/* 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.
 *
 * Data structures used for handling backgrounds
 */

#ifndef TINSEL_BACKGND_H     // prevent multiple includes
#define TINSEL_BACKGND_H

#include "common/coroutines.h"
#include "common/frac.h"
#include "common/rect.h"
#include "tinsel/dw.h"	// for SCNHANDLE
#include "tinsel/palette.h"	// palette definitions

namespace Tinsel {

struct OBJECT;


/** Scrolling padding. Needed because scroll process does not normally run on every frame */
enum {
	SCROLLX_PAD	= 64,
	SCROLLY_PAD	= 64
};

/** When module BLK_INFO list is this long, switch from a binary to linear search */
#define	LINEAR_SEARCH	5

/** background playfield structure - a playfield is a container for modules */
struct PLAYFIELD {
	OBJECT *pDispList;	///< object display list for this playfield
	frac_t fieldX;		///< current world x position of playfield
	frac_t fieldY;		///< current world y position of playfield
	frac_t fieldXvel;	///< current x velocity of playfield
	frac_t fieldYvel;	///< current y velocity of playfield
	Common::Rect rcClip;	///< clip rectangle for this playfield
	bool bMoved;		///< set when playfield has moved
};

/** multi-playfield background structure - a backgnd is a container of playfields */
struct BACKGND {
	COLORREF rgbSkyColor;	///< background sky color
	Common::Point ptInitWorld;		///< initial world position
	Common::Rect rcScrollLimits;	///< scroll limits
	int refreshRate;		///< background update process refresh rate
	frac_t *pXscrollTable;	///< pointer to x direction scroll table for this background
	frac_t *pYscrollTable;	///< pointer to y direction scroll table for this background
	int numPlayfields;		///< number of playfields for this background
	PLAYFIELD *fieldArray;	///< pointer to array of all playfields for this background
	bool bAutoErase;		///< when set - screen is cleared before anything is plotted (unused)
};


/*----------------------------------------------------------------------*\
|*			Background Function Prototypes			*|
\*----------------------------------------------------------------------*/

void InitBackground(		// called to initialize a background
	const BACKGND *pBgnd);	// pointer to data struct for current background

void StartupBackground(CORO_PARAM, SCNHANDLE hFilm);

void StopBgndScrolling();	// Stops all background playfields from scrolling

void PlayfieldSetPos(		// Sets the xy position of the specified playfield in the current background
	int which,		// which playfield
	int newXpos,		// new x position
	int newYpos);		// new y position

void PlayfieldGetPos(		// Returns the xy position of the specified playfield in the current background
	int which,		// which playfield
	int *pXpos,		// returns current x position
	int *pYpos);		// returns current y position

int PlayfieldGetCenterX(	// Returns the xy position of the specified playfield in the current background
	int which);		// which playfield

OBJECT **GetPlayfieldList(	// Returns the display list for the specified playfield
	int which);		// which playfield

void KillPlayfieldList(		// Kills all the objects on the display list for the specified playfield
	int which);		// which playfield

void DrawBackgnd();		// Draws all playfields for the current background

void RedrawBackgnd();	// Completely redraws all the playfield object lists for the current background

OBJECT *GetBgObject();

SCNHANDLE BgPal();

int BgWidth();

int BgHeight();

} // End of namespace Tinsel

#endif	// TINSEL_BACKGND_H
