	byte		*pBase;
	byte		*pCurr;
	byte		*pTop;
} tmpMemInt_t;

void* X42_CALL tmpMem_alloc( size_t cb, void *baton )
{
	byte *ret;
	tmpMemInt_t *tmpi = (tmpMemInt_t*)baton;

	cb = align( cb, sizeof( byte* ) );
	
#ifdef DEBUG
	cb += sizeof( byte* );
#endif

	if( tmpi->pCurr + cb >= tmpi->pTop )
		return NULL;

	ret = tmpi->pCurr;
	tmpi->pCurr += cb;

#ifdef DEBUG
	*(byte**)(tmpi->pCurr - sizeof( byte* )) = ret;
#endif

	return ret;
}

void X42_CALL tmpMem_free( void *p, void *baton )
{
	tmpMemInt_t *tmpi = (tmpMemInt_t*)baton;

	if( !p )
		return;

#ifdef DEBUG
	assert( *(byte**)(tmpi->pCurr - sizeof( byte* )) == (byte*)p,
		X42_ERR_BADPTR, "Mismatched alloc/free pair." );
#endif

	tmpi->pCurr = (byte*)p;
}

//create a temp memory allocator, set max_size to zero for the default (512K)
X42_EXPORT x42tempMem_t* X42_CALL x42_CreateTempMem( size_t max_size )
{
	size_t mem_size;
	
	x42tempMem_t *ret;
	tmpMemInt_t *tmpi;

	if( !max_size )
		max_size = 512 * 1024;

	mem_size = sizeof( x42tempMem_t ) + sizeof( tmpMemInt_t ) + max_size;	

	ret = (x42tempMem_t*)malloc( mem_size );
	demand_rn( ret != NULL, X42_ERR_OUTOFMEMORY, "can't allocate on the heap" );

	tmpi = (tmpMemInt_t*)(ret + 1);

	tmpi->pBase = (byte*)(tmpi + 1);
	tmpi->pCurr = tmpi->pBase;
	tmpi->pTop = tmpi->pBase + mem_size; 

	ret->alloc = tmpMem_alloc;
	ret->free = tmpMem_free;
	ret->baton = (void*)tmpi;

	return ret;
}

X42_EXPORT void X42_CALL x42_FreeTempMem( x42tempMem_t *mem )
{
	free( mem );
}

#else

#ifdef _MSC_VER
#pragma warning( disable : 4206 ) //nonstandard extension: empty tanslation unit
#endif

#endif