/* ScummVM - Graphic Adventure Engine
 *
 * ScummVM is the legal property of its developers, whose names
 * are too numerous to list here. Please refer to the COPYRIGHT
 * file distributed with this source distribution.
 *
 * 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.
 *
 * $URL$
 * $Id$
 *
 */

#ifndef UTIL_H
#define UTIL_H

#include "common/scummsys.h"

/* An excercise in bloated macro writing ;-)*/

/*Declare a flexarray type*/
#define FLEXARRAY(type, extra) struct{\
	type* data;\
	int used, size, itemsize;\
	extra\
}

/* [DJ] Declare a flexarray type without extra fields - Visual C++ complains
** when the FLEXARRAY macro is used and extra parameter is not specified
*/
#define FLEXARRAY_NOEXTRA(type) struct{\
	type* data;\
	int used, size, itemsize;\
}

/*Initialize a flexarray*/
#define FLEXARRAY_INIT(type, array) do {(array).itemsize=sizeof(type); (array).size=0; (array).used=0;} while(0)

/*Prints an error message and returns (from the function using the macro)*/
#define FLEXARRAY_PANIC(message, errorcode) do{\
	fprintf message;\
	errorcode;\
} while(0)

/*Use if the state of the array is incnsistent*/
#define FLEXARRAY_PANIC_BADSTATE(array, errorcode) FLEXARRAY_PANIC((stderr, "PANIC: flexarray "#array" is in an inconsistent state (%d,%d).\n", (array).used, (array).size), errorcode)

/*Use if memory allocation fails*/
#define FLEXARRAY_PANIC_MEMORY(array, bytes, errorcode) FLEXARRAY_PANIC((stderr, "PANIC: Unable to allocate %d bytes for flexarray"#array"\n", bytes), errorcode)

/*Allocates an initial array*/
#define FLEXARRAY_ALLOCATE_INITIAL(type, array, errorcode) do{\
	(array).data= (type*)sci_malloc(4*(array).itemsize);\
	if((array).data==0) FLEXARRAY_PANIC_MEMORY(array, 4*(array).itemsize, errorcode);\
	(array).size=4;\
	(array).used=0;\
} while(0)

/*Doubles the size of the allocated area*/
#define FLEXARRAY_RESIZE(type, array, errorcode) do{\
	int size=(array).size*2*(array).itemsize;\
	(array).data= (type*)sci_realloc((array).data, size);\
	if((array).data==0) FLEXARRAY_PANIC_MEMORY(array, size, errorcode);\
	(array).size*=2;\
} while(0)

/*Appends /value/ at the end of the array, resizing as necessary*/
#define FLEXARRAY_APPEND(type, array, value, errorcode) do\
{\
	if((array).used>=(array).size)\
	{\
		if((array).size==0) FLEXARRAY_ALLOCATE_INITIAL(type, array, errorcode);\
		else {\
			if((array).used==(array).size) FLEXARRAY_RESIZE(type, array, errorcode);\
			else FLEXARRAY_PANIC_BADSTATE(array, errorcode);\
		}\
	}\
	(array).data[(array).used++]=(value);\
}while(0)

/*Adds space for a value at the end of the array, resizing as necessary, but
 *does not initialize the value*/
#define FLEXARRAY_ADD_SPACE(type, array, items, errorcode) do{\
	if((array).used+items>(array).size)\
	{\
		if((array).size==0) FLEXARRAY_ALLOCATE_INITIAL(type, array, errorcode);\
		else if((array).used==(array).size) FLEXARRAY_RESIZE(type, array, errorcode);\
		else FLEXARRAY_PANIC_BADSTATE(array, errorcode);\
	}\
	(array).used++;\
} while(0)

#endif