//////////

//

//  File:       VRHash.c

//

//  Contains:   Functions for hash table management.

//

//  Written by: Tim Monroe

//

//  Copyright:  © 1998 by Apple Computer, Inc., all rights reserved.

//

//  Change History (most recent first):

//

//     <4>      12/02/98        rtm     renamed VRHash_CreateHashTable and _DestroyHashTable to _Init and _Stop

//     <3>      12/02/98        rtm     simplified VRHash_DestroyHashTable

//     <2>      11/29/98        rtm     minor clean-up to some routines

//     <1>      11/28/98        rtm     first file (Happy Thanksgiving!)

//  

//  Our hash table is an array of "bucket pointers"; each bucket (defined by the VRScriptHash

//  data structure) contains the command word, its corresponding command code, and a pointer to

//  the next bucket in the linked list (or NULL if there is no next bucket).

//

//  There are many ways to implement a hash table management scheme; the one used here is eerily

//  similar (as I now discover) to the one described by Kernighan & Ritchie in The C Programming

//  Language.

//

//////////

//////////

//

// header files

//     

//////////

#include "VRHash.h"

//////////

//

// global variables

//     

//////////

static VRScriptHashPtr          gHashTable[kNumEntriesInTable];         // the hash table

//////////

//

// VRHash_Init

// Create the hash table.

//

//////////

void VRHash_Init (void)

{

    short           myIndex;

    // initialize the bucket pointers in the hash table

    for (myIndex = 0; myIndex < kNumEntriesInTable; myIndex++)

        gHashTable[myIndex] = NULL;

    // insert entries into the hash table

    VRHash_PutCommandIntoTable("SetVerboseState", kSetVerboseState);

    VRHash_PutCommandIntoTable("OpenQTVRMovieFile", kOpenQTVRMovieFile);

    VRHash_PutCommandIntoTable("ReplaceMainMovie", kReplaceMainMovie);

    VRHash_PutCommandIntoTable("SetCurrentDirectory", kSetCurrentDirectory);

    VRHash_PutCommandIntoTable("SetBarState", kSetBarState);

    VRHash_PutCommandIntoTable("SetButtonState", kSetButtonState);

    VRHash_PutCommandIntoTable("SetResizeState", kSetResizeState);

    VRHash_PutCommandIntoTable("SetWindowSize", kSetWindowSize);

    VRHash_PutCommandIntoTable("SetMaxWindowSize", kSetMaxWindowSize);

    VRHash_PutCommandIntoTable("ReplaceCursor", kReplaceCursor);

    VRHash_PutCommandIntoTable("SetHotSpotIDCursors", kSetHotSpotIDCursors);

    VRHash_PutCommandIntoTable("SetHotSpotTypeCursors", kSetHotSpotTypeCursors);

    VRHash_PutCommandIntoTable("GoToNodeID", kGoToNodeID);

    VRHash_PutCommandIntoTable("ShowDefaultView", kShowDefaultView);

    VRHash_PutCommandIntoTable("OpenResourceFile", kOpenResourceFile);

    VRHash_PutCommandIntoTable("SetCorrection", kSetCorrection);

    VRHash_PutCommandIntoTable("SetQuality", kSetQuality);

    VRHash_PutCommandIntoTable("SetSwingSpeed", kSetSwingSpeed);

    VRHash_PutCommandIntoTable("SetSwingDirection", kSetSwingDirection);

    VRHash_PutCommandIntoTable("SetSwingState", kSetSwingState);

    VRHash_PutCommandIntoTable("SetPanAngle", kSetPanAngle);

    VRHash_PutCommandIntoTable("SetTiltAngle", kSetTiltAngle);

    VRHash_PutCommandIntoTable("SetPanTiltZoom", kSetPanTiltZoom);

    VRHash_PutCommandIntoTable("SetFieldOfView", kSetFieldOfView);

    VRHash_PutCommandIntoTable("SetViewCenter", kSetViewCenter);

    VRHash_PutCommandIntoTable("SetPanLimits", kSetPanLimits);

    VRHash_PutCommandIntoTable("SetTiltLimits", kSetTiltLimits);

    VRHash_PutCommandIntoTable("SetZoomLimits", kSetZoomLimits);

    VRHash_PutCommandIntoTable("SetHotSpotState", kSetHotSpotState);

    VRHash_PutCommandIntoTable("SetTranslateState", kSetTranslateState);

    VRHash_PutCommandIntoTable("SetClickRadius", kSetClickRadius);

    VRHash_PutCommandIntoTable("SetClickTimeout", kSetClickTimeout);

    VRHash_PutCommandIntoTable("SetPanTiltSpeed", kSetPanTiltSpeed);

    VRHash_PutCommandIntoTable("SetZoomSpeed", kSetZoomSpeed);

    VRHash_PutCommandIntoTable("SetMouseScale", kSetMouseScale);

    VRHash_PutCommandIntoTable("SetFrameRate", kSetFrameRate);

    VRHash_PutCommandIntoTable("SetViewRate", kSetViewRate);

    VRHash_PutCommandIntoTable("SetViewTime", kSetViewTime);

    VRHash_PutCommandIntoTable("SetViewState", kSetViewState);

    VRHash_PutCommandIntoTable("SetAnimationState", kSetAnimationState);

    VRHash_PutCommandIntoTable("SetControlState", kSetControlState);

    VRHash_PutCommandIntoTable("SetFrameAnimState", kSetFrameAnimState);

    VRHash_PutCommandIntoTable("SetViewAnimState", kSetViewAnimState);

    VRHash_PutCommandIntoTable("SetQTVRVisState", kSetQTVRVisState);

    VRHash_PutCommandIntoTable("SetCachePrefs", kSetCachePrefs);

    VRHash_PutCommandIntoTable("SetMovieVolume", kSetMovieVolume);

    VRHash_PutCommandIntoTable("SetTrackVolume", kSetTrackVolume);

    VRHash_PutCommandIntoTable("SetSoundVolume", kSetSoundVolume);

    VRHash_PutCommandIntoTable("SetSoundBalance", kSetSoundBalance);

    VRHash_PutCommandIntoTable("PlaySceneSound", kPlaySceneSound);

    VRHash_PutCommandIntoTable("PlaySceneQTMidi", kPlaySceneQTMidi);

    VRHash_PutCommandIntoTable("PlayNodeQTMidi", kPlayNodeQTMidi);

    VRHash_PutCommandIntoTable("PlayNodeSound", kPlayNodeSound);

    VRHash_PutCommandIntoTable("PlayNode3DSound", kPlayNode3DSound);

    VRHash_PutCommandIntoTable("HotSpotQTMidi", kHotSpotQTMidi);

    VRHash_PutCommandIntoTable("HotSpotSound", kHotSpotSound);

    VRHash_PutCommandIntoTable("HotSpot3DSound", kHotSpot3DSound);

    VRHash_PutCommandIntoTable("HotSpotMovie", kHotSpotMovie);

    VRHash_PutCommandIntoTable("TriggerHotSpot", kTriggerHotSpot);

    VRHash_PutCommandIntoTable("PlayQTMidi", kPlayQTMidi);

    VRHash_PutCommandIntoTable("PlaySndResource", kPlaySndResource);

    VRHash_PutCommandIntoTable("PlaySound", kPlaySndResource);              // synonym

    VRHash_PutCommandIntoTable("PlaySoundFile", kPlaySoundFile);

    VRHash_PutCommandIntoTable("Play3DSndResource", kPlay3DSndResource);

    VRHash_PutCommandIntoTable("Play3DSndResourceAngle", kPlay3DSndResourceAngle);

    VRHash_PutCommandIntoTable("ShowPicture", kShowPicture);

    VRHash_PutCommandIntoTable("ShowNodePicture", kShowNodePicture);

    VRHash_PutCommandIntoTable("AtTime", kAtTime);

    VRHash_PutCommandIntoTable("AtAppLaunch", kAtAppLaunch);

    VRHash_PutCommandIntoTable("AtAppQuit", kAtAppQuit);

    VRHash_PutCommandIntoTable("AtMouseOverHSID", kAtMouseOverHSID);

    VRHash_PutCommandIntoTable("AtMouseOverHSType", kAtMouseOverHSType);

    VRHash_PutCommandIntoTable("AtClickHSID", kAtClickHSID);

    VRHash_PutCommandIntoTable("AtClickHS", kAtClickHSID);                  // synonym

    VRHash_PutCommandIntoTable("AtClickHSType", kAtClickHSType);

    VRHash_PutCommandIntoTable("AtClickCustomButton", kAtClickCustomButton);

    VRHash_PutCommandIntoTable("AtClickSprite", kAtClickSprite);

    VRHash_PutCommandIntoTable("AtTriggerWiredAction", kAtTriggerWiredAction);

    VRHash_PutCommandIntoTable("AtNodeEntry", kAtNodeEntry);

    VRHash_PutCommandIntoTable("AtNodeExit", kAtNodeExit);

    VRHash_PutCommandIntoTable("AtPanAngle", kAtPanAngle);

    VRHash_PutCommandIntoTable("AtTiltAngle", kAtTiltAngle);

    VRHash_PutCommandIntoTable("AtZoomAngle", kAtZoomAngle);

    VRHash_PutCommandIntoTable("DoBoth", kDoBoth);

    VRHash_PutCommandIntoTable("DoNothing", kDoNothing);

    VRHash_PutCommandIntoTable("PlayMovie", kPlayMovie);

    VRHash_PutCommandIntoTable("PlayTransMovie", kPlayTransMovie);

    VRHash_PutCommandIntoTable("PlayTransEffect", kPlayTransEffect);

    VRHash_PutCommandIntoTable("MoveScreen", kMoveScreen);

    VRHash_PutCommandIntoTable("Beep", kBeep);

    VRHash_PutCommandIntoTable("ProcessScript", kProcessScript);

    VRHash_PutCommandIntoTable("CreateBox", kCreateBox);

    VRHash_PutCommandIntoTable("CreateCone", kCreateCone);

    VRHash_PutCommandIntoTable("CreateCylinder", kCreateCylinder);

    VRHash_PutCommandIntoTable("CreateEllipsoid", kCreateEllipsoid);

    VRHash_PutCommandIntoTable("CreateTorus", kCreateTorus);

    VRHash_PutCommandIntoTable("CreateRectangle", kCreateRectangle);

    VRHash_PutCommandIntoTable("Open3DMFFile", kOpen3DMFFile);

    VRHash_PutCommandIntoTable("Set3DObjLocation", kSet3DObjLocation);

    VRHash_PutCommandIntoTable("Set3DObjColor", kSet3DObjColor);

    VRHash_PutCommandIntoTable("Set3DObjTransp", kSet3DObjTransp);

    VRHash_PutCommandIntoTable("Set3DObjInterp", kSet3DObjInterp);

    VRHash_PutCommandIntoTable("Set3DObjBackface", kSet3DObjBackface);

    VRHash_PutCommandIntoTable("Set3DObjFill", kSet3DObjFill);

    VRHash_PutCommandIntoTable("Set3DObjRotation", kSet3DObjRotation);

    VRHash_PutCommandIntoTable("Set3DObjRotState", kSet3DObjRotState);

    VRHash_PutCommandIntoTable("Set3DObjVisState", kSet3DObjVisState);

    VRHash_PutCommandIntoTable("Set3DObjTexture", kSet3DObjTexture);

    VRHash_PutCommandIntoTable("Destroy3DObject", kDestroy3DObject);

    VRHash_PutCommandIntoTable("Set3DSndLocation", kSet3DSndLocation);

    VRHash_PutCommandIntoTable("SetVariable", kSetVariable);

    VRHash_PutCommandIntoTable("If", kIf);

    VRHash_PutCommandIntoTable("SetSpriteVisState", kSetSpriteVisState);

    VRHash_PutCommandIntoTable("SetSpriteLayer", kSetSpriteLayer);

    VRHash_PutCommandIntoTable("SetSpriteGraphicsMode", kSetSpriteGraphicsMode);

    VRHash_PutCommandIntoTable("SetSpriteImageIndex", kSetSpriteImageIndex);

    VRHash_PutCommandIntoTable("SetSpriteMatrix", kSetSpriteMatrix);

    VRHash_PutCommandIntoTable("SetSpriteLocation", kSetSpriteLocation);

    VRHash_PutCommandIntoTable("SetTrackState", kSetTrackState);

    VRHash_PutCommandIntoTable("SetTrackLayer", kSetTrackLayer);

    VRHash_PutCommandIntoTable("SetMovieTime", kSetMovieTime);

    VRHash_PutCommandIntoTable("SetMovieRate", kSetMovieRate);

    VRHash_PutCommandIntoTable("SetMovieTimeScale", kSetMovieTimeScale);

}

//////////

//

// VRHash_Stop

// Destroy the hash table.

//

//////////

void VRHash_Stop (void)

{

    UInt32              myIndex;

    VRScriptHashPtr     myBucketPtr;

    VRScriptHashPtr     myNextBucketPtr;

    for (myIndex = 0; myIndex < kNumEntriesInTable; myIndex++) {

        // get the bucket pointer at this offset in the hash table

        myBucketPtr = gHashTable[myIndex];

        while (myBucketPtr != NULL) {

            myNextBucketPtr = myBucketPtr->fNextEntry;

            free(myBucketPtr->fCommandWord);

            DisposePtr((Ptr)myBucketPtr);

            myBucketPtr = myNextBucketPtr;

        }

    }

}

//////////

//

// VRHash_HashCommandWord

// Get the hash value for the specified command word.

//

// This hash function returns a value in the range 0 to kNumEntriesInTable - 1. It's

// a simple additive hash function. (As K&R put it, "[t]his is not the best possible

// algorithm, but it has the merit of extreme simplicity".)

//

//////////

UInt32 VRHash_HashCommandWord (char *theCommandWord)

{

    UInt32      myHashVal;

    for (myHashVal = 0; *theCommandWord != '\0'; myHashVal += *theCommandWord++)

        ;

    return(myHashVal % kNumEntriesInTable);

}

//////////

//

// VRHash_PutCommandIntoTable

// Insert an entry for the specified command word and command code into the hash table.

//

//////////

void VRHash_PutCommandIntoTable (char *theCommandWord, UInt32 theCommandCode)

{

    UInt32              myHashVal;

    VRScriptHashPtr     myBucketPtr;

    if (theCommandWord == NULL)

        return;

    // get the hash value for the specified command word

    myHashVal = VRHash_HashCommandWord(theCommandWord);

    // create a new bucket and insert it at the head of the linked list

    myBucketPtr = (VRScriptHashPtr)NewPtrClear(sizeof(VRScriptHash));

    if (myBucketPtr != NULL) {

        myBucketPtr->fCommandCode = theCommandCode;

        myBucketPtr->fCommandWord = malloc(strlen(theCommandWord) + 1);

        strncpy(myBucketPtr->fCommandWord, theCommandWord, strlen(theCommandWord) + 1);

        myBucketPtr->fNextEntry = gHashTable[myHashVal];

        gHashTable[myHashVal] = myBucketPtr;

    }

}

//////////

//

// VRHash_GetCommandCode

// Get the command code associated with the specified command word.

//

//////////

UInt32 VRHash_GetCommandCode (char *theCommandWord)

{

    UInt32              myCode = kInvalidCommand;

    UInt32              myHashVal;

    VRScriptHashPtr     myBucketPtr;

    if (theCommandWord == NULL)

        return(myCode);

    // get the hash value for the specified command word

    myHashVal = VRHash_HashCommandWord(theCommandWord);

    for (myBucketPtr = gHashTable[myHashVal]; myBucketPtr != NULL; myBucketPtr = myBucketPtr->fNextEntry)

        if (strcmp(theCommandWord, myBucketPtr->fCommandWord) == 0)

            return(myBucketPtr->fCommandCode);

    return(myCode);

}