/* ScummVM - Scumm Interpreter
 * Copyright (C) 2004-2005 The ScummVM project
 *
 * The ReInherit Engine is (C)2000-2003 by Daniel Balsom.
 *
 * 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., 59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.
 *
 * $Header$
 *
 */

// Palette animation module
#include "saga/saga.h"
#include "saga/gfx.h"

#include "saga/events.h"

#include "saga/palanim.h"
#include "saga/stream.h"

namespace Saga {

PalAnim::PalAnim(SagaEngine *vm) : _vm(vm) {
	_loaded = false;
	_entryCount = 0;
	_entries = NULL;
}

PalAnim::~PalAnim(void) {
}

int PalAnim::loadPalAnim(const byte *resdata, size_t resdata_len) {
	void *test_p;

	uint16 i;

	if (_loaded) {
		freePalAnim();
	}

	if (resdata == NULL) {
		return FAILURE;
	}

	MemoryReadStreamEndian readS(resdata, resdata_len, IS_BIG_ENDIAN);

	if (_vm->getGameType() == GType_IHNM) {
		return SUCCESS;
	}

	_entryCount = readS.readUint16();

	debug(0, "PalAnim::loadPalAnim(): Loading %d PALANIM entries.", _entryCount);

	test_p = calloc(_entryCount, sizeof(PALANIM_ENTRY));
	if (test_p == NULL) {
		warning("PalAnim::loadPalAnim(): Allocation failure");
		return MEM;
	}

	_entries = (PALANIM_ENTRY *)test_p;

	for (i = 0; i < _entryCount; i++) {
		int color_count;
		int pal_count;
		int p, c;

		color_count = readS.readUint16();
		pal_count = readS.readUint16();

		_entries[i].pal_count = pal_count;
		_entries[i].color_count = color_count;

		debug(2, "PalAnim::loadPalAnim(): Entry %d: Loading %d palette indices.\n", i, pal_count);

		test_p = calloc(1, sizeof(char) * pal_count);
		if (test_p == NULL) {
			warning("PalAnim::loadPalAnim(): Allocation failure");
			return MEM;
		}

		_entries[i].pal_index = (byte *)test_p;

		debug(2, "PalAnim::loadPalAnim(): Entry %d: Loading %d SAGA_COLOR structures.", i, color_count);

		test_p = calloc(1, sizeof(COLOR) * color_count);
		if (test_p == NULL) {
			warning("PalAnim::loadPalAnim(): Allocation failure");
			return MEM;
		}

		_entries[i].colors = (COLOR *)test_p;

		for (p = 0; p < pal_count; p++) {
			_entries[i].pal_index[p] = readS.readByte();
		}

		for (c = 0; c < color_count; c++) {
			_entries[i].colors[c].red = readS.readByte();
			_entries[i].colors[c].green = readS.readByte();
			_entries[i].colors[c].blue = readS.readByte();
		}
	}

	_loaded = true;
	return SUCCESS;
}

int PalAnim::cycleStart() {
	EVENT event;

	if (!_loaded) {
		return FAILURE;
	}

	event.type = ONESHOT_EVENT;
	event.code = PALANIM_EVENT;
	event.op = EVENT_CYCLESTEP;
	event.time = PALANIM_CYCLETIME;

	_vm->_events->queue(&event);

	return SUCCESS;
}

int PalAnim::cycleStep(int vectortime) {
	SURFACE *back_buf;

	static PALENTRY pal[256];
	uint16 pal_index;
	uint16 col_index;

	uint16 i, j;
	uint16 cycle;
	uint16 cycle_limit;

	EVENT event;

	if (!_loaded) {
		return FAILURE;
	}

	_vm->_gfx->getCurrentPal(pal);
	back_buf = _vm->_gfx->getBackBuffer();

	for (i = 0; i < _entryCount; i++) {
		cycle = _entries[i].cycle;
		cycle_limit = _entries[i].color_count;
		for (j = 0; j < _entries[i].pal_count; j++) {
			pal_index = (unsigned char)_entries[i].pal_index[j];
			col_index = (cycle + j) % cycle_limit;
			pal[pal_index].red = (byte) _entries[i].colors[col_index].red;
			pal[pal_index].green = (byte) _entries[i].colors[col_index].green;
			pal[pal_index].blue = (byte) _entries[i].colors[col_index].blue;
		}

		_entries[i].cycle++;

		if (_entries[i].cycle == cycle_limit) {
			_entries[i].cycle = 0;
		}
	}

	_vm->_gfx->setPalette(back_buf, pal);

	event.type = ONESHOT_EVENT;
	event.code = PALANIM_EVENT;
	event.op = EVENT_CYCLESTEP;
	event.time = vectortime + PALANIM_CYCLETIME;

	_vm->_events->queue(&event);

	return SUCCESS;
}

int PalAnim::freePalAnim() {
	uint16 i;

	if (!_loaded) {
		return FAILURE;
	}

	for (i = 0; i < _entryCount; i++) {
		debug(2, "PalAnim::freePalAnim(): Entry %d: Freeing colors.", i);
		free(_entries[i].colors);
		debug(2, "PalAnim::freePalAnim(): Entry %d: Freeing indices.", i);
		free(_entries[i].pal_index);
	}

	debug(0, "PalAnim::freePalAnim(): Freeing entries.");

	free(_entries);

	_loaded = false;

	return SUCCESS;
}

} // End of namespace Saga