vm.h

/* 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 3 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, see <http://www.gnu.org/licenses/>.
 *
 */

#ifndef SCI_ENGINE_VM_H
#define SCI_ENGINE_VM_H

/* VM and kernel declarations */

#include "sci/engine/vm_types.h"    // for reg_t
#include "sci/resource/resource.h"  // for SciVersion

#include "common/util.h"

namespace Sci {

class SegManager;
struct EngineState;
class Object;
class ResourceManager;
class Script;

#define VM_STACK_SIZE 0x1000

#define SCRIPT_OBJECT_MAGIC_NUMBER 0x1234

#define SCRIPT_OBJECT_MAGIC_OFFSET (getSciVersion() < SCI_VERSION_1_1 ? -8 : 0)

#define CALL_SP_CARRY NULL

enum SelectorType {
    kSelectorNone = 0,
    kSelectorVariable,
    kSelectorMethod
};

struct Class {
    int script; 
    reg_t reg; 
};

// A reference to an object's variable.
// The object is stored as a reg_t, the variable as an index into _variables
struct ObjVarRef {
    reg_t obj;
    int varindex;

    reg_t* getPointer(SegManager *segMan) const;
};

enum ExecStackType {
    EXEC_STACK_TYPE_CALL = 0,
    EXEC_STACK_TYPE_KERNEL = 1,
    EXEC_STACK_TYPE_VARSELECTOR = 2
};

struct ExecStack {
    reg_t objp;  
    reg_t sendp; 

    union {
        ObjVarRef varp; // Variable pointer for r/w access
        reg_t pc;       // Pointer to the initial program counter. Not accurate for the TOS element
    } addr;

    StackPtr fp; // Frame pointer
    StackPtr sp; // Stack pointer

    int argc;
    StackPtr variables_argp; // Argument pointer

    int tempCount;           // Number of temp variables allocated by link opcode

    SegmentId local_segment; // local variables etc

    Selector debugSelector;     // The selector which was used to call or -1 if not applicable
    int debugExportId;          // The exportId which was called or -1 if not applicable
    int debugLocalCallOffset;   // Local call offset or -1 if not applicable
    int debugOrigin;            // The stack frame position the call was made from, or -1 if it was the initial call
    int debugKernelFunction;    // The kernel function called, or -1 if not applicable
    int debugKernelSubFunction; // The kernel subfunction called, or -1 if not applicable
    ExecStackType type;

    reg_t* getVarPointer(SegManager *segMan) const;

    ExecStack(reg_t objp_, reg_t sendp_, StackPtr sp_, int argc_, StackPtr argp_,
                SegmentId localsSegment_, reg_t pc_, Selector debugSelector_,
                int debugKernelFunction_, int debugKernelSubFunction_,
                int debugExportId_, int debugLocalCallOffset_, int debugOrigin_,
                ExecStackType type_) {
        objp = objp_;
        sendp = sendp_;
        // varp is set separately for varselector calls
        addr.pc = pc_;
        fp = sp = sp_;
        argc = argc_;
        variables_argp = argp_;
        tempCount = 0;
        if (localsSegment_ != kUninitializedSegment)
            local_segment = localsSegment_;
        else
            local_segment = pc_.getSegment();
        debugSelector = debugSelector_;
        debugKernelFunction = debugKernelFunction_;
        debugKernelSubFunction = debugKernelSubFunction_;
        debugExportId = debugExportId_;
        debugLocalCallOffset = debugLocalCallOffset_;
        debugOrigin = debugOrigin_;
        type = type_;
    }
};

enum {
    VAR_GLOBAL = 0,
    VAR_LOCAL  = 1,
    VAR_TEMP   = 2,
    VAR_PARAM  = 3
};

enum GlobalVar {
    kGlobalVarEgo            = 0,
    kGlobalVarGame           = 1,
    kGlobalVarCurrentRoom    = 2,
    kGlobalVarSpeed          = 3,  // SCI16
    kGlobalVarQuit           = 4,
    kGlobalVarCast           = 5,
    kGlobalVarSounds         = 8,
    kGlobalVarPlanes         = 10, // SCI32
    kGlobalVarCurrentRoomNo  = 11,
    kGlobalVarPreviousRoomNo = 12,
    kGlobalVarNewRoomNo      = 13,
    kGlobalVarScore          = 15,
    kGlobalVarVersionNew     = 27, // version string or object in later games
    kGlobalVarVersionOld     = 28, // version string in earlier games
    kGlobalVarGK2MusicVolume = 76, // 0 to 127
    kGlobalVarPhant2SecondaryVolume = 76, // 0 to 127
    kGlobalVarUser                 = 80,
    kGlobalVarFastCast             = 84, // SCI16
    kGlobalVarMessageType          = 90,
    kGlobalVarTextSpeed            = 94, // SCI32; 0 is fastest, 8 is slowest
    kGlobalVarGK1Music1            = 102, // 0 to 127
    kGlobalVarGK1Music2            = 103, // 0 to 127
    kGlobalVarRamaCatalogFile      = 130,
    kGlobalVarLSL6HiresGameFlags   = 137,
    kGlobalVarKQ7UpscaleVideos     = 160,
    kGlobalVarGK1NarratorMode      = 166, // 0 for text, 1 for speech
    kGlobalVarRamaMusicVolume      = 176, // 0 to 16
    kGlobalVarPhant1MusicVolume    = 187, // 0 to 15
    kGlobalVarPhant1DACVolume      = 188, // 0 to 127
    kGlobalVarLSL6MusicVolume      = 194, // 0 to 13
    kGlobalVarGK1DAC1              = 207, // 0 to 127
    kGlobalVarPhant2CensorshipFlag = 207,
    kGlobalVarGK1DAC2              = 208, // 0 to 127
    kGlobalVarLSL6HiresRestoreTextWindow = 210,
    kGlobalVarGK1DAC3              = 211, // 0 to 127
    kGlobalVarShiversFlags         = 211,
    kGlobalVarTorinMusicVolume     = 227, // 0 to 100
    kGlobalVarTorinSFXVolume       = 228, // 0 to 100
    kGlobalVarTorinSpeechVolume    = 229, // 0 to 100
    // Phant2 labels its volume slider as "music volume" but it is actually
    // a master volume that affects both music *and* sound effects
    kGlobalVarPhant2MasterVolume   = 236, // 0 to 127
    kGlobalVarPhant2ControlPanel   = 250,
    kGlobalVarShivers1Score        = 349,
    kGlobalVarQFG4Flags            = 500,
    kGlobalVarHoyle5MusicVolume    = 897
};

enum {
    GC_INTERVAL = 0x8000
};

enum SciOpcodes {
    op_bnot     = 0x00, // 000
    op_add      = 0x01, // 001
    op_sub      = 0x02, // 002
    op_mul      = 0x03, // 003
    op_div      = 0x04, // 004
    op_mod      = 0x05, // 005
    op_shr      = 0x06, // 006
    op_shl      = 0x07, // 007
    op_xor      = 0x08, // 008
    op_and      = 0x09, // 009
    op_or       = 0x0a, // 010
    op_neg      = 0x0b, // 011
    op_not      = 0x0c, // 012
    op_eq_      = 0x0d, // 013
    op_ne_      = 0x0e, // 014
    op_gt_      = 0x0f, // 015
    op_ge_      = 0x10, // 016
    op_lt_      = 0x11, // 017
    op_le_      = 0x12, // 018
    op_ugt_     = 0x13, // 019
    op_uge_     = 0x14, // 020
    op_ult_     = 0x15, // 021
    op_ule_     = 0x16, // 022
    op_bt       = 0x17, // 023
    op_bnt      = 0x18, // 024
    op_jmp      = 0x19, // 025
    op_ldi      = 0x1a, // 026
    op_push     = 0x1b, // 027
    op_pushi    = 0x1c, // 028
    op_toss     = 0x1d, // 029
    op_dup      = 0x1e, // 030
    op_link     = 0x1f, // 031
    op_call     = 0x20, // 032
    op_callk    = 0x21, // 033
    op_callb    = 0x22, // 034
    op_calle    = 0x23, // 035
    op_ret      = 0x24, // 036
    op_send     = 0x25, // 037
    op_info     = 0x26, // 038
    op_superP   = 0x27, // 039
    op_class    = 0x28, // 040
    // dummy      0x29, // 041
    op_self     = 0x2a, // 042
    op_super    = 0x2b, // 043
    op_rest     = 0x2c, // 044
    op_lea      = 0x2d, // 045
    op_selfID   = 0x2e, // 046
    // dummy      0x2f  // 047
    op_pprev    = 0x30, // 048
    op_pToa     = 0x31, // 049
    op_aTop     = 0x32, // 050
    op_pTos     = 0x33, // 051
    op_sTop     = 0x34, // 052
    op_ipToa    = 0x35, // 053
    op_dpToa    = 0x36, // 054
    op_ipTos    = 0x37, // 055
    op_dpTos    = 0x38, // 056
    op_lofsa    = 0x39, // 057
    op_lofss    = 0x3a, // 058
    op_push0    = 0x3b, // 059
    op_push1    = 0x3c, // 060
    op_push2    = 0x3d, // 061
    op_pushSelf = 0x3e, // 062
    op_line     = 0x3f, // 063
    //
    op_lag      = 0x40, // 064
    op_lal      = 0x41, // 065
    op_lat      = 0x42, // 066
    op_lap      = 0x43, // 067
    op_lsg      = 0x44, // 068
    op_lsl      = 0x45, // 069
    op_lst      = 0x46, // 070
    op_lsp      = 0x47, // 071
    op_lagi     = 0x48, // 072
    op_lali     = 0x49, // 073
    op_lati     = 0x4a, // 074
    op_lapi     = 0x4b, // 075
    op_lsgi     = 0x4c, // 076
    op_lsli     = 0x4d, // 077
    op_lsti     = 0x4e, // 078
    op_lspi     = 0x4f, // 079
    //
    op_sag      = 0x50, // 080
    op_sal      = 0x51, // 081
    op_sat      = 0x52, // 082
    op_sap      = 0x53, // 083
    op_ssg      = 0x54, // 084
    op_ssl      = 0x55, // 085
    op_sst      = 0x56, // 086
    op_ssp      = 0x57, // 087
    op_sagi     = 0x58, // 088
    op_sali     = 0x59, // 089
    op_sati     = 0x5a, // 090
    op_sapi     = 0x5b, // 091
    op_ssgi     = 0x5c, // 092
    op_ssli     = 0x5d, // 093
    op_ssti     = 0x5e, // 094
    op_sspi     = 0x5f, // 095
    //
    op_plusag   = 0x60, // 096
    op_plusal   = 0x61, // 097
    op_plusat   = 0x62, // 098
    op_plusap   = 0x63, // 099
    op_plussg   = 0x64, // 100
    op_plussl   = 0x65, // 101
    op_plusst   = 0x66, // 102
    op_plussp   = 0x67, // 103
    op_plusagi  = 0x68, // 104
    op_plusali  = 0x69, // 105
    op_plusati  = 0x6a, // 106
    op_plusapi  = 0x6b, // 107
    op_plussgi  = 0x6c, // 108
    op_plussli  = 0x6d, // 109
    op_plussti  = 0x6e, // 110
    op_plusspi  = 0x6f, // 111
    //
    op_minusag  = 0x70, // 112
    op_minusal  = 0x71, // 113
    op_minusat  = 0x72, // 114
    op_minusap  = 0x73, // 115
    op_minussg  = 0x74, // 116
    op_minussl  = 0x75, // 117
    op_minusst  = 0x76, // 118
    op_minussp  = 0x77, // 119
    op_minusagi = 0x78, // 120
    op_minusali = 0x79, // 121
    op_minusati = 0x7a, // 122
    op_minusapi = 0x7b, // 123
    op_minussgi = 0x7c, // 124
    op_minussli = 0x7d, // 125
    op_minussti = 0x7e, // 126
    op_minusspi = 0x7f  // 127
};

void script_adjust_opcode_formats();

ExecStack *execute_method(EngineState *s, uint16 script, uint16 pubfunct,
        StackPtr sp, reg_t calling_obj, uint16 argc, StackPtr argp);


ExecStack *send_selector(EngineState *s, reg_t send_obj, reg_t work_obj,
    StackPtr sp, int framesize, StackPtr argp);


void run_vm(EngineState *s);

SelectorType lookupSelector(SegManager *segMan, reg_t obj, Selector selectorid,
        ObjVarRef *varp, reg_t *fptr);

int readPMachineInstruction(const byte *src, byte &extOpcode, int16 opparams[4]);

uint32 findOffset(const int16 relOffset, const Script *scr, const uint32 pcOffset);

} // End of namespace Sci

#endif // SCI_ENGINE_VM_H