scummvm/scumm/gfx.cpp

/* ScummVM - Scumm Interpreter
 * Copyright (C) 2001  Ludvig Strigeus
 * Copyright (C) 2001-2003 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., 59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.
 *
 * $Header$
 *
 */

#include "stdafx.h"
#include "scumm.h"
#include "actor.h"
#include "charset.h"
#include "resource.h"
#include "usage_bits.h"
#include "util.h"


#ifdef _MSC_VER
#	pragma warning( disable : 4068 ) // turn off "unknown pragma" warning
#endif


// If you wan to try buggy hacked smooth scrolling support in The Dig, enable
// the following preprocessor flag by uncommenting it.
//
// Note: This is purely experimental, NOT WORKING COMPLETLY and very buggy.
// Please do not make reports about problems with it - this is only in CVS
// to get it fixed and so that really interested parties can experiment it.
// It is NOT FIT FOR GENERAL USAGE! You have been warned.
//
// Doing this correctly will be quite some more complicated. Basically, with smooth
// scrolling, the virtual screen strips don't match the display screen strips.
// Hence we either have to draw partial strips - but that'd be rather cumbersome.
// Or the much simple (and IMHO more elegant) solution is to simply use a screen pitch
// that is 8 pixel wider than the real screen width, and always draw one strip more than 
// needed to the backbuf. This will still require quite some code to be changed but
// should otherwise be relatively easy to understand, and using VirtScreen::pitch
// will actually clean up the code.
//
// #define V7_SMOOTH_SCROLLING_HACK


enum {
	kScrolltime = 500,  // ms scrolling is supposed to take
	kPictureDelay = 20
};

#define NUM_SHAKE_POSITIONS 8
static const int8 shake_positions[NUM_SHAKE_POSITIONS] = {
	0, 1 * 2, 2 * 2, 1 * 2, 0 * 2, 2 * 2, 3 * 2, 1 * 2
};

/*
 * The following structs define four basic fades/transitions used by 
 * transitionEffect(), each looking differently to the user.
 * Note that the stripTables contain strip numbers, and they assume
 * that the screen has 40 vertical strips (i.e. 320 pixel), and 25 horizontal
 * strips (i.e. 200 pixel). There is a hack in transitionEffect that
 * makes it work correctly in games which have a different screen height
 * (for example, 240 pixel), but nothing is done regarding the width, so this
 * code won't work correctly in COMI. Also, the number of iteration depends
 * on min(vertStrips, horizStrips}. So the 13 is derived from 25/2, rounded up.
 * And the 25 = min(25,40). Hence for Zak256 instead of 13 and 25, the values
 * 15 and 30 should be used, and for COMI probably 30 and 60. 
 */

struct TransitionEffect {
	byte numOfIterations;
	int8 deltaTable[16];	// four times l / t / r / b
	byte stripTable[16];	// ditto
};
#ifdef __PALM_OS__
static const TransitionEffect *transitionEffects;
#else
static const TransitionEffect transitionEffects[4] = {
	// Iris effect (looks like an opening/closing camera iris)
	{
		13,		// Number of iterations
		{
			1,  1, -1,  1,
		   -1,  1, -1, -1,
			1, -1, -1, -1,
			1,  1,  1, -1
		},
		{
			0,  0, 39,  0,
		   39,  0, 39, 24,
			0, 24, 39, 24,
			0,  0,  0, 24
		}
	},
	
	// Box wipe (a box expands from the upper-left corner to the lower-right corner)
	{
		25,		// Number of iterations
		{
			0,  1,  2,  1,
			2,  0,  2,  1,
			2,  0,  2,  1,
			0,  0,  0,  0
		},
		{
			0,  0,  0,  0,
			0,  0,  0,  0,
			1,  0,  1,  0,
		  255,  0,  0,  0
		}
	},
	
	
	// Box wipe (a box expands from the lower-right corner to the upper-left corner)
	{
		25,		// Number of iterations
		{
		   -2, -1,  0, -1,
		   -2, -1, -2,  0,
		   -2, -1, -2,  0,
			0,  0,  0,  0
		},
		{
		   39, 24, 39, 24,
		   39, 24, 39, 24,
		   38, 24, 38, 24,
		  255,  0,  0,  0
		}
	},
	
	// Inverse box wipe
	{
		25,		// Number of iterations
		{
			0, -1, -2, -1,
		   -2,  0, -2, -1,
		   -2,  0, -2, -1,
		    0,  0,  0,  0
		},
		{
			0, 24, 39, 24,
		   39,  0, 39, 24,
		   38,  0, 38, 24,
		  255,  0,  0,  0
		}
	}
};
#endif

/*
 * Mouse cursor cycle colors (for the default crosshair).
 */
static const byte default_cursor_colors[4] = {
	15, 15, 7, 8
};

static const uint16 default_cursor_images[5][16] = {
	/* cross-hair */
	{ 0x0080, 0x0080, 0x0080, 0x0080, 0x0080, 0x0080, 0x0000, 0x7e3f,
	  0x0000, 0x0080, 0x0080, 0x0080, 0x0080, 0x0080, 0x0080, 0x0000 },
	/* hourglass */
	{ 0x0000, 0x7ffe, 0x6006, 0x300c, 0x1818, 0x0c30, 0x0660, 0x03c0,
	  0x0660, 0x0c30, 0x1998, 0x33cc, 0x67e6, 0x7ffe, 0x0000, 0x0000 },
	/* arrow */
	{ 0x0000, 0x4000, 0x6000, 0x7000, 0x7800, 0x7c00, 0x7e00, 0x7f00,
	  0x7f80, 0x78c0, 0x7c00, 0x4600, 0x0600, 0x0300, 0x0300, 0x0180 },
	/* hand */
	{ 0x1e00, 0x1200, 0x1200, 0x1200, 0x1200, 0x13ff, 0x1249, 0x1249,
	  0xf249, 0x9001, 0x9001, 0x9001, 0x8001, 0x8001, 0x8001, 0xffff },
	/* cross-hair zak256 - chrilith palmos */
/*
	{ 0x0080, 0x0080, 0x02a0, 0x01c0, 0x0080, 0x1004, 0x0808, 0x7c1f,
	  0x0808, 0x1004, 0x0080, 0x01c0, 0x02a0, 0x0080, 0x0080, 0x0000 },
*/
	{ 0x0080, 0x02a0, 0x01c0, 0x0080, 0x0000, 0x2002, 0x1004, 0x780f,
	  0x1004, 0x2002, 0x0000, 0x0080, 0x01c0, 0x02a0, 0x0080, 0x0000 },
};

static const byte default_cursor_hotspots[10] = {
	8, 7,   8, 7,   1, 1,   5, 0,
	8, 7, //zak256
};


static inline uint colorWeight(int red, int green, int blue) {
	return 3 * red * red + 6 * green * green + 2 * blue * blue;
}

void Scumm::getGraphicsPerformance() {
	int i;

	for (i = 10; i != 0; i--) {
		initScreens(0, 0, _realWidth, _realHeight);
	}

	if (!(_features & GF_SMALL_HEADER))	// Variable is reserved for game scripts in earlier games
		VAR(VAR_PERFORMANCE_1) = 0;

	for (i = 10; i != 0; i--) {
		setDirtyRange(0, 0, _realHeight);	//ender
		drawDirtyScreenParts();
	}

	if (!(_features & GF_SMALL_HEADER))	// Variable is reserved for game scripts in earlier games
		VAR(VAR_PERFORMANCE_2) = 0;

	if (_features & GF_AFTER_V7)
		initScreens(0, 0, _realWidth, _realHeight);
	else
		initScreens(0, 16, _realWidth, 144);
}

void Scumm::initScreens(int a, int b, int w, int h) {
	int i;

	for (i = 0; i < 3; i++) {
		nukeResource(rtBuffer, i + 1);
		nukeResource(rtBuffer, i + 5);
	}

	if (!getResourceAddress(rtBuffer, 4)) {
		if (_features & GF_AFTER_V7) {
			initVirtScreen(3, 0, (_realHeight / 2) - 10, _realWidth, 13, false, false);
		} else {
			initVirtScreen(3, 0, 80, _realWidth, 13, false, false);
		}
	}
	initVirtScreen(0, 0, b, _realWidth, h - b, true, true);
	initVirtScreen(1, 0, 0, _realWidth, b, false, false);
	initVirtScreen(2, 0, h, _realWidth, _realHeight - h, false, false);

	_screenB = b;
	_screenH = h;

}

void Scumm::initVirtScreen(int slot, int number, int top, int width, int height, bool twobufs,
													 bool scrollable) {
	VirtScreen *vs = &virtscr[slot];
	int size;

	assert(height >= 0);
	assert(slot >= 0 && slot < 4);

	if (_features & GF_AFTER_V7) {
		if ((!slot) && (_scrHeight != 0))
			height = _scrHeight;
	}

	vs->number = slot;
	vs->width = _realWidth;
	vs->topline = top;
	vs->height = height;
	vs->alloctwobuffers = twobufs;
	vs->scrollable = scrollable;
	vs->xstart = 0;
	size = vs->width * vs->height;
	vs->size = size;
	vs->backBuf = NULL;

	if (vs->scrollable) {
		if (_features & GF_AFTER_V7) {
			size += _realWidth * 8;
		} else {
			size += _realWidth * 4;
		}
	}

	createResource(rtBuffer, slot + 1, size);
	vs->screenPtr = getResourceAddress(rtBuffer, slot + 1);
	memset(vs->screenPtr, 0, size);			// reset background

	if (twobufs) {
		createResource(rtBuffer, slot + 5, size);
	}

	if (slot != 3) {
		setDirtyRange(slot, 0, height);
	}
}

VirtScreen *Scumm::findVirtScreen(int y) {
	VirtScreen *vs = virtscr;
	int i;

	for (i = 0; i < 3; i++, vs++) {
		if (y >= vs->topline && y < vs->topline + vs->height) {
			return vs;
		}
	}
	return NULL;
}

void Scumm::updateDirtyRect(int virt, int left, int right, int top, int bottom, int dirtybit) {
	VirtScreen *vs = &virtscr[virt];
	int lp, rp;

	if (top > vs->height || left > vs->width || right < 0 || bottom < 0)
		return;

	if (top < 0)
		top = 0;
	if (left < 0)
		left = 0;
	if (bottom > vs->height)
		bottom = vs->height;
	if (right > vs->width)
		right = vs->width;

	if (virt == 0 && dirtybit) {
		lp = (left >> 3) + _screenStartStrip;
		if (lp < 0)
			lp = 0;
		if (_features & GF_AFTER_V7) {
#ifdef V7_SMOOTH_SCROLLING_HACK
			rp = (right + vs->xstart) >> 3;
#else
			rp = (right >> 3) + _screenStartStrip;
#endif
			if (rp > 409)
				rp = 409;
		} else {
			rp = (right >> 3) + _screenStartStrip;
			if (rp >= 200)
				rp = 200;
		}
		for (; lp <= rp; lp++)
			setGfxUsageBit(lp, dirtybit);
	}

	setVirtscreenDirty(vs, left, top, right, bottom);
}

void Scumm::setVirtscreenDirty(VirtScreen *vs, int left, int top, int right, int bottom) {
	int lp = left >> 3;
	int rp = right >> 3;

	if ((lp >= gdi._numStrips) || (rp < 0))
		return;
	if (lp < 0)
		lp = 0;
	if (rp >= gdi._numStrips)
		rp = gdi._numStrips - 1;

	while (lp <= rp) {
		if (top < vs->tdirty[lp])
			vs->tdirty[lp] = top;
		if (bottom > vs->bdirty[lp])
			vs->bdirty[lp] = bottom;
		lp++;
	}
}

void Scumm::setDirtyRange(int slot, int top, int bottom) {
	int i;
	VirtScreen *vs = &virtscr[slot];
	for (i = 0; i < gdi._numStrips; i++) {
		vs->tdirty[i] = top;
		vs->bdirty[i] = bottom;
	}
}

void Scumm::drawDirtyScreenParts() {
	int i;
	VirtScreen *vs;
	byte *src;

	updateDirtyScreen(2);
	if (_features & GF_AFTER_V3)
		updateDirtyScreen(1);

	if (camera._last.x == camera._cur.x && (camera._last.y == camera._cur.y || !(_features & GF_AFTER_V7))) {
		updateDirtyScreen(0);
	} else {
		vs = &virtscr[0];

		src = vs->screenPtr + vs->xstart + _screenTop * _realWidth;
		_system->copy_rect(src, _realWidth, 0, vs->topline, _realWidth, vs->height - _screenTop);

		for (i = 0; i < gdi._numStrips; i++) {
			vs->tdirty[i] = vs->height;
			vs->bdirty[i] = 0;
		}
	}

	/* Handle shaking */
	if (_shakeEnabled) {
		_shakeFrame = (_shakeFrame + 1) & (NUM_SHAKE_POSITIONS - 1);
		_system->set_shake_pos(shake_positions[_shakeFrame]);
	} else if (!_shakeEnabled &&_shakeFrame != 0) {
		_shakeFrame = 0;
		_system->set_shake_pos(shake_positions[_shakeFrame]);
	}
}

void Scumm::updateDirtyScreen(int slot) {
	gdi.updateDirtyScreen(&virtscr[slot]);
}

// Blit the data from the given VirtScreen to the display. If the camera moved,
// a full blit is done, otherwise only the visible dirty areas are updated.
void Gdi::updateDirtyScreen(VirtScreen *vs) {
	if (vs->height == 0)
		return;

	if (_vm->_features & GF_AFTER_V7 && (_vm->camera._cur.y != _vm->camera._last.y)) {
		drawStripToScreen(vs, 0, _numStrips << 3, 0, vs->height);
	} else {
		int i;
		int start, w, top, bottom;

		w = 8;
		start = 0;

		for (i = 0; i < _numStrips; i++) {
			bottom = vs->bdirty[i];

			if (bottom) {
				top = vs->tdirty[i];
				vs->tdirty[i] = vs->height;
				vs->bdirty[i] = 0;
				if (i != (_numStrips - 1) && vs->bdirty[i + 1] == bottom && vs->tdirty[i + 1] == top) {
					// Simple optimizations: if two or more neighbouring strips form one bigger rectangle,
					// blit them all at once.
					w += 8;
					continue;
				}
				// handle vertically scrolling rooms
				if (_vm->_features & GF_AFTER_V7)
					drawStripToScreen(vs, start * 8, w, 0, vs->height);
				else
					drawStripToScreen(vs, start * 8, w, top, bottom);
				w = 8;
			}
			start = i + 1;
		}
	}
}

// Blit the specified rectangle from the given virtual screen to the display.
void Gdi::drawStripToScreen(VirtScreen *vs, int x, int w, int t, int b) {
	byte *ptr;
	int height;

	if (b <= t)
		return;

	if (t > vs->height)
		t = 0;

	if (b > vs->height)
		b = vs->height;

	height = b - t;
	if (height > _vm->_realHeight)
		height = _vm->_realHeight;

	// Normally, _vm->_screenTop should always be >= 0, but for some old save games
	// it is not, hence we check & correct it here.
	if (_vm->_screenTop < 0)
		_vm->_screenTop = 0;

	ptr = vs->screenPtr + (x + vs->xstart) + (_vm->_screenTop + t) * _vm->_realWidth;
	_vm->_system->copy_rect(ptr, _vm->_realWidth, x, vs->topline + t, w, height);
}

void Gdi::clearUpperMask() {
	memset(_vm->getResourceAddress(rtBuffer, 9), 0, _imgBufOffs[1] - _imgBufOffs[0]);
}

// Reset the background behind an actor or blast object
void Gdi::resetBackground(int top, int bottom, int strip) {
	VirtScreen *vs = &_vm->virtscr[0];
	byte *backbuff_ptr, *bgbak_ptr;
	int offs, numLinesToProcess;

	if (top < vs->tdirty[strip])
		vs->tdirty[strip] = top;

	if (bottom > vs->bdirty[strip])
		vs->bdirty[strip] = bottom;

	offs = (top * _numStrips + _vm->_screenStartStrip + strip);
	_mask_ptr = _vm->getResourceAddress(rtBuffer, 9) + offs;
	bgbak_ptr = _vm->getResourceAddress(rtBuffer, 5) + (offs << 3);
	backbuff_ptr = vs->screenPtr + (offs << 3);

	numLinesToProcess = bottom - top;
	if (numLinesToProcess) {
		if ((_vm->_features & GF_AFTER_V6) || (_vm->VAR(_vm->VAR_CURRENT_LIGHTS) & LIGHTMODE_screen)) {
			if (_vm->hasCharsetMask(strip << 3, top, (strip + 1) << 3, bottom))
				draw8ColWithMasking(backbuff_ptr, bgbak_ptr, numLinesToProcess, _mask_ptr);
			else
				draw8Col(backbuff_ptr, bgbak_ptr, numLinesToProcess);
		} else {
			clear8Col(backbuff_ptr, numLinesToProcess);
		}
	}
}

void Scumm::blit(byte *dst, byte *src, int w, int h) {
	assert(h > 0);
	assert(src != NULL);
	assert(dst != NULL);

	do {
		memcpy(dst, src, w);
		dst += _realWidth;
		src += _realWidth;
	} while (--h);
}

#pragma mark -

void Scumm::initBGBuffers(int height) {
	byte *ptr;
	int size, itemsize, i;
	byte *room;

	if (_features & GF_AFTER_V7) {
		initVirtScreen(0, 0, virtscr[0].topline, _realWidth, height, 1, 1);
	}

	room = getResourceAddress(rtRoom, _roomResource);
	if ((_features & GF_AFTER_V2) || (_features & GF_AFTER_V3)) {
		gdi._numZBuffer = 2;
	} else if (_features & GF_SMALL_HEADER) {
		int off;
		ptr = findResourceData(MKID('SMAP'), room);
		gdi._numZBuffer = 0;

		if (_gameId == GID_MONKEY_EGA)
			off = READ_LE_UINT16(ptr);
		else
			off = READ_LE_UINT32(ptr);

		while (off && gdi._numZBuffer < 4) {
			gdi._numZBuffer++;
			ptr += off;
			off = READ_LE_UINT16(ptr);
		}
	} else if (_features & GF_AFTER_V8) {
		// in V8 there is no RMIH and num z buffers is in RMHD
		ptr = findResource(MKID('RMHD'), room);
		gdi._numZBuffer = READ_LE_UINT32(ptr + 24) + 1;
	} else {
		ptr = findResource(MKID('RMIH'), findResource(MKID('RMIM'), room));
		gdi._numZBuffer = READ_LE_UINT16(ptr + 8) + 1;
	}
	assert(gdi._numZBuffer >= 1 && gdi._numZBuffer <= 8);

	if (_features & GF_AFTER_V7)
		itemsize = (_scrHeight + 10) * gdi._numStrips;
	else
		itemsize = (_scrHeight + 4) * gdi._numStrips;


	size = itemsize * gdi._numZBuffer;
	memset(createResource(rtBuffer, 9, size), 0, size);

	for (i = 0; i < (int)ARRAYSIZE(gdi._imgBufOffs); i++) {
		if (i < gdi._numZBuffer)
			gdi._imgBufOffs[i] = i * itemsize;
		else
			gdi._imgBufOffs[i] = (gdi._numZBuffer - 1) * itemsize;
	}
}

void Scumm::drawFlashlight() {
	int i, j, offset, x, y;

	// Remove the flash light first if it was previously drawn
	if (_flashlightIsDrawn) {
		updateDirtyRect(0, _flashlight.x, _flashlight.x + _flashlight.w,
										_flashlight.y, _flashlight.y + _flashlight.h, USAGE_BIT_DIRTY);
		
		if (_flashlight.buffer) {
			i = _flashlight.h;
			do {
				memset(_flashlight.buffer, 0, _flashlight.w);
				_flashlight.buffer += _realWidth;
			} while (--i);
		}
		_flashlightIsDrawn = false;
	}

	if (_flashlightXStrips == 0 || _flashlightYStrips == 0)
		return;

	// Calculate the area of the flashlight
	if (_gameId == GID_ZAK256) {
		x = _virtual_mouse_x;
		y = _virtual_mouse_y;
	} else {
		Actor *a = a = derefActorSafe(VAR(VAR_EGO), "drawFlashlight");
		x = a->x;
		y = a->y;
	}
	_flashlight.w = _flashlightXStrips * 8;
	_flashlight.h = _flashlightYStrips * 8;
	_flashlight.x = x - _flashlight.w / 2 - _screenStartStrip * 8;
	_flashlight.y = y - _flashlight.h / 2;

	if (_gameId == GID_LOOM || _gameId == GID_LOOM256)
		_flashlight.y -= 12;

	// Clip the flashlight at the borders
	if (_flashlight.x < 0)
		_flashlight.x = 0;
	else if (_flashlight.x + _flashlight.w > gdi._numStrips * 8)
		_flashlight.x = gdi._numStrips * 8 - _flashlight.w;
	if (_flashlight.y < 0)
		_flashlight.y = 0;
	else if (_flashlight.y + _flashlight.h> virtscr[0].height)
		_flashlight.y = virtscr[0].height - _flashlight.h;

	// Redraw any actors "under" the flashlight
	for (i = _flashlight.x / 8; i < (_flashlight.x + _flashlight.w) / 8; i++) {
		setGfxUsageBit(_screenStartStrip + i, USAGE_BIT_DIRTY);
		virtscr[0].tdirty[i] = 0;
		virtscr[0].bdirty[i] = virtscr[0].height;
	}

	byte *bgbak;
	offset = _flashlight.y * _realWidth + virtscr[0].xstart + _flashlight.x;
	_flashlight.buffer = virtscr[0].screenPtr + offset;
	bgbak = getResourceAddress(rtBuffer, 5) + offset;

	blit(_flashlight.buffer, bgbak, _flashlight.w, _flashlight.h);

	// Round the corners. To do so, we simply hard-code a set of nicely
	// rounded corners.
	int corner_data[] = { 8, 6, 4, 3, 2, 2, 1, 1 };
	int minrow = 0;
	int maxcol = _flashlight.w - 1;
	int maxrow = (_flashlight.h - 1) * _realWidth;

	for (i = 0; i < 8; i++, minrow += _realWidth, maxrow -= _realWidth) {
		int d = corner_data[i];

		for (j = 0; j < d; j++) {
			_flashlight.buffer[minrow + j] = 0;
			_flashlight.buffer[minrow + maxcol - j] = 0;
			_flashlight.buffer[maxrow + j] = 0;
			_flashlight.buffer[maxrow + maxcol - j] = 0;
		}
	}
	
	_flashlightIsDrawn = true;
}

// Redraw background as needed, i.e. the left/right sides if scrolling took place etc.
// Note that this only updated the virtual screen, not the actual display.
void Scumm::redrawBGAreas() {
	int i;
	int val;
	int diff;

	if (!(_features & GF_AFTER_V7))
		if (camera._cur.x != camera._last.x && _charset->_hasMask)
			stopTalk();

	val = 0;

	// Redraw parts of the background which are marked as dirty.
	if (!_fullRedraw && _BgNeedsRedraw) {
		for (i = 0; i != gdi._numStrips; i++) {
			if (testGfxUsageBit(_screenStartStrip + i, USAGE_BIT_DIRTY)) {
				redrawBGStrip(i, 1);
			}
		}
	}

	if (_features & GF_AFTER_V7) {
		diff = (camera._cur.x >> 3) - (camera._last.x >> 3);
		if (_fullRedraw == 0 && diff == 1) {
			val = 2;
			redrawBGStrip(gdi._numStrips - 1, 1);
		} else if (_fullRedraw == 0 && diff == -1) {
			val = 1;
			redrawBGStrip(0, 1);
		} else if (_fullRedraw != 0 || diff != 0) {
			_BgNeedsRedraw = false;
			redrawBGStrip(0, gdi._numStrips);
		}
	} else {
		if (_fullRedraw == 0 && camera._cur.x - camera._last.x == 8) {
			val = 2;
			redrawBGStrip(gdi._numStrips - 1, 1);
		} else if (_fullRedraw == 0 && camera._cur.x - camera._last.x == -8) {
			val = 1;
			redrawBGStrip(0, 1);
		} else if (_fullRedraw != 0 || camera._cur.x != camera._last.x) {
			_BgNeedsRedraw = false;
			_flashlightIsDrawn = false;
			redrawBGStrip(0, gdi._numStrips);
		}
	}

	drawRoomObjects(val);
	_BgNeedsRedraw = false;
}

void Scumm::redrawBGStrip(int start, int num) {
	int s = _screenStartStrip + start;

	assert(s >= 0 && (size_t) s < sizeof(gfxUsageBits) / (3 * sizeof(gfxUsageBits[0])));

	for (int i = 0; i < num; i++)
		setGfxUsageBit(s + i, USAGE_BIT_DIRTY);

	gdi.drawBitmap(getResourceAddress(rtRoom, _roomResource) + _IM00_offs,
								&virtscr[0], s, 0, virtscr[0].width, virtscr[0].height, s, num, 0);
}

void Scumm::restoreCharsetBg() {
	if (gdi._mask_left != -1) {
		restoreBG(gdi._mask_left, gdi._mask_top, gdi._mask_right, gdi._mask_bottom);
		_charset->_hasMask = false;
		gdi._mask_left = -1;
		_charset->_strLeft = -1;
		_charset->_left = -1;
	}

	_charset->_nextLeft = _string[0].xpos;
	_charset->_nextTop = _string[0].ypos;
}

void Scumm::restoreBG(int left, int top, int right, int bottom, byte backColor) {
	VirtScreen *vs;
	int topline, height, width;
	byte *backbuff, *bgbak;
	bool lightsOn;

	if (left == right || top == bottom)
		return;
	if (top < 0)
		top = 0;

	if ((vs = findVirtScreen(top)) == NULL)
		return;

	topline = vs->topline;
	height = topline + vs->height;

	if (left < 0)
		left = 0;
	if (right < 0)
		right = 0;
	if (left > _realWidth)
		return;
	if (right > _realWidth)
		right = _realWidth;
	if (bottom >= height)
		bottom = height;

	updateDirtyRect(vs->number, left, right, top - topline, bottom - topline, USAGE_BIT_RESTORED);

	int offset = (top - topline) * _realWidth + vs->xstart + left;
	backbuff = vs->screenPtr + offset;
	bgbak = getResourceAddress(rtBuffer, vs->number + 5) + offset;

	height = bottom - top;
	width = right - left;

	// Check whether lights are turned on or not
	lightsOn = (_features & GF_AFTER_V6) || (vs->number != 0) || (VAR(VAR_CURRENT_LIGHTS) & LIGHTMODE_screen);

	if (vs->alloctwobuffers && _currentRoom != 0 && lightsOn ) {
		blit(backbuff, bgbak, width, height);
		if (vs->number == 0 && _charset->_hasMask && height) {
			byte *mask;
			int mask_width = (width >> 3);

			if (width & 0x07)
				mask_width++;

			mask = getResourceAddress(rtBuffer, 9) + top * gdi._numStrips + (left >> 3) + _screenStartStrip;
			if (vs->number == 0)
				mask += vs->topline * gdi._numStrips;

			do {
				memset(mask, 0, mask_width);
				mask += gdi._numStrips;
			} while (--height);
		}
	} else {
		while (height--) {
			memset(backbuff, backColor, width);
			backbuff += _realWidth;
		}
	}
}

int Scumm::hasCharsetMask(int x, int y, int x2, int y2) {
	if (!_charset->_hasMask || y > gdi._mask_bottom || x > gdi._mask_right ||
			y2 < gdi._mask_top || x2 < gdi._mask_left)
		return 0;
	return 1;
}

byte Scumm::isMaskActiveAt(int l, int t, int r, int b, byte *mem) {
	int w, h, i;

	l >>= 3;
	if (l < 0)
		l = 0;
	if (t < 0)
		t = 0;

	r >>= 3;
	if (r > gdi._numStrips - 1)
		r = gdi._numStrips - 1;

	mem += l + t * gdi._numStrips;

	w = r - l;
	h = b - t + 1;

	do {
		for (i = 0; i <= w; i++)
			if (mem[i]) {
				return true;
			}
		mem += gdi._numStrips;
	} while (--h);

	return false;
}

void Gdi::drawBitmap(byte *ptr, VirtScreen *vs, int x, int y, const int width, const int height,
                     int stripnr, int numstrip, byte flag) {
	assert(ptr);
	assert(height > 0);
	byte *backbuff_ptr, *bgbak_ptr, *smap_ptr;
	int i;
	byte *zplane_list[9];

	int bottom;
	int numzbuf;
	int sx;
	bool lightsOn;
	bool useOrDecompress = false;

	// Check whether lights are turned on or not
	lightsOn = (_vm->_features & GF_AFTER_V6) || (vs->number != 0) || (_vm->VAR(_vm->VAR_CURRENT_LIGHTS) & LIGHTMODE_screen);

	CHECK_HEAP;
	if (_vm->_features & GF_SMALL_HEADER)
		smap_ptr = ptr;
	else if (_vm->_features & GF_AFTER_V8)
		smap_ptr = ptr;
	else
		smap_ptr = findResource(MKID('SMAP'), ptr);

	assert(smap_ptr);

	zplane_list[0] = smap_ptr;

	if (_disable_zbuffer)
		numzbuf = 0;
	else if (_numZBuffer <= 1)
		numzbuf = _numZBuffer;
	else {
		numzbuf = _numZBuffer;
		assert(numzbuf <= (int)ARRAYSIZE(zplane_list));
		
		if (_vm->_features & GF_OLD256) {
			zplane_list[1] = smap_ptr + READ_LE_UINT32(smap_ptr);
			if (0 == READ_LE_UINT32(zplane_list[1]))
				zplane_list[1] = 0;
		} else if (_vm->_features & GF_SMALL_HEADER) {
			if (_vm->_features & GF_16COLOR)
				zplane_list[1] = smap_ptr + READ_LE_UINT16(smap_ptr);
			else
				zplane_list[1] = smap_ptr + READ_LE_UINT32(smap_ptr);
			for (i = 2; i < numzbuf; i++) {
				zplane_list[i] = zplane_list[i-1] + READ_LE_UINT16(zplane_list[i-1]);
			}
		} else if (_vm->_features & GF_AFTER_V8) {
			// Find the OFFS chunk of the ZPLN chunk
			byte *zplnOffsChunkStart = smap_ptr + READ_BE_UINT32(smap_ptr + 12) + 24;
			
			// Each ZPLN contains a WRAP chunk, which has (as always) an OFFS subchunk pointing
			// at ZSTR chunks. These once more contain a WRAP chunk which contains nothing but
			// an OFFS chunk. The content of this OFFS chunk contains the offsets to the
			// Z-planes.
			// We do not directly make use of this, but rather hard code offsets (like we do
			// for all other Scumm-versions, too). Clearly this is a bit hackish, but works
			// well enough, and there is no reason to assume that there are any cases where it
			// might fail. Still, doing this properly would have the advantage of catching
			// invalid/damaged data files, and allow us to exit gracefully instead of segfaulting.
			for (i = 1; i < numzbuf; i++) {
				zplane_list[i] = zplnOffsChunkStart + READ_LE_UINT32(zplnOffsChunkStart + 4 + i*4) + 16;
			}
		} else {
			const uint32 zplane_tags[] = {
				MKID('ZP00'),
				MKID('ZP01'),
				MKID('ZP02'),
				MKID('ZP03'),
				MKID('ZP04')
			};
			
			for (i = 1; i < numzbuf; i++) {
				zplane_list[i] = findResource(zplane_tags[i], ptr);
			}
		}
	}
	
	if (_vm->_features & GF_AFTER_V8) {	
		// A small hack to skip to the BSTR->WRAP->OFFS chunk. Note: order matters, we do this
		// *after* the Z buffer code because that assumes' the orginal value of smap_ptr. 
		smap_ptr += 24;
	}

	bottom = y + height;
	if (bottom > vs->height) {
		warning("Gdi::drawBitmap, strip drawn to %d below window bottom %d", bottom, vs->height);
	}

	_vertStripNextInc = height * _vm->_realWidth - 1;

	sx = x;
	if (vs->scrollable)
		sx -= vs->xstart >> 3;

	//////
	//////
	//////   START OF BIG HACK!
	//////
	//////
	if (_vm->_features & GF_AFTER_V2) {
		
		backbuff_ptr = vs->screenPtr + (y * _numStrips + x) * 8;
		if (vs->alloctwobuffers)
			bgbak_ptr = _vm->getResourceAddress(rtBuffer, vs->number + 5) + (y * _numStrips + x) * 8;
		else
			bgbak_ptr = backbuff_ptr;

		_mask_ptr = _vm->getResourceAddress(rtBuffer, 9) + (y * _numStrips + x);

		const int left = stripnr << 3;
		const int right = left + numstrip << 3;
		byte *dst = bgbak_ptr;
		byte *src = smap_ptr;
		byte color = 0, data = 0;
		int run = 1;
		bool dither = false;
		byte dither_table[128];
		byte *ptr_dither_table;
		memset(dither_table, 0, sizeof(dither_table));
		int theX, theY;
		
		// Draw image data. To do this, we decode the full RLE graphics data,
		// but only draw those parts we actually want to display.
		assert(height <= 128);
		for (theX = 0; theX < width; theX++) {
			ptr_dither_table = dither_table;
			for (theY = 0; theY < height; theY++) {
				if (--run == 0) {
					data = *src++;
					if (data & 0x80) {
						run = data & 0x7f;
						dither = true;
					} else {
						run = data >> 4;
						dither = false;
					}
					if (run == 0) {
						run = *src++;
					}
					color = data & 0x0f;
				}
				if (!dither) {
					*ptr_dither_table = color;
				}
				if (left <= theX && theX < right) {
					*dst = *ptr_dither_table++;
					dst += _vm->_realWidth;
				}
			}
			if (left <= theX && theX < right) {
				dst -= _vm->_realWidth * height;
				dst++;
			}
		}

		// Draw mask (zplane) data
		theY = 0;
		theX = 0;
		while (theX < width) {
			run = *src++;
			if (run & 0x80) {
				run &= 0x7f;
				data = *src++;
				do {
					if (left <= theX && theX < right) {
						*_mask_ptr = data;
						_mask_ptr += _numStrips;
					}
					theY++;
					if (theY >= height) {
						if (left <= theX && theX < right) {
							_mask_ptr -= _numStrips * height;
							_mask_ptr++;
						}
						theY = 0;
						theX += 8;
						if (theX >= width)
							break;
					}
				} while (--run);
			} else {
				do {
					data = *src++;
					
					if (left <= theX && theX < right) {
						*_mask_ptr = data;
						_mask_ptr += _numStrips;
					}
					theY++;
					if (theY >= height) {
						if (left <= theX && theX < right) {
							_mask_ptr -= _numStrips * height;
							_mask_ptr++;
						}
						theY = 0;
						theX += 8;
						if (theX >= width)
							break;
					}
				} while (--run);
			}
		}
	}

	//////
	//////
	//////   END OF BIG HACK!
	//////
	//////

	while (numstrip--) {
		CHECK_HEAP;

		if (sx < 0)
			goto next_iter;

		if (sx >= _numStrips)
			return;

		if (y < vs->tdirty[sx])
			vs->tdirty[sx] = y;

		if (bottom > vs->bdirty[sx])
			vs->bdirty[sx] = bottom;

		backbuff_ptr = vs->screenPtr + (y * _numStrips + x) * 8;
		if (vs->alloctwobuffers)
			bgbak_ptr = _vm->getResourceAddress(rtBuffer, vs->number + 5) + (y * _numStrips + x) * 8;
		else
			bgbak_ptr = backbuff_ptr;

		_mask_ptr = _vm->getResourceAddress(rtBuffer, 9) + (y * _numStrips + x);

		if (!(_vm->_features & GF_AFTER_V2)) {
			if (_vm->_features & GF_16COLOR) {
				decodeStripEGA(bgbak_ptr, smap_ptr + READ_LE_UINT16(smap_ptr + stripnr * 2 + 2), height);
			} else if (_vm->_features & GF_SMALL_HEADER) {
				useOrDecompress = decompressBitmap(bgbak_ptr, smap_ptr + READ_LE_UINT32(smap_ptr + stripnr * 4 + 4), height);
			} else {
				useOrDecompress = decompressBitmap(bgbak_ptr, smap_ptr + READ_LE_UINT32(smap_ptr + stripnr * 4 + 8), height);
			}
		}

		CHECK_HEAP;
		if (vs->alloctwobuffers) {
			if (_vm->hasCharsetMask(sx << 3, y, (sx + 1) << 3, bottom)) {
				if (flag & dbClear || !lightsOn)
					clear8ColWithMasking(backbuff_ptr, height, _mask_ptr);
				else
					draw8ColWithMasking(backbuff_ptr, bgbak_ptr, height, _mask_ptr);
			} else {
				if (flag & dbClear || !lightsOn)
					clear8Col(backbuff_ptr, height);
				else
					draw8Col(backbuff_ptr, bgbak_ptr, height);
			}
		}
		CHECK_HEAP;

		if (!(_vm->_features & GF_AFTER_V2)) {
			// Do nothing here for V2 games - zplane was handled already.
		} else if (flag & dbDrawMaskOnAll) {
			// Sam & Max uses dbDrawMaskOnAll for things like the inventory
			// box and the speech icons. While these objects only have one
			// mask, it should be applied to all the Z-planes in the room,
			// i.e. they should mask every actor.
			//
			// This flag used to be called dbDrawMaskOnBoth, and all it
			// would do was to mask Z-plane 0. (Z-plane 1 would also be
			// masked, because what is now the else-clause used to be run
			// always.) While this seems to be the only way there is to
			// mask Z-plane 0, this wasn't good enough since actors in
			// Z-planes >= 2 would not be masked.
			//
			// The flag is also used by The Dig and Full Throttle, but I
			// don't know what for. At the time of writing, these games
			// are still too unstable for me to investigate.

			byte *z_plane_ptr;
			if (_vm->_features & GF_AFTER_V8)
				z_plane_ptr = zplane_list[1] + READ_LE_UINT32(zplane_list[1] + stripnr * 4 + 8);
			else
				z_plane_ptr = zplane_list[1] + READ_LE_UINT16(zplane_list[1] + stripnr * 2 + 8);
			for (i = 0; i < numzbuf; i++) {
				_mask_ptr_dest = _vm->getResourceAddress(rtBuffer, 9) + y * _numStrips + x + _imgBufOffs[i];
				if (useOrDecompress && (flag & dbAllowMaskOr))
					decompressMaskImgOr(_mask_ptr_dest, z_plane_ptr, height);
				else
					decompressMaskImg(_mask_ptr_dest, z_plane_ptr, height);
			}
		} else {
			for (i = 1; i < numzbuf; i++) {
				uint16 offs;

				if (!zplane_list[i])
					continue;

				if (_vm->_features & GF_AFTER_V2)
					offs = 0;
				else if (_vm->_features & GF_OLD_BUNDLE)
					offs = READ_LE_UINT16(zplane_list[i] + stripnr * 2);
				else if (_vm->_features & GF_OLD256)
					offs = READ_LE_UINT16(zplane_list[i] + stripnr * 2 + 4);
				else if (_vm->_features & GF_SMALL_HEADER)
					offs = READ_LE_UINT16(zplane_list[i] + stripnr * 2 + 2);
				else if (_vm->_features & GF_AFTER_V8)
					offs = (uint16) READ_LE_UINT32(zplane_list[i] + stripnr * 4 + 8);
				else
					offs = READ_LE_UINT16(zplane_list[i] + stripnr * 2 + 8);

				_mask_ptr_dest = _vm->getResourceAddress(rtBuffer, 9) + y * _numStrips + x + _imgBufOffs[i];

				if (offs) {
					byte *z_plane_ptr = zplane_list[i] + offs;

					if (useOrDecompress && (flag & dbAllowMaskOr)) {
						decompressMaskImgOr(_mask_ptr_dest, z_plane_ptr, height);
					} else {
						decompressMaskImg(_mask_ptr_dest, z_plane_ptr, height);
					}

				} else {
					if (!(useOrDecompress && (flag & dbAllowMaskOr)))
						for (int h = 0; h < height; h++)
							_mask_ptr_dest[h * _numStrips] = 0;
					// FIXME: needs better abstraction
				}
			}
		}

next_iter:
		CHECK_HEAP;
		x++;
		sx++;
		stripnr++;
	}
}

void Gdi::decodeStripEGA(byte *dst, byte *src, int height) {
	byte color = 0;
	int run = 0, x = 0, y = 0, z;

	while(x < 8) {
		color = *src++;
		
		if(color & 0x80) {
			run = color & 0x3f;

			if(color & 0x40) {
				color = *src++;

				if(run == 0) {
					run = *src++;
				}
				const register byte colors[2] = { color >> 4, color & 0xf };
				for(z = 0; z < run; z++) {
					*(dst + y * _vm->_realWidth + x) = colors[z&1];

					y++;
					if(y >= height) {
						y = 0;
						x++;
					}
				}
			} else {
				if(run == 0) {
					run = *src++;
				}

				for(z = 0; z < run; z++) {
					*(dst + y * _vm->_realWidth + x) = *(dst + y * _vm->_realWidth + x - 1);

					y++;
					if(y >= height) {
						y = 0;
						x++;
					}
				}
			}
		} else {
			run = color >> 4;
			if(run == 0) {
				run = *src++;
			}
			
			for(z = 0; z < run; z++) {
				*(dst + y * _vm->_realWidth + x) = color & 0xf;

				y++;
				if(y >= height) {
					y = 0;
					x++;
				}
			}
		}
	}
}

bool Gdi::decompressBitmap(byte *bgbak_ptr, byte *smap_ptr, int numLinesToProcess) {
	assert(numLinesToProcess);

	byte code = *smap_ptr++;

	if (_vm->_features & GF_AMIGA)
		_palette_mod = 16;
	else
		_palette_mod = 0;

	bool useOrDecompress = false;
	_decomp_shr = code % 10;
	_decomp_mask = 0xFF >> (8 - _decomp_shr);
	
	switch (code) {
	case 1:
		unkDecode7(bgbak_ptr, smap_ptr, numLinesToProcess);
		break;

	case 2:
		unkDecode8(bgbak_ptr, smap_ptr, numLinesToProcess);       /* Ender - Zak256/Indy256 */
		break;

	case 3:
		unkDecode9(bgbak_ptr, smap_ptr, numLinesToProcess);       /* Ender - Zak256/Indy256 */
		break;

	case 4:
		unkDecode10(bgbak_ptr, smap_ptr, numLinesToProcess);      /* Ender - Zak256/Indy256 */
		break;

	case 7:
		unkDecode11(bgbak_ptr, smap_ptr, numLinesToProcess);      /* Ender - Zak256/Indy256 */
		break;

	case 14:
	case 15:
	case 16:
	case 17:
	case 18:
		unkDecodeC(bgbak_ptr, smap_ptr, numLinesToProcess);
		break;

	case 24:
	case 25:
	case 26:
	case 27:
	case 28:
		unkDecodeB(bgbak_ptr, smap_ptr, numLinesToProcess);
		break;

	case 34:
	case 35:
	case 36:
	case 37:
	case 38:
		useOrDecompress = true;
		unkDecodeC_trans(bgbak_ptr, smap_ptr, numLinesToProcess);
		break;

	case 44:
	case 45:
	case 46:
	case 47:
	case 48:
		useOrDecompress = true;
		unkDecodeB_trans(bgbak_ptr, smap_ptr, numLinesToProcess);
		break;

	case 64:
	case 65:
	case 66:
	case 67:
	case 68:
	case 104:
	case 105:
	case 106:
	case 107:
	case 108:
		unkDecodeA(bgbak_ptr, smap_ptr, numLinesToProcess);
		break;

	case 84:
	case 85:
	case 86:
	case 87:
	case 88:
	case 124:
	case 125:
	case 126:
	case 127:
	case 128:
		useOrDecompress = true;
		unkDecodeA_trans(bgbak_ptr, smap_ptr, numLinesToProcess);
		break;

	default:
		error("Gdi::decompressBitmap: default case %d", code);
	}
	
	return useOrDecompress;
}

void Gdi::draw8ColWithMasking(byte *dst, byte *src, int height, byte *mask) {
	byte maskbits;

	do {
		maskbits = *mask;
		if (maskbits) {
			if (!(maskbits & 0x80))
				dst[0] = src[0];
			if (!(maskbits & 0x40))
				dst[1] = src[1];
			if (!(maskbits & 0x20))
				dst[2] = src[2];
			if (!(maskbits & 0x10))
				dst[3] = src[3];
			if (!(maskbits & 0x08))
				dst[4] = src[4];
			if (!(maskbits & 0x04))
				dst[5] = src[5];
			if (!(maskbits & 0x02))
				dst[6] = src[6];
			if (!(maskbits & 0x01))
				dst[7] = src[7];
		} else {
#if defined(SCUMM_NEED_ALIGNMENT)
			memcpy(dst, src, 8);
#else
			((uint32 *)dst)[0] = ((uint32 *)src)[0];
			((uint32 *)dst)[1] = ((uint32 *)src)[1];
#endif
		}
		src += _vm->_realWidth;
		dst += _vm->_realWidth;
		mask += _numStrips;
	} while (--height);
}

void Gdi::clear8ColWithMasking(byte *dst, int height, byte *mask) {
	byte maskbits;

	do {
		maskbits = *mask;
		if (maskbits) {
			if (!(maskbits & 0x80))
				dst[0] = 0;
			if (!(maskbits & 0x40))
				dst[1] = 0;
			if (!(maskbits & 0x20))
				dst[2] = 0;
			if (!(maskbits & 0x10))
				dst[3] = 0;
			if (!(maskbits & 0x08))
				dst[4] = 0;
			if (!(maskbits & 0x04))
				dst[5] = 0;
			if (!(maskbits & 0x02))
				dst[6] = 0;
			if (!(maskbits & 0x01))
				dst[7] = 0;
		} else {
#if defined(SCUMM_NEED_ALIGNMENT)
			memset(dst, 0, 8);
#else
			((uint32 *)dst)[0] = 0;
			((uint32 *)dst)[1] = 0;
#endif
		}
		dst += _vm->_realWidth;
		mask += _numStrips;
	} while (--height);
}

void Gdi::draw8Col(byte *dst, byte *src, int height) {
	do {
#if defined(SCUMM_NEED_ALIGNMENT)
		memcpy(dst, src, 8);
#else
		((uint32 *)dst)[0] = ((uint32 *)src)[0];
		((uint32 *)dst)[1] = ((uint32 *)src)[1];
#endif
		dst += _vm->_realWidth;
		src += _vm->_realWidth;
	} while (--height);
}
void Gdi::clear8Col(byte *dst, int height)
{
	do {
#if defined(SCUMM_NEED_ALIGNMENT)
		memset(dst, 0, 8);
#else
		((uint32 *)dst)[0] = 0;
		((uint32 *)dst)[1] = 0;
#endif
		dst += _vm->_realWidth;
	} while (--height);
}

void Gdi::decompressMaskImg(byte *dst, byte *src, int height) {
	byte b, c;

	while (height) {
		b = *src++;

		if (b & 0x80) {
			b &= 0x7F;
			c = *src++;

			do {
				*dst = c;
				dst += _numStrips;
				--height;
			} while (--b && height);
		} else {
			do {
				*dst = *src++;
				dst += _numStrips;
				--height;
			} while (--b && height);
		}
	}
}

void Gdi::decompressMaskImgOr(byte *dst, byte *src, int height) {
	byte b, c;

	while (height) {
		b = *src++;
		
		if (b & 0x80) {
			b &= 0x7F;
			c = *src++;

			do {
				*dst |= c;
				dst += _numStrips;
				--height;
			} while (--b && height);
		} else {
			do {
				*dst |= *src++;
				dst += _numStrips;
				--height;
			} while (--b && height);
		}
	}
}

#define READ_BIT (cl--, bit = bits&1, bits>>=1,bit)
#define FILL_BITS do {												\
										if (cl <= 8) {						\
											bits |= (*src++ << cl);	\
											cl += 8;								\
										}													\
									} while (0)

void Gdi::unkDecodeA(byte *dst, byte *src, int height) {
	byte color = *src++;
	uint bits = *src++;
	byte cl = 8;
	byte bit;
	byte incm, reps;

	do {
		int x = 8;
		do {
			FILL_BITS;
			*dst++ = color + _palette_mod;

		againPos:
			if (!READ_BIT) {
			} else if (!READ_BIT) {
				FILL_BITS;
				color = bits & _decomp_mask;
				bits >>= _decomp_shr;
				cl -= _decomp_shr;
			} else {
				incm = (bits & 7) - 4;
				cl -= 3;
				bits >>= 3;
				if (incm) {
					color += incm;
				} else {
					FILL_BITS;
					reps = bits & 0xFF;
					do {
						if (!--x) {
							x = 8;
							dst += _vm->_realWidth - 8;
							if (!--height)
								return;
						}
						*dst++ = color + _palette_mod;
					} while (--reps);
					bits >>= 8;
					bits |= (*src++) << (cl - 8);
					goto againPos;
				}
			}
		} while (--x);
		dst += _vm->_realWidth - 8;
	} while (--height);
}

void Gdi::unkDecodeA_trans(byte *dst, byte *src, int height) {
	byte color = *src++;
	uint bits = *src++;
	byte cl = 8;
	byte bit;
	byte incm, reps;

	do {
		int x = 8;
		do {
			FILL_BITS;
			if (color != _transparentColor)
				*dst = color + _palette_mod;
			dst++;

		againPos:
			if (!READ_BIT) {
			} else if (!READ_BIT) {
				FILL_BITS;
				color = bits & _decomp_mask;
				bits >>= _decomp_shr;
				cl -= _decomp_shr;
			} else {
				incm = (bits & 7) - 4;
				cl -= 3;
				bits >>= 3;
				if (incm) {
					color += incm;
				} else {
					FILL_BITS;
					reps = bits & 0xFF;
					do {
						if (!--x) {
							x = 8;
							dst += _vm->_realWidth - 8;
							if (!--height)
								return;
						}
						if (color != _transparentColor)
							*dst = color + _palette_mod;
						dst++;
					} while (--reps);
					bits >>= 8;
					bits |= (*src++) << (cl - 8);
					goto againPos;
				}
			}
		} while (--x);
		dst += _vm->_realWidth - 8;
	} while (--height);
}

void Gdi::unkDecodeB(byte *dst, byte *src, int height) {
	byte color = *src++;
	uint bits = *src++;
	byte cl = 8;
	byte bit;
	int8 inc = -1;

	do {
		int x = 8;
		do {
			FILL_BITS;
			*dst++ = color + _palette_mod;
			if (!READ_BIT) {
			} else if (!READ_BIT) {
				FILL_BITS;
				color = bits & _decomp_mask;
				bits >>= _decomp_shr;
				cl -= _decomp_shr;
				inc = -1;
			} else if (!READ_BIT) {
				color += inc;
			} else {
				inc = -inc;
				color += inc;
			}
		} while (--x);
		dst += _vm->_realWidth - 8;
	} while (--height);
}

void Gdi::unkDecodeB_trans(byte *dst, byte *src, int height) {
	byte color = *src++;
	uint bits = *src++;
	byte cl = 8;
	byte bit;
	int8 inc = -1;

	do {
		int x = 8;
		do {
			FILL_BITS;
			if (color != _transparentColor)
				*dst = color + _palette_mod;
			dst++;
			if (!READ_BIT) {
			} else if (!READ_BIT) {
				FILL_BITS;
				color = bits & _decomp_mask;
				bits >>= _decomp_shr;
				cl -= _decomp_shr;
				inc = -1;
			} else if (!READ_BIT) {
				color += inc;
			} else {
				inc = -inc;
				color += inc;
			}
		} while (--x);
		dst += _vm->_realWidth - 8;
	} while (--height);
}

void Gdi::unkDecodeC(byte *dst, byte *src, int height) {
	byte color = *src++;
	uint bits = *src++;
	byte cl = 8;
	byte bit;
	int8 inc = -1;

	int x = 8;
	do {
		int h = height;
		do {
			FILL_BITS;
			*dst = color + _palette_mod;
			dst += _vm->_realWidth;
			if (!READ_BIT) {
			} else if (!READ_BIT) {
				FILL_BITS;
				color = bits & _decomp_mask;
				bits >>= _decomp_shr;
				cl -= _decomp_shr;
				inc = -1;
			} else if (!READ_BIT) {
				color += inc;
			} else {
				inc = -inc;
				color += inc;
			}
		} while (--h);
		dst -= _vertStripNextInc;
	} while (--x);
}

void Gdi::unkDecodeC_trans(byte *dst, byte *src, int height) {
	byte color = *src++;
	uint bits = *src++;
	byte cl = 8;
	byte bit;
	int8 inc = -1;

	int x = 8;
	do {
		int h = height;
		do {
			FILL_BITS;
			if (color != _transparentColor)
				*dst = color + _palette_mod;
			dst += _vm->_realWidth;
			if (!READ_BIT) {
			} else if (!READ_BIT) {
				FILL_BITS;
				color = bits & _decomp_mask;
				bits >>= _decomp_shr;
				cl -= _decomp_shr;
				inc = -1;
			} else if (!READ_BIT) {
				color += inc;
			} else {
				inc = -inc;
				color += inc;
			}
		} while (--h);
		dst -= _vertStripNextInc;
	} while (--x);
}

#undef READ_BIT
#undef FILL_BITS

/* Ender - Zak256/Indy256 decoders */
#define READ_256BIT																\
											if ((mask <<= 1) == 256) {	\
												buffer = *src++;					\
												mask = 1;									\
											}														\
											bits = ((buffer & mask) != 0);

#define NEXT_ROW										\
				dst += _vm->_realWidth;			\
				if (--h == 0) {							\
					if (!--x)									\
						return;									\
					dst -= _vertStripNextInc;	\
					h = height;								\
				}

void Gdi::unkDecode7(byte *dst, byte *src, int height) {
	uint h = height;

	if (_vm->_features & GF_OLD256) {
		int x = 8;
		for (;;) {
			*dst = *src++;
			NEXT_ROW
		}
		return;
	}

	do {
#if defined(SCUMM_NEED_ALIGNMENT)
		memcpy(dst, src, 8);
#else
		((uint32 *)dst)[0] = ((uint32 *)src)[0];
		((uint32 *)dst)[1] = ((uint32 *)src)[1];
#endif
		dst += _vm->_realWidth;
		src += 8;
	} while (--height);
}

void Gdi::unkDecode8(byte *dst, byte *src, int height) {
	uint h = height;

	int x = 8;
	for (;;) {
		uint run = (*src++) + 1;
		byte color = *src++;

		do {
			*dst = color;
			NEXT_ROW
		} while (--run);
	}
}

void Gdi::unkDecode9(byte *dst, byte *src, int height) {
	unsigned char c, bits, color, run;
	int i, j;
	uint buffer = 0, mask = 128;
	int h = height;
	i = j = run = 0;

	int x = 8;
	for (;;) {
		c = 0;
		for (i = 0; i < 4; i++) {
			READ_256BIT;
			c += (bits << i);
		}

		switch ((c >> 2)) {
		case 0:
			color = 0;
			for (i = 0; i < 4; i++) {
				READ_256BIT;
				color += bits << i;
			}
			for (i = 0; i < ((c & 3) + 2); i++) {
				*dst = (run * 16 + color);
				NEXT_ROW
			}
			break;

		case 1:
			for (i = 0; i < ((c & 3) + 1); i++) {
				color = 0;
				for (j = 0; j < 4; j++) {
					READ_256BIT;
					color += bits << j;
				}
				*dst = (run * 16 + color);
				NEXT_ROW
			}
			break;

		case 2:
			run = 0;
			for (i = 0; i < 4; i++) {
				READ_256BIT;
				run += bits << i;
			}
			break;
		}
	}
}

void Gdi::unkDecode10(byte *dst, byte *src, int height) {
	int i;
	unsigned char local_palette[256], numcolors = *src++;
	uint h = height;

	for (i = 0; i < numcolors; i++)
		local_palette[i] = *src++;

	int x = 8;

	for (;;) {
		byte color = *src++;
		if (color < numcolors) {
			*dst = local_palette[color];
			NEXT_ROW
		} else {
			uint run = color - numcolors + 1;
			color = *src++;
			do {
				*dst = color;
				NEXT_ROW
			} while (--run);
		}
	}
}


void Gdi::unkDecode11(byte *dst, byte *src, int height) {
	int bits, i;
	uint buffer = 0, mask = 128;
	unsigned char inc = 1, color = *src++;

	int x = 8;
	do {
		int h = height;
		do {
			*dst = color;
			dst += _vm->_realWidth;
			for (i = 0; i < 3; i++) {
				READ_256BIT
				if (!bits)
					break;
			}
			switch (i) {
			case 1:
				inc = -inc;
				color -= inc;
				break;

			case 2:
				color -= inc;
				break;

			case 3:
				color = 0;
				inc = 1;
				for (i = 0; i < 8; i++) {
					READ_256BIT
					color += bits << i;
				}
				break;
			}
		} while (--h);
		dst -= _vertStripNextInc;
	} while (--x);
}

#undef NEXT_ROW
#undef READ_256BIT

#pragma mark -
#pragma mark --- Camera ---
#pragma mark -

void Scumm::setCameraAtEx(int at) {
	if (!(_features & GF_AFTER_V7)) {
		camera._mode = CM_NORMAL;
		camera._cur.x = at;
		setCameraAt(at, 0);
		camera._movingToActor = false;
	}
}

void Scumm::setCameraAt(int pos_x, int pos_y) {
	if (_features & GF_AFTER_V7) {
		ScummPoint old;

		old = camera._cur;

		camera._cur.x = pos_x;
		camera._cur.y = pos_y;

		clampCameraPos(&camera._cur);

		camera._dest = camera._cur;
		VAR(VAR_CAMERA_DEST_X) = camera._dest.x;
		VAR(VAR_CAMERA_DEST_Y) = camera._dest.y;

		assert(camera._cur.x >= (_realWidth / 2) && camera._cur.y >= (_realHeight / 2));

		if ((camera._cur.x != old.x || camera._cur.y != old.y)
				&& VAR(VAR_SCROLL_SCRIPT)) {
			VAR(VAR_CAMERA_POS_X) = camera._cur.x;
			VAR(VAR_CAMERA_POS_Y) = camera._cur.y;
			runScript(VAR(VAR_SCROLL_SCRIPT), 0, 0, 0);
		}
	} else {

		if (camera._mode != CM_FOLLOW_ACTOR || abs(pos_x - camera._cur.x) > (_realWidth / 2)) {
			camera._cur.x = pos_x;
		}
		camera._dest.x = pos_x;

		if (camera._cur.x < VAR(VAR_CAMERA_MIN_X))
			camera._cur.x = VAR(VAR_CAMERA_MIN_X);

		if (camera._cur.x > VAR(VAR_CAMERA_MAX_X))
			camera._cur.x = VAR(VAR_CAMERA_MAX_X);

		if (VAR_SCROLL_SCRIPT != 0xFF && VAR(VAR_SCROLL_SCRIPT)) {
			VAR(VAR_CAMERA_POS_X) = camera._cur.x;
			runScript(VAR(VAR_SCROLL_SCRIPT), 0, 0, 0);
		}

		if (camera._cur.x != camera._last.x && _charset->_hasMask)
			stopTalk();
	}
}

void Scumm::setCameraFollows(Actor *a) {
	if (_features & GF_AFTER_V7) {
		byte oldfollow = camera._follows;
		int ax, ay;

		camera._follows = a->number;
		VAR(VAR_CAMERA_FOLLOWED_ACTOR) = a->number;

		if (!a->isInCurrentRoom()) {
			startScene(a->getRoom(), 0, 0);
		}

		ax = abs(a->x - camera._cur.x);
		ay = abs(a->y - camera._cur.y);

		if (ax > VAR(VAR_CAMERA_THRESHOLD_X) || ay > VAR(VAR_CAMERA_THRESHOLD_Y) || ax > (_realWidth / 2) || ay > (_realHeight / 2)) {
			setCameraAt(a->x, a->y);
		}

		if (a->number != oldfollow)
			runHook(0);
	} else {
		int t, i;

		camera._mode = CM_FOLLOW_ACTOR;
		camera._follows = a->number;

		if (!a->isInCurrentRoom()) {
			startScene(a->getRoom(), 0, 0);
			camera._mode = CM_FOLLOW_ACTOR;
			camera._cur.x = a->x;
			setCameraAt(camera._cur.x, 0);
		}

		t = (a->x >> 3);

		if (t - _screenStartStrip < camera._leftTrigger || t - _screenStartStrip > camera._rightTrigger)
			setCameraAt(a->x, 0);

		for (i = 1; i < NUM_ACTORS; i++) {
			a = derefActor(i);
			if (a->isInCurrentRoom())
				a->needRedraw = true;
		}
		runHook(0);
	}
}

void Scumm::clampCameraPos(ScummPoint *pt) {
	if (pt->x < VAR(VAR_CAMERA_MIN_X))
		pt->x = VAR(VAR_CAMERA_MIN_X);

	if (pt->x > VAR(VAR_CAMERA_MAX_X))
		pt->x = VAR(VAR_CAMERA_MAX_X);

	if (pt->y < VAR(VAR_CAMERA_MIN_Y))
		pt->y = VAR(VAR_CAMERA_MIN_Y);

	if (pt->y > VAR(VAR_CAMERA_MAX_Y))
		pt->y = VAR(VAR_CAMERA_MAX_Y);
}

void Scumm::moveCamera() {
	if (_features & GF_AFTER_V7) {
		ScummPoint old = camera._cur;
		Actor *a = NULL;

		if (camera._follows) {
			a = derefActorSafe(camera._follows, "moveCamera");
			if (abs(camera._cur.x - a->x) > VAR(VAR_CAMERA_THRESHOLD_X) ||
					abs(camera._cur.y - a->y) > VAR(VAR_CAMERA_THRESHOLD_Y)) {
				camera._movingToActor = true;
				if (VAR(VAR_CAMERA_THRESHOLD_X) == 0)
					camera._cur.x = a->x;
				if (VAR(VAR_CAMERA_THRESHOLD_Y) == 0)
					camera._cur.y = a->y;
				clampCameraPos(&camera._cur);
			}
		} else {
			camera._movingToActor = false;
		}

		if (camera._movingToActor) {
			VAR(VAR_CAMERA_DEST_X) = camera._dest.x = a->x;
			VAR(VAR_CAMERA_DEST_Y) = camera._dest.y = a->y;
		}

		assert(camera._cur.x >= (_realWidth / 2) && camera._cur.y >= (_realHeight / 2));

		clampCameraPos(&camera._dest);

		if (camera._cur.x < camera._dest.x) {
			camera._cur.x += VAR(VAR_CAMERA_SPEED_X);
			if (camera._cur.x > camera._dest.x)
				camera._cur.x = camera._dest.x;
		}

		if (camera._cur.x > camera._dest.x) {
			camera._cur.x -= VAR(VAR_CAMERA_SPEED_X);
			if (camera._cur.x < camera._dest.x)
				camera._cur.x = camera._dest.x;
		}

		if (camera._cur.y < camera._dest.y) {
			camera._cur.y += VAR(VAR_CAMERA_SPEED_Y);
			if (camera._cur.y > camera._dest.y)
				camera._cur.y = camera._dest.y;
		}

		if (camera._cur.y > camera._dest.y) {
			camera._cur.y -= VAR(VAR_CAMERA_SPEED_Y);
			if (camera._cur.y < camera._dest.y)
				camera._cur.y = camera._dest.y;
		}

		if (camera._cur.x == camera._dest.x && camera._cur.y == camera._dest.y) {

			camera._movingToActor = false;
			camera._accel.x = camera._accel.y = 0;
			VAR(VAR_CAMERA_SPEED_X) = VAR(VAR_CAMERA_SPEED_Y) = 0;
		} else {

			camera._accel.x += VAR(VAR_CAMERA_ACCEL_X);
			camera._accel.y += VAR(VAR_CAMERA_ACCEL_Y);

			VAR(VAR_CAMERA_SPEED_X) += camera._accel.x / 100;
			VAR(VAR_CAMERA_SPEED_Y) += camera._accel.y / 100;

			if (VAR(VAR_CAMERA_SPEED_X) < 8)
				VAR(VAR_CAMERA_SPEED_X) = 8;

			if (VAR(VAR_CAMERA_SPEED_Y) < 8)
				VAR(VAR_CAMERA_SPEED_Y) = 8;

		}

		cameraMoved();

		if (camera._cur.x != old.x || camera._cur.y != old.y) {
			VAR(VAR_CAMERA_POS_X) = camera._cur.x;
			VAR(VAR_CAMERA_POS_Y) = camera._cur.y;

			if (VAR(VAR_SCROLL_SCRIPT))
				runScript(VAR(VAR_SCROLL_SCRIPT), 0, 0, 0);
		}
	} else {
		int pos = camera._cur.x;
		int actorx, t;
		Actor *a = NULL;

		camera._cur.x &= 0xFFF8;

		if (camera._cur.x < VAR(VAR_CAMERA_MIN_X)) {
			if (VAR_CAMERA_FAST_X != 0xFF && VAR(VAR_CAMERA_FAST_X))
				camera._cur.x = VAR(VAR_CAMERA_MIN_X);
			else
				camera._cur.x += 8;
			cameraMoved();
			return;
		}

		if (camera._cur.x > VAR(VAR_CAMERA_MAX_X)) {
			if (VAR_CAMERA_FAST_X != 0xFF && VAR(VAR_CAMERA_FAST_X))
				camera._cur.x = VAR(VAR_CAMERA_MAX_X);
			else
				camera._cur.x -= 8;
			cameraMoved();
			return;
		}

		if (camera._mode == CM_FOLLOW_ACTOR) {
			a = derefActorSafe(camera._follows, "moveCamera");

			actorx = a->x;
			t = (actorx >> 3) - _screenStartStrip;

			if (t < camera._leftTrigger || t > camera._rightTrigger) {
				if (VAR_CAMERA_FAST_X != 0xFF && VAR(VAR_CAMERA_FAST_X)) {
					if (t > 35)
						camera._dest.x = actorx + 80;
					if (t < 5)
						camera._dest.x = actorx - 80;
				} else
					camera._movingToActor = true;
			}
		}

		if (camera._movingToActor) {
			a = derefActorSafe(camera._follows, "moveCamera(2)");
			camera._dest.x = a->x;
		}

		if (camera._dest.x < VAR(VAR_CAMERA_MIN_X))
			camera._dest.x = VAR(VAR_CAMERA_MIN_X);

		if (camera._dest.x > VAR(VAR_CAMERA_MAX_X))
			camera._dest.x = VAR(VAR_CAMERA_MAX_X);

		if (VAR_CAMERA_FAST_X != 0xFF && VAR(VAR_CAMERA_FAST_X)) {
			camera._cur.x = camera._dest.x;
		} else {
			if (camera._cur.x < camera._dest.x)
				camera._cur.x += 8;
			if (camera._cur.x > camera._dest.x)
				camera._cur.x -= 8;
		}

		/* a is set a bit above */
		if (camera._movingToActor && (camera._cur.x >> 3) == (a->x >> 3)) {
			camera._movingToActor = false;
		}

		cameraMoved();
	
		if (VAR_SCROLL_SCRIPT != 0xFF && VAR(VAR_SCROLL_SCRIPT) && pos != camera._cur.x) {
			VAR(VAR_CAMERA_POS_X) = camera._cur.x;
			runScript(VAR(VAR_SCROLL_SCRIPT), 0, 0, 0);
		}
	}
}

void Scumm::cameraMoved() {
	if (_features & GF_AFTER_V7) {
		assert(camera._cur.x >= (_realWidth / 2) && camera._cur.y >= (_realHeight / 2));
	} else {
		if (camera._cur.x < (_realWidth / 2)) {
			camera._cur.x = (_realWidth / 2);
		} else if (camera._cur.x > _scrWidth - (_realWidth / 2)) {
			camera._cur.x = _scrWidth - (_realWidth / 2);
		}
	}

	_screenStartStrip = (camera._cur.x - (_realWidth / 2)) >> 3;
	_screenEndStrip = _screenStartStrip + gdi._numStrips - 1;

	_screenTop = camera._cur.y - (_realHeight / 2);
	if (_features & GF_AFTER_V7) {

		_screenLeft = camera._cur.x - (_realWidth / 2);
	} else {

		_screenLeft = _screenStartStrip << 3;
	}

#ifdef V7_SMOOTH_SCROLLING_HACK
	virtscr[0].xstart = _screenLeft;
#else
	virtscr[0].xstart = _screenStartStrip << 3;
#endif
}

void Scumm::panCameraTo(int x, int y) {
	if (_features & GF_AFTER_V7) {

		VAR(VAR_CAMERA_FOLLOWED_ACTOR) = camera._follows = 0;
		VAR(VAR_CAMERA_DEST_X) = camera._dest.x = x;
		VAR(VAR_CAMERA_DEST_Y) = camera._dest.y = y;
	} else {

		camera._dest.x = x;
		camera._mode = CM_PANNING;
		camera._movingToActor = false;
	}
}

void Scumm::actorFollowCamera(int act) {
	if (!(_features & GF_AFTER_V7)) {
		int old;

		/* mi1 compatibilty */
		if (act == 0) {
			camera._mode = CM_NORMAL;
			camera._follows = 0;
			camera._movingToActor = false;
			return;
		}

		old = camera._follows;
		setCameraFollows(derefActorSafe(act, "actorFollowCamera"));
		if (camera._follows != old)
			runHook(0);

		camera._movingToActor = false;
	}
}

#pragma mark -
#pragma mark --- Transition effects ---
#pragma mark -

void Scumm::fadeIn(int effect) {
	updatePalette();
	switch (effect) {
	case 1:
	case 2:
	case 3:
	case 4:
		transitionEffect(effect - 1);
		break;
	case 128:
		unkScreenEffect6();
		break;
	case 130:
	case 131:
	case 132:
	case 133:
		scrollEffect(133 - effect);
		break;
	case 134:
		dissolveEffect(1, 1);
		break;
	case 135:
		unkScreenEffect5(1);
		break;
	case 129:
		break;
	default:
		warning("Unknown screen effect, %d", effect);
	}
	_screenEffectFlag = true;
}

void Scumm::fadeOut(int effect) {
	VirtScreen *vs;

	updatePalette();

	setDirtyRange(0, 0, 0);
	if (!(_features & GF_AFTER_V7))
		camera._last.x = camera._cur.x;

	if (!_screenEffectFlag)
		return;
	_screenEffectFlag = false;

	if (effect == 0)
		return;

	// Fill screen 0 with black
	vs = &virtscr[0];
	memset(vs->screenPtr + vs->xstart, 0, vs->size);

	// Fade to black with the specified effect, if any.
	switch (effect) {
	case 1:
	case 2:
	case 3:
	case 4:
		transitionEffect(effect - 1);
		break;
	case 128:
		unkScreenEffect6();
		break;
	case 129:
		// Just blit screen 0 to the display (i.e. display will be black)
		setDirtyRange(0, 0, vs->height);
		updateDirtyScreen(0);
		break;
	case 134:
		dissolveEffect(1, 1);
		break;
	case 135:
		unkScreenEffect5(1);
		break;
	default:
		warning("fadeOut: default case %d", effect);
	}
}

/* Transition effect. There are four different effects possible,
 * indicated by the value of a:
 * 0: Iris effect
 * 1: Box wipe (a black box expands from the upper-left corner to the lower-right corner)
 * 2: Box wipe (a black box expands from the lower-right corner to the upper-left corner)
 * 3: Inverse box wipe
 * All effects operate on 8x8 blocks of the screen. These blocks are updated
 * in a certain order; the exact order determines how the effect appears to the user.
 */
void Scumm::transitionEffect(int a) {
	int delta[16];								// Offset applied during each iteration
	int tab_2[16];
	int i, j;
	int bottom;
	int l, t, r, b;

	for (i = 0; i < 16; i++) {
		delta[i] = transitionEffects[a].deltaTable[i];
		j = transitionEffects[a].stripTable[i];
		if (j == 24)
			j = (virtscr[0].height >> 3) - 1;
		tab_2[i] = j;
	}

	bottom = virtscr[0].height >> 3;
	for (j = 0; j < transitionEffects[a].numOfIterations; j++) {
		for (i = 0; i < 4; i++) {
			l = tab_2[i * 4];
			t = tab_2[i * 4 + 1];
			r = tab_2[i * 4 + 2];
			b = tab_2[i * 4 + 3];
			if (t == b) {
				while (l <= r) {
					if (l >= 0 && l < gdi._numStrips && (uint) t < (uint) bottom) {
						virtscr[0].tdirty[l] = t << 3;
						virtscr[0].bdirty[l] = (t + 1) << 3;
					}
					l++;
				}
			} else {
				if (l < 0 || l >= gdi._numStrips || b <= t)
					continue;
				if (b > bottom)
					b = bottom;
				virtscr[0].tdirty[l] = t << 3;
				virtscr[0].bdirty[l] = (b + 1) << 3;
			}
			updateDirtyScreen(0);
		}

		for (i = 0; i < 16; i++)
			tab_2[i] += delta[i];

		// Draw the current state to the screen and wait half a sec so the user
		// can watch the effect taking place.
		_system->update_screen();
		waitForTimer(30);
	}
}

// Update width x height areas of the screen, in random order, until the whole
// screen has been updated. For instance:
//
// dissolveEffect(1, 1) produces a pixel-by-pixel dissolve
// dissolveEffect(8, 8) produces a square-by-square dissolve
// dissolveEffect(virtsrc[0].width, 1) produces a line-by-line dissolve

void Scumm::dissolveEffect(int width, int height) {
	VirtScreen *vs = &virtscr[0];
	int *offsets;
	int blits_before_refresh, blits;
	int x, y;
	int w, h;
	int i;

	// There's probably some less memory-hungry way of doing this. But
	// since we're only dealing with relatively small images, it shouldn't
	// be too bad.

	w = vs->width / width;
	h = vs->height / height;

	// When used used correctly, vs->width % width and vs->height % height
	// should both be zero, but just to be safe...

	if (vs->width % width)
		w++;

	if (vs->height % height)
		h++;

	offsets = (int *) malloc(w * h * sizeof(int));
	if (offsets == NULL) {
		warning("dissolveEffect: out of memory");
		return;
	}

	// Create a permutation of offsets into the frame buffer

	if (width == 1 && height == 1) {
		// Optimized case for pixel-by-pixel dissolve

		for (i = 0; i < vs->size; i++)
			offsets[i] = i;

		for (i = 1; i < w * h; i++) {
			int j;

			j = _rnd.getRandomNumber(i - 1);
			offsets[i] = offsets[j];
			offsets[j] = i;
		}
	} else {
		int *offsets2;

		for (i = 0, x = 0; x < vs->width; x += width)
			for (y = 0; y < vs->height; y += height)
				offsets[i++] = y * vs->width + x;

		offsets2 = (int *) malloc(w * h * sizeof(int));
		if (offsets2 == NULL) {
			warning("dissolveEffect: out of memory");
			free(offsets);
			return;
		}

		memcpy(offsets2, offsets, w * h * sizeof(int));

		for (i = 1; i < w * h; i++) {
			int j;

			j = _rnd.getRandomNumber(i - 1);
			offsets[i] = offsets[j];
			offsets[j] = offsets2[i];
		}

		free(offsets2);
	}

	// Blit the image piece by piece to the screen. The idea here is that
	// the whole update should take about a quarter of a second, assuming
	// most of the time is spent in waitForTimer(). It looks good to me,
	// but might still need some tuning.

	blits = 0;
	blits_before_refresh = (3 * w * h) / 25;
	
	// Speed up the effect for Loom
	if (_gameId == GID_LOOM256)
		blits_before_refresh *= 4;

	for (i = 0; i < w * h; i++) {
		x = offsets[i] % vs->width;
		y = offsets[i] / vs->width;
		_system->copy_rect(vs->screenPtr + vs->xstart + y * vs->width + x, vs->width, x, y + vs->topline, width, height);

		if (++blits >= blits_before_refresh) {
			blits = 0;
			_system->update_screen();
			waitForTimer(30);
		}
	}

	free(offsets);

	if (blits != 0) {
		_system->update_screen();
		waitForTimer(30);
	}
}

void Scumm::scrollEffect(int dir) {
	VirtScreen *vs = &virtscr[0];

	int x, y;
	int step;

	if ((dir == 0) || (dir == 1))
		step = vs->height;
	else
		step = vs->width;

	step = (step * kPictureDelay) / kScrolltime;

	switch (dir) {
	case 0:
		//up
		y = 1 + step;
		while (y < vs->height) {
			_system->move_screen(0, -step, vs->height);
			_system->copy_rect(vs->screenPtr + vs->xstart + (y - step) * vs->width,
				vs->width,
				0, vs->height - step,
				vs->width, step);
			_system->update_screen();
			waitForTimer(kPictureDelay);

			y += step;
		}
		break;
	case 1:
		// down
		y = 1 + step;
		while (y < vs->height) {
			_system->move_screen(0, step, vs->height);
			_system->copy_rect(vs->screenPtr + vs->xstart + vs->width * (vs->height-y),
				vs->width,
				0, 0,
				vs->width, step);
			_system->update_screen();
			waitForTimer(kPictureDelay);

			y += step;
		}
		break;
	case 2:
		// left
		x = 1 + step;
		while (x < vs->width) {
			_system->move_screen(-step, 0, vs->height);
			_system->copy_rect(vs->screenPtr + vs->xstart + x - step,
				vs->width,
				vs->width - step, 0,
				step, vs->height);
			_system->update_screen();
			waitForTimer(kPictureDelay);

			x += step;
		}
		break;
	case 3:
		// right
		x = 1 + step;
		while (x < vs->width) {
			_system->move_screen(step, 0, vs->height);
			_system->copy_rect(vs->screenPtr + vs->xstart + vs->width - x,
				vs->width,
				0, 0,
				step, vs->height);
			_system->update_screen();
			waitForTimer(kPictureDelay);

			x += step;
		}
		break;
	}
}

void Scumm::unkScreenEffect6() {
	if (_gameId == GID_LOOM256)
		dissolveEffect(1, 1);
	else
		dissolveEffect(8, 4);
}

void Scumm::unkScreenEffect5(int a) {
	// unkScreenEffect5(0), which is used by FOA during the opening
	// cutscene when Indy opens the small statue, has been replaced by
	// dissolveEffect(1, 1).
	//
	// I still don't know what unkScreenEffect5(1) is supposed to do.

	/* XXX: not implemented */
	warning("stub unkScreenEffect(%d)", a);
}

void Scumm::setShake(int mode) {
	if (_shakeEnabled != (mode != 0))
		_fullRedraw = true;

	_shakeEnabled = mode != 0;
	_shakeFrame = 0;
	_system->set_shake_pos(0);
}

#pragma mark -
#pragma mark --- Palette ---
#pragma mark -

void Scumm::setupEGAPalette() {
	setPalColor( 0,   0,   0,   0);
	setPalColor( 1,   0,   0, 168);
	setPalColor( 2,   0, 168,   0);
	setPalColor( 3,   0, 168, 168);
	setPalColor( 4, 168,   0,   0);
	setPalColor( 5, 168,   0, 168);
	setPalColor( 6, 168,  84,   0);
	setPalColor( 7, 168, 168, 168);
	setPalColor( 8,  84,  84,  84);
	setPalColor( 9,  84,  84, 168);
	setPalColor(10,   0, 252,   0);
	setPalColor(11,   0, 252, 252);
	setPalColor(12, 252,  84,  84);
	setPalColor(13, 252,   0, 252);
	setPalColor(14, 252, 252,   0);
	setPalColor(15, 252, 252, 252);
}

void Scumm::setPaletteFromPtr(byte *ptr) {
	int i;
	byte *dest, r, g, b;
	int numcolor;

	if (_features & GF_SMALL_HEADER) {
		if (_features & GF_OLD256)
			numcolor = 256;
		else
			numcolor = READ_LE_UINT16(ptr + 6) / 3;
		ptr += 8;
	} else {
		numcolor = getResourceDataSize(ptr) / 3;
	}

	checkRange(256, 0, numcolor, "Too many colors (%d) in Palette");

	dest = _currentPalette;

	for (i = 0; i < numcolor; i++) {
		r = *ptr++;
		g = *ptr++;
		b = *ptr++;

		// This comparison might look wierd, but it's what the disassembly (DOTT) says!
		// FIXME: Fingolfin still thinks it looks weird: the value 252 = 4*63 clearly comes from
		// the days 6/6/6 palettes were used, OK. But it breaks MonkeyVGA, so I had to add a
		// check for that. And somebody before me added a check for V7 games, turning this
		// off there, too... I wonder if it hurts other games, too? What exactly is broken
		// if we remove this patch?
		if ((_gameId == GID_MONKEY_VGA) || (_features & GF_AFTER_V7) || (i <= 15 || r < 252 || g < 252 || b < 252)) {
			*dest++ = r;
			*dest++ = g;
			*dest++ = b;
		} else {
			dest += 3;
		}
	}
	setDirtyColors(0, numcolor - 1);
}

void Scumm::setPaletteFromRes() {
	byte *ptr;
	ptr = getResourceAddress(rtRoom, _roomResource) + _CLUT_offs;
	setPaletteFromPtr(ptr);
}

void Scumm::setDirtyColors(int min, int max) {
	if (_palDirtyMin > min)
		_palDirtyMin = min;
	if (_palDirtyMax < max)
		_palDirtyMax = max;
}

void Scumm::initCycl(byte *ptr) {
	int j;
	ColorCycle *cycl;

	memset(_colorCycle, 0, sizeof(_colorCycle));

	while ((j = *ptr++) != 0) {
		if (j < 1 || j > 16) {
			error("Invalid color cycle index %d", j);
		}
		cycl = &_colorCycle[j - 1];

		ptr += 2;
		cycl->counter = 0;
		cycl->delay = 16384 / READ_BE_UINT16_UNALIGNED(ptr);
		ptr += 2;
		cycl->flags = READ_BE_UINT16_UNALIGNED(ptr);
		ptr += 2;
		cycl->start = *ptr++;
		cycl->end = *ptr++;
	}
}

void Scumm::stopCycle(int i) {
	ColorCycle *cycl;

	checkRange(16, 0, i, "Stop Cycle %d Out Of Range");
	if (i != 0) {
		_colorCycle[i - 1].delay = 0;
		return;
	}

	for (i = 0, cycl = _colorCycle; i < 16; i++, cycl++)
		cycl->delay = 0;
}

void Scumm::cyclePalette() {
	ColorCycle *cycl;
	int valueToAdd;
	int i, num;
	byte *start, *end;
	byte tmp[3];

	if (_features & GF_AFTER_V2) {
		// FIXME - no idea if this is right :-/
		valueToAdd = VAR(VAR_TIMER_NEXT);
	} else {
		valueToAdd = VAR(VAR_TIMER);
		if (valueToAdd < VAR(VAR_TIMER_NEXT))
			valueToAdd = VAR(VAR_TIMER_NEXT);
	}

	if (!_colorCycle)							// FIXME
		return;

	for (i = 0, cycl = _colorCycle; i < 16; i++, cycl++) {
		if (cycl->delay && (cycl->counter += valueToAdd) >= cycl->delay) {
			do {
				cycl->counter -= cycl->delay;
			} while (cycl->delay <= cycl->counter);

			setDirtyColors(cycl->start, cycl->end);
			moveMemInPalRes(cycl->start, cycl->end, cycl->flags & 2);
			start = &_currentPalette[cycl->start * 3];
			end = &_currentPalette[cycl->end * 3];

			num = cycl->end - cycl->start;

			if (!(cycl->flags & 2)) {
				memmove(tmp, end, 3);
				memmove(start + 3, start, num * 3);
				memmove(start, tmp, 3);
			} else {
				memmove(tmp, start, 3);
				memmove(start, start + 3, num * 3);
				memmove(end, tmp, 3);
			}
		}
	}
}

// Perform color cycling on the palManipulate data, too, otherwise
// color cycling will be disturbed by the palette fade.
void Scumm::moveMemInPalRes(int start, int end, byte direction) {
	byte *startptr, *endptr;
	byte *startptr2, *endptr2;
	int num;
	byte tmp[6];

	if (!_palManipCounter)
		return;

	startptr = _palManipPalette + start * 3;
	endptr = _palManipPalette + end * 3;
	startptr2 = _palManipIntermediatePal + start * 6;
	endptr2 = _palManipIntermediatePal + end * 6;
	num = end - start;

	if (!endptr) {
		warning("moveMemInPalRes(%d,%d): Bad end pointer\n", start, end);
		return;
	}

	if (!direction) {
		memmove(tmp, endptr, 3);
		memmove(startptr + 3, startptr, num * 3);
		memmove(startptr, tmp, 3);
		memmove(tmp, endptr2, 6);
		memmove(startptr2 + 6, startptr2, num * 6);
		memmove(startptr2, tmp, 6);
	} else {
		memmove(tmp, startptr, 3);
		memmove(startptr, startptr + 3, num * 3);
		memmove(endptr, tmp, 3);
		memmove(tmp, startptr2, 6);
		memmove(startptr2, startptr2 + 6, num * 6);
		memmove(endptr2, tmp, 6);
	}
}

void Scumm::palManipulateInit(int start, int end, int string_id, int time) {
	byte *pal, *target, *between;
	byte *string1, *string2, *string3;
	int i;

	string1 = getStringAddress(string_id);
	string2 = getStringAddress(string_id + 1);
	string3 = getStringAddress(string_id + 2);
	if (!string1 || !string2 || !string3) {
		warning("palManipulateInit(%d,%d,%d,%d): Cannot obtain string resources %d, %d and %d\n",
		        start, end, string_id, time, string_id, string_id + 1, string_id + 2);
		return;
	}

	string1+=start;
	string2+=start;
	string3+=start;

	_palManipStart = start;
	_palManipEnd = end;
	_palManipCounter = 0;
	
	if (!_palManipPalette)
		_palManipPalette = (byte *)calloc(0x300, 1);
	if (!_palManipIntermediatePal)
		_palManipIntermediatePal = (byte *)calloc(0x600, 1);

	pal = _currentPalette + start * 3;
	target = _palManipPalette + start * 3;
	between = _palManipIntermediatePal + start * 6;

	for (i = start; i < end; ++i) {
		*target++ = *string1++;
		*target++ = *string2++;
		*target++ = *string3++;
		*(uint16 *)between = ((uint16) *pal++) << 8;
		between += 2;
		*(uint16 *)between = ((uint16) *pal++) << 8;
		between += 2;
		*(uint16 *)between = ((uint16) *pal++) << 8;
		between += 2;
	}

	_palManipCounter = time;
}

void Scumm::palManipulate() {
	byte *target, *pal, *between;
	int i, j;

	if (!_palManipCounter || !_palManipPalette || !_palManipIntermediatePal)
		return;
	
	target = _palManipPalette + _palManipStart * 3;
	pal = _currentPalette + _palManipStart * 3;
	between = _palManipIntermediatePal + _palManipStart * 6;

	for (i = _palManipStart; i < _palManipEnd; ++i) {
		j = (*((uint16 *)between) += ((*target++ << 8) - *((uint16 *)between)) / _palManipCounter);
		*pal++ = j >> 8;
		between += 2;
		j = (*((uint16 *)between) += ((*target++ << 8) - *((uint16 *)between)) / _palManipCounter);
		*pal++ = j >> 8;
		between += 2;
		j = (*((uint16 *)between) += ((*target++ << 8) - *((uint16 *)between)) / _palManipCounter);
		*pal++ = j >> 8;
		between += 2;
	}
	setDirtyColors(_palManipStart, _palManipEnd);
	_palManipCounter--;
}

void Scumm::setupShadowPalette(int slot, int redScale, int greenScale, int blueScale, int startColor, int endColor) {
	byte *table;
	int i;
	byte *curpal;

	if (slot < 0 || slot > 7)
		error("setupShadowPalette: invalid slot %d", slot);

	if (startColor < 0 || startColor > 255 || endColor < 0 || startColor > 255 || endColor < startColor)
		error("setupShadowPalette: invalid range from %d to %d", startColor, endColor);

	table = _shadowPalette + slot * 256;
	for (i = 0; i < 256; i++)
		table[i] = i;

	table += startColor;
	curpal = _currentPalette + startColor * 3;
	for (i = startColor; i <= endColor; i++) {
		*table++ = remapPaletteColor((curpal[0] * redScale) >> 8,
									 (curpal[1] * greenScale) >> 8,
									 (curpal[2] * blueScale) >> 8,
									 (uint) - 1);
		curpal += 3;
	}
}

void Scumm::setupShadowPalette(int redScale, int greenScale, int blueScale, int startColor, int endColor) {
	byte *basepal = getPalettePtr();
	byte *pal = basepal;
	byte *compareptr;
	byte *table = _shadowPalette;
	int i;

	// This is a correction of the patch supplied for BUG #588501.
	// It has been tested in all four known rooms where unkRoomFunc3 is used:
	//
	// 1) FOA Room 53: subway departing Knossos for Atlantis.
	// 2) FOA Room 48: subway crashing into the Atlantis entrance area
	// 3) FOA Room 82: boat/sub shadows while diving near Thera
	// 4) FOA Room 23: the big machine room inside Atlantis
	//
	// The implementation behaves well in all tests.
	// Pixel comparisons show that the resulting palette entries being
	// derived from the shadow palette generated here occassionally differ
	// slightly from the ones derived in the LEC executable.
	// Not sure yet why, but the differences are VERY minor.
	//
	// There seems to be no explanation for why this function is called
	// from within Room 23 (the big machine), as it has no shadow effects
	// and thus doesn't result in any visual differences.

	for (i = 0; i <= 255; i++) {
		int r = (int) (*pal++ * redScale) >> 8;
		int g = (int) (*pal++ * greenScale) >> 8;
		int b = (int) (*pal++ * blueScale) >> 8;

		// The following functionality is similar to remapPaletteColor, except
		// 1) we have to work off the original CLUT rather than the current palette, and
		// 2) the target shadow palette entries must be bounded to the upper and lower
		//    bounds provided by the opcode. (This becomes significant in Room 48, but
		//    is not an issue in all other known case studies.)
		int j;
		int ar, ag, ab;
		uint sum, bestsum, bestitem = 0;

		if (r > 255)
			r = 255;
		if (g > 255)
			g = 255;
		if (b > 255)
			b = 255;

		bestsum = (uint)-1;

		r &= ~3;
		g &= ~3;
		b &= ~3;

		compareptr = basepal + startColor * 3;
		for (j = startColor; j <= endColor; j++, compareptr += 3) {
			ar = compareptr[0] & ~3;
			ag = compareptr[1] & ~3;
			ab = compareptr[2] & ~3;
			if (ar == r && ag == g && ab == b) {
				bestitem = j;
				break;
			}

			sum = colorWeight(ar - r, ag - g, ab - b);

			if (sum < bestsum) {
				bestsum = sum;
				bestitem = j;
			}
		}
		*table++ = bestitem;
	}
}

/* Yazoo: This function create the specialPalette used for semi-transparency in SamnMax */
void Scumm::createSpecialPalette(int16 from, int16 to, int16 redScale, int16 greenScale, int16 blueScale,
			int16 startColor, int16 endColor) {
	byte *palPtr;
	byte *curPtr;
	byte *searchPtr;

	uint bestResult;
	uint currentResult;

	byte currentIndex;

	int i, j;

	palPtr = getPalettePtr();

	for (i = 0; i < 256; i++)
		_proc_special_palette[i] = i;

	curPtr = palPtr + startColor * 3;

	for (i = startColor; i < endColor; i++) {
		int r = (int) (*curPtr++ * redScale) >> 8;
		int g = (int) (*curPtr++ * greenScale) >> 8;
		int b = (int) (*curPtr++ * blueScale) >> 8;

		searchPtr = palPtr;
		bestResult = 32000;
		currentIndex = 0;

		for (j = from; j < to; j++) {
			int ar = (*searchPtr++);
			int ag = (*searchPtr++);
			int ab = (*searchPtr++);

			currentResult = colorWeight(ar - r, ag - g, ab - b);

			if (currentResult < bestResult) {
				_proc_special_palette[i] = currentIndex;
				bestResult = currentResult;
			}
			currentIndex++;
		}
	}
}

void Scumm::darkenPalette(int redScale, int greenScale, int blueScale, int startColor, int endColor) {
	if (_roomResource == 0) // FIXME - HACK to get COMI demo working
		return;

	if (startColor <= endColor) {
		byte *cptr, *cur;
		int j;
		int color;

		cptr = getPalettePtr() + startColor * 3;
		cur = _currentPalette + startColor * 3;

		for (j = startColor; j <= endColor; j++) {
			color = *cptr++;
			color = color * redScale / 0xFF;
			if (color > 255)
				color = 255;
			*cur++ = color;

			color = *cptr++;
			color = color * greenScale / 0xFF;
			if (color > 255)
				color = 255;
			*cur++ = color;

			color = *cptr++;
			color = color * blueScale / 0xFF;
			if (color > 255)
				color = 255;
			*cur++ = color;
		}
		setDirtyColors(startColor, endColor);
	}
}

static double value(double n1, double n2, double hue)
{
	if (hue > 360.0)
		hue = hue - 360.0;
	else if (hue < 0.0)
		hue = hue + 360.0;

	if (hue < 60.0)
		return n1 + (n2 - n1) * hue / 60.0;
	if (hue < 180.0)
		return n2;
	if (hue < 240.0)
		return n1 + (n2 - n1) * (240.0 - hue) / 60.0;
	return n1;
}

void Scumm::desaturatePalette(int hueScale, int satScale, int lightScale, int startColor, int endColor)
{
	// This function scales the HSL (Hue, Saturation and Lightness)
	// components of the palette colours. It's used in CMI when Guybrush
	// walks from the beach towards the swamp.
	//
	// I don't know if this function is correct, but the output seems to
	// match the original fairly closely.
	//
	// FIXME: Rewrite using integer arithmetics only?

	if (startColor <= endColor) {
		byte *cptr, *cur;
		int j;

		cptr = getPalettePtr() + startColor * 3;
		cur = _currentPalette + startColor * 3;

		for (j = startColor; j <= endColor; j++) {
			double R, G, B;
			double H, S, L;
			double min, max;
			int red, green, blue;

			R = ((double) *cptr++) / 255.0;
			G = ((double) *cptr++) / 255.0;
			B = ((double) *cptr++) / 255.0;

			// RGB to HLS (Foley and VanDam)

			min = MIN(R, MIN(G, B));
			max = MAX(R, MAX(G, B));

			L = (max + min) / 2.0;

			if (max != min) {
				if (L <= 0.5)
					S = (max - min) / (max + min);
				else
					S = (max - min) / (2.0 - max - min);

				if (R == max)
					H = (G - B) / (max - min);
				else if (G == max)
					H = 2.0 + (B - R) / (max - min);
				else
					H = 4.0 + (R - G) / (max - min);

				H = H * 60.0;
				if (H < 0.0)
					H = H + 360.0;
			} else {
				S = 0.0;
				H = 0.0; // undefined
			}

			// Scale the result

			H = (H * hueScale) / 255.0;
			S = (S * satScale) / 255.0;
			L = (L * lightScale) / 255.0;

			// HLS to RGB (Foley and VanDam)

			double m1, m2;

			if (min != max) {
				if (L <= 0.5)
					m2 = L * (1 + S);
				else
					m2 = L + S - L * S;

				m1 = 2.0 * L - m2;

				R = value(m1, m2, H + 120);
				G = value(m1, m2, H);
				B = value(m1, m2, H - 120);
			} else {
				R = L;
				G = L;
				B = L;
			}

			red = (int) (255.0 * R + 0.5);
			green = (int) (255.0 * G + 0.5);
			blue = (int) (255.0 * B + 0.5);

			*cur++ = red;
			*cur++ = green;
			*cur++ = blue;
		}

		setDirtyColors(startColor, endColor);
	}
}

int Scumm::remapPaletteColor(int r, int g, int b, uint threshold) {
	int i;
	int ar, ag, ab;
	uint sum, bestsum, bestitem = 0;
	byte *pal = _currentPalette;

	if (r > 255)
		r = 255;
	if (g > 255)
		g = 255;
	if (b > 255)
		b = 255;

	bestsum = (uint) - 1;

	r &= ~3;
	g &= ~3;
	b &= ~3;

	for (i = 0; i < 256; i++, pal += 3) {
		ar = pal[0] & ~3;
		ag = pal[1] & ~3;
		ab = pal[2] & ~3;
		if (ar == r && ag == g && ab == b)
			return i;

		sum = colorWeight(ar - r, ag - g, ab - b);

		if (sum < bestsum) {
			bestsum = sum;
			bestitem = i;
		}
	}

	if (threshold != (uint) - 1 && bestsum > colorWeight(threshold, threshold, threshold)) {
		// Best match exceeded threshold. Try to find an unused palette entry and
		// use it for our purpose.
		pal = _currentPalette + (256 - 2) * 3;
		for (i = 254; i > 48; i--, pal -= 3) {
			if (pal[0] >= 252 && pal[1] >= 252 && pal[2] >= 252) {
				setPalColor(i, r, g, b);
				return i;
			}
		}
	}

	return bestitem;
}

void Scumm::swapPalColors(int a, int b) {
	byte *ap, *bp;
	byte t;

	if ((uint) a >= 256 || (uint) b >= 256)
		error("swapPalColors: invalid values, %d, %d", a, b);

	ap = &_currentPalette[a * 3];
	bp = &_currentPalette[b * 3];

	t = ap[0];
	ap[0] = bp[0];
	bp[0] = t;
	t = ap[1];
	ap[1] = bp[1];
	bp[1] = t;
	t = ap[2];
	ap[2] = bp[2];
	bp[2] = t;

	setDirtyColors(a, a);
	setDirtyColors(b, b);
}

void Scumm::copyPalColor(int dst, int src) {
	byte *dp, *sp;

	if ((uint) dst >= 256 || (uint) src >= 256)
		error("copyPalColor: invalid values, %d, %d", dst, src);

	dp = &_currentPalette[dst * 3];
	sp = &_currentPalette[src * 3];

	dp[0] = sp[0];
	dp[1] = sp[1];
	dp[2] = sp[2];

	setDirtyColors(dst, dst);
}

void Scumm::setPalColor(int idx, int r, int g, int b) {
	_currentPalette[idx * 3 + 0] = r;
	_currentPalette[idx * 3 + 1] = g;
	_currentPalette[idx * 3 + 2] = b;
	setDirtyColors(idx, idx);
}

void Scumm::setPalette(int palindex) {
	byte *pals;

	_curPalIndex = palindex;
	pals = getPalettePtr();
	setPaletteFromPtr(pals);
}

byte *Scumm::findPalInPals(byte *pal, int idx) {
	byte *offs;
	uint32 size;

	pal = findResource(MKID('WRAP'), pal);
	if (pal == NULL)
		return NULL;

	offs = findResourceData(MKID('OFFS'), pal);
	if (offs == NULL)
		return NULL;

	size = getResourceDataSize(offs) >> 2;

	if ((uint32)idx >= (uint32)size)
		return NULL;

	return offs + READ_LE_UINT32(offs + idx * sizeof(uint32));
}

byte *Scumm::getPalettePtr() {
	byte *cptr;

	cptr = getResourceAddress(rtRoom, _roomResource);
	assert(cptr);
	if (_CLUT_offs) {
		cptr += _CLUT_offs;
	} else {
		cptr = findPalInPals(cptr + _PALS_offs, _curPalIndex);
	}
	assert(cptr);
	return cptr;
}

#pragma mark -
#pragma mark --- Cursor ---
#pragma mark -

void Scumm::grabCursor(int x, int y, int w, int h) {
	VirtScreen *vs = findVirtScreen(y);

	if (vs == NULL) {
		warning("grabCursor: invalid Y %d", y);
		return;
	}

	grabCursor(vs->screenPtr + (y - vs->topline) * _realWidth + x, w, h);

}

void Scumm::grabCursor(byte *ptr, int width, int height) {
	uint size;
	byte *dst;

	size = width * height;
	if (size > sizeof(_grabbedCursor))
		error("grabCursor: grabbed cursor too big");

	_cursor.width = width;
	_cursor.height = height;
	_cursor.animate = 0;

	dst = _grabbedCursor;
	for (; height; height--) {
		memcpy(dst, ptr, width);
		dst += width;
		ptr += _realWidth;
	}

	updateCursor();
}

void Scumm::useIm01Cursor(byte *im, int w, int h) {
	VirtScreen *vs = &virtscr[0];

	w <<= 3;
	h <<= 3;

	drawBox(0, 0, w - 1, h - 1, 0xFF);

	vs->alloctwobuffers = false;
	gdi._disable_zbuffer = true;
	gdi.drawBitmap(im, vs, _screenStartStrip, 0, w, h, 0, w >> 3, 0);
	vs->alloctwobuffers = true;
	gdi._disable_zbuffer = false;

	grabCursor(vs->screenPtr + vs->xstart, w, h);

	blit(vs->screenPtr + vs->xstart, getResourceAddress(rtBuffer, 5) + vs->xstart, w, h);
}

void Scumm::setCursor(int cursor) {
	if (cursor >= 0 && cursor <= 3)
		_currentCursor = cursor;
	else
		warning("setCursor(%d)", cursor);
}

void Scumm::setCursorHotspot(int x, int y) {
	_cursor.hotspotX = x;
	_cursor.hotspotY = y;
	// FIXME this hacks around offset cursor in the humongous games
	if (_features & GF_HUMONGOUS) {
		_cursor.hotspotX += 15;
		_cursor.hotspotY += 15;
	}
}

void Scumm::updateCursor() {
	_system->set_mouse_cursor(_grabbedCursor, _cursor.width, _cursor.height,
	                          _cursor.hotspotX, _cursor.hotspotY);
}

void Scumm::animateCursor() {
	if (_cursor.animate) {
		if (!(_cursor.animateIndex & 0x3)) {
			decompressDefaultCursor((_cursor.animateIndex >> 2) & 3);
		}
		_cursor.animateIndex++;
	}
}

void Scumm::useBompCursor(byte *im, int width, int height) {
	uint size;

	width <<= 3;
	height <<= 3;

	size = width * height;
	if (size > sizeof(_grabbedCursor))
		error("useBompCursor: cursor too big (%d)", size);

	_cursor.width = width;
	_cursor.height = height;
	_cursor.animate = 0;

	decompressBomp(_grabbedCursor, im, width, height);

	updateCursor();
}

void Scumm::decompressDefaultCursor(int idx) {
	int i, j;
	byte color;

	memset(_grabbedCursor, 0xFF, sizeof(_grabbedCursor));

	color = default_cursor_colors[idx];

	// FIXME: None of the stock cursors are right for Loom. Why is that?

	if ((_gameId == GID_LOOM256) || (_gameId == GID_LOOM)) {
		int w = 0;

		_cursor.width = 8;
		_cursor.height = 8;
		_cursor.hotspotX = 0;
		_cursor.hotspotY = 0;
		
		for (i = 0; i < 8; i++) {
			w += (i >= 6) ? -2 : 1;
			for (j = 0; j < w; j++)
				_grabbedCursor[i * 8 + j] = color;
		}
	} else {
		byte currentCursor = _currentCursor;

#ifdef __PALM_OS__
		if (_gameId == GID_ZAK256 && currentCursor == 0)
			currentCursor = 4;
#endif

		_cursor.width = 16;
		_cursor.height = 16;
		_cursor.hotspotX = default_cursor_hotspots[2 * currentCursor];
		_cursor.hotspotY = default_cursor_hotspots[2 * currentCursor + 1];

		for (i = 0; i < 16; i++) {
			for (j = 0; j < 16; j++) {
				if (default_cursor_images[currentCursor][i] & (1 << j))	
					_grabbedCursor[16 * i + 15 - j] = color;
			}
		}
	}

	updateCursor();
}

void Scumm::makeCursorColorTransparent(int a) {
	int i, size;

	size = _cursor.width * _cursor.height;

	for (i = 0; i < size; i++)
		if (_grabbedCursor[i] == (byte)a)
			_grabbedCursor[i] = 0xFF;

	updateCursor();
}

#pragma mark -
#pragma mark --- Bomp ---
#pragma mark -

int32 Scumm::bompDecodeLineMode0(byte *src, byte *line_buffer, int32 size) {
	if (size <= 0)
		return size;

	for (int32 l = 0; l < size; l++) {
		*(line_buffer++) = *(src++);
	}
	return size;
}

int32 Scumm::bompDecodeLineMode1(byte *src, byte *line_buffer, int32 size) {
	int32 t_size = READ_LE_UINT16(src) + 2;
	if (size <= 0)
		return t_size;
	
	int32 len = size;
	src += 2;
	while (len) {
		byte code = *src++;
		int32 num = (code >> 1) + 1;
		if (num > len)
			num = len;
		len -= num;
		if (code & 1) {
			byte color = *src++;
			do
				*line_buffer++ = color;
			while (--num);
		} else {
			do
				*line_buffer++ = *src++;
			while (--num);
		}
	}
	return t_size;
}

int32 Scumm::bompDecodeLineMode3(byte *src, byte *line_buffer, int32 size) {
	int32 t_size = READ_LE_UINT16(src) + 2;
	line_buffer += size;
	if (size <= 0)
		return t_size;
	
	int32 len = size;
	src += 2;
	while (len) {
		byte code = *src++;
		int32 num = (code >> 1) + 1;
		if (num > len)
			num = len;
		len -= num;
		if (code & 1) {
			byte color = *src++;
			do
				*--line_buffer = color;
			while (--num);
		} else {
			do
				*--line_buffer = *src++;
			while (--num);
		}
	}
	return t_size;
}

void Scumm::bompApplyMask(byte *line_buffer, byte *mask_src, byte bits, int32 size) {
	while(1) {
		byte tmp = *(mask_src++);
		do {
			if (size-- == 0) 
				return;
			if (tmp & bits) {
				*(line_buffer) = 255;
			}
			line_buffer++;
			bits >>= 1;
		} while	(bits);
		bits = 128;
	}
}

void Scumm::bompApplyShadow0(byte *line_buffer, byte *dst, int32 size) {
	while(1) {
		if (size-- == 0)
			return;
		byte tmp = *(line_buffer++);
		if (tmp != 255) {
			*(dst) = tmp;
		}
		dst++;
	}
}

void Scumm::bompApplyShadow1(byte *line_buffer, byte *dst, int32 size) {
	while(1) {
		if (size-- == 0)
			return;
		byte tmp = *(line_buffer++);
		if (tmp != 255) {
			if (tmp == 13) {
				tmp = _shadowPalette[*(dst)];
			}
			*(dst) = tmp;
		}
		dst++;
	}
}

void Scumm::bompApplyShadow3(byte *line_buffer, byte *dst, int32 size) {
	while(1) {
		if (size-- == 0)
			return;
		byte tmp = *(line_buffer++);
		if (tmp != 255) {
			if (tmp < 8) {
				tmp = _shadowPalette[*(dst) + (tmp << 8)];
			}
			*(dst) = tmp;
		}
		dst++;
	}
}

void Scumm::bompApplyActorPalette(byte *line_buffer, int32 size) {
	if (_bompActorPalletePtr != 0) {
		*(_bompActorPalletePtr + 255) = 255;
		while(1) {
			if (size-- == 0)
				break;
			*line_buffer = *(_bompActorPalletePtr + *line_buffer);
			line_buffer++;
		}
	}
}

void Scumm::bompScaleFuncX(byte *line_buffer, byte *scalling_x_ptr, byte skip, int32 size) {
	byte * line_ptr1 = line_buffer;
	byte * line_ptr2 = line_buffer;

	byte tmp = *(scalling_x_ptr++);

	while (size--) {
		if ((skip & tmp) == 0) {
			*(line_ptr1++) = *(line_ptr2);
		}
		line_ptr2++;
		skip >>= 1;
		if (skip == 0) {
			skip = 128;
			tmp = *(scalling_x_ptr++);
		}
	}
}

void Scumm::decompressBomp(byte *dst, byte *src, int w, int h) {
	int len, num;
	byte code, color;

	// Skip the header
	if (_features & GF_AFTER_V8) {
		src += 16;
	} else {
		src += 18;
	}

	do {
		len = w;
		src += 2;
		while (len) {
			code = *src++;
			num = (code >> 1) + 1;
			if (num > len)
				num = len;
			len -= num;
			if (code & 1) {
				color = *src++;
				memset(dst, color, num);
			} else {
				memcpy(dst, src, num);
				src += num;
			}
			dst += num;
		}
	} while (--h);
}

void Scumm::drawBomp(BompDrawData *bd, int decode_mode, int mask) {
	byte skip_y = 128;
	byte skip_y_new = 0;
	byte bits;
	byte *mask_out = 0;
	byte *charset_mask;
	byte tmp;
	int32 clip_left, clip_right, clip_top, clip_bottom, tmp_x, tmp_y, mask_offset, mask_pitch;

	if (bd->x < 0) {
		clip_left = -bd->x;
	} else {
		clip_left = 0;
	}

	if (bd->y < 0) {
		clip_top = -bd->y;
	} else {
		clip_top = 0;
	}

	clip_right = bd->srcwidth - clip_left;
	tmp_x = bd->x + bd->srcwidth;
	if (tmp_x > bd->outwidth) {
		clip_right -= tmp_x - bd->outwidth;
	}

	clip_bottom = bd->srcheight;
	tmp_y = bd->y + bd->srcheight;
	if (tmp_y > bd->outheight) {
		clip_bottom -= tmp_y - bd->outheight;
	}

	byte *src = bd->dataptr;
	byte *dst = bd->out + bd->y * bd->outwidth + bd->x + clip_left;

	mask_pitch = _realWidth / 8;
	mask_offset = _screenStartStrip + (bd->y * mask_pitch) + ((bd->x + clip_left) >> 3);

	charset_mask = getResourceAddress(rtBuffer, 9) + mask_offset;
	bits = 128 >> ((bd->x + clip_left) & 7);

	if (mask == 1) {
		mask_out = _bompMaskPtr + mask_offset;
	}

	if (mask == 3) {
		if (_bompScallingYPtr != NULL) {
			skip_y_new = *(_bompScallingYPtr++);
		}

		if ((clip_right + clip_left) > _bompScaleRight) {
			clip_right = _bompScaleRight - clip_left;
		}

		if (clip_bottom > _bompScaleBottom) {
			clip_bottom = _bompScaleBottom;
		}
	}

	if ((clip_right <= 0) || (clip_bottom <= 0))
		return;

	int32 pos_y = 0;

	byte line_buffer[1024];

	byte *line_ptr = line_buffer + clip_left;

	while(1) {
		switch(decode_mode) {
		case 0:
			src += bompDecodeLineMode0(src, line_buffer, bd->srcwidth);
			break;
		case 1:
			src += bompDecodeLineMode1(src, line_buffer, bd->srcwidth);
			break;
		case 3:
			src += bompDecodeLineMode3(src, line_buffer, bd->srcwidth);
			break;
		default:
			error("Unknown bomp decode_mode %d", decode_mode);
		}

		if (mask == 3) {
			if (bd->scale_y != 255) {
				tmp = skip_y_new & skip_y;
				skip_y >>= 1;
				if (skip_y == 0) {
					skip_y = 128;
					skip_y_new = *(_bompScallingYPtr++);
				}

				if (tmp != 0) 
					continue;
			}

			if (bd->scale_x != 255) {
				bompScaleFuncX(line_buffer, _bompScallingXPtr, 128, bd->srcwidth);
			}
		}

		if (clip_top > 0) {
			clip_top--;
		} else {

			if (mask == 1) {
				bompApplyMask(line_ptr, mask_out, bits, clip_right);
			}
	
			bompApplyMask(line_ptr, charset_mask, bits, clip_right);
			bompApplyActorPalette(line_ptr, clip_right);
	
			switch(bd->shadowMode) {
			case 0:
				bompApplyShadow0(line_ptr, dst, clip_right);
				break;
			case 1:
				bompApplyShadow1(line_ptr, dst, clip_right);
				break;
			case 3:
				bompApplyShadow3(line_ptr, dst, clip_right);
				break;
			default:
				error("Unknown bomp shadowMode %d", bd->shadowMode);
			}
		}

		mask_out += mask_pitch;
		charset_mask += mask_pitch;
		pos_y++;
		dst += bd->outwidth;
		if (pos_y >= clip_bottom)
			break;
	}
}


#ifdef __PALM_OS__
#include "scumm_globals.h" // init globals
void Gfx_initGlobals()		{	
	GSETPTR(transitionEffects, GBVARS_TRANSITIONEFFECTS_INDEX, TransitionEffect, GBVARS_SCUMM)
}
void Gfx_releaseGlobals()	{	GRELEASEPTR(GBVARS_TRANSITIONEFFECTS_INDEX, GBVARS_SCUMM)}
#endif