HUGO: Adding engine to the main tree

svn-id: r52137

1 files changed, 677 insertions, 0 deletions

diff --git a/engines/hugo/schedule.cpp b/engines/hugo/schedule.cpp
new file mode 100755
index 0000000000..b14fef10f3
--- /dev/null
+++ b/engines/hugo/schedule.cpp
@@ -0,0 +1,677 @@
+/* ScummVM - Graphic Adventure Engine
+ *
+ * ScummVM is the legal property of its developers, whose names
+ * are too numerous to list here. Please refer to the COPYRIGHT
+ * file distributed with this source distribution.
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * as published by the Free Software Foundation; either version 2
+ * of the License, or (at your option) any later version.
+
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
+ *
+ * $URL$
+ * $Id$
+ *
+ */
+
+/*
+ * This code is based on original Hugo Trilogy source code
+ *
+ * Copyright (c) 1989-1995 David P. Gray
+ *
+ */
+
+// This module contains all the scheduling and timing stuff
+
+#include "common/system.h"
+#include "common/stream.h"
+
+#include "hugo/game.h"
+#include "hugo/hugo.h"
+#include "hugo/schedule.h"
+#include "hugo/global.h"
+#include "hugo/file.h"
+#include "hugo/display.h"
+#include "hugo/parser.h"
+#include "hugo/util.h"
+#include "hugo/sound.h"
+
+namespace Hugo {
+
+#define SIGN(X)       (X < 0 ? -1 : 1)
+
+Scheduler::Scheduler(HugoEngine &vm) : _vm(vm) {
+}
+
+// Initialise the timer event queue
+void Scheduler::initEventQueue() {
+	debugC(1, kDebugSchedule, "initEventQueue");
+
+	// Chain next_p from first to last
+	for (int i = kMaxEvents; --i;)
+		_events[i - 1].nextEvent = &_events[i];
+	_events[kMaxEvents - 1].nextEvent = 0;
+
+	// Chain prev_p from last to first
+	for (int i = 1; i < kMaxEvents; i++)
+		_events[i].prevEvent = &_events[i - 1];
+	_events[0].prevEvent = 0;
+
+	_headEvent = _tailEvent = 0;                    // Event list is empty
+	_freeEvent = _events;                           // Free list is full
+}
+
+// Return a ptr to an event structure from the free list
+event_t *Scheduler::getQueue() {
+	debugC(4, kDebugSchedule, "getQueue");
+	event_t *resEvent;
+
+	if (!_freeEvent)                                // Error: no more events available
+		Utils::Error(EVNT_ERR, "getQueue");
+	resEvent = _freeEvent;
+	_freeEvent = _freeEvent->nextEvent;
+	resEvent->nextEvent = 0;
+	return resEvent;
+}
+
+// Delete an event structure (i.e. return it to the free list)
+// Historical note:  Originally event p was assumed to be at head of queue
+// (i.e. earliest) since all events were deleted in order when proceeding to
+// a new screen.  To delete an event from the middle of the queue, the action
+// was overwritten to be ANULL.  With the advent of GLOBAL events, Del_queue
+// was modified to allow deletes anywhere in the list, and the DEL_EVENT
+// action was modified to perform the actual delete.
+void Scheduler::delQueue(event_t *curEvent) {
+	debugC(4, kDebugSchedule, "delQueue");
+	if (curEvent == _headEvent)                     // If p was the head ptr
+		_headEvent = curEvent->nextEvent;           // then make new head_p
+	else {                                          // Unlink p
+		curEvent->prevEvent->nextEvent = curEvent->nextEvent;
+		if (curEvent->nextEvent)
+			curEvent->nextEvent->prevEvent = curEvent->prevEvent;
+		else
+			_tailEvent = curEvent->prevEvent;
+	}
+
+	if (_headEvent)
+		_headEvent->prevEvent = 0;                  // Mark end of list
+	else
+		_tailEvent = 0;                             // Empty queue
+
+	curEvent->nextEvent = _freeEvent;               // Return p to free list
+	if (_freeEvent)                                 // Special case, if free list was empty
+		_freeEvent->prevEvent = curEvent;
+	_freeEvent = curEvent;
+}
+
+// Insert the action pointed to by p into the timer event queue
+// The queue goes from head (earliest) to tail (latest) timewise
+void Scheduler::insertAction(act *action) {
+	debugC(1, kDebugSchedule, "insertAction - Action type A%d", action->a0.actType);
+
+	// First, get and initialise the event structure
+	event_t *curEvent = getQueue();
+	curEvent->action = action;
+	switch (action->a0.actType) {                   // Assign whether local or global
+	case AGSCHEDULE:
+		curEvent->localActionFl = false;            // Lasts over a new screen
+		break;
+	default:
+		curEvent->localActionFl = true;             // Rest are for current screen only
+		break;
+	}
+
+	curEvent->time = action->a0.timer + getTicks(); // Convert rel to abs time
+
+	// Now find the place to insert the event
+	if (!_tailEvent) {                              // Empty queue
+		_tailEvent = _headEvent = curEvent;
+		curEvent->nextEvent = curEvent->prevEvent = NULL;
+	} else {
+		event_t *wrkEvent = _tailEvent;             // Search from latest time back
+		bool found = false;
+
+		while (wrkEvent && !found) {
+			if (wrkEvent->time <= curEvent->time) { // Found if new event later
+				found = true;
+				if (wrkEvent == _tailEvent)         // New latest in list
+					_tailEvent = curEvent;
+				else
+					wrkEvent->nextEvent->prevEvent = curEvent;
+				curEvent->nextEvent = wrkEvent->nextEvent;
+				wrkEvent->nextEvent = curEvent;
+				curEvent->prevEvent = wrkEvent;
+			}
+			wrkEvent = wrkEvent->prevEvent;
+		}
+
+		if (!found) {                               // Must be earliest in list
+			_headEvent->prevEvent = curEvent;       // So insert as new head
+			curEvent->nextEvent = _headEvent;
+			curEvent->prevEvent = NULL;
+			_headEvent = curEvent;
+		}
+	}
+}
+
+void Scheduler::insertActionList(uint16 actIndex) {
+// Call Insert_action for each action in the list supplied
+	debugC(1, kDebugSchedule, "insertActionList(%d)", actIndex);
+
+	if (_vm._actListArr[actIndex])
+		for (int i = 0; _vm._actListArr[actIndex][i].a0.actType != ANULL; i++)
+			insertAction(&_vm._actListArr[actIndex][i]);
+}
+
+void Scheduler::decodeString(char *line) {
+// Decode a string
+	debugC(1, kDebugSchedule, "decodeString(%s)", line);
+
+	static char cypher[] = "Copyright 1992, Gray Design Associates";
+
+	for (uint16 i = 0; i < strlen(line); i++)
+		line[i] -= cypher[i % strlen(cypher)];
+	debugC(1, kDebugSchedule, "result : %s", line);
+}
+
+event_t *Scheduler::doAction(event_t *curEvent) {
+// This function performs the action in the event structure pointed to by p
+// It dequeues the event and returns it to the free list.  It returns a ptr
+// to the next action in the list, except special case of NEW_SCREEN
+	event_t  *wrkEvent;                             // Save ev_p->next_p for return
+	event_t  *saveEvent;                            // Used in DEL_EVENTS
+	char     *response;                             // User's response string
+	object_t *obj1;
+	object_t *obj2;
+	int       dx, dy;
+	act      *action;                               // Ptr to action structure
+
+	status_t &gameStatus = _vm.getGameStatus();
+
+	action = curEvent->action;
+	debugC(1, kDebugSchedule, "doAction - Event action type : %d", action->a0.actType);
+
+	switch (action->a0.actType) {
+	case ANULL:                                     // Big NOP from DEL_EVENTS
+		break;
+	case ASCHEDULE:                                 // act0: Schedule an action list
+		insertActionList(action->a0.actIndex);
+		break;
+	case START_OBJ:                                 // act1: Start an object cycling
+		_vm._objects[action->a1.objNumb].cycleNumb = action->a1.cycleNumb;
+		_vm._objects[action->a1.objNumb].cycling = action->a1.cycle;
+		break;
+	case INIT_OBJXY:                                // act2: Initialise an object
+		_vm._objects[action->a2.objNumb].x = action->a2.x;          // Coordinates
+		_vm._objects[action->a2.objNumb].y = action->a2.y;
+		break;
+	case PROMPT:                                    // act3: Prompt user for key phrase
+// TODO : Add specific code for Hugo 1 DOS, which is handled differently,
+		response = Utils::Box(BOX_PROMPT, _vm.file().fetchString(action->a3.promptIndex));
+
+		warning("STUB: doAction(act3), expecting answer %s", response);
+
+// TODO : The answer of the player is not handled currently! Once it'll be read in the messageBox, uncomment this block
+#if 0
+		bool      found;
+		char     *tmpStr;                           // General purpose string ptr
+
+		for (found = false, dx = 0; !found && (action->a3.responsePtr[dx] != -1); dx++) {
+			tmpStr = _vm.file().Fetch_string(action->a3.responsePtr[dx]);
+			if (strstr(_vm.parser().strlwr(response) , tmpStr))
+				found = true;
+		}
+
+		if (found)
+			insertActionList(action->a3.actPassIndex);
+		else
+			insertActionList(action->a3.actFailIndex);
+#endif
+
+//HACK: As the answer is not read, currently it's always considered correct
+		insertActionList(action->a3.actPassIndex);
+		break;
+	case BKGD_COLOR:                                // act4: Set new background color
+		HugoEngine::get().screen().setBackgroundColor(action->a4.newBackgroundColor);
+		break;
+	case INIT_OBJVXY:                               // act5: Initialise an object
+		_vm._objects[action->a5.objNumb].vx = action->a5.vx;        // velocities
+		_vm._objects[action->a5.objNumb].vy = action->a5.vy;
+		break;
+	case INIT_CARRY:                                // act6: Initialise an object
+		_vm._objects[action->a6.objNumb].carriedFl = action->a6.carriedFl;  // carried status
+		break;
+	case INIT_HF_COORD:                             // act7: Initialise an object to hero's "feet" coords
+		_vm._objects[action->a7.objNumb].x = _vm._hero->x - 1;
+		_vm._objects[action->a7.objNumb].y = _vm._hero->y + _vm._hero->currImagePtr->y2 - 1;
+		_vm._objects[action->a7.objNumb].screenIndex = *_vm._screen_p;  // Don't forget screen!
+		break;
+	case NEW_SCREEN:                                // act8: Start new screen
+		newScreen(action->a8.screenIndex);
+		break;
+	case INIT_OBJSTATE:                             // act9: Initialise an object state
+		_vm._objects[action->a9.objNumb].state = action->a9.newState;
+		break;
+	case INIT_PATH:                                 // act10: Initialise an object path and velocity
+		_vm._objects[action->a10.objNumb].pathType = (path_t) action->a10.newPathType;
+		_vm._objects[action->a10.objNumb].vxPath = action->a10.vxPath;
+		_vm._objects[action->a10.objNumb].vyPath = action->a10.vyPath;
+		break;
+	case COND_R:                                    // act11: action lists conditional on object state
+		if (_vm._objects[action->a11.objNumb].state == action->a11.stateReq)
+			insertActionList(action->a11.actPassIndex);
+		else
+			insertActionList(action->a11.actFailIndex);
+		break;
+	case TEXT:                                      // act12: Text box (CF WARN)
+		Utils::Box(BOX_ANY, _vm.file().fetchString(action->a12.stringIndex));   // Fetch string from file
+		break;
+	case SWAP_IMAGES:                               // act13: Swap 2 object images
+		swapImages(action->a13.obj1, action->a13.obj2);
+		break;
+	case COND_SCR:                                  // act14: Conditional on current screen
+		if (_vm._objects[action->a14.objNumb].screenIndex == action->a14.screenReq)
+			insertActionList(action->a14.actPassIndex);
+		else
+			insertActionList(action->a14.actFailIndex);
+		break;
+	case AUTOPILOT:                                 // act15: Home in on a (stationary) object
+		// object p1 will home in on object p2
+		obj1 = &_vm._objects[action->a15.obj1];
+		obj2 = &_vm._objects[action->a15.obj2];
+		obj1->pathType = AUTO;
+		dx = obj1->x + obj1->currImagePtr->x1 - obj2->x - obj2->currImagePtr->x1;
+		dy = obj1->y + obj1->currImagePtr->y1 - obj2->y - obj2->currImagePtr->y1;
+
+		if (dx == 0)                                // Don't EVER divide by zero!
+			dx = 1;
+		if (dy == 0)
+			dy = 1;
+
+		if (abs(dx) > abs(dy)) {
+			obj1->vx = action->a15.dx * -SIGN(dx);
+			obj1->vy = abs((action->a15.dy * dy) / dx) * -SIGN(dy);
+		} else {
+			obj1->vy = action->a15.dy * -SIGN(dy);
+			obj1->vx = abs((action->a15.dx * dx) / dy) * -SIGN(dx);
+		}
+		break;
+	case INIT_OBJ_SEQ:                              // act16: Set sequence number to use
+		// Note: Don't set a sequence at time 0 of a new screen, it causes
+		// problems clearing the boundary bits of the object!  t>0 is safe
+		_vm._objects[action->a16.objNumb].currImagePtr = _vm._objects[action->a16.objNumb].seqList[action->a16.seqIndex].seqPtr;
+		break;
+	case SET_STATE_BITS:                            // act17: OR mask with curr obj state
+		_vm._objects[action->a17.objNumb].state |= action->a17.stateMask;
+		break;
+	case CLEAR_STATE_BITS:                          // act18: AND ~mask with curr obj state
+		_vm._objects[action->a18.objNumb].state &= ~action->a18.stateMask;
+		break;
+	case TEST_STATE_BITS:                           // act19: If all bits set, do apass else afail
+		if ((_vm._objects[action->a19.objNumb].state & action->a19.stateMask) == action->a19.stateMask)
+			insertActionList(action->a19.actPassIndex);
+		else
+			insertActionList(action->a19.actFailIndex);
+		break;
+	case DEL_EVENTS:                                // act20: Remove all events of this action type
+		// Note: actions are not deleted here, simply turned into NOPs!
+		wrkEvent = _headEvent;                      // The earliest event
+		while (wrkEvent) {                          // While events found in list
+			saveEvent = wrkEvent->nextEvent;
+			if (wrkEvent->action->a20.actType == action->a20.actTypeDel)
+				delQueue(wrkEvent);
+			wrkEvent = saveEvent;
+		}
+		break;
+	case GAMEOVER:                                  // act21: Game over!
+		// NOTE: Must wait at least 1 tick before issuing this action if
+		// any objects are to be made invisible!
+		gameStatus.gameOverFl = true;
+		break;
+	case INIT_HH_COORD:                             // act22: Initialise an object to hero's actual coords
+		_vm._objects[action->a22.objNumb].x = _vm._hero->x;
+		_vm._objects[action->a22.objNumb].y = _vm._hero->y;
+		_vm._objects[action->a22.objNumb].screenIndex = *_vm._screen_p;// Don't forget screen!
+		break;
+	case EXIT:                                      // act23: Exit game back to DOS
+		_vm.endGame();
+		break;
+	case BONUS:                                     // act24: Get bonus score for action
+		processBonus(action->a24.pointIndex);
+		break;
+	case COND_BOX:                                  // act25: Conditional on bounding box
+		obj1 = &_vm._objects[action->a25.objNumb];
+		dx = obj1->x + obj1->currImagePtr->x1;
+		dy = obj1->y + obj1->currImagePtr->y2;
+		if ((dx >= action->a25.x1) && (dx <= action->a25.x2) &&
+		        (dy >= action->a25.y1) && (dy <= action->a25.y2))
+			insertActionList(action->a25.actPassIndex);
+		else
+			insertActionList(action->a25.actFailIndex);
+		break;
+	case SOUND:                                     // act26: Play a sound (or tune)
+		if (action->a26.soundIndex < _vm._tunesNbr)
+			_vm.sound().playMusic(action->a26.soundIndex);
+		else
+			_vm.sound().playSound(action->a26.soundIndex, BOTH_CHANNELS, MED_PRI);
+		break;
+	case ADD_SCORE:                                 // act27: Add object's value to score
+		_vm.adjustScore(_vm._objects[action->a27.objNumb].objValue);
+		break;
+	case SUB_SCORE:                                 // act28: Subtract object's value from score
+		_vm.adjustScore(-_vm._objects[action->a28.objNumb].objValue);
+		break;
+	case COND_CARRY:                                // act29: Conditional on object being carried
+		if (_vm._objects[action->a29.objNumb].carriedFl)
+			insertActionList(action->a29.actPassIndex);
+		else
+			insertActionList(action->a29.actFailIndex);
+		break;
+	case INIT_MAZE:                                 // act30: Enable and init maze structure
+		_maze.enabledFl = true;
+		_maze.size = action->a30.mazeSize;
+		_maze.x1 = action->a30.x1;
+		_maze.y1 = action->a30.y1;
+		_maze.x2 = action->a30.x2;
+		_maze.y2 = action->a30.y2;
+		_maze.x3 = action->a30.x3;
+		_maze.x4 = action->a30.x4;
+		_maze.firstScreenIndex = action->a30.firstScreenIndex;
+		break;
+	case EXIT_MAZE:                                 // act31: Disable maze mode
+		_maze.enabledFl = false;
+		break;
+	case INIT_PRIORITY:
+		_vm._objects[action->a32.objNumb].priority = action->a32.priority;
+		break;
+	case INIT_SCREEN:
+		_vm._objects[action->a33.objNumb].screenIndex = action->a33.screenIndex;
+		break;
+	case AGSCHEDULE:                                // act34: Schedule a (global) action list
+		insertActionList(action->a34.actIndex);
+		break;
+	case REMAPPAL:                                  // act35: Remap a palette color
+		HugoEngine::get().screen().remapPal(action->a35.oldColorIndex, action->a35.newColorIndex);
+		break;
+	case COND_NOUN:                                 // act36: Conditional on noun mentioned
+		if (_vm.parser().isWordPresent(_vm._arrayNouns[action->a36.nounIndex]))
+			insertActionList(action->a36.actPassIndex);
+		else
+			insertActionList(action->a36.actFailIndex);
+		break;
+	case SCREEN_STATE:                              // act37: Set new screen state
+		_vm._screenStates[action->a37.screenIndex] = action->a37.newState;
+		break;
+	case INIT_LIPS:                                 // act38: Position lips on object
+		_vm._objects[action->a38.lipsObjNumb].x = _vm._objects[action->a38.objNumb].x + action->a38.dxLips;
+		_vm._objects[action->a38.lipsObjNumb].y = _vm._objects[action->a38.objNumb].y + action->a38.dyLips;
+		_vm._objects[action->a38.lipsObjNumb].screenIndex = *_vm._screen_p; // Don't forget screen!
+		_vm._objects[action->a38.lipsObjNumb].cycling = CYCLE_FORWARD;
+		break;
+	case INIT_STORY_MODE:                           // act39: Init story_mode flag
+		// This is similar to the QUIET path mode, except that it is
+		// independant of it and it additionally disables the ">" prompt
+		gameStatus.storyModeFl = action->a39.storyModeFl;
+
+		// End the game after story if this is special vendor demo mode
+		if (gameStatus.demoFl && action->a39.storyModeFl == false)
+			_vm.endGame();
+		break;
+	case WARN:                                      // act40: Text box (CF TEXT)
+		Utils::Box(BOX_OK, _vm.file().fetchString(action->a40.stringIndex));
+		break;
+	case COND_BONUS:                                // act41: Perform action if got bonus
+		if (_vm._points[action->a41.BonusIndex].scoredFl)
+			insertActionList(action->a41.actPassIndex);
+		else
+			insertActionList(action->a41.actFailIndex);
+		break;
+	case TEXT_TAKE:                                 // act42: Text box with "take" message
+		Utils::Box(BOX_ANY, TAKE_TEXT, _vm._arrayNouns[_vm._objects[action->a42.objNumb].nounIndex][TAKE_NAME]);
+		break;
+	case YESNO:                                     // act43: Prompt user for Yes or No
+		warning("doAction(act43) - Yes/No Box");
+		if (Utils::Box(BOX_YESNO, _vm.file().fetchString(action->a43.promptIndex)) != NULL)
+			insertActionList(action->a43.actYesIndex);
+		else
+			insertActionList(action->a43.actNoIndex);
+		break;
+	case STOP_ROUTE:                                // act44: Stop any route in progress
+		gameStatus.routeIndex = -1;
+		break;
+	case COND_ROUTE:                                // act45: Conditional on route in progress
+		if (gameStatus.routeIndex >= action->a45.routeIndex)
+			insertActionList(action->a45.actPassIndex);
+		else
+			insertActionList(action->a45.actFailIndex);
+		break;
+	case INIT_JUMPEXIT:                             // act46: Init status.jumpexit flag
+		// This is to allow left click on exit to get there immediately
+		// For example the plane crash in Hugo2 where hero is invisible
+		// Couldn't use INVISIBLE flag since conflicts with boat in Hugo1
+		gameStatus.jumpExitFl = action->a46.jumpExitFl;
+		break;
+	case INIT_VIEW:                                 // act47: Init object.viewx, viewy, dir
+		_vm._objects[action->a47.objNumb].viewx = action->a47.viewx;
+		_vm._objects[action->a47.objNumb].viewy = action->a47.viewy;
+		_vm._objects[action->a47.objNumb].direction = action->a47.direction;
+		break;
+	case INIT_OBJ_FRAME:                            // act48: Set seq,frame number to use
+		// Note: Don't set a sequence at time 0 of a new screen, it causes
+		// problems clearing the boundary bits of the object!  t>0 is safe
+		_vm._objects[action->a48.objNumb].currImagePtr = _vm._objects[action->a48.objNumb].seqList[action->a48.seqIndex].seqPtr;
+		for (dx = 0; dx < action->a48.frameIndex; dx++)
+			_vm._objects[action->a48.objNumb].currImagePtr = _vm._objects[action->a48.objNumb].currImagePtr->nextSeqPtr;
+		break;
+	case OLD_SONG:
+		//TODO For Hugo 1 and Hugo2 DOS: The songs were not stored in a DAT file, but directly as
+		//strings. the current play_music should be modified to use a strings instead of reading
+		//the file, in those cases. This replaces, for those DOS versions, act26.
+		warning("STUB: doAction(act49)");
+		break;
+	default:
+		Utils::Error(EVNT_ERR, "doAction");
+		break;
+	}
+
+	if (action->a0.actType == NEW_SCREEN)           // New_screen() deletes entire list
+		return (NULL);                              // next_p = NULL since list now empty
+	else {
+		wrkEvent = curEvent->nextEvent;
+		delQueue(curEvent);                         // Return event to free list
+		return(wrkEvent);                           // Return next event ptr
+	}
+}
+
+// This is the scheduler which runs every tick.  It examines the event queue
+// for any events whose time has come.  It dequeues these events and performs
+// the action associated with the event, returning it to the free queue
+void Scheduler::runScheduler() {
+	debugC(6, kDebugSchedule, "runScheduler");
+
+	status_t &gameStatus = _vm.getGameStatus();
+
+	event_t *curEvent = _headEvent;                 // The earliest event
+	while (curEvent && curEvent->time <= gameStatus.tick) // While mature events found
+		curEvent = doAction(curEvent);              // Perform the action (returns next_p)
+	gameStatus.tick++;                              // Accessed elsewhere via getTicks()
+}
+
+uint32 Scheduler::getTicks() {
+// Return system time in ticks.  A tick is 1/TICKS_PER_SEC mS
+	debugC(3, kDebugSchedule, "getTicks");
+
+	return _vm.getGameStatus().tick;
+}
+
+void Scheduler::processBonus(int bonusIndex) {
+// Add indecated bonus to score if not added already
+	debugC(1, kDebugSchedule, "processBonus(%d)", bonusIndex);
+
+	if (!_vm._points[bonusIndex].scoredFl) {
+		_vm.adjustScore(_vm._points[bonusIndex].score);
+		_vm._points[bonusIndex].scoredFl = true;
+	}
+}
+
+// Transition to a new screen as follows:
+//	1. Clear out all non-global events from event list.
+//	2. Set the new screen (in the hero object and any carried objects)
+//	3. Read in the screen files for the new screen
+//	4. Schedule action list for new screen
+//	5. Initialise prompt line and status line
+void Scheduler::newScreen(int screenIndex) {
+	debugC(1, kDebugSchedule, "newScreen(%d)", screenIndex);
+
+	// Make sure the background file exists!
+	if (!_vm.isPacked()) {
+		char line[32];
+		if (!_vm.file().fileExists(strcat(strncat(strcpy(line, _vm._picDir), _vm._screenNames[screenIndex], NAME_LEN), BKGEXT)) &&
+		        !_vm.file().fileExists(strcat(strcpy(line, _vm._screenNames[screenIndex]), ".ART"))) {
+			Utils::Box(BOX_ANY, _vm._textSchedule[kSsNoBackground]);
+			return;
+		}
+	}
+
+	// 1. Clear out all local events
+	event_t *curEvent = _headEvent;                 // The earliest event
+	event_t *wrkEvent;                              // Event ptr
+	while (curEvent) {                              // While mature events found
+		wrkEvent = curEvent->nextEvent;             // Save p (becomes undefined after Del)
+		if (curEvent->localActionFl)
+			delQueue(curEvent);                     // Return event to free list
+		curEvent = wrkEvent;
+	}
+
+	// 2. Set the new screen in the hero object and any being carried
+	_vm.setNewScreen(screenIndex);
+
+	// 3. Read in new screen files
+	_vm.readScreenFiles(screenIndex);
+
+	// 4. Schedule action list for this screen
+	_vm.screenActions(screenIndex);
+
+	// 5. Initialise prompt line and status line
+	_vm.initNewScreenDisplay();
+}
+
+// Write the event queue to the file with handle f
+// Note that we convert all the event structure ptrs to indexes
+// using -1 for NULL.  We can't convert the action ptrs to indexes
+// so we save address of first dummy action ptr to compare on restore.
+void Scheduler::saveEvents(Common::WriteStream *f) {
+	uint32   curTime;
+	event_t  saveEvents_[kMaxEvents];                // Convert event ptrs to indexes
+	event_t *wrkEvent;                              // Event ptr
+	int16    freeIndex;                             // Free list index
+	int16    headIndex;                             // Head of list index
+	int16    tailIndex;                             // Tail of list index
+
+	debugC(1, kDebugSchedule, "saveEvents");
+
+	curTime = getTicks();
+
+	// Convert event ptrs to indexes
+	for (int16 i = 0; i < kMaxEvents; i++) {
+		wrkEvent = &_events[i];
+		saveEvents_[i] = *wrkEvent;
+		saveEvents_[i].prevEvent = (wrkEvent->prevEvent == NULL) ? (event_t *) - 1 : (event_t *)(wrkEvent->prevEvent - _events);
+		saveEvents_[i].nextEvent = (wrkEvent->nextEvent == NULL) ? (event_t *) - 1 : (event_t *)(wrkEvent->nextEvent - _events);
+	}
+	freeIndex = (_freeEvent == 0) ? -1 : _freeEvent - _events;
+	headIndex = (_headEvent == 0) ? -1 : _headEvent - _events;
+	tailIndex = (_tailEvent == 0) ? -1 : _tailEvent - _events;
+
+	f->write(&curTime,   sizeof(curTime));
+	f->write(&freeIndex, sizeof(freeIndex));
+	f->write(&headIndex, sizeof(headIndex));
+	f->write(&tailIndex, sizeof(tailIndex));
+	f->write(saveEvents_, sizeof(saveEvents_));
+}
+
+// Restore the event list from file with handle f
+void Scheduler::restoreEvents(Common::SeekableReadStream *f) {
+	uint32   curTime, saveTime;
+	event_t *wrkEvent;                              // Event ptr
+	event_t  savedEvents[kMaxEvents];               // Convert event ptrs to indexes
+	int16    freeIndex;                             // Free list index
+	int16    headIndex;                             // Head of list index
+	int16    tailIndex;                             // Tail of list index
+
+	debugC(1, kDebugSchedule, "restoreEvents");
+
+	f->read(&saveTime,  sizeof(saveTime));          // time of save
+	f->read(&freeIndex, sizeof(freeIndex));
+	f->read(&headIndex, sizeof(headIndex));
+	f->read(&tailIndex, sizeof(tailIndex));
+	f->read(savedEvents, sizeof(savedEvents));
+
+	// Restore events indexes to pointers
+	for (int i = 0; i < kMaxEvents; i++) {
+		wrkEvent = &savedEvents[i];
+		_events[i] = *wrkEvent;
+		_events[i].prevEvent = (wrkEvent->prevEvent == (event_t *) - 1) ? (event_t *)0 : &_events[(size_t)wrkEvent->prevEvent ];
+		_events[i].nextEvent = (wrkEvent->nextEvent == (event_t *) - 1) ? (event_t *)0 : &_events[(size_t)wrkEvent->nextEvent ];
+	}
+	_freeEvent = (freeIndex == -1) ? NULL : &_events[freeIndex];
+	_headEvent = (headIndex == -1) ? NULL : &_events[headIndex];
+	_tailEvent = (tailIndex == -1) ? NULL : &_events[tailIndex];
+
+	// Adjust times to fit our time
+	curTime = getTicks();
+	wrkEvent = _headEvent;                              // The earliest event
+	while (wrkEvent) {                              // While mature events found
+		wrkEvent->time = wrkEvent->time - saveTime + curTime;
+		wrkEvent = wrkEvent->nextEvent;
+	}
+}
+
+void Scheduler::restoreScreen(int screenIndex) {
+// Transition to a new screen as follows:
+//	1. Set the new screen (in the hero object and any carried objects)
+//	2. Read in the screen files for the new screen
+//	3. Initialise prompt line and status line
+
+	debugC(1, kDebugSchedule, "restoreScreen(%d)", screenIndex);
+
+	// 1. Set the new screen in the hero object and any being carried
+	_vm.setNewScreen(screenIndex);
+
+	// 2. Read in new screen files
+	_vm.readScreenFiles(screenIndex);
+
+	// 3. Initialise prompt line and status line
+	_vm.initNewScreenDisplay();
+}
+
+void Scheduler::swapImages(int objNumb1, int objNumb2) {
+// Swap all the images of one object with another.  Set hero_image (we make
+// the assumption for now that the first obj is always the HERO) to the object
+// number of the swapped image
+	seqList_t tmpSeqList[MAX_SEQUENCES];
+
+	debugC(1, kDebugSchedule, "swapImages(%d, %d)", objNumb1, objNumb2);
+
+	_vm.file().saveSeq(&_vm._objects[objNumb1]);
+	memcpy(tmpSeqList, _vm._objects[objNumb1].seqList, sizeof(seqList_t));
+	memcpy(_vm._objects[objNumb1].seqList, _vm._objects[objNumb2].seqList, sizeof(seqList_t));
+	memcpy(_vm._objects[objNumb2].seqList, tmpSeqList, sizeof(seqList_t));
+	_vm.file().restoreSeq(&_vm._objects[objNumb1]);
+	_vm._objects[objNumb2].currImagePtr = _vm._objects[objNumb2].seqList[0].seqPtr;
+	_vm._heroImage = (_vm._heroImage == HERO) ? objNumb2 : HERO;
+
+	// Make sure baseline stays constant
+	_vm._objects[objNumb1].y += _vm._objects[objNumb2].currImagePtr->y2 - _vm._objects[objNumb1].currImagePtr->y2;
+}
+
+} // end of namespace Hugo