/* ScummVM - Scumm Interpreter
 * Copyright (C) 2005-2006 The ScummVM project
 *
 * 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.
 *
 * $URL$
 * $Id$
 *
 */

#include "lure/screen.h"
#include "lure/luredefs.h"
#include "lure/memory.h"
#include "lure/disk.h"
#include "lure/decode.h"

namespace Lure {

static Screen *int_disk = NULL;

Screen &Screen::getReference() {
	return *int_disk;
}

Screen::Screen(OSystem &system): _system(system), 
		_screen(new Surface(FULL_SCREEN_WIDTH, FULL_SCREEN_HEIGHT)), 
		_disk(Disk::getReference()),
		_palette(new Palette(GAME_PALETTE_RESOURCE_ID)) {
	int_disk = this;
	_screen->empty();
	_system.setPalette(_palette->data(), 0, GAME_COLOURS);
}

Screen::~Screen() {
	delete _screen;
	delete _palette;
}

// setPaletteEmpty
// Defaults the palette to an empty set

void Screen::setPaletteEmpty() {
	delete _palette;
	_palette = new Palette();

	_system.setPalette(_palette->data(), 0, GAME_COLOURS);
	_system.updateScreen();
}

// setPalette
// Sets the current palette to the passed palette

void Screen::setPalette(Palette *p) {
	_palette->copyFrom(p);
	_system.setPalette(_palette->data(), 0, GAME_COLOURS);
	_system.updateScreen();
}

// paletteFadeIn
// Fades in the palette. For proper operation, the palette should have been
// previously set to empty

void Screen::paletteFadeIn(Palette *p) {
	bool changed;
	byte *const pDest = p->data();
	byte *const pTemp = _palette->data();

	do {
		changed = false;

		for (int palCtr = 0; palCtr < p->numEntries() * 4; ++palCtr)
		{
			if (palCtr % PALETTE_FADE_INC_SIZE == (PALETTE_FADE_INC_SIZE - 1)) continue;
			bool isDifferent = pTemp[palCtr] < pDest[palCtr];
			if (isDifferent) {
				if (pDest[palCtr] - pTemp[palCtr] < PALETTE_FADE_INC_SIZE) 
					pTemp[palCtr] = pDest[palCtr];
				else pTemp[palCtr] += PALETTE_FADE_INC_SIZE;
				changed = true;
			}
		}

		if (changed) {
			_system.setPalette(_palette->data(), 0, GAME_COLOURS);
			_system.updateScreen();
			_system.delayMillis(20);
		}
	} while (changed);
}

// paletteFadeOut
// Fades the screen to black by gradually decreasing the palette colours

void Screen::paletteFadeOut() {
	bool changed;

	do {
		byte *pTemp = _palette->data();
		changed = false;

		for (uint32 palCtr = 0; palCtr < _palette->palette()->size(); ++palCtr, ++pTemp) {
			if (palCtr % PALETTE_FADE_INC_SIZE == (PALETTE_FADE_INC_SIZE - 1)) 
				continue;
			bool isDifferent = *pTemp > 0;
			if (isDifferent) {
				if (*pTemp < PALETTE_FADE_INC_SIZE) *pTemp = 0;
				else *pTemp -= PALETTE_FADE_INC_SIZE;
				changed = true;
			}
		}

		if (changed) {
			_system.setPalette(_palette->data(), 0, GAME_COLOURS);
			_system.updateScreen();
			_system.delayMillis(20);
		}
	} while (changed);
}

void Screen::resetPalette() {
	Palette p(GAME_PALETTE_RESOURCE_ID);
	setPalette(&p);
}

void Screen::empty() {
	_screen->empty();
	update();
}

void Screen::update() {
	_system.copyRectToScreen(screen_raw(), FULL_SCREEN_WIDTH, 0, 0, FULL_SCREEN_WIDTH, FULL_SCREEN_HEIGHT);
	_system.updateScreen();
}

void Screen::updateArea(uint16 x, uint16 y, uint16 w, uint16 h) {
	_system.copyRectToScreen(screen_raw(), FULL_SCREEN_WIDTH, x, y, w, h);
	_system.updateScreen();
}

} // end of namespace Lure