Index: exec.c
==================================================================
--- exec.c
+++ exec.c
@@ -8,10 +8,11 @@
 #include <stdio.h>
 #include <stdlib.h>
 #include <string.h>
 #include "sqlite3.h"
 #include "smallxrm.h"
+#include "quarks.h"
 #include "heromesh.h"
 #include "instruc.h"
 
 #ifndef VSTACKSIZE
 #define VSTACKSIZE 0x400
@@ -26,10 +27,11 @@
 Uint32 lastobj=VOIDLINK;
 Uint32 playfield[64*64];
 Uint8 pfwidth,pfheight;
 Sint8 gameover,key_ignored;
 Uint8 generation_number_inc;
+Uint32 move_number;
 
 typedef struct {
   Uint16 msg;
   Uint32 from;
   Value arg1,arg2,arg3;
@@ -39,10 +41,11 @@
 static const char*my_error;
 static MessageVars msgvars;
 static char lastimage_processing,changed;
 static Value vstack[VSTACKSIZE];
 static int vstackptr;
+static const char*traceprefix;
 
 #define Throw(x) (my_error=(x),longjmp(my_env,1))
 #define StackReq(x,y) do{ if(vstackptr<(x)) Throw("Stack underflow"); if(vstackptr-(x)+(y)>=VSTACKSIZE) Throw("Stack overflow"); }while(0)
 #define Push(x) (vstack[vstackptr++]=(x))
 #define Pop() (vstack[--vstackptr])
@@ -161,10 +164,31 @@
     return v.u;
   } else {
     Throw("Cannot convert non-object to object");
   }
 }
+
+static void trace_stack(Uint32 obj) {
+  Value t2=Pop();
+  Value t1=Pop();
+  Value t0=Pop();
+  Object*o;
+  if(!main_options['t']) return;
+  if(!traceprefix) {
+    optionquery[1]=Q_tracePrefix;
+    traceprefix=xrm_get_resource(resourcedb,optionquery,optionquery,2);
+    if(!traceprefix) traceprefix="";
+  }
+  printf("%sTrace : %d : %u %u",traceprefix,vstackptr,t0.t,t0.u);
+  if(t0.t>TY_MAXTYPE && t0.u<nobjects && objects[t0.u] && objects[t0.u]->generation==t0.t) {
+    o=objects[t0.u];
+    printf(" [$%s %d %d]",classes[o->class]->name,o->x,o->y);
+  }
+  o=objects[obj];
+  printf(" : %u %u [$%s %d %d]",o->generation,obj,classes[o->class]->name,o->x,o->y);
+  printf(" : %u %u : %u %u\n",t1.t,t1.u,t2.t,t2.u);
+}
 
 // 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))
 static void execute_program(Uint16*code,int ptr,Uint32 obj) {
@@ -200,10 +224,11 @@
     case OP_LOR: StackReq(2,1); t1=Pop(); t2=Pop(); if(v_bool(t1) || v_bool(t2)) Push(NVALUE(1)); else Push(NVALUE(0)); break;
     case OP_LOSELEVEL: gameover=-1; Throw(0); break;
     case OP_NIP: StackReq(2,1); t1=Pop(); Pop(); Push(t1); break;
     case OP_RET: return;
     case OP_SWAP: StackReq(2,2); t1=Pop(); t2=Pop(); Push(t1); Push(t2); break;
+    case OP_TRACE: StackReq(3,0); trace_stack(obj); break;
     case OP_WINLEVEL: key_ignored=0; gameover=1; Throw(0); break;
     default: Throw("Internal error: Unrecognized opcode");
   }
 }
 
@@ -263,9 +288,10 @@
   gameover=0;
   changed=0;
   key_ignored=0;
   lastimage_processing=0;
   vstackptr=0;
+  move_number=0;
   
   if(generation_number<=TY_MAXTYPE) return "Too many generations of objects";
   return 0;
 }

Index: function.c
==================================================================
--- function.c
+++ function.c
@@ -301,10 +301,15 @@
   sqlite3_int64 a;
   if(sqlite3_value_type(*argv)==SQLITE_NULL) return;
   a=sqlite3_value_int64(*argv)&0xFFFFFFFF;
   sqlite3_result_int64(cxt,a-(a&0x80000000?0x100000000LL:0));
 }
+
+static void fn_trace_on(sqlite3_context*cxt,int argc,sqlite3_value**argv) {
+  const char*v=sqlite3_user_data(cxt);
+  if(main_options['t']=*v) puts("[Tracing enabled]"); else puts("[Tracing disabled]");
+}
 
 static void fn_zero_extend(sqlite3_context*cxt,int argc,sqlite3_value**argv) {
   sqlite3_int64 a;
   if(sqlite3_value_type(*argv)==SQLITE_NULL) return;
   a=sqlite3_value_int64(*argv)&0xFFFFFFFF;
@@ -940,12 +945,14 @@
   sqlite3_create_function(userdb,"PICTURE_SIZE",0,SQLITE_UTF8|SQLITE_DETERMINISTIC,0,fn_picture_size,0,0);
   sqlite3_create_function(userdb,"READ_LUMP_AT",2,SQLITE_UTF8,0,fn_read_lump_at,0,0);
   sqlite3_create_function(userdb,"RESOURCE",-1,SQLITE_UTF8|SQLITE_DETERMINISTIC,0,fn_resource,0,0);
   sqlite3_create_function(userdb,"SIGN_EXTEND",1,SQLITE_UTF8|SQLITE_DETERMINISTIC,0,fn_sign_extend,0,0);
   sqlite3_create_function(userdb,"SOLUTION_CACHEID",0,SQLITE_UTF8|SQLITE_DETERMINISTIC,ptr1,fn_cacheid,0,0);
+  sqlite3_create_function(userdb,"TRACE_OFF",0,SQLITE_UTF8,"",fn_trace_on,0,0);
+  sqlite3_create_function(userdb,"TRACE_ON",0,SQLITE_UTF8,"\x01",fn_trace_on,0,0);
   sqlite3_create_function(userdb,"ZERO_EXTEND",1,SQLITE_UTF8|SQLITE_DETERMINISTIC,0,fn_zero_extend,0,0);
   sqlite3_create_module(userdb,"CLASSES",&vt_classes,"CREATE TABLE `CLASSES`(`ID` INTEGER PRIMARY KEY, `NAME` TEXT, `EDITORHELP` TEXT, `HELP` TEXT,"
    "`INPUT` INT, `QUIZ` INT, `TRACEIN` INT, `TRACEOUT` INT, `GROUP` TEXT, `PLAYER` INT);");
   sqlite3_create_module(userdb,"MESSAGES",&vt_messages,"CREATE TABLE `MESSAGES`(`ID` INTEGER PRIMARY KEY, `NAME` TEXT, `TRACE` INT);");
   sqlite3_create_module(userdb,"OBJECTS",&vt_objects,"CREATE TABLE `OBJECTS`(`ID` INTEGER PRIMARY KEY, `CLASS` INT, `MISC1` INT, `MISC2` INT, `MISC3` INT,"
    "`IMAGE` INT, `DIR` INT, `X` INT, `Y` INT, `UP` INT, `DOWN` INT, `DENSITY` INT HIDDEN);");
 }

Index: heromesh.h
==================================================================
--- heromesh.h
+++ heromesh.h
@@ -192,10 +192,11 @@
 extern Uint32 firstobj,lastobj;
 extern Uint32 playfield[64*64];
 extern Uint8 pfwidth,pfheight;
 extern Sint8 gameover,key_ignored;
 extern Uint8 generation_number_inc;
+extern Uint32 move_number;
 
 void pfunlink(Uint32 n);
 void pflink(Uint32 n);
 Uint32 objalloc(Uint16 c);
 void objtrash(Uint32 n);