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/* Copyright (C) 1994-2003 Revolution Software Ltd
*
* 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 "common/stdafx.h"
#include "common/util.h"
#include "sword2/sword2.h"
#include "sword2/interpreter.h"
namespace Sword2 {
// The machine code table
#define OPCODE(x) { &Logic::x, #x }
typedef int32 (Logic::*OpcodeProc)(int32 *);
struct OpcodeEntry {
OpcodeProc proc;
const char *desc;
};
static const OpcodeEntry opcodes[] = {
/* 00 */
OPCODE(fnTestFunction),
OPCODE(fnTestFlags),
OPCODE(fnRegisterStartPoint),
OPCODE(fnInitBackground),
/* 04 */
OPCODE(fnSetSession),
OPCODE(fnBackSprite),
OPCODE(fnSortSprite),
OPCODE(fnForeSprite),
/* 08 */
OPCODE(fnRegisterMouse),
OPCODE(fnAnim),
OPCODE(fnRandom),
OPCODE(fnPreLoad),
/* 0C */
OPCODE(fnAddSubject),
OPCODE(fnInteract),
OPCODE(fnChoose),
OPCODE(fnWalk),
/* 10 */
OPCODE(fnWalkToAnim),
OPCODE(fnTurn),
OPCODE(fnStandAt),
OPCODE(fnStand),
/* 14 */
OPCODE(fnStandAfterAnim),
OPCODE(fnPause),
OPCODE(fnMegaTableAnim),
OPCODE(fnAddMenuObject),
/* 18 */
OPCODE(fnStartConversation),
OPCODE(fnEndConversation),
OPCODE(fnSetFrame),
OPCODE(fnRandomPause),
/* 1C */
OPCODE(fnRegisterFrame),
OPCODE(fnNoSprite),
OPCODE(fnSendSync),
OPCODE(fnUpdatePlayerStats),
/* 20 */
OPCODE(fnPassGraph),
OPCODE(fnInitFloorMouse),
OPCODE(fnPassMega),
OPCODE(fnFaceXY),
/* 24 */
OPCODE(fnEndSession),
OPCODE(fnNoHuman),
OPCODE(fnAddHuman),
OPCODE(fnWeWait),
/* 28 */
OPCODE(fnTheyDoWeWait),
OPCODE(fnTheyDo),
OPCODE(fnWalkToTalkToMega),
OPCODE(fnFadeDown),
/* 2C */
OPCODE(fnISpeak),
OPCODE(fnTotalRestart),
OPCODE(fnSetWalkGrid),
OPCODE(fnSpeechProcess),
/* 30 */
OPCODE(fnSetScaling),
OPCODE(fnStartEvent),
OPCODE(fnCheckEventWaiting),
OPCODE(fnRequestSpeech),
/* 34 */
OPCODE(fnGosub),
OPCODE(fnTimedWait),
OPCODE(fnPlayFx),
OPCODE(fnStopFx),
/* 38 */
OPCODE(fnPlayMusic),
OPCODE(fnStopMusic),
OPCODE(fnSetValue),
OPCODE(fnNewScript),
/* 3C */
OPCODE(fnGetSync),
OPCODE(fnWaitSync),
OPCODE(fnRegisterWalkGrid),
OPCODE(fnReverseMegaTableAnim),
/* 40 */
OPCODE(fnReverseAnim),
OPCODE(fnAddToKillList),
OPCODE(fnSetStandbyCoords),
OPCODE(fnBackPar0Sprite),
/* 44 */
OPCODE(fnBackPar1Sprite),
OPCODE(fnForePar0Sprite),
OPCODE(fnForePar1Sprite),
OPCODE(fnSetPlayerActionEvent),
/* 48 */
OPCODE(fnSetScrollCoordinate),
OPCODE(fnStandAtAnim),
OPCODE(fnSetScrollLeftMouse),
OPCODE(fnSetScrollRightMouse),
/* 4C */
OPCODE(fnColour),
OPCODE(fnFlash),
OPCODE(fnPreFetch),
OPCODE(fnGetPlayerSaveData),
/* 50 */
OPCODE(fnPassPlayerSaveData),
OPCODE(fnSendEvent),
OPCODE(fnAddWalkGrid),
OPCODE(fnRemoveWalkGrid),
/* 54 */
OPCODE(fnCheckForEvent),
OPCODE(fnPauseForEvent),
OPCODE(fnClearEvent),
OPCODE(fnFaceMega),
/* 58 */
OPCODE(fnPlaySequence),
OPCODE(fnShadedSprite),
OPCODE(fnUnshadedSprite),
OPCODE(fnFadeUp),
/* 5C */
OPCODE(fnDisplayMsg),
OPCODE(fnSetObjectHeld),
OPCODE(fnAddSequenceText),
OPCODE(fnResetGlobals),
/* 60 */
OPCODE(fnSetPalette),
OPCODE(fnRegisterPointerText),
OPCODE(fnFetchWait),
OPCODE(fnRelease),
/* 64 */
OPCODE(fnPrepareMusic),
OPCODE(fnSoundFetch),
OPCODE(fnPrepareMusic), // Again, apparently
OPCODE(fnSmackerLeadIn),
/* 68 */
OPCODE(fnSmackerLeadOut),
OPCODE(fnStopAllFx),
OPCODE(fnCheckPlayerActivity),
OPCODE(fnResetPlayerActivityDelay),
/* 6C */
OPCODE(fnCheckMusicPlaying),
OPCODE(fnPlayCredits),
OPCODE(fnSetScrollSpeedNormal),
OPCODE(fnSetScrollSpeedSlow),
/* 70 */
OPCODE(fnRemoveChooser),
OPCODE(fnSetFxVolAndPan),
OPCODE(fnSetFxVol),
OPCODE(fnRestoreGame),
/* 74 */
OPCODE(fnRefreshInventory),
OPCODE(fnChangeShadows)
};
#define push(value) \
do { \
assert(stackPtr < ARRAYSIZE(stack)); \
stack[stackPtr++] = (value); \
} while (false)
#define pop() (assert(stackPtr < ARRAYSIZE(stack)), stack[--stackPtr])
void Logic::setGlobalInterpreterVariables(int32 *vars) {
_globals = vars;
}
int Logic::runScript(char *scriptData, char *objectData, uint32 *offset) {
// Interestingly, unlike our BASS engine the stack is a local variable.
// This has some interesting implications which may or may not be
// necessary to the BS2 engine.
int32 stack[STACK_SIZE];
int32 stackPtr = 0;
bool checkPyramidBug = false;
StandardHeader *header = (StandardHeader *) scriptData;
scriptData += sizeof(StandardHeader) + sizeof(ObjectHub);
// The script data format:
// int32_TYPE 1 Size of variable space in bytes
// ... The variable space
// int32_TYPE 1 numberOfScripts
// int32_TYPE numberOfScripts The offsets for each script
// Initialise some stuff
uint32 ip = 0; // Code pointer
int scriptNumber;
// Get the start of variables and start of code
uint32 *variables = (uint32 *) (scriptData + sizeof(int32));
const char *code = scriptData + (int32) READ_LE_UINT32(scriptData) + sizeof(int32);
uint32 noScripts = (int32) READ_LE_UINT32(code);
code += sizeof(int32);
const uint32 *offsetTable = (const uint32 *) code;
if (*offset < noScripts) {
ip = READ_LE_UINT32(&offsetTable[*offset]);
scriptNumber = *offset;
debug(4, "Start script %d with offset %d", *offset, ip);
} else {
uint i;
ip = *offset;
for (i = 1; i < noScripts; i++) {
if (ip < READ_LE_UINT32(code + 4 * i))
break;
}
scriptNumber = i - 1;
debug(4, "Resume script %d with offset %d", scriptNumber, ip);
}
// WORKAROUND: The dreaded pyramid makes the torch untakeable when you
// speak to Titipoco. This is because one of the conditions for the
// torch to be takeable is that Titipoco isn't doing anything out of
// the ordinary. Global variable 913 has to be 0 to signify that he is
// in his "idle" state.
//
// Unfortunately, simply the act of speaking to him sets variable 913
// to 1 (probably to stop him from turning around every now and then).
// The script may then go on to set the variable to different values
// to trigger various behaviours in him, but if you have run out of
// these cases the script won't ever set it back to 0 again.
//
// So if his click hander (action script number 2) finishes, and
// variable 913 is 1, we set it back to 0 manually.
checkPyramidBug = strcmp((char *) header->name, "titipoco_81") == 0 && scriptNumber == 2;
code += noScripts * sizeof(int32);
// Code should nop be pointing at an identifier and a checksum
const int *checksumBlock = (const int *) code;
code += sizeof(int32) * 3;
if (READ_LE_UINT32(checksumBlock) != 12345678) {
error("Invalid script in object %s", header->name);
return 0;
}
int codeLen = READ_LE_UINT32(checksumBlock + 1);
int checksum = 0;
for (int i = 0; i < codeLen; i++)
checksum += (unsigned char) code[i];
if (checksum != (int32) READ_LE_UINT32(checksumBlock + 2)) {
error("Checksum error in object %s", header->name);
return 0;
}
bool runningScript = true;
int parameterReturnedFromMcodeFunction = 0; // Allow scripts to return things
int savedStartOfMcode = 0; // For saving start of mcode commands
while (runningScript) {
int32 a, b;
int curCommand, parameter, value; // Command and parameter variables
int retVal;
int caseCount;
bool foundCase;
int32 ptrval;
int i;
curCommand = code[ip++];
switch (curCommand) {
// Script-related opcodes
case CP_END_SCRIPT:
// End the script
debug(5, "End script");
runningScript = false;
// WORKAROUND: Pyramid Bug. See explanation above.
if (checkPyramidBug && _globals[913] == 1) {
warning("Working around Titipoco script bug (the \"Pyramid Bug\")");
_globals[913] = 0;
}
break;
case CP_QUIT:
// Quit out for a cycle
debug(5, "Quit script for a cycle");
*offset = ip;
return 0;
case CP_TERMINATE:
// Quit out immediately without affecting the offset
// pointer
debug(5, "Terminate script");
return 3;
case CP_RESTART_SCRIPT:
// Start the script again
debug(5, "Restart script");
ip = READ_LE_UINT32(&offsetTable[scriptNumber]);
break;
// Stack-related opcodes
case CP_PUSH_INT32:
// Push a long word value on to the stack
Read32ip(parameter);
debug(5, "Push int32 %d", parameter);
push(parameter);
break;
case CP_PUSH_LOCAL_VAR32:
// Push the contents of a local variable
Read16ip(parameter);
parameter /= 4;
debug(5, "Push local var %d (%d)", parameter, variables[parameter]);
push(variables[parameter]);
break;
case CP_PUSH_GLOBAL_VAR32:
// Push a global variable
Read16ip(parameter);
assert(_globals);
debug(5, "Push global var %d (%d)", parameter, _globals[parameter]);
push(_globals[parameter]);
break;
case CP_PUSH_LOCAL_ADDR:
// push the address of a local variable
Read16ip(parameter);
parameter /= 4;
ptrval = _vm->_memory->ptrToInt((const uint8 *) &variables[parameter]);
debug(5, "Push address of local variable %d (%x)", parameter, ptrval);
push(ptrval);
break;
case CP_PUSH_STRING:
// Push the address of a string on to the stack
// Get the string size
Read8ip(parameter);
// ip points to the string
ptrval = _vm->_memory->ptrToInt((const uint8 *) (code + ip));
debug(5, "Push address of string (%x)\n", ptrval);
push(ptrval);
ip += (parameter + 1);
break;
case CP_PUSH_DEREFERENCED_STRUCTURE:
// Push the address of a dereferenced structure
Read32ip(parameter);
ptrval = _vm->_memory->ptrToInt((const uint8 *) (objectData + sizeof(int32) + sizeof(StandardHeader) + sizeof(ObjectHub) + parameter));
debug(5, "Push address of far variable (%x)", ptrval);
push(ptrval);
break;
case CP_POP_LOCAL_VAR32:
// Pop a value into a local word variable
Read16ip(parameter);
parameter /= 4;
value = pop();
debug(5, "Pop %d into local var %d", value, parameter);
variables[parameter] = value;
break;
case CP_POP_GLOBAL_VAR32:
// Pop a global variable
Read16ip(parameter);
value = pop();
debug(5, "Pop %d into global var %d", value, parameter);
_globals[parameter] = value;
break;
case CP_ADDNPOP_LOCAL_VAR32:
Read16ip(parameter);
parameter /= 4;
value = pop();
variables[parameter] += value;
debug(5, "+= %d into local var %d -> %d", value, parameter, variables[parameter]);
break;
case CP_SUBNPOP_LOCAL_VAR32:
Read16ip(parameter);
parameter /= 4;
value = pop();
variables[parameter] -= value;
debug(5, "-= %d into local var %d -> %d", value, parameter, variables[parameter]);
break;
case CP_ADDNPOP_GLOBAL_VAR32:
// Add and pop a global variable
Read16ip(parameter);
value = pop();
_globals[parameter] += value;
debug(5, "+= %d into global var %d -> %d", value, parameter, _globals[parameter]);
break;
case CP_SUBNPOP_GLOBAL_VAR32:
// Sub and pop a global variable
Read16ip(parameter);
value = pop();
_globals[parameter] -= value;
debug(5, "-= %d into global var %d -> %d", value, parameter, _globals[parameter]);
break;
// Jump opcodes
case CP_SKIPONTRUE:
// Skip if the value on the stack is true
Read32ipLeaveip(parameter);
value = pop();
debug(5, "Skip %d if %d is false", parameter, value);
if (!value)
ip += sizeof(int32);
else
ip += parameter;
break;
case CP_SKIPONFALSE:
// Skip if the value on the stack is false
Read32ipLeaveip(parameter);
value = pop();
debug(5, "Skip %d if %d is false", parameter, value);
if (value)
ip += sizeof(int32);
else
ip += parameter;
break;
case CP_SKIPALWAYS:
// skip a block
Read32ipLeaveip(parameter);
debug(5, "Skip %d", parameter);
ip += parameter;
break;
case CP_SWITCH:
// switch
value = pop();
Read32ip(caseCount);
// Search the cases
foundCase = false;
for (i = 0; i < caseCount && !foundCase; i++) {
if (value == (int32) READ_LE_UINT32(code + ip)) {
// We have found the case, so lets
// jump to it
foundCase = true;
ip += READ_LE_UINT32(code + ip + sizeof(int32));
} else
ip += sizeof(int32) * 2;
}
// If we found no matching case then use the default
if (!foundCase)
ip += READ_LE_UINT32(code + ip);
break;
case CP_SAVE_MCODE_START:
// Save the start position on an mcode instruction in
// case we need to restart it again
savedStartOfMcode = ip - 1;
break;
case CP_CALL_MCODE:
// Call an mcode routine
Read16ip(parameter);
assert(parameter < ARRAYSIZE(opcodes));
// amount to adjust stack by (no of parameters)
Read8ip(value);
debug(5, "Calling '%s' with %d parameters", opcodes[parameter].desc, value);
stackPtr -= value;
assert(stackPtr >= 0);
retVal = (this->*opcodes[parameter].proc)(&stack[stackPtr]);
switch (retVal & 7) {
case IR_STOP:
// Quit out for a cycle
*offset = ip;
return 0;
case IR_CONT:
// Continue as normal
break;
case IR_TERMINATE:
// Return without updating the offset
return 2;
case IR_REPEAT:
// Return setting offset to start of this
// function call
*offset = savedStartOfMcode;
return 0;
case IR_GOSUB:
// that's really neat
*offset = ip;
return 2;
default:
error("Bad return code (%d) from '%s'", opcodes[parameter].desc, retVal & 7);
}
parameterReturnedFromMcodeFunction = retVal >> 3;
break;
case CP_JUMP_ON_RETURNED:
// Jump to a part of the script depending on
// the return value from an mcode routine
// Get the maximum value
Read8ip(parameter);
ip += READ_LE_UINT32(code + ip + parameterReturnedFromMcodeFunction * 4);
break;
// Operators
case OP_ISEQUAL:
b = pop();
a = pop();
push(a == b);
debug(5, "operation %d == %d", a, b);
break;
case OP_NOTEQUAL:
b = pop();
a = pop();
push(a != b);
debug(5, "operation %d != %d", a, b);
break;
case OP_GTTHAN:
b = pop();
a = pop();
push(a > b);
debug(5, "operation %d > %d", a, b);
break;
case OP_LSTHAN:
b = pop();
a = pop();
push(a < b);
debug(5, "operation %d < %d", a, b);
break;
case OP_GTTHANE:
b = pop();
a = pop();
push(a >= b);
debug(5, "operation %d >= %d", a, b);
break;
case OP_LSTHANE:
b = pop();
a = pop();
push(a <= b);
debug(5, "operation %d <= %d", a, b);
break;
case OP_PLUS:
b = pop();
a = pop();
push(a + b);
debug(5, "operation %d + %d", a, b);
break;
case OP_MINUS:
b = pop();
a = pop();
push(a - b);
debug(5, "operation %d - %d", a, b);
break;
case OP_TIMES:
b = pop();
a = pop();
push(a * b);
debug(5, "operation %d * %d", a, b);
break;
case OP_DIVIDE:
b = pop();
a = pop();
push(a / b);
debug(5, "operation %d / %d", a, b);
break;
case OP_ANDAND:
b = pop();
a = pop();
push(a && b);
debug(5, "operation %d && %d", a, b);
break;
case OP_OROR:
b = pop();
a = pop();
push(a || b);
debug(5, "operation %d || %d", a, b);
break;
// Debugging opcodes, I think
case CP_DEBUGON:
// Turn debugging on
_debugFlag = true;
break;
case CP_DEBUGOFF:
// Turn debugging on
_debugFlag = false;
break;
case CP_TEMP_TEXT_PROCESS:
// Process a text line
Read32ip(parameter);
debug(5, "Process text id %d", parameter);
break;
default:
error("Invalid script command %d", curCommand);
return 3;
}
}
return 1;
}
} // End of namespace Sword2
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