Free Hero Mesh

#if 0
gcc ${CFLAGS:--s -O2} -c exec.c `sdl-config --cflags`
exit
#endif

#include "SDL.h"
#include <setjmp.h>
#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
#endif

Uint32 max_objects;
Uint32 generation_number;
Object**objects;
Uint32 nobjects;
Value globals[0x800];
Uint32 firstobj=VOIDLINK;
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;
} MessageVars;

static jmp_buf my_env;
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])

void pfunlink(Uint32 n) {

    if(v.u>=nobjects || !objects[v.u]) Throw("Attempt to use a nonexistent object");
    if(objects[v.u]->generation!=v.t) Throw("Attempt to use a nonexistent object");
    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) {
  Uint32 i;
  Object*o=objects[obj];

    case OP_LAND: StackReq(2,1); t1=Pop(); t2=Pop(); if(v_bool(t1) && v_bool(t2)) Push(NVALUE(1)); else Push(NVALUE(0)); break;
    case OP_LNOT: StackReq(1,1); if(v_bool(Pop())) Push(NVALUE(0)); else Push(NVALUE(1)); break;
    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");
  }
}

static Value send_message(Uint32 from,Uint32 to,Uint16 msg,Value arg1,Value arg2,Value arg3) {
  MessageVars saved=msgvars;

const char*init_level(void) {
  if(setjmp(my_env)) return my_error;
  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;
}