/* 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.
 *
 * $Header$
 *
 */

// Isometric level module
#include "saga/saga.h"

#include "saga/gfx.h"

#include "saga/resnames.h"
#include "saga/scene.h"
#include "saga/isomap.h"
#include "saga/stream.h"

namespace Saga {

enum MaskRules {
	kMaskRuleNever = 0,
	kMaskRuleAlways,
	kMaskRuleUMIN,
	kMaskRuleUMID,
	kMaskRuleUMAX,
	kMaskRuleVMIN,
	kMaskRuleVMID,
	kMaskRuleVMAX,
	kMaskRuleYMIN,
	kMaskRuleYMID,
	kMaskRuleYMAX,
	kMaskRuleUVMAX,
	kMaskRuleUVMIN,
	kMaskRuleUorV,
	kMaskRuleUandV
};


static const IsoMap::TilePoint normalDirTable[8] = {
	{ 1, 1, 0, SAGA_DIAG_NORMAL_COST},
	{ 1, 0, 0, SAGA_STRAIGHT_NORMAL_COST},
	{ 1,-1, 0, SAGA_DIAG_NORMAL_COST},
	{ 0,-1, 0, SAGA_STRAIGHT_NORMAL_COST},
	{-1,-1, 0, SAGA_DIAG_NORMAL_COST},
	{-1, 0, 0, SAGA_STRAIGHT_NORMAL_COST},
	{-1, 1, 0, SAGA_DIAG_NORMAL_COST},
	{ 0, 1, 0, SAGA_STRAIGHT_NORMAL_COST},
};

static const IsoMap::TilePoint easyDirTable[8] = {
	{ 1, 1, 0, SAGA_DIAG_EASY_COST},
	{ 1, 0, 0, SAGA_STRAIGHT_EASY_COST},
	{ 1,-1, 0, SAGA_DIAG_EASY_COST},
	{ 0,-1, 0, SAGA_STRAIGHT_EASY_COST},
	{-1,-1, 0, SAGA_DIAG_EASY_COST},
	{-1, 0, 0, SAGA_STRAIGHT_EASY_COST},
	{-1, 1, 0, SAGA_DIAG_EASY_COST},
	{ 0, 1, 0, SAGA_STRAIGHT_EASY_COST},
};

static const IsoMap::TilePoint hardDirTable[8] = {
	{ 1, 1, 0, SAGA_DIAG_HARD_COST},
	{ 1, 0, 0, SAGA_STRAIGHT_HARD_COST},
	{ 1,-1, 0, SAGA_DIAG_HARD_COST},
	{ 0,-1, 0, SAGA_STRAIGHT_HARD_COST},
	{-1,-1, 0, SAGA_DIAG_HARD_COST},
	{-1, 0, 0, SAGA_STRAIGHT_HARD_COST},
	{-1, 1, 0, SAGA_DIAG_HARD_COST},
	{ 0, 1, 0, SAGA_STRAIGHT_HARD_COST},
};

IsoMap::IsoMap(SagaEngine *vm) : _vm(vm) {
	_tileData = NULL;
	_tilesCount = 0;
	_tilePlatformList = NULL;
	_tilePlatformsCount = 0;
	_metaTileList = NULL;
	_metaTilesCount = 0;
	_multiTable = NULL;
	_multiCount = 0;
	_multiTableData = NULL;
	_multiDataCount = 0;
	_viewScroll.x = (128 - 8) * 16;
	_viewScroll.x = (128 - 8) * 16 - 64;
	_viewDiff = 1;

}

void IsoMap::loadImages(const byte *resourcePointer, size_t resourceLength) {
	IsoTileData *tileData;
	uint16 i;

	if (resourceLength == 0) {
		error("IsoMap::loadImages wrong resourceLength");
	}

	_tileData = (byte*)malloc(resourceLength);
	_tileDataLength = resourceLength;
	memcpy(_tileData, resourcePointer, resourceLength);
	
	MemoryReadStreamEndian readS(_tileData, _tileDataLength, IS_BIG_ENDIAN);
	readS.readUint16(); // skip
	_tilesCount = readS.readUint16();
	_tilesCount = _tilesCount / SAGA_ISOTILEDATA_LEN;

	readS.seek(0);

	_tilesTable = (IsoTileData *)malloc(_tilesCount * sizeof(*_tilesTable));
	if (_tilesTable == NULL) {
		memoryError("IsoMap::loadImages");
	}

	for (i = 0; i < _tilesCount; i++) {
		tileData = &_tilesTable[i];
		tileData->height = readS.readByte();
		tileData->attributes = readS.readSByte();
		tileData->offset = readS.readUint16();
		tileData->terrainMask = readS.readUint16();
		tileData->FGDBGDAttr = readS.readByte();
		readS.readByte(); //skip
	}

}

void IsoMap::loadPlatforms(const byte * resourcePointer, size_t resourceLength) {
	TilePlatformData *tilePlatformData;
	uint16 i, x, y;

	if (resourceLength == 0) {
		error("IsoMap::loadPlatforms wrong resourceLength");
	}

	MemoryReadStreamEndian readS(resourcePointer, resourceLength, IS_BIG_ENDIAN);

	_tilePlatformsCount = resourceLength / SAGA_TILEPLATFORMDATA_LEN;
	_tilePlatformList = (TilePlatformData *)malloc(_tilePlatformsCount * sizeof(*_tilePlatformList));
	if (_tilePlatformList == NULL) {
		memoryError("IsoMap::loadPlatforms");
	}

	for (i = 0; i < _tilePlatformsCount; i++) {
		tilePlatformData = &_tilePlatformList[i];
		tilePlatformData->metaTile = readS.readSint16();
		tilePlatformData->height = readS.readSint16();
		tilePlatformData->highestPixel = readS.readSint16();
		tilePlatformData->vBits = readS.readByte();
		tilePlatformData->uBits = readS.readByte();
		for (x = 0; x < SAGA_PLATFORM_W; x++) {
			for (y = 0; y < SAGA_PLATFORM_W; y++) {
				tilePlatformData->tiles[x][y] = readS.readSint16();
			}
		}
	}

}

void IsoMap::loadMap(const byte * resourcePointer, size_t resourceLength) {
	uint16 x, y;

	if (resourceLength != SAGA_TILEMAP_LEN) {
		error("IsoMap::loadMap wrong resourceLength");
	}

	MemoryReadStreamEndian readS(resourcePointer, resourceLength, IS_BIG_ENDIAN);
	_tileMap.edgeType = readS.readByte();
	readS.readByte(); //skip

	for (x = 0; x < SAGA_TILEMAP_W; x++) {
		for (y = 0; y < SAGA_TILEMAP_H; y++) {
			_tileMap.tilePlatforms[x][y] = readS.readSint16();
		}
	}

}

void IsoMap::loadMetaTiles(const byte * resourcePointer, size_t resourceLength) {
	MetaTileData *metaTileData;
	uint16 i, j;

	if (resourceLength == 0) {
		error("IsoMap::loadMetaTiles wrong resourceLength");
	}

	MemoryReadStreamEndian readS(resourcePointer, resourceLength, IS_BIG_ENDIAN);
	_metaTilesCount = resourceLength / SAGA_METATILEDATA_LEN;

	_metaTileList = (MetaTileData *)malloc(_metaTilesCount * sizeof(*_metaTileList));
	if (_metaTileList == NULL) {
		memoryError("IsoMap::loadMetaTiles");
	}

	for (i = 0; i < _metaTilesCount; i++) {
		metaTileData = &_metaTileList[i];
		metaTileData->highestPlatform = readS.readUint16();
		metaTileData->highestPixel = readS.readUint16();
		for (j = 0; j < SAGA_MAX_PLATFORM_H; j++) {
			metaTileData->stack[j] = readS.readSint16();
		}
	}
}

void IsoMap::loadMulti(const byte * resourcePointer, size_t resourceLength) {
	MultiTileEntryData *multiTileEntryData;
	uint16 i;
	int16 offsetDiff;

	if (resourceLength < 2) {
		error("IsoMap::loadMetaTiles wrong resourceLength");
	}

	MemoryReadStreamEndian readS(resourcePointer, resourceLength, IS_BIG_ENDIAN);
	_multiCount = readS.readUint16();
	_multiTable = (MultiTileEntryData *)malloc(_multiCount * sizeof(*_multiTable));
	if (_multiTable == NULL) {
		memoryError("IsoMap::loadMulti");
	}

	for (i = 0; i < _multiCount; i++) {
		multiTileEntryData = &_multiTable[i];
		readS.readUint32();//skip
		multiTileEntryData->offset = readS.readSint16();
		multiTileEntryData->u = readS.readByte();
		multiTileEntryData->v = readS.readByte();
		multiTileEntryData->h = readS.readByte();
		multiTileEntryData->uSize = readS.readByte();
		multiTileEntryData->vSize = readS.readByte();
		multiTileEntryData->numStates = readS.readByte();
		multiTileEntryData->currentState = readS.readByte();
		readS.readByte();//skip
	}
	
	offsetDiff = (readS.pos() - 2);

	for (i = 0; i < _multiCount; i++) {
		_multiTable[i].offset -= offsetDiff;
	}

	_multiDataCount = (readS.size() - readS.pos()) / 2;

	_multiTableData = (int16 *)malloc(_multiDataCount * sizeof(*_multiTableData));
	for (i = 0; i < _multiDataCount; i++) {
		_multiTableData[i] = readS.readSint16();
	}
}

void IsoMap::freeMem() {
	free(_tileData);
	_tileData = NULL;
	_tilesCount = 0;
	free(_tilePlatformList);
	_tilePlatformList = NULL;
	_tilePlatformsCount = 0;
	free(_metaTileList);
	_metaTileList = NULL;
	_metaTilesCount = 0;
	free(_multiTable);
	_multiTable = NULL;
	_multiCount = 0;
	free(_multiTableData);
	_multiTableData = NULL;
	_multiDataCount = 0;
}

void IsoMap::adjustScroll(bool jump) {
	Point playerPoint;
	Point minScrollPos;
	Point maxScrollPos;
	

	tileCoordsToScreenPoint(_vm->_actor->_centerActor->location, playerPoint);

	if (_vm->_scene->currentSceneResourceId() == RID_ITE_OVERMAP_SCENE) {
		_mapPosition.x = (playerPoint.x + _viewScroll.x) * 30 / 100 - (381);
		_mapPosition.y = (playerPoint.y + _viewScroll.y) * 30 / 100 - (342);
	}

	if (_vm->_actor->_centerActor != _vm->_actor->_protagonist) {
		playerPoint.y -= 24;
	}
	playerPoint.y -= 28;

	playerPoint.x += _viewScroll.x - _vm->getDisplayWidth()/2;
	playerPoint.y += _viewScroll.y - _vm->getSceneHeight()/2;

	minScrollPos.x = playerPoint.x - SAGA_SCROLL_LIMIT_X1;
	minScrollPos.y = playerPoint.y - SAGA_SCROLL_LIMIT_Y1;

	maxScrollPos.x = playerPoint.x + SAGA_SCROLL_LIMIT_X1;
	maxScrollPos.y = playerPoint.y + SAGA_SCROLL_LIMIT_Y2;

	if (jump) {
		if (_viewScroll.y < minScrollPos.y) {
			_viewScroll.y = minScrollPos.y;
		}
		if (_viewScroll.y > maxScrollPos.y) {
			_viewScroll.y = maxScrollPos.y;
		}
		if (_viewScroll.x < minScrollPos.x) {
			_viewScroll.x = minScrollPos.x;
		}
		if (_viewScroll.x > maxScrollPos.x) {
			_viewScroll.x = maxScrollPos.x;
		}
	} else {
		_viewScroll.y = smoothSlide( _viewScroll.y, minScrollPos.y, maxScrollPos.y );
		_viewScroll.x = smoothSlide( _viewScroll.x, minScrollPos.x, maxScrollPos.x );
	}

	if (_vm->_scene->currentSceneResourceId() == RID_ITE_OVERMAP_SCENE) {
		ObjectData *obj;
		uint16 objectId;
		objectId = _vm->_actor->objIndexToId(ITE_OBJ_MAP);
		obj = _vm->_actor->getObj(objectId);
		if (obj->sceneNumber != ITE_SCENE_INV) {
			_viewScroll.x = 1552 + 8;
			_viewScroll.y = 1456 + 8;
		}
	}
}

int16 IsoMap::findMulti(int16 tileIndex, int16 absU, int16 absV, int16 absH) {
	MultiTileEntryData *multiTileEntryData;
	int16 ru;
	int16 rv;
	int16 mu;
	int16 mv;
	int16 state;
	uint16 i, offset;
	int16 *tiles;

	ru = (tileIndex >> 13) & 0x03;
	rv = (tileIndex >> 11) & 0x03;
	mu = absU - ru;
	mv = absV - rv;
	
	tileIndex = 0;
	for (i = 0; i < _multiCount; i++) {
		multiTileEntryData = &_multiTable[i];

		if ((multiTileEntryData->u == mu) && 
			(multiTileEntryData->v == mv) && 
			(multiTileEntryData->h == absH)) {
			state = multiTileEntryData->currentState;
			
			offset = (ru + state * multiTileEntryData->uSize) * multiTileEntryData->vSize + rv;
			offset *= sizeof(*_multiTableData);
			offset += multiTileEntryData->offset;
			if (offset + sizeof(*_multiTableData) - 1 >= _multiDataCount * sizeof(*_multiTableData)) {
				error("wrong multiTileEntryData->offset");
			}
			tiles = (int16*)((byte*)_multiTableData + offset);
			tileIndex = *tiles;
			if (tileIndex >= 256) {
				warning("something terrible happened");
				return 1;
			}
			return tileIndex;
		}
	}
		
	return 1;
}

int IsoMap::draw(SURFACE *ds) {
	
	Rect isoRect(_vm->getDisplayWidth(), _vm->getDisplayInfo().sceneHeight);
	drawRect(ds, isoRect, 0);
	_tileClip = isoRect;
	drawTiles(ds, NULL);

	return SUCCESS;
}

void IsoMap::setMapPosition(int x, int y) {
	_mapPosition.x = x;
	_mapPosition.y = y;
}

void IsoMap::drawSprite(SURFACE *ds, SpriteList &spriteList, int spriteNumber, const Location &location, const Point &screenPosition, int scale) {
	int width;
	int height;
	int xAlign;
	int yAlign;
	const byte *spriteBuffer;
	Point spritePointer;
	Rect clip(_vm->getDisplayWidth(),_vm->getSceneHeight());

	_vm->_sprite->getScaledSpriteBuffer(spriteList,spriteNumber,scale, width, height, xAlign, yAlign, spriteBuffer);

	spritePointer.x = screenPosition.x + xAlign;
	spritePointer.y = screenPosition.y + yAlign;

	_tileClip.left = spritePointer.x;
	_tileClip.top = spritePointer.y;
	_tileClip.right = spritePointer.x + width;
	_tileClip.bottom = spritePointer.y + height;

	if (_tileClip.left < 0) {
		_tileClip.left = 0;
	}
	if (_tileClip.right > _vm->getDisplayWidth()) {
		_tileClip.right = _vm->getDisplayWidth();
	}
	if (_tileClip.top < 0) {
		_tileClip.top = 0;
	}
	if (_tileClip.bottom > _vm->getSceneHeight()) {
		_tileClip.bottom = _vm->getSceneHeight();
	}

	_vm->_sprite->drawClip(ds, clip, spritePointer, width, height, spriteBuffer);
	drawTiles(ds, &location);
}


void IsoMap::drawTiles(SURFACE *ds,  const Location *location) {
	Point view1;
	Point fineScroll;
	Point tileScroll;
	Point metaTileY;
	Point metaTileX;
	int16 u0, v0, 
		  u1, v1,
		  u2, v2,
		  uc, vc;
	uint16 metaTileIndex;
	Location rLocation;
	int16 workAreaWidth;
	int16 workAreaHeight;

	tileScroll.x = _viewScroll.x >> 4;
	tileScroll.y = _viewScroll.y >> 4;

	fineScroll.x = _viewScroll.x & 0xf;
	fineScroll.y = _viewScroll.y & 0xf;

	view1.x = tileScroll.x - (8 * SAGA_TILEMAP_W);
	view1.y = (8 * SAGA_TILEMAP_W) - tileScroll.y;

	u0 = ((view1.y + 64) * 2 + view1.x) >> 4;
	v0 = ((view1.y + 64) * 2 - view1.x) >> 4;
	
	metaTileY.x = (u0 - v0) * 128 - (view1.x * 16 + fineScroll.x);
	metaTileY.y = (view1.y * 16 - fineScroll.y) - (u0 + v0) * 64;

	workAreaWidth = _vm->getDisplayWidth() + 128;
	workAreaHeight = _vm->getDisplayInfo().sceneHeight + 128 + 80;

	for (u1 = u0, v1 = v0; metaTileY.y < workAreaHeight; u1--, v1-- ) {
		metaTileX = metaTileY;

		for (u2 = u1, v2 = v1; metaTileX.x < workAreaWidth; u2++, v2--, metaTileX.x += 256) {

			uc = u2 & (SAGA_TILEMAP_W - 1);
			vc = v2 & (SAGA_TILEMAP_W - 1);

			if (uc != u2 || vc != v2) {					
				metaTileIndex = 0;
				switch ( _tileMap.edgeType) {				
				case kEdgeTypeBlack: 
					continue;
				case kEdgeTypeFill0: 
					break;
				case kEdgeTypeFill1:
					metaTileIndex = 1; 
					break;
				case kEdgeTypeRpt:
					uc = clamp( 0, u2, SAGA_TILEMAP_W - 1);
					vc = clamp( 0, v2, SAGA_TILEMAP_W - 1);
					metaTileIndex = _tileMap.tilePlatforms[uc][vc];
					break;
				case kEdgeTypeWrap:
					metaTileIndex = _tileMap.tilePlatforms[uc][vc];
					break;
				}
			} else {
				metaTileIndex = _tileMap.tilePlatforms[uc][vc];
			}

			if (location != NULL) {
				rLocation.u() = location->u() - (u2 << 7);
				rLocation.v() = location->v() - (v2 << 7);
				rLocation.z = location->z;
				drawSpriteMetaTile(ds, metaTileIndex, metaTileX, rLocation, u2 << 3, v2 << 3);
			} else {
				drawMetaTile(ds, metaTileIndex, metaTileX, u2 << 3, v2 << 3);
			}
		}

		metaTileY.y += 64;

		metaTileX = metaTileY;

		metaTileX.x -= 128;

		for (u2 = u1 - 1, v2 = v1; metaTileX.x < workAreaWidth; u2++, v2--, metaTileX.x += 256) {

			uc = u2 & (SAGA_TILEMAP_W - 1);
			vc = v2 & (SAGA_TILEMAP_W - 1);

			if (uc != u2 || vc != v2) {
				metaTileIndex = 0;
				switch ( _tileMap.edgeType) {				
				case kEdgeTypeBlack: 
					continue;
				case kEdgeTypeFill0: 
					break;
				case kEdgeTypeFill1:
					metaTileIndex = 1; 
					break;
				case kEdgeTypeRpt:
					uc = clamp( 0, u2, SAGA_TILEMAP_W - 1);
					vc = clamp( 0, v2, SAGA_TILEMAP_W - 1);
					metaTileIndex = _tileMap.tilePlatforms[uc][vc];
					break;
				case kEdgeTypeWrap:
					metaTileIndex = _tileMap.tilePlatforms[uc][vc];
					break;
				}
			} else {
				metaTileIndex = _tileMap.tilePlatforms[uc][vc];
			}

			if (location != NULL) {
				rLocation.u() = location->u() - (u2 << 7);
				rLocation.v() = location->v() - (v2 << 7);
				rLocation.z = location->z;
				drawSpriteMetaTile(ds, metaTileIndex, metaTileX, rLocation, u2 << 3, v2 << 3);
			} else {
				drawMetaTile(ds, metaTileIndex, metaTileX, u2 << 3, v2 << 3);
			}
		}
		metaTileY.y += 64;
	}

}

void IsoMap::drawSpriteMetaTile(SURFACE *ds, uint16 metaTileIndex, const Point &point, Location &location, int16 absU, int16 absV) {
	MetaTileData * metaTile;
	uint16 high;
	int16 platformIndex;
	Point platformPoint;
	platformPoint = point;

	if (_metaTilesCount <= metaTileIndex) {
		error("IsoMap::drawMetaTile wrong metaTileIndex");
	}

	metaTile = &_metaTileList[metaTileIndex];

	if (metaTile->highestPlatform > 18) {
		metaTile->highestPlatform = 0;
	}

	for (high = 0; high <= metaTile->highestPlatform; high++, platformPoint.y -= 8, location.z -= 8) {
		assert(SAGA_MAX_PLATFORM_H > high);
		platformIndex = metaTile->stack[high];

		if (platformIndex >= 0) {
			drawSpritePlatform( ds, platformIndex, platformPoint, location, absU, absV, high );
		}
	}	
}

void IsoMap::drawMetaTile(SURFACE *ds, uint16 metaTileIndex, const Point &point, int16 absU, int16 absV) {
	MetaTileData * metaTile;
	uint16 high;
	int16 platformIndex;
	Point platformPoint;
	platformPoint = point;

	if (_metaTilesCount <= metaTileIndex) {
		error("IsoMap::drawMetaTile wrong metaTileIndex");
	}

	metaTile = &_metaTileList[metaTileIndex];

	if (metaTile->highestPlatform > 18) {
		metaTile->highestPlatform = 0;
	}

	for (high = 0; high <= metaTile->highestPlatform; high++, platformPoint.y -= 8) {
		assert(SAGA_MAX_PLATFORM_H > high);
		platformIndex = metaTile->stack[high];

		if (platformIndex >= 0) {
			drawPlatform( ds, platformIndex, platformPoint, absU, absV, high );
		}
	}	
}

void IsoMap::drawSpritePlatform(SURFACE *ds, uint16 platformIndex, const Point &point, const Location &location, int16 absU, int16 absV, int16 absH) {
	TilePlatformData *tilePlatform;
	int16 u, v;
	Point s;
	Point s0;
	uint16 tileIndex;
	Location copyLocation(location);

	if (_tilePlatformsCount <= platformIndex) {
		error("IsoMap::drawPlatform wrong platformIndex");
	}

	tilePlatform = &_tilePlatformList[platformIndex];

	if ((point.y <= _tileClip.top) || (point.y - SAGA_MAX_TILE_H - SAGA_PLATFORM_W * SAGA_TILE_NOMINAL_H >= _tileClip.bottom)) {
		return;
	}

	s0 = point;
	s0.y -= (((SAGA_PLATFORM_W - 1) + (SAGA_PLATFORM_W - 1)) * 8);

	for (v = SAGA_PLATFORM_W - 1,
		copyLocation.v() = location.v() - ((SAGA_PLATFORM_W - 1) << 4);
		v >= 0 && s0.y - SAGA_MAX_TILE_H < _tileClip.bottom && s0.x - 128 < _tileClip.right;
		v--, copyLocation.v() += 16, s0.x += 16, s0.y += 8) {

		if ((tilePlatform->vBits & (1 << v)) == 0) {
			continue;
		}

		if (s0.x + 128 + 32 < _tileClip.left) {
			continue;
		}

		s = s0;

		for (u = SAGA_PLATFORM_W - 1,
			copyLocation.u() = location.u() - ((SAGA_PLATFORM_W - 1) << 4); 
			 u >= 0 && s.x + 32 > _tileClip.left && s.y - SAGA_MAX_TILE_H < _tileClip.bottom; 
			 u--, copyLocation.u() += 16, s.x -= 16, s.y += 8 ) {
			if (s.x < _tileClip.right && s.y > _tileClip.top) {

				tileIndex = tilePlatform->tiles[u][v];
				if (tileIndex != 0) {
					if (tileIndex & SAGA_MULTI_TILE) {
						tileIndex = findMulti(tileIndex, absU + u, absV + v, absH);
					}

					drawTile(ds, tileIndex, s, &copyLocation);
				}
			}
		}
	}
}

void IsoMap::drawPlatform(SURFACE *ds, uint16 platformIndex, const Point &point, int16 absU, int16 absV, int16 absH) {
	TilePlatformData *tilePlatform;
	int16 u, v;
	Point s;
	Point s0;
	uint16 tileIndex;

	if (_tilePlatformsCount <= platformIndex) {
		error("IsoMap::drawPlatform wrong platformIndex");
	}

	tilePlatform = &_tilePlatformList[platformIndex];

	if ((point.y <= _tileClip.top) || (point.y - SAGA_MAX_TILE_H - SAGA_PLATFORM_W * SAGA_TILE_NOMINAL_H >= _tileClip.bottom)) {
		return;
	}
		
	s0 = point;
	s0.y -= (((SAGA_PLATFORM_W - 1) + (SAGA_PLATFORM_W - 1)) * 8);

	for (v = SAGA_PLATFORM_W - 1;
		v >= 0 && s0.y - SAGA_MAX_TILE_H < _tileClip.bottom && s0.x - 128 < _tileClip.right;
		v--, s0.x += 16, s0.y += 8) {

		if ((tilePlatform->vBits & (1 << v)) == 0) {
			continue;
		}

		if (s0.x + 128 + 32 < _tileClip.left) {
			continue;
		}

		s = s0;

		for (u = SAGA_PLATFORM_W - 1;
			u >= 0 && s.x + 32 > _tileClip.left && s.y - SAGA_MAX_TILE_H < _tileClip.bottom;
			u--, s.x -= 16, s.y += 8 ) {
			if (s.x < _tileClip.right && s.y > _tileClip.top) {
				
				tileIndex = tilePlatform->tiles[u][v];
				if (tileIndex > 1) {
					if (tileIndex & SAGA_MULTI_TILE) {
						tileIndex = findMulti(tileIndex, absU + u, absV + v, absH);
					}

					drawTile(ds, tileIndex, s, NULL);
				}
			}
		}
	}
}

#define THRESH0			0
#define THRESH8			8
#define THRESH16		16

void IsoMap::drawTile(SURFACE *ds, uint16 tileIndex, const Point &point, const Location *location) {
	const byte *tilePointer;
	const byte *readPointer;
	byte *drawPointer;
	Point drawPoint;
	int height;
	int widthCount = 0;
	int row, col, count, lowBound;
	int bgRunCount;
	int fgRunCount;


	if (tileIndex >= _tilesCount) {
		error("IsoMap::drawTile wrong tileIndex");
	}


	if (point.x + SAGA_ISOTILE_WIDTH < _tileClip.left) {
		return;
	}

	if (point.x - SAGA_ISOTILE_WIDTH >= _tileClip.right) {
		return;
	}

	tilePointer = _tileData + _tilesTable[tileIndex].offset;
	height = _tilesTable[tileIndex].height;

	if ((height <= 8) || (height > 64)) {
		return;
	}

	drawPoint = point;
	drawPoint.y -= height;

	if (drawPoint.y >= _tileClip.bottom) {
		return;
	}

	if (location != NULL) {
		if (location->z <= -16) {
			if (location->z <= -48) {
				if (location->u() < -THRESH8 || location->v() < -THRESH8) {
					return;
				}
			} else {
				if (location->u() < THRESH0 || location->v() < THRESH0) {
					return;
				}
			}
		} else {
			if (location->z >= 16) {
				return;
			} else {
				switch (_tilesTable[tileIndex].GetMaskRule()) {
				case kMaskRuleNever:
					return;
				case kMaskRuleAlways:
					break;
				case kMaskRuleUMIN:
					if (location->u() < THRESH0) {
						return; 
					}
					break;
				case kMaskRuleUMID:	
					if (location->u() < THRESH8) {
						return;
					}
					break;
				case kMaskRuleUMAX:
					if (location->u() < THRESH16) {
						return; 
					}
					break;
				case kMaskRuleVMIN:
					if (location->v() < THRESH0) {
						return;
					}
					break;
				case kMaskRuleVMID:
					if (location->v() < THRESH8) {
						return; 
					}
					break;
				case kMaskRuleVMAX:
					if (location->v() < THRESH16) {
						return; 
					}
					break;
				case kMaskRuleYMIN:
					if (location->uv() < THRESH0 * 2) {
						return;
					}
					break;
				case kMaskRuleYMID:
					if (location->uv() < THRESH8 * 2) {
						return;
					}
					break;
				case kMaskRuleYMAX:
					if (location->uv() < THRESH16 * 2) {
						return;
					}
					break;
				case kMaskRuleUVMAX:
					if (location->u() < THRESH16 && location->v() < THRESH16) {
						return;
					}
					break;
				case kMaskRuleUVMIN:
					if (location->u() < THRESH0 || location->v() < THRESH0) {
						return;
					}
					break;
				case kMaskRuleUorV:
					if (location->u() < THRESH8 && location->v() < THRESH8) {
						return;
					}
					break;
				case kMaskRuleUandV:
					if (location->u() < THRESH8 || location->v() < THRESH8) {
						return;
					}
					break;
				}
			}
		}
	}

	readPointer = tilePointer;
	lowBound = MIN((int)(drawPoint.y + height), (int)_tileClip.bottom);
	for (row = drawPoint.y; row < lowBound; row++) {
		widthCount = 0;
		if (row >= _tileClip.top) {
			drawPointer = (byte *)ds->pixels + drawPoint.x + (row * ds->pitch);
			col = drawPoint.x;
			for (;;) {
				bgRunCount = *readPointer++;
				widthCount += bgRunCount;
				if (widthCount >= SAGA_ISOTILE_WIDTH) {
					break;
				}

				drawPointer += bgRunCount;
				col += bgRunCount;
				fgRunCount = *readPointer++;
				widthCount += fgRunCount;
				
				count = 0;
				while ((col < _tileClip.left) && (count < fgRunCount)) {
					count++;
					col++;
				}
				while ((col < _tileClip.right) && (count < fgRunCount)) {
					assert((uint)ds->pixels <= (uint)(drawPointer + count));
					assert(((uint)ds->pixels + (_vm->getDisplayWidth() * _vm->getDisplayHeight())) > (uint)(drawPointer + count));
					drawPointer[count] = readPointer[count];
					count++;
					col++;
				}
				readPointer += fgRunCount;
				drawPointer += fgRunCount;
			}
		} else {
			for (;;) {
				bgRunCount = *readPointer++;
				widthCount += bgRunCount;
				if (widthCount >= SAGA_ISOTILE_WIDTH) {
					break;
				}

				fgRunCount = *readPointer++;
				widthCount += fgRunCount;
				
				readPointer += fgRunCount;
			}
		}
	}

}

//

void IsoMap::pushPoint(int16 u, int16 v, uint16 cost, uint16 direction) {
	int16 upper;
	int16 lower;
	int16 mid;
	TilePoint *tilePoint;
	PathCell *pathCell;
	
	upper = _queueCount;
	lower = 0;

	if ((u < 1) || (u >= SAGA_SEARCH_DIAMETER - 1) || (v < 1) || (v >= SAGA_SEARCH_DIAMETER - 1)) {
			return;
	}
		
	pathCell = _searchArray.getPathCell(u, v);

	if ((pathCell->visited) && (pathCell->cost <= cost)) {
		return;
	}

	if (_queueCount >= SAGA_SEARCH_QUEUE_SIZE) {
		return;
	}

	while (1) {
		mid = (upper + lower) / 2;
		tilePoint = _searchArray.getQueue(mid);

		if (upper <= lower) {
			break;
		}

		if (cost < tilePoint->cost) {
			lower = mid + 1;
		} else {
			upper = mid;
		}
	}

	if (mid < _queueCount ) {
		memmove(tilePoint + 1, tilePoint, (_queueCount - mid) * sizeof (*tilePoint));
	}
	_queueCount++;

	tilePoint->u = u;
	tilePoint->v = v;
	tilePoint->cost = cost;
	tilePoint->direction = direction;

	pathCell->visited = 1;
	pathCell->direction = direction;
	pathCell->cost = cost;
}

IsoTileData *IsoMap::getTile(int16 u, int16 v, int16 z) {
	int16 mtileU;
	int16 mtileV;
	int16 uc;
	int16 vc;
	int16 u0;
	int16 v0;
	int16 tileIndex;
	int16 platformIndex;
	int16 metaTileIndex;

	mtileU = u >> 3;
	mtileV = v >> 3;
	uc = mtileU & (SAGA_TILEMAP_W - 1);
	vc = mtileV & (SAGA_TILEMAP_W - 1);
	u0 = u & (SAGA_PLATFORM_W - 1);
	v0 = v & (SAGA_PLATFORM_W - 1);

	if ((uc != mtileU) || (vc != mtileV)) {
		metaTileIndex = 0;
		switch ( _tileMap.edgeType) {
		case kEdgeTypeBlack: 
			return NULL;
		case kEdgeTypeFill0: 
			break;
		case kEdgeTypeFill1:
			metaTileIndex = 1; 
			break;
		case kEdgeTypeRpt:
			uc = clamp( 0, mtileU, SAGA_TILEMAP_W - 1);
			vc = clamp( 0, mtileV, SAGA_TILEMAP_W - 1);
			metaTileIndex = _tileMap.tilePlatforms[uc][vc];
			break;
		case kEdgeTypeWrap:
			metaTileIndex = _tileMap.tilePlatforms[uc][vc];
			break;
		}
	} else {
		metaTileIndex = _tileMap.tilePlatforms[uc][vc];
	}

	if (_metaTilesCount <= metaTileIndex) {
		error("IsoMap::getTile wrong metaTileIndex");
	}

	platformIndex = _metaTileList[metaTileIndex].stack[z];
	if (platformIndex < 0) {
		return NULL;
	}

	if (_tilePlatformsCount <= platformIndex) {
		error("IsoMap::getTile wrong platformIndex");
	}

	tileIndex = _tilePlatformList[platformIndex].tiles[u0][v0];

	if (tileIndex == 0) {
		return NULL;
	}

	if (tileIndex & SAGA_MULTI_TILE) {
		tileIndex = findMulti(tileIndex, u, v, z);
	}

	return &_tilesTable[tileIndex];
}

void IsoMap::testPossibleDirections(int16 u, int16 v, uint16 terraComp[8], int skipCenter) {
	IsoTileData *tile;
	uint16 fgdMask;
	uint16 bgdMask;
	uint16 mask;


	memset(terraComp, 0, 8 * sizeof(uint16));

#define FILL_MASK(index, testMask)		\
	if ( mask & testMask) {				\
		terraComp[index] |= fgdMask;	\
	}									\
	if (~mask & testMask) {				\
		terraComp[index] |= bgdMask;	\
	}

#define TEST_TILE_PROLOG(offsetU, offsetV)						\
	tile = getTile(u + offsetU, v + offsetV , _platformHeight);	\
	if (tile != NULL) {											\
		fgdMask = tile->GetFGDMask();							\
		bgdMask = tile->GetBGDMask();							\
		mask = tile->terrainMask;

#define TEST_TILE_EPILOG(index)									\
	} else {													\
		if (_vm->_actor->_protagonist->location.z > 0) {		\
			terraComp[index] = SAGA_IMPASSABLE;					\
		}														\
	}	

	
	TEST_TILE_PROLOG(0, 0)
		if (skipCenter) {
			if ((mask & 0x0660) && (fgdMask & SAGA_IMPASSABLE)) {
				fgdMask = 0;
			}
			if ((~mask & 0x0660) && (bgdMask & SAGA_IMPASSABLE)) {
				bgdMask = 0;
			}
		}
		
		FILL_MASK(0, 0xcc00)
		FILL_MASK(1, 0x6600)
		FILL_MASK(2, 0x3300)
		FILL_MASK(3, 0x0330)
		FILL_MASK(4, 0x0033)
		FILL_MASK(5, 0x0066)
		FILL_MASK(6, 0x00cc)
		FILL_MASK(7, 0x0cc0)
	}

	TEST_TILE_PROLOG(1, 1)
		FILL_MASK(0, 0x0673)
	TEST_TILE_EPILOG(0)


	TEST_TILE_PROLOG(1, 0)
		FILL_MASK(0, 0x0008)
		FILL_MASK(1, 0x0666)
		FILL_MASK(2, 0x0001)
	TEST_TILE_EPILOG(1)


	TEST_TILE_PROLOG(1, -1)
		FILL_MASK(2, 0x06ec)
	TEST_TILE_EPILOG(2)

	TEST_TILE_PROLOG(0, 1)
		FILL_MASK(0, 0x1000)
		FILL_MASK(7, 0x0770)
		FILL_MASK(6, 0x0001)
	TEST_TILE_EPILOG(7)


	TEST_TILE_PROLOG(0, -1)
		FILL_MASK(2, 0x8000)
		FILL_MASK(3, 0x0ee0)
		FILL_MASK(4, 0x0008)
	TEST_TILE_EPILOG(3)


	TEST_TILE_PROLOG(-1, 1)
		FILL_MASK(6, 0x3670)
	TEST_TILE_EPILOG(6)


	TEST_TILE_PROLOG(-1, 0)
		FILL_MASK(6, 0x8000)
		FILL_MASK(5, 0x6660)
		FILL_MASK(4, 0x1000)
	TEST_TILE_EPILOG(5)

	TEST_TILE_PROLOG(-1, -1)
		FILL_MASK(4, 0xce60)
	TEST_TILE_EPILOG(4)
}

void IsoMap::placeOnTileMap(const Location &start, Location &result, int16 distance, uint16 direction) {
	int16 bestDistance;
	int16 bestU;
	int16 bestV;
	int16 uBase;
	int16 vBase;
	int16 u;
	int16 v;
	int i;
	ActorData *actor;
	TilePoint tilePoint;
	uint16 dir;
	int16 dist;
	uint16 terraComp[8];
	const TilePoint *tdir;
	uint16 terrainMask;

	bestDistance = 0;


	uBase = (start.u() >> 4) - SAGA_SEARCH_CENTER;
	vBase = (start.v() >> 4) - SAGA_SEARCH_CENTER;

	bestU = SAGA_SEARCH_CENTER;
	bestV = SAGA_SEARCH_CENTER;

	_platformHeight = _vm->_actor->_protagonist->location.z / 8;

	memset( &_searchArray, 0, sizeof(_searchArray));

	for (i = 0; i < _vm->_actor->_actorsCount; i++) {
		actor = _vm->_actor->_actors[i];
		if (actor->disabled) continue;
		if (actor->sceneNumber != _vm->_scene->currentSceneNumber()) continue;

		u = (actor->location.u() >> 4) - uBase;
		v = (actor->location.v() >> 4) - vBase;
		if ((u >= 0) && (u < SAGA_SEARCH_DIAMETER) &&
			(v >= 0) && (v < SAGA_SEARCH_DIAMETER) && 
			((u != SAGA_SEARCH_CENTER) || (v != SAGA_SEARCH_CENTER))) {
			_searchArray.getPathCell(u, v)->visited = 1;
		}
	}

	_queueCount = 0;
	pushPoint(SAGA_SEARCH_CENTER, SAGA_SEARCH_CENTER, 0, 0);

	while (_queueCount > 0) {	

		_queueCount--;
		tilePoint = *_searchArray.getQueue(_queueCount);


		dist = ABS(tilePoint.u - SAGA_SEARCH_CENTER) + ABS(tilePoint.v - SAGA_SEARCH_CENTER);

		if (dist > bestDistance) {
			bestU = tilePoint.u;
			bestV = tilePoint.v;
			bestDistance = dist;

			if (dist >= distance) {
				break;
			}
		}

		testPossibleDirections(uBase + tilePoint.u, vBase + tilePoint.v, terraComp, 0);


		for (dir = 0; dir < 8; dir++) {
			terrainMask = terraComp[dir];

			if (terrainMask & SAGA_IMPASSABLE ) {
				continue;
			}

			if (dir == direction) {
				tdir = &easyDirTable[ dir ];
			} else {
				if (dir + 1 == direction || dir - 1 == direction) {
					tdir = &normalDirTable[ dir ];
				} else {
					tdir = &hardDirTable[ dir ];
				}
			}

			pushPoint(tilePoint.u + tdir->u,tilePoint.v + tdir->v, tilePoint.cost + tdir->cost, dir);
		}
	}

	result.u() = ((uBase + bestU) << 4) + 8;
	result.v() = ((vBase + bestV) << 4) + 8;
}

void IsoMap::findTilePath(ActorData* actor, const Location &start, const Location &end) {
	ActorData *other;
	int i;
	int16 u;
	int16 v;
	int16 bestDistance;
	int16 bestU;
	int16 bestV;

	int16 uBase;
	int16 vBase;
	int16 uFinish;
	int16 vFinish;

	TilePoint tilePoint;
	uint16 dir;
	int16 dist;
	uint16 terraComp[8];
	const TilePoint *tdir;
	uint16 terrainMask;
	const PathCell *pcell;
	byte *res;


	bestDistance = SAGA_SEARCH_DIAMETER;
	bestU = SAGA_SEARCH_CENTER,
	bestV = SAGA_SEARCH_CENTER;

	uBase = (start.u() >> 4) - SAGA_SEARCH_CENTER;
	vBase = (start.v() >> 4) - SAGA_SEARCH_CENTER;
	uFinish = (end.u() >> 4) - uBase;
	vFinish = (end.v() >> 4) - vBase;

	_platformHeight = _vm->_actor->_protagonist->location.z / 8;



	memset( &_searchArray, 0, sizeof(_searchArray));

	if (!(actor->actorFlags & kActorNoCollide) && 
		(_vm->_scene->currentSceneResourceId() != RID_ITE_OVERMAP_SCENE)) {
			for (i = 0; i < _vm->_actor->_actorsCount; i++) {
				other = _vm->_actor->_actors[i];
				if (other->disabled) continue;
				if (other->sceneNumber != _vm->_scene->currentSceneNumber()) continue;
				if (other==actor) continue;

				u = (other->location.u() >> 4) - uBase;
				v = (other->location.v() >> 4) - vBase;
				if ((u >= 1) && (u < SAGA_SEARCH_DIAMETER) &&
					(v >= 1) && (v < SAGA_SEARCH_DIAMETER) && 
					((u != SAGA_SEARCH_CENTER) || (v != SAGA_SEARCH_CENTER))) {
						_searchArray.getPathCell(u, v)->visited = 1;
					}
			}
		}

	_queueCount = 0;
	pushPoint(SAGA_SEARCH_CENTER, SAGA_SEARCH_CENTER, 0, 0);


	while (_queueCount > 0) {	

		_queueCount--;
		tilePoint = *_searchArray.getQueue(_queueCount);

		if (tilePoint.cost > 100 && actor == _vm->_actor->_protagonist) continue;

		dist = ABS(tilePoint.u - uFinish) + ABS(tilePoint.v - vFinish);

		if (dist < bestDistance) {
			bestU = tilePoint.u;
			bestV = tilePoint.v;
			bestDistance = dist;

			if (dist == 0) {
				break;
			}
		}

		testPossibleDirections(uBase + tilePoint.u, vBase + tilePoint.v, terraComp, 
			(tilePoint.u == SAGA_SEARCH_CENTER && tilePoint.v == SAGA_SEARCH_CENTER));

		for (dir = 0; dir < 8; dir++) {
			terrainMask = terraComp[dir];

			if (terrainMask & SAGA_IMPASSABLE) {
				continue;
			} else {
				if (terrainMask & (1 << kTerrRough)) {
					tdir = &hardDirTable[ dir ];
				} else {
					if (terrainMask & (1 << kTerrNone)) {
						tdir = &normalDirTable[ dir ];
					} else {
						tdir = &easyDirTable[ dir ];
					}
				}
			}


			pushPoint(tilePoint.u + tdir->u, tilePoint.v + tdir->v, tilePoint.cost + tdir->cost, dir);
		}
	}

	res = &_pathDirections[SAGA_MAX_PATH_DIRECTIONS];
	i = 0;
	while ((bestU != SAGA_SEARCH_CENTER) || (bestV != SAGA_SEARCH_CENTER)) {
		pcell = _searchArray.getPathCell(bestU, bestV);

		*--res = pcell->direction;
		i++;
		if (i >= SAGA_MAX_PATH_DIRECTIONS) {
			break;
		}

		dir = (pcell->direction + 4) & 0x07;

		bestU += normalDirTable[dir].u;
		bestV += normalDirTable[dir].v;
	}

/*	if (i > 64) {
		i = 64;
	}*/
	actor->walkStepsCount = i;
	if (i) {
		actor->setTileDirectionsSize(i, false);
		memcpy(actor->tileDirections, res, i );
	}
}

void IsoMap::setTileDoorState(int doorNumber, int doorState) {
	MultiTileEntryData *multiTileEntryData;

	if ((doorNumber < 0) || (doorNumber >= _multiCount)) {
		error("setTileDoorState: doorNumber >= _multiCount");
	}
	
	multiTileEntryData = &_multiTable[doorNumber];
	multiTileEntryData->currentState = doorState;
}

static const int16 directions[8][2] = {
	{	16,		16},
	{	16,		0},
	{	16,		-16},
	{	0,		-16},
	{	-16,	-16},
	{	-16,	0},
	{	-16,	16},
	{	0,		16}
};



bool IsoMap::nextTileTarget(ActorData* actor) {
	uint16 dir;

	if (actor->walkStepIndex >= actor->walkStepsCount) {
		return false;
	}


	actor->actionDirection = dir = actor->tileDirections[actor->walkStepIndex++];

	actor->partialTarget.u() =
		(actor->location.u() & ~0x0f) + 8 + directions[dir][0];

	actor->partialTarget.v() =
		(actor->location.v() & ~0x0f) + 8 + directions[dir][1];


	if (dir == 0) {
		actor->facingDirection = kDirUp;
	} else {
		if (dir == 4) {
			actor->facingDirection = kDirDown;
		} else {
			if (dir < 4) {
				actor->facingDirection = kDirRight;
			} else {
				actor->facingDirection = kDirLeft;
			}
		}
	}

	return true;
}

void IsoMap::screenPointToTileCoords(const Point &position, Location &location) {
	Point mPos(position);
	int x,y;

	if (_vm->_scene->currentSceneResourceId() == RID_ITE_OVERMAP_SCENE){
		if (mPos.y < 16) {
			mPos.y = 16;
		}
	}

	x = mPos.x + _viewScroll.x - (128 * SAGA_TILEMAP_W) - 16;
	y = mPos.y + _viewScroll.y - (128 * SAGA_TILEMAP_W) + _vm->_actor->_protagonist->location.z;

	location.u() = (x - y * 2) >> 1;
	location.v() = - (x + y * 2) >> 1;
	location.z = _vm->_actor->_protagonist->location.z;
}

} // End of namespace Saga