Free Hero Mesh

  labelptr=0;
}

static int parse_pattern(int cla,int ptr,Hash*hash) {
  Class*cl=classes[cla];
  Uint8 depth=0;
  Uint16 nest[32];
  Uint16 nest0[32];
  int x,y;
  for(;;) {
    nxttok();
    if(Tokenf(TF_MACRO)) ParseError("Unexpected macro\n");
    if(Tokenf(TF_DIR)) {
      cl->codes[ptr++]=tokenv&15;
    } else if(Tokenf(TF_NAME)) {
      switch(tokenv) {
        case OP_ADD: case OP_CLIMB: case OP_EIGHT: case OP_FOUR:
        case OP_HEIGHT: case OP_LOC: case OP_MARK: case OP_SUB:
        case OP_DIR: case OP_DIR_C: case OP_DIR_E: case OP_DIR_EC:
        case OP_OBJTOPAT: case OP_OBJBOTTOMAT: case OP_CUT: case OP_MUL:
        case OP_OBJABOVE: case OP_OBJBELOW: case OP_TRACE:
        case 0x0200 ... 0x02FF: // message
        case 0x4000 ... 0x7FFF: // class
        case 0xC000 ... 0xFFFF: // message
          cl->codes[ptr++]=tokenv;
          break;
        case OP_BEGIN: case OP_IF:
          if(depth==31) ParseError("Too much pattern nesting\n");
          nest0[depth]=nest[depth]=ptr;
          cl->codes[ptr++]=tokenv;
          cl->codes[ptr++]=0;
          depth++;
          break;
        case OP_ELSE:
          if(!depth) ParseError("Premature end of subpattern\n");
          cl->codes[nest[depth-1]+1]=ptr;
          cl->codes[ptr++]=OP_ELSE;
          cl->codes[ptr++]=cl->codes[nest[depth-1]];
          cl->codes[nest[depth-1]]=OP_IF;
          cl->codes[ptr++]=0;
          break;
        case OP_THEN:
          if(!depth) ParseError("Premature end of subpattern\n");
          cl->codes[nest[--depth]+1]=ptr;
          cl->codes[ptr++]=OP_THEN;
          break;
        case OP_AGAIN:
          if(!depth) ParseError("Premature end of subpattern\n");
          cl->codes[ptr++]=OP_AGAIN;
          cl->codes[ptr++]=nest0[depth-1];
          cl->codes[nest[--depth]+1]=ptr;
          cl->codes[ptr++]=OP_THEN;
          break;
        case OP_USERFLAG:
          x=look_hash(glohash,HASH_SIZE,0x1000,0x10FF,0,"user flags");
          if(!x) ParseError("User flag ^%s not defined\n",tokenstr);
          if(Tokenf(TF_COMMA)) x+=0x100;
          if(Tokenf(TF_EQUAL)) ParseError("Improper token in pattern\n");
          cl->codes[ptr++]=x;

this case, a warp occurs. The movement is restarted, using the specified
object as the origin of the movement, and that object's direction as the
direction of movement.


=== Pattern matching ===

Where an instruction is expected, you can have pattern matching. This can
be (P <pattern...>) or (,P <pattern...>) where the first one uses the
current location, and the second kind uses the position and direction of
the specified object as the matching. It pushes the found object to the
stack, or pushes zero if the pattern does not match.

<class>
  Match an object of the specified class.

<dir>
  Move in the specified direction. (This does not move any objects; it
  only moves the cursor for pattern matching.) The direction can be
  relative to the current direction (initially the Dir variable of the
  origin object) or absolute.

<message>
  Send the message to all objects at the current location. From is the
  position from which pattern matching started. Arg1 is the direction.
  Arg2 is the currently matched object (which may be zero). If the
  return value is zero, it continues normally; if one, the match fails;
  if two, it continues without sending more messages at this location;
  if an object, sets the matched object and current location.

<userflag>
  Match an object with the specified flag.

,<userflag>
  Fail if there are any objects having the specified flag here.

+
  Push the matched object to the stack.

-
  Push zero to the stack.

*
  Update the current choice point with the location and direction.

_
  Push a mark to the stack.

again
  End a block with begin or if, allowing it to occur more than once; it
  is repeated until it no longer matches. If the first word is begin,
  then it must match at least once; if it is if, then it can match zero
  or more times. The match is greedy; it will match as much as possible.

begin
  Begin a block.

Climb
  Fail the match if the origin object cannot climb here.

(Climb <number>)
  Fail the match if the height here is greater than this number.

cut
  Discards the most recent choice point.

else
  Delimits alternatives within a block.

Four
  Try four directions (E, N, W, and S).

Eight
  Try all eight directions.

Height
  Fail the match if the origin object can climb here.

(Height <number>)
  Fail the match if the height here isn't greater than this number.

if
  Begin a block that can optionally match.

ObjAbove
  Match the object above the currently matched object.

ObjBelow
  Match the object below the currently matched object.

ObjBottomAt
  Match the object at the bottom of this location.

ObjTopAt
  Match the object at the top of this location.

then
  Ends a block started with begin or if.

Trace
  Used for debugging.


=== Compatibility ===

Compatible objects have the following differences from the default:

* VisualOnly implies Stealthy.

static int colocation(Uint32 a,Uint32 b) {
  if(a==VOIDLINK || b==VOIDLINK) return 0;
  if((objects[a]->oflags|objects[b]->oflags)&OF_DESTROYED) return 0;
  if((objects[a]->oflags^objects[b]->oflags)&OF_BIZARRO) return 0;
  return (objects[a]->x==objects[b]->x && objects[a]->y==objects[b]->y);
}

static Uint32 pat_find_at(int xy,Uint32 m4,Uint32 m5,Uint32 m6,Uint32 m7,Uint8 cl) {
  Uint8 n=playfield[xy];
  Object*o;
  while(n!=VOIDLINK) {
    o=objects[n];
    if(!(o->oflags&(OF_DESTROYED|OF_VISUALONLY))) {
      if(o->misc4.t==TY_SOUND || o->misc4.t==TY_USOUND) Throw("Cannot convert sound to type");
      if(o->misc5.t==TY_SOUND || o->misc5.t==TY_USOUND) Throw("Cannot convert sound to type");
      if(o->misc6.t==TY_SOUND || o->misc6.t==TY_USOUND) Throw("Cannot convert sound to type");
      if(o->misc7.t==TY_SOUND || o->misc7.t==TY_USOUND) Throw("Cannot convert sound to type");
      if(o->misc4.t==TY_NUMBER && (o->misc4.u&m4)) return n;
      if(o->misc5.t==TY_NUMBER && (o->misc5.u&m5)) return n;
      if(o->misc6.t==TY_NUMBER && (o->misc6.u&m6)) return n;
      if(o->misc7.t==TY_NUMBER && (o->misc7.u&m7)) return n;
      if(classes[o->class]->collisionLayers&cl) return n;
    }
    n=o->up;
  }
  return VOIDLINK;
}

typedef struct {
  Uint16 ptr,depth;
  Uint8 x,y,dir,t;
} ChoicePoint;

#define MAXCHOICE 80
static Uint32 v_pattern(Uint16*code,int ptr,Uint32 obj,char all) {
  Uint8 x=objects[obj]->x;
  Uint8 y=objects[obj]->y;
  Uint8 d=objects[obj]->dir;
  Uint32 n=VOIDLINK;
  Uint32 m;
  Uint16 g;
  Value v;
  static ChoicePoint cp[MAXCHOICE];
  Uint8 cpi=0;
  cp->depth=vstackptr;
  again: switch(code[ptr++]) {
    case 0 ... 7:
      n=VOIDLINK;
      x+=x_delta[code[ptr-1]];
      y+=y_delta[code[ptr-1]];
      if(x<1 || x>pfwidth || y<1 || y>pfheight) goto fail;
      break;
    case 8 ... 15:
      n=VOIDLINK;
      x+=x_delta[(code[ptr-1]+objects[obj]->dir)&7];
      y+=y_delta[(code[ptr-1]+objects[obj]->dir)&7];
      if(x<1 || x>pfwidth || y<1 || y>pfheight) goto fail;
      break;
    case 0x0200 ... 0x02FF:
      g=code[ptr-1]&255;
      goto message;
    case 0x1000 ... 0x10FF:
      g=code[ptr-1]&255;
      if(g<0x20) n=pat_find_at(x+y*64-65,1UL<<(g&31),0,0,0,0);
      else if(g<0x40) n=pat_find_at(x+y*64-65,0,1UL<<(g&31),0,0,0);
      else if(g<0x60) n=pat_find_at(x+y*64-65,0,0,1UL<<(g&31),0,0);
      else if(g<0x80) n=pat_find_at(x+y*64-65,0,0,0,1UL<<(g&31),0);
      else n=pat_find_at(x+y*64-65,0,0,0,0,1U<<(g&7));
      if(n==VOIDLINK) goto fail;
      break;
    case 0x4000 ... 0x7FFF:
      n=obj_class_at(code[ptr-1]&0x3FFF,x,y);
      if(n==VOIDLINK) goto fail;
      break;
    case 0xC000 ... 0xFFFF:
      g=(code[ptr-1]&0x3FFF)+256;
    message:
      m=playfield[x+y*64-65];
      while(m!=VOIDLINK) {
        v=send_message(obj,m,g,NVALUE(d),OVALUE(n),NVALUE(0));
        if(v.t==TY_NUMBER) {
          if(v.u==1) goto fail;
          else if(v.u==2) break;
          else if(v.u) Throw("Invalid return value from message in pattern matching");
        } else if(v.t>TY_MAXTYPE) {
          n=v_object(v);
          x=objects[n]->x;
          y=objects[n]->y;
        } else {
          Throw("Type mismatch");
        }
        m=objects[m]->up;
      }
      break;
    case OP_ADD:
      if(vstackptr>=VSTACKSIZE-1) Throw("Stack overflow");
      m=(n==VOIDLINK?obj_bottom_at(x,y):n);
      Push(OVALUE(m));
      break;
    case OP_AGAIN:
      if(cp[cpi].ptr!=ptr+1) {
        if(cpi>=MAXCHOICE-1) Throw("Choice overflow");
        cpi++;
        cp[cpi].ptr=ptr+1;
      }
      cp[cpi].x=x;
      cp[cpi].y=y;
      cp[cpi].dir=d;
      cp[cpi].depth=vstackptr;
      ptr=code[ptr]+2;
      break;
    case OP_BEGIN:
      ptr++;
      break;
    case OP_CLIMB:
      if(playfield[x+y*64-65]==VOIDLINK || height_at(x,y)>objects[obj]->climb) goto fail;
      break;
    case OP_CLIMB_C:
      g=code[ptr++];
      if(playfield[x+y*64-65]==VOIDLINK || height_at(x,y)>g) goto fail;
      break;
    case OP_CUT:
      if(cpi) cpi--;
      break;
    case OP_DIR:
      d=objects[obj]->dir;
      break;
    case OP_DIR_C:
      if(n==VOIDLINK) Throw("No object specified in pattern");
      d=objects[n]->dir;
      break;
    case OP_DIR_E:
      changed=1;
      objects[obj]->dir=d;
      break;
    case OP_DIR_EC:
      if(n==VOIDLINK) Throw("No object specified in pattern");
      changed=1;
      objects[n]->dir=d;
      break;
    case OP_EIGHT:
      if(cpi>=MAXCHOICE-8) Throw("Choice overflow");
      d=0;
      cpi+=7;
      cp[cpi].x=x;
      cp[cpi].y=y;
      cp[cpi].depth=vstackptr;
      cp[cpi].ptr=ptr;
      cp[cpi-1]=cp[cpi-2]=cp[cpi-3]=cp[cpi-4]=cp[cpi-5]=cp[cpi-6]=cp[cpi];
      cp[cpi].dir=1;
      cp[cpi-1].dir=2;
      cp[cpi-2].dir=3;
      cp[cpi-3].dir=4;
      cp[cpi-4].dir=5;
      cp[cpi-5].dir=6;
      cp[cpi-6].dir=7;
      break;
    case OP_ELSE:
      ptr--;
      while(code[ptr]==OP_ELSE) ptr=code[ptr+2];
      break;
    case OP_FOUR:
      if(cpi>=MAXCHOICE-4) Throw("Choice overflow");
      d=0;
      cpi+=3;
      cp[cpi].x=x;
      cp[cpi].y=y;
      cp[cpi].depth=vstackptr;
      cp[cpi].ptr=ptr;
      cp[cpi-1]=cp[cpi-2]=cp[cpi];
      cp[cpi].dir=2;
      cp[cpi-1].dir=4;
      cp[cpi-2].dir=6;
      break;
    case OP_HEIGHT:
      if(playfield[x+y*64-65]==VOIDLINK || height_at(x,y)<=objects[obj]->climb) goto fail;
      break;
    case OP_HEIGHT_C:
      g=code[ptr++];
      if(playfield[x+y*64-65]==VOIDLINK || height_at(x,y)<=g) goto fail;
      break;
    case OP_IF:
      if(cpi>=MAXCHOICE-1) Throw("Pattern stack overflow");
      cpi++;
      cp[cpi].x=x;
      cp[cpi].y=y;
      cp[cpi].dir=d;
      cp[cpi].depth=vstackptr;
      cp[cpi].ptr=code[ptr++];
      break;
    case OP_LOC:
      if(vstackptr>=VSTACKSIZE-2) Throw("Stack overflow");
      Push(NVALUE(x));
      Push(NVALUE(y));
      break;
    case OP_MARK:
      if(vstackptr>=VSTACKSIZE-1) Throw("Stack overflow");
      Push(UVALUE(0,TY_MARK));
      break;
    case OP_MUL:
      cp[cpi].x=x;
      cp[cpi].y=y;
      cp[cpi].dir=d;
      break;
    case OP_OBJABOVE:
      if(n==VOIDLINK) Throw("No object specified in pattern");
      n=obj_above(n);
      break;
    case OP_OBJBELOW:
      if(n==VOIDLINK) Throw("No object specified in pattern");
      n=obj_below(n);
      break;
    case OP_OBJBOTTOMAT:
      n=obj_bottom_at(x,y);
      break;
    case OP_OBJTOPAT:
      n=obj_top_at(x,y);
      break;
    case OP_RET:
      return n==VOIDLINK?obj_bottom_at(x,y):n;
    case OP_SUB:
      if(vstackptr>=VSTACKSIZE-1) Throw("Stack overflow");
      Push(NVALUE(0));
      break;
    case OP_THEN:
      // This opcode does nothing
      break;
    case OP_TRACE:
      if(main_options['t']) {
        printf("ptr=%d cpi=%d x=%d y=%d dir=%d obj=%lu ",ptr,cpi,x,y,d,(long)n);
        printf("[ptr=%d x=%d y=%d dir=%d]\n",cp[cpi].ptr,cp[cpi].x,cp[cpi].y,cp[cpi].dir);
      }
      break;
    default: Throw("Unimplemented opcode in pattern");
  }
  goto again;
  fail:
  if(vstackptr<cp->depth) Throw("Stack underflow in pattern matching");
  vstackptr=cp[cpi].depth;
  if(!cpi) return VOIDLINK;
  x=cp[cpi].x;
  y=cp[cpi].y;
  d=cp[cpi].dir;
  ptr=cp[cpi].ptr;
  n=VOIDLINK;
  cpi--;
  goto again;
}

// Here is where the execution of a Free Hero Mesh bytecode subroutine is executed.
#define NoIgnore() do{ changed=1; }while(0)
#define GetVariableOf(a,b) (i=v_object(Pop()),i==VOIDLINK?NVALUE(0):b(objects[i]->a))
#define GetVariableOrAttributeOf(a,b) (t2=Pop(),t2.t==TY_CLASS?NVALUE(classes[t2.u]->a):(i=v_object(t2),i==VOIDLINK?NVALUE(0):b(objects[i]->a)))
#define Numeric(a) do{ if((a).t!=TY_NUMBER) Throw("Type mismatch"); }while(0)
#define DivideBy(a) do{ Numeric(a); if(!(a).u) Throw("Division by zero"); }while(0)

    case OP_OBJCLASSAT: StackReq(3,1); t3=Pop(); t2=Pop(); t1=Pop(); Push(v_obj_class_at(t1,t2,t3)); break;
    case OP_OBJDIR: StackReq(1,1); t2=Pop(); Numeric(t2); i=obj_dir(obj,t2.u); Push(OVALUE(i)); break;
    case OP_OBJDIR_C: StackReq(2,1); t2=Pop(); Numeric(t2); i=obj_dir(v_object(Pop()),t2.u); Push(OVALUE(i)); break;
    case OP_OBJLAYERAT: StackReq(3,1); t3=Pop(); Numeric(t3); t2=Pop(); Numeric(t2); t1=Pop(); Numeric(t1); i=obj_layer_at(t1.u,t2.u,t3.u); Push(OVALUE(i)); break;
    case OP_OBJMOVINGTO: StackReq(2,0); t2=Pop(); Numeric(t2); t1=Pop(); Numeric(t1); v_obj_moving_to(t1.u,t2.u); break;
    case OP_OBJTOPAT: StackReq(2,1); t2=Pop(); Numeric(t2); t1=Pop(); Numeric(t1); i=obj_top_at(t1.u,t2.u); Push(OVALUE(i)); break;
    case OP_OVER: StackReq(2,3); t2=Pop(); t1=Pop(); Push(t1); Push(t2); Push(t1); break;
    case OP_PATTERN: StackReq(0,1); i=code[ptr++]; j=v_pattern(code,ptr,obj,0); ptr=i; Push(OVALUE(j)); break;
    case OP_PATTERN_C: StackReq(1,1); i=code[ptr++]; j=v_object(Pop()); if(j!=VOIDLINK) j=v_pattern(code,ptr,j,0); ptr=i; Push(OVALUE(j)); break;
    case OP_PICK: StackReq(0,1); t1=Pop(); Numeric(t1); if(t1.u>=vstackptr) Throw("Stack index out of range"); t1=vstack[vstackptr-t1.u-1]; Push(t1); break;
    case OP_PLAYER: StackReq(0,1); if(classes[o->class]->cflags&CF_PLAYER) Push(NVALUE(1)); else Push(NVALUE(0)); break;
    case OP_PLAYER_C: StackReq(1,1); GetClassFlagOf(CF_PLAYER); break;
    case OP_PLUSMOVE: StackReq(1,1); t1=Pop(); Numeric(t1); i=defer_move(obj,t1.u,1); Push(NVALUE(i)); break;
    case OP_PLUSMOVE_C: StackReq(2,1); t1=Pop(); Numeric(t1); i=v_object(Pop()); i=defer_move(i,t1.u,1); Push(NVALUE(i)); break;
    case OP_PLUSMOVE_D: StackReq(1,0); t1=Pop(); Numeric(t1); defer_move(obj,t1.u,1); break;
    case OP_PLUSMOVE_CD: StackReq(2,1); t1=Pop(); Numeric(t1); i=v_object(Pop()); defer_move(i,t1.u,1); break;

ArrayCell

; Pattern matching
-,=Pattern "P"
-,=PatternS "P*"
-Four
-Eight
-cut

; Specials
*Function
*Local
*Label
*String
*Int16
*Int32
*Dispatch
*UserFlag

#define OP_PATTERN_EC 39118
#define OP_PATTERNS 32975
#define OP_PATTERNS_C 35023
#define OP_PATTERNS_E 37071
#define OP_PATTERNS_EC 39119
#define OP_FOUR 32976
#define OP_EIGHT 32977
#define OP_CUT 32978
#define OP_FUNCTION 32979
#define OP_LOCAL 32980
#define OP_LABEL 32981
#define OP_STRING 32982
#define OP_INT16 32983
#define OP_INT32 32984
#define OP_DISPATCH 32985
#define OP_USERFLAG 32986
#ifdef HEROMESH_CLASS
static const Op_Names op_names[]={
{"*",8486937},
{"+",8421399},
{"+Move",10584230},
{"-",8421400},
{"-Move",10584231},

{"bit8",8423400},
{"bit9",8423401},
{"bnot",8421412},
{"bor",8421410},
{"bxor",8421411},
{"c?",8421427},
{"chain",8421520},
{"cut",8683730},
{"cz?",8421428},
{"dup",8421377},
{"el",8683532},
{"else",8683530},
{"eq",8421418},
{"eq2",8421419},
{"flip",8421576},

{"swap",8421378},
{"then",8683531},
{"tmark",8421572},
{"tuck",8421380},
{"until",8683535},
{"while",8683536},
};
#define N_OP_NAMES 319
#endif