/* 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. * * $URL$ * $Id$ * */ #ifndef SCI_ENGINE_VM_H #define SCI_ENGINE_VM_H /* VM and kernel declarations */ #include "sci/include/versions.h" // for sci_version_t #include "sci/include/vm_types.h" // for reg_t #include "sci/include/heapmgr.h" #include "sci/engine/intmap.h" #include "sci/engine/sys_strings.h" namespace Sci { struct IntMapper; // from intmap.h #define VM_STACK_SIZE 0x1000 /* Number of bytes to be allocated for the stack */ #define SCRIPT_MAX_EXEC_STACK 256 /* Maximum number of calls residing on the stack */ #define SCRIPT_MAX_CLASSTABLE_SIZE 256 /* Maximum number of entries in the class table */ #define SCRIPT_MAX_CLONES 256 /* Maximum number of cloned objects on the heap */ #define SCRIPT_SELECTOR_OFFSET 8 -8 /* Object-relative offset of the selector area inside a script */ #define SCRIPT_LOCALVARPTR_OFFSET 2 -8 /* Object-relative offset of the pointer to the underlying script's local variables */ #define SCRIPT_SELECTORCTR_OFFSET 6 -8 /* Object-relative offset of the selector counter */ #define SCRIPT_FUNCTAREAPTR_OFFSET 4 -8 /* Object-relative offset of the offset of the function area */ #define SCRIPT_FUNCTAREAPTR_MAGIC 8 -8 /* Offset that has to be added to the function area pointer */ #define SCRIPT_NAME_OFFSET (s->version < SCI_VERSION(1,001,000) ? 14 -8 : 16) /* Offset of the name pointer */ #define SCRIPT_NAME_SELECTOR (s->version < SCI_VERSION(1,001,000) ? 3 : 8) #define SCRIPT_INFO_OFFSET (s->version < SCI_VERSION(1,001,000) ? 12 -8 : 14) /* Object-relative offset of the -info- selector */ #define SCRIPT_INFO_SELECTOR (s->version < SCI_VERSION(1,001,000) ? 2 : 7) #define SCRIPT_INFO_CLONE 0x0001 /* Flag fo the -info- selector */ #define SCRIPT_INFO_CLASS 0x8000 /* Flag for the -info- selector */ #define SCRIPT_OBJECT_MAGIC_NUMBER 0x1234 /* Magical object identifier */ #define SCRIPT_OBJECT_MAGIC_OFFSET (s->version < SCI_VERSION(1,001,000) ? -8 : 0) /* Offset of this identifier */ #define SCRIPT_SPECIES_OFFSET 8 -8 /* Script-relative offset of the species ID */ #define SCRIPT_SUPERCLASS_OFFSET (s->version < SCI_VERSION(1,001,000) ? 10 -8 : 12) /*---------------------------------*/ /* Script selector index variables */ /*---------------------------------*/ #define SCRIPT_SPECIES_SELECTOR (s->version < SCI_VERSION(1,001,000) ? 0 : 5) #define SCRIPT_SUPERCLASS_SELECTOR (s->version < SCI_VERSION(1,001,000) ? 1 : 6) #define SCRIPT_LOFS_MAGIC 3 /* Magic adjustment value for lofsa and lofss */ #define CALL_SP_CARRY NULL /* Stack pointer value: Use predecessor's value */ #define SELECTOR_NONE 0 #define SELECTOR_VARIABLE 1 #define SELECTOR_METHOD 2 /* Types of selectors as returned by grep_selector() below */ struct class_t { int script; /* number of the script the class is in, -1 for non-existing */ reg_t reg; /* offset; script-relative offset, segment: 0 if not instantiated */ }; #define RAW_GET_CLASS_INDEX(scr, reg) ((scr)->obj_indices->checkKey(reg.offset, false)) #define RAW_IS_OBJECT(datablock) (getUInt16(((byte *) datablock) + SCRIPT_OBJECT_MAGIC_OFFSET) == SCRIPT_OBJECT_MAGIC_NUMBER) #define IS_CLASS(obj) (obj->variables[SCRIPT_INFO_SELECTOR].offset & SCRIPT_INFO_CLASS) /* This struct is used to buffer the list of send calls in send_selector() */ struct calls_struct_t { union { reg_t func; reg_t *var; } address; stack_ptr_t argp; int argc; selector_t selector; stack_ptr_t sp; /* Stack pointer */ int type; /* Same as exec_stack_t.type */ }; struct local_variables_t { int script_id; /* Script ID this local variable block belongs to */ reg_t *locals; int nr; }; #define OBJECT_FLAG_FREED (0x1 << 0) /* Clone has been marked as 'freed' */ struct object_t { int flags; reg_t pos; /* Object offset within its script; for clones, this is their base */ int variables_nr; int variable_names_nr; /* Number of variable names, may be less than variables_nr */ int methods_nr; byte *base; /* Points to a buffer all relative references (code, strings) point to */ byte *base_obj; /* base + object offset within base */ uint16 *base_method; /* Pointer to the method selector area for this object */ uint16 *base_vars; /* Pointer to the varselector area for this object */ reg_t *variables; }; struct code_block_t { reg_t pos; int size; }; #define VM_OBJECT_GET_VARSELECTOR(obj, i) \ (s->version < SCI_VERSION(1,001,000) ? \ getUInt16(obj->base_obj + obj->variables_nr * 2 + i*2) : \ *(obj->base_vars + i)) #define VM_OBJECT_READ_PROPERTY(obj, i) (obj->variables[i]) #define VM_OBJECT_GET_FUNCSELECTOR(obj, i) \ (s->version < SCI_VERSION(1,001,000) ? \ getUInt16((byte *) (obj->base_method + i)) : \ getUInt16((byte *) (obj->base_method + i*2 + 1))) #define VM_OBJECT_READ_FUNCTION(obj, i) \ (s->version < SCI_VERSION(1,001,000) ? \ make_reg(obj->pos.segment, \ getUInt16((byte *) (obj->base_method \ + obj->methods_nr + 1 \ + i))) : \ make_reg(obj->pos.segment, \ getUInt16((byte *) (obj->base_method \ + i * 2 + 2)))) struct script_t { int nr; /* Script number */ byte* buf; /* Static data buffer, or NULL if not used */ size_t buf_size; size_t script_size; size_t heap_size; byte *synonyms; /* Synonyms block or 0 if not present*/ byte *heap_start; /* Start of heap if SCI1.1, NULL otherwise */ uint16 *export_table; /* Abs. offset of the export table or 0 if not present */ IntMapper *obj_indices; int exports_nr; /* Number of entries in the exports table */ int synonyms_nr; /* Number of entries in the synonyms block */ int lockers; /* Number of classes and objects that require this script */ object_t *objects; /* Table for objects, contains property variables */ /* Indexed by the value stored at SCRIPT_LOCALVARPTR_OFFSET, ** see VM_OBJECT_[GS]ET_INDEX() */ int objects_nr; /* Number of objects and classes */ int objects_allocated; /* Number of allocated objects */ int locals_offset; int locals_segment; /* The local variable segment */ local_variables_t *locals_block; code_block_t *code; int code_blocks_nr; int code_blocks_allocated; int relocated; int marked_as_deleted; }; struct dstack_t { int nr; /* Number of stack entries */ reg_t *entries; }; /* Data stack */ #define CLONE_USED -1 #define CLONE_NONE -1 typedef object_t clone_t; struct node_t { reg_t pred, succ; /* Predecessor, successor */ reg_t key; reg_t value; }; /* List nodes */ struct list_t { reg_t first; reg_t last; }; struct hunk_t { void *mem; unsigned int size; const char *type; }; /* clone_table_t */ DECLARE_HEAPENTRY(clone) /* node_table_t */ DECLARE_HEAPENTRY(node) /* list_table_t */ DECLARE_HEAPENTRY(list) /* list entries */ /* hunk_table_t */ DECLARE_HEAPENTRY(hunk) struct dynmem_t { int size; const char *description; byte *buf; }; /* Free-style memory */ enum memObjType { MEM_OBJ_INVALID = 0, MEM_OBJ_SCRIPT = 1, MEM_OBJ_CLONES = 2, MEM_OBJ_LOCALS = 3, MEM_OBJ_STACK = 4, MEM_OBJ_SYS_STRINGS = 5, MEM_OBJ_LISTS = 6, MEM_OBJ_NODES = 7, MEM_OBJ_HUNK = 8, MEM_OBJ_DYNMEM = 9, MEM_OBJ_RESERVED = 10, MEM_OBJ_MAX = MEM_OBJ_RESERVED // For sanity checking }; struct mem_obj_t { memObjType type; int segmgr_id; /* Internal value used by the seg_manager's hash map */ union { script_t script; clone_table_t clones; local_variables_t locals; dstack_t stack; sys_strings_t sys_strings; list_table_t lists; node_table_t nodes; hunk_table_t hunks; dynmem_t dynmem; char *reserved; } data; }; struct selector_map_t { selector_t init; /* Init function */ selector_t play; /* Play function (first function to be called) */ selector_t replay; /* Replay function */ selector_t x, y, z; /* Coordinates */ selector_t priority; selector_t view, loop, cel; /* Description of a specific image */ selector_t brLeft, brRight, brTop, brBottom; /* Bounding Rectangle */ selector_t xStep, yStep; /* BR adjustments */ selector_t nsLeft, nsRight, nsTop, nsBottom; /* View boundaries ('now seen') */ selector_t text, font; /* Used by controls */ selector_t type, state; /* Used by contols as well */ selector_t doit; /* Called (!) by the Animate() system call */ selector_t signal; /* Used by Animate() to control a view's behaviour */ selector_t underBits; /* Used by the graphics subroutines to store backupped BG pic data */ /* The following selectors are used by the Bresenham syscalls: */ selector_t canBeHere; /* Funcselector: Checks for movement validity */ selector_t client; /* The object that wants to be moved */ selector_t cycler; /* The cycler of the client */ selector_t dx, dy; /* Deltas */ selector_t edgeHit; selector_t b_movCnt, b_i1, b_i2, b_di, b_xAxis, b_incr; /* Various Bresenham vars */ selector_t completed; selector_t illegalBits; /* Used by CanBeHere */ selector_t dispose; selector_t prevSignal; /* Used by DoSound */ selector_t message, modifiers; /* Used by GetEvent */ selector_t owner, handle; selector_t cue; selector_t number; selector_t max, cursor; /* Used by EditControl */ selector_t mode; /* Used by text controls (-> DrawControl()) */ selector_t wordFail, syntaxFail, semanticFail; /* Used by Parse() */ selector_t claimed; /* Used generally by the event mechanism */ selector_t elements; /* Used by SetSynonyms() */ selector_t lsTop, lsBottom, lsRight, lsLeft; /* Used by Animate() subfunctions and scroll list controls */ selector_t baseSetter; /* Alternative baseSetter */ selector_t who, distance; /* Used for 'chasing' movers */ selector_t looper, mover, isBlocked, heading; /* Used in DoAvoider */ selector_t caller, moveDone, moveSpeed; /* Used for DoBresen */ selector_t delete_; /* Called by Animate() to dispose a view object */ selector_t vol; selector_t pri; selector_t min; /* SMPTE time format */ selector_t sec; selector_t frame; selector_t dataInc; selector_t size; selector_t palette; selector_t cantBeHere; selector_t nodePtr; selector_t flags; selector_t points; /* Used by AvoidPath() */ }; /* Contains selector IDs for a few selected selectors */ struct view_object_t { reg_t obj; reg_t *signalp; /* Used only indirectly */ reg_t *underBitsp; /* The same goes for the handle storage */ int underBits; /* Copy of the underbits: Needed for cleanup */ int x, y; int priority; byte *view; int view_nr, loop, cel; /* view_nr is ised for save/restore */ int nsTop, nsLeft, nsRight, nsBottom; int real_y, z, index_nr; /* Used for sorting */ }; #define VAR_GLOBAL 0 #define VAR_LOCAL 1 #define VAR_TEMP 2 #define VAR_PARAM 3 #define EXEC_STACK_TYPE_CALL 0 #define EXEC_STACK_TYPE_KERNEL 1 #define EXEC_STACK_TYPE_VARSELECTOR 2 struct exec_stack_t { reg_t objp; reg_t sendp; /* Pointer to the object containing the invoked method */ union { reg_t *varp; /* Variable pointer for read/write access */ reg_t pc; /* Not accurate for the TOS element */ } addr; stack_ptr_t fp; /* Frame pointer */ stack_ptr_t sp; /* Stack pointer */ int argc; /* former variables[4]: [all other values are derived] */ stack_ptr_t variables_argp; /* Argument pointer */ seg_id_t local_segment; /* local variables etc. */ selector_t selector; /* The selector which was used to call or -1 if not applicable */ int origin; /* The stack frame position the call was made from, or -1 if it ** was the initial call. */ byte type; /* EXEC_STACK_TYPE* */ }; struct breakpoint_t { int type; union { uint32 address; /* Breakpoints on exports */ char *name; /* Breakpoints on selector names */ } data; breakpoint_t *next; }; #define BREAK_SELECTOR 1 /* Break when selector is executed. data contains (char *) selector name (in the format Object::Method) */ #define BREAK_EXPORT 2 /* Break when an exported function is called. data contains script_no << 16 | export_no. */ extern int script_debug_flag; /* Set this to 1 to activate script debugging */ extern int script_error_flag; /* Set to 1 to move pc back to last position, even though action is executed */ extern int script_checkloads_flag; /* Displays the numbers of scripts when they are (un)loaded */ #define SCRIPT_ABORT_WITH_REPLAY 1025 extern int script_abort_flag; /* Set this to 1 to abort script execution immediately. Aborting will leave the ** debug exec stack intact. ** Set it to SCRIPT_ABORT_WITH_REPLAY to force a replay afterwards. */ #define GC_INTERVAL 32768 /* Number of kernel calls in between gcs; should be < 50000 */ extern int script_gc_interval; /* Initially GC_DELAY, can be set at runtime */ extern int script_step_counter; /* Number of steps executed */ extern const char *(*_debug_get_input)(void); /* The function used to get input for debugging */ extern int _debugstate_valid; extern int _debug_seeking; extern int _debug_step_running; typedef int kernel_function(struct EngineState *s); extern kernel_function* kfuncs[]; extern int max_instance; /*inline*/ exec_stack_t *execute_method(EngineState *s, uint16 script, uint16 pubfunct, stack_ptr_t sp, reg_t calling_obj, uint16 argc, stack_ptr_t argp); /* Executes function pubfunct of the specified script. ** Parameters: (EngineState *) s: The state which is to be executed with ** (uint16) script: The script which is called ** (uint16) pubfunct: The exported script function which is to be called ** (stack_ptr_t) sp: Stack pointer position ** (reg_t) calling_obj: The heap address of the object which executed the call ** (uint16) argc: Number of arguments supplied ** (stack_ptr_t) argp: Pointer to the first supplied argument ** Returns : (exec_stack_t *): A pointer to the new exec stack TOS entry */ exec_stack_t *send_selector(EngineState *s, reg_t send_obj, reg_t work_obj, stack_ptr_t sp, int framesize, stack_ptr_t argp); /* Executes a "send" or related operation to a selector ** Parameters: (EngineState *) s: The EngineState to operate on ** (reg_t) send_obj: Heap address of the object to send to ** (reg_t) work_obj: Heap address of the object initiating the send ** (stack_ptr_t) sp: Stack pointer position ** (int) framesize: Size of the send as determined by the "send" operation ** (stack_ptr_t) argp: Pointer to the beginning of the heap block containing the ** data to be send. This area is a succession of one or more ** sequences of [selector_number][argument_counter] and then ** "argument_counter" word entries with the parameter values. ** Returns : (exec_stack_t *): A pointer to the new execution stack TOS entry */ #define SCI_XS_CALLEE_LOCALS -1 exec_stack_t *add_exec_stack_entry(EngineState *s, reg_t pc, stack_ptr_t sp, reg_t objp, int argc, stack_ptr_t argp, selector_t selector, reg_t sendp, int origin, seg_id_t local_segment); /* Adds an entry to the top of the execution stack ** Parameters: (EngineState *) s: The state with which to execute ** (reg_t) pc: The initial program counter ** (stack_ptr_t) sp: The initial stack pointer ** (reg_t) objp: Pointer to the beginning of the current object ** (int) argc: Number of parameters to call with ** (stack_ptr_t) argp: Heap pointer to the first parameter ** (selector_t) selector: The selector by which it was called or ** NULL_SELECTOR if n.a. For debugging. ** (reg_t) sendp: Pointer to the object which the message was sent to. ** Equal to objp for anything but super. ** (int) origin: Number of the execution stack element this entry was created by ** (usually the current TOS number, except for multiple sends). ** (seg_id_t) local_segment: The segment to use for local variables, ** or SCI_XS_CALLEE_LOCALS to use obj's segment. ** Returns : (exec_stack_t *): A pointer to the new exec stack TOS entry */ exec_stack_t *add_exec_stack_varselector(EngineState *s, reg_t objp, int argc, stack_ptr_t argp, selector_t selector, reg_t *address, int origin); /* Adds one varselector access to the execution stack ** Parameters: (EngineState *) s: The EngineState to use ** (reg_t) objp: Pointer to the object owning the selector ** (int) argc: 1 for writing, 0 for reading ** (stack_ptr_t) argp: Pointer to the address of the data to write -2 ** (int) selector: Selector name ** (reg_t *) address: Heap address of the selector ** (int) origin: Stack frame which the access originated from ** Returns : (exec_stack_t *): Pointer to the new exec-TOS element ** This function is called from send_selector only. */ void run_vm(EngineState *s, int restoring); /* Executes the code on s->heap[pc] until it hits a 'ret' operation while (stack_base == stack_pos) ** Parameters: (EngineState *) s: The state to use ** (int) restoring: 1 if s has just been restored, 0 otherwise ** Returns : (void) ** This function will execute SCI bytecode. It requires s to be set up ** correctly. */ void vm_handle_fatal_error(EngineState *s, int line, const char *file); /* Handles a fatal error condition ** Parameters: (EngineState *) s: The state to recover from ** (int) line: Source code line number the error occured in ** (const char *) file: File the error occured in */ void script_debug(EngineState *s, reg_t *pc, stack_ptr_t *sp, stack_ptr_t *pp, reg_t *objp, int *restadjust, seg_id_t *segids, reg_t **variables, reg_t **variables_base, int *variables_nr, int bp); /* Debugger functionality ** Parameters: (EngineState *) s: The state at which debugging should take place ** (reg_t *) pc: Pointer to the program counter ** (stack_ptr_t *) sp: Pointer to the stack pointer ** (stack_ptr_t *) pp: Pointer to the frame pointer ** (reg_t *) objp: Pointer to the object base pointer ** (int *) restadjust: Pointer to the &rest adjustment value ** (seg_id_t *) segids: four-element array containing segment IDs for locals etc. ** (reg_t **) variables: four-element array referencing registers for globals etc. ** (reg_t **) variables_base: four-element array referencing ** register bases for temps etc. ** (int *) variables_nr: four-element array giving sizes for params etc. (may be NULL) ** (int) bp: Flag, set to 1 when a breakpoint is triggered ** Returns : (void) */ int script_init_engine(EngineState *s, sci_version_t version); /* Initializes a EngineState block ** Parameters: (EngineState *) s: The state to initialize ** Returns : 0 on success, 1 if vocab.996 (the class table) is missing or corrupted */ void script_set_gamestate_save_dir(EngineState *s, const char *path); /* Sets the gamestate's save_dir to the parameter path ** Parameters: (EngineState *) s: The state to set ** (const char *) path: Path where save_dir will point to ** Returns : (void) */ void script_free_engine(EngineState *s); /* Frees all additional memory associated with a EngineState block ** Parameters: (EngineState *) s: The EngineState whose elements should be cleared ** Returns : (void) */ void script_free_vm_memory(EngineState *s); /* Frees all script memory (heap, hunk, and class tables). ** Parameters: (EngineState *) s: The EngineState to free ** Returns : (void) ** This operation is implicit in script_free_engine(), but is required for restoring ** the game state. */ int lookup_selector(EngineState *s, reg_t obj, selector_t selectorid, reg_t **vptr, reg_t *fptr); /* Looks up a selector and returns its type and value ** Parameters: (EngineState *) s: The EngineState to use ** (reg_t) obj: Address of the object to look the selector up in ** (selector_t) selectorid: The selector to look up ** Returns : (int) SELECTOR_NONE if the selector was not found in the object or its superclasses. ** SELECTOR_VARIABLE if the selector represents an object-relative variable ** SELECTOR_METHOD if the selector represents a method ** (reg_t *) *vptr: A pointer to the storage space associated with the selector, if ** it is a variable ** (reg_t) *fptr: A reference to the function described by that selector, if it is ** a valid function selector. ** *vptr is written to iff it is non-NULL and the selector indicates a property of the object. ** *fptr is written to iff it is non-NULL and the selector indicates a member function of that object. */ #define SCRIPT_GET_DONT_LOAD 0 /* Fail if not loaded */ #define SCRIPT_GET_LOAD 1 /* Load, if neccessary */ #define SCRIPT_GET_LOCK 3 /* Load, if neccessary, and lock */ seg_id_t script_get_segment(EngineState *s, int script_id, int load); /* Determines the segment occupied by a certain script ** Parameters: (EngineState *) s: The state to operate on ** (int) script_id: The script in question ** (int) load: One of SCRIPT_GET_* ** Returns : The script's segment, or 0 on failure */ reg_t script_lookup_export(EngineState *s, int script_nr, int export_index); /* Looks up an entry of the exports table of a script ** Parameters: (EngineState *) s: The state to operate on ** (int) script_nr: The script to look up in ** Returns : (int) export_index: index of the export entry to look up */ int script_instantiate(EngineState *s, int script_nr); /* Makes sure that a script and its superclasses get loaded to the heap ** Parameters: (EngineState *) s: The state to operate on ** (int) script_nr: The script number to load ** Returns : (int) The script's segment ID or 0 if out of heap ** If the script already has been loaded, only the number of lockers is increased. ** All scripts containing superclasses of this script aret loaded recursively as well, ** unless 'recursive' is set to zero. ** The complementary function is "script_uninstantiate()" below. */ void script_uninstantiate(EngineState *s, int script_nr); /* Decreases the numer of lockers of a script and unloads it if that number reaches zero ** Parameters: (EngineState *) s: The state to operate on ** (int) script_nr: The script number that is requestet to be unloaded ** Returns : (void) ** This function will recursively unload scripts containing its superclasses, if those ** aren't locked by other scripts as well. */ int game_save_state(EngineState *s, char *name, int coredump); /* Saves the game state to the harddisk ** Parameters: (EngineState *) s: The game state to save ** (char *) name: Name of the subdirectory (relative to s->save_dir) ** (int) coredump: Set to non-zero in order to write additional debug information ** Returns : (int) 0 on success, 1 otherwise */ EngineState *game_restore_state(char *name); /* Restores the game state from a file ** Parameters: (char *) name: Name of the saved game state to restore ** Returns : (EngineState *): The restored game state, or NULL on failure */ int game_init(EngineState *s); /* Initializes an SCI game ** Parameters: (EngineState *) s: The state to operate on ** Returns : (int): 0 on success, 1 if an error occured. ** This function must be run before script_run() is executed. ** Graphics data is initialized iff s->gfx_state != NULL. */ int game_init_graphics(EngineState *s); /* Initializes the graphics part of an SCI game ** Parameters: (EngineState *) s: The state to initialize the graphics in ** Returns : (int) 0 on success, 1 if an error occured ** This function may only be called if game_init() did not initialize ** the graphics data. */ int game_init_sound(EngineState *s, int sound_flags); /* Initializes the sound part of an SCI game ** Parameters: (EngineState *) s: The state to initialize the sound in ** (int) sound_flags: Flags to pass to the sound subsystem ** Returns : (int) 0 on success, 1 if an error occured ** This function may only be called if game_init() did not initialize ** the graphics data. */ int game_run(EngineState **s); /* Runs an SCI game ** Parameters: (EngineState **) s: Pointer to the pointer of the state to operate on ** Returns : (int): 0 on success, 1 if an error occured. ** This is the main function for SCI games. It takes a valid state, loads script 0 to it, ** finds the game object, allocates a stack, and runs the init method of the game object. ** In layman's terms, this runs an SCI game. ** By the way, *s may be changed during the game, e.g. if a game state is restored. */ int game_restore(EngineState **s, char *savegame_name); /* Restores an SCI game state and runs the game ** Parameters: (EngineState **) s: Pointer to the pointer of the state to operate on ** (char *) savegame_name: Name of the savegame to restore ** Returns : (int): 0 on success, 1 if an error occured. ** This restores a savegame; otherwise, it behaves just like game_run(). */ int game_exit(EngineState *s); /* Uninitializes an initialized SCI game ** Parameters: (EngineState *) s: The state to operate on ** Returns : (int): 0 on success, 1 if an error occured. ** This function should be run after each script_run() call. */ void quit_vm(); /* Instructs the virtual machine to abort ** Paramteres: (void) ** Returns : (void) */ void script_map_selectors(EngineState *s, selector_map_t *map); /* Maps special selectors ** Parameters: (EngineState *) s: The state from which the selector information should be taken ** (selector_map_t *) map: Pointer to the selector map to map ** Returns : (void) ** Called by script_run(); */ int script_map_kernel(EngineState *s); /* Maps kernel functions ** Parameters: (EngineState *) s: The state which the kernel_names are retrieved from ** Returns : (void) ** This function reads from and writes to s. It is called by script_run(). */ void script_detect_versions(EngineState *s); /* Detects SCI versions by their different script header ** Parameters: (EngineState *) s: The state to operate on ** Returns : (void) */ reg_t kalloc(EngineState *s, const char *type, int space); /* Allocates "kernel" memory and returns a handle suitable to be passed on to SCI scripts ** Parameters: (EngineState *) s: Pointer to the EngineState to operate on ** (const char *) type: A free-form type description string (static) ** (int) space: The space to allocate ** Returns : (reg_t) The handle */ int has_kernel_function(EngineState *s, const char *kname); /* Detects whether a particular kernel function is required in the game ** Parameters: (EngineState *) s: Pointer to the EngineState to operate on ** (const char *) kname: The name of the desired kernel function ** Returns : (int) 1 if the kernel function is listed in the kernel table, ** 0 otherwise */ byte *kmem(EngineState *s, reg_t handle); /* Returns a pointer to "kernel" memory based on the handle ** Parameters: (EngineState *) s: Pointer to the EngineState to operate on ** (reg_t) handle: The handle to use ** Returns : (byte *) A pointer to the allocated memory */ int kfree(EngineState *s, reg_t handle); /* Frees all "kernel" memory associated with a handle ** Parameters: (EngineState *) s: Pointer to the EngineState to operate on ** (reg_t) handle: The handle to free ** Returns : (int) 0 on success, 1 otherwise */ const char *obj_get_name(EngineState *s, reg_t pos); /* Determines the name of an object ** Parameters: (EngineState *) s: Pointer to the EngineState to operate on ** (reg_t) pos: Location of the object whose name we want to ** inspect ** Returns : (const char *) A name for that object, or a string describing ** an error that occured while looking it up ** The string is stored in a static buffer and need not be freed (neither ** may it be modified). */ object_t *obj_get(EngineState *s, reg_t offset); /* Retreives an object from the specified location ** Parameters: (EngineState *) s: Pointer to the EngineState to operate on ** (reg_t) offset: The object's offset ** Returns : (object_t *) The object in question, or NULL if there is none */ } // End of namespace Sci #endif // SCI_ENGINE_VM_H