/* advexe.c - adventure code executer */ /* Copyright (c) 1986, by David Michael Betz All rights reserved */ #include "advint.h" #include "advdbs.h" /* external variables */ extern char line[]; extern int nouns[],*adjectives[]; /* local variables */ int pc,opcode,p2,p3,sts; int stack[STKSIZE],*sp,*fp,*top; long rseed = 1L; /* external routines */ extern long time(); /* execute - execute adventure code */ int execute(code) int code; { /* setup initial program counter */ if ((pc = code) == NIL) return (CHAIN); /* initialize */ sp = fp = top = stack + STKSIZE; /* execute the code */ for (sts = 0; sts == 0; ) exe_one(); return (sts); } /* exe_one - execute one instruction */ exe_one() { /* get the opcode */ opcode = getcbyte(pc); pc++; /* execute the instruction */ switch (opcode) { case OP_CALL: *--sp = getboperand(); *--sp = pc; *--sp = (int)(top - fp); fp = sp; pc = getafield(fp[fp[2]+3],A_CODE); break; case OP_SEND: *--sp = getboperand(); *--sp = pc; *--sp = (int)(top - fp); fp = sp; if (p2 = fp[fp[2]+3]) p2 = getofield(p2,O_CLASS); else p2 = fp[fp[2]+2]; if (p2 && (p2 = getp(p2,fp[fp[2]+1]))) { pc = getafield(p2,A_CODE); break; } *sp = NIL; /* return NIL if there is no method for this message */ case OP_RETURN: if (fp == top) sts = CHAIN; else { p2 = *sp; sp = fp; fp = top - *sp++; pc = *sp++; p3 = *sp++; sp += p3; *sp = p2; } break; case OP_TSPACE: sp -= getboperand(); break; case OP_TMP: p2 = getboperand(); *sp = fp[-p2-1]; break; case OP_TSET: p2 = getboperand(); fp[-p2-1] = *sp; break; case OP_ARG: p2 = getboperand(); if (p2 >= fp[2]) error("too few arguments"); *sp = fp[p2+3]; break; case OP_ASET: p2 = getboperand(); if (p2 >= fp[2]) error("too few arguments"); fp[p2+3] = *sp; break; case OP_BRT: pc = (*sp ? getwoperand() : pc+2); break; case OP_BRF: pc = (*sp ? pc+2 : getwoperand()); break; case OP_BR: pc = getwoperand(); break; case OP_T: *sp = T; break; case OP_NIL: *sp = NIL; break; case OP_PUSH: *--sp = NIL; break; case OP_NOT: *sp = (*sp ? NIL : T); break; case OP_ADD: p2 = *sp++; *sp += p2; break; case OP_SUB: p2 = *sp++; *sp -= p2; break; case OP_MUL: p2 = *sp++; *sp *= p2; break; case OP_DIV: p2 = *sp++; *sp = (p2 == 0 ? 0 : *sp / p2); break; case OP_REM: p2 = *sp++; *sp = (p2 == 0 ? 0 : *sp % p2); break; case OP_BAND: p2 = *sp++; *sp &= p2; break; case OP_BOR: p2 = *sp++; *sp |= p2; break; case OP_BNOT: *sp = ~*sp; break; case OP_LT: p2 = *sp++; *sp = (*sp < p2 ? T : NIL); break; case OP_EQ: p2 = *sp++; *sp = (*sp == p2 ? T : NIL); break; case OP_GT: p2 = *sp++; *sp = (*sp > p2 ? T : NIL); break; case OP_LIT: *sp = getwoperand(); break; case OP_SPLIT: *sp = getboperand(); break; case OP_SNLIT: *sp = -getboperand(); break; case OP_VAR: *sp = getvalue(getwoperand()); break; case OP_SVAR: *sp = getvalue(getboperand()); break; case OP_SET: setvalue(getwoperand(),*sp); break; case OP_SSET: setvalue(getboperand(),*sp); break; case OP_GETP: p2 = *sp++; *sp = getp(*sp,p2); break; case OP_SETP: p3 = *sp++; p2 = *sp++; *sp = setp(*sp,p2,p3); break; case OP_PRINT: print(*sp); break; case OP_PNUMBER: pnumber(*sp); break; case OP_PNOUN: show_noun(*sp); break; case OP_TERPRI: trm_chr('\n'); break; case OP_FINISH: sts = FINISH; break; case OP_CHAIN: sts = CHAIN; break; case OP_ABORT: sts = ABORT; break; case OP_EXIT: #ifdef MAC macpause(); #endif trm_done(); exit(); break; case OP_YORN: trm_get(line); *sp = (line[0] == 'Y' || line[0] == 'y' ? T : NIL); break; case OP_CLASS: *sp = getofield(*sp,O_CLASS); break; case OP_MATCH: p2 = *sp++; *sp = (match(*sp,nouns[p2-1],adjectives[p2-1]) ? T : NIL); break; case OP_SAVE: if ((*sp = db_save()) == NIL) // VB: added if trm_str("Sorry, I couldn't save to this file.\n"); break; case OP_RESTORE: if ((*sp = db_restore()) == NIL) // VB: added if trm_str("Sorry, I couldn't restore from this file.\n"); break; case OP_RESTART: *sp = db_restart(); break; case OP_RAND: *sp = getrand(*sp); break; case OP_RNDMIZE: setrand(time(0L)); *sp = NIL; break; case OP_VOWEL: // patch for smart articles by MRP *sp = vowel(*sp); // patch for smart articles by MRP break; // patch for smart articles by MRP default: if (opcode >= OP_XVAR && opcode < OP_XSET) *sp = getvalue(opcode - OP_XVAR); else if (opcode >= OP_XSET && opcode < OP_XPLIT) setvalue(opcode - OP_XSET,*sp); else if (opcode >= OP_XPLIT && opcode < OP_XNLIT) *sp = opcode - OP_XPLIT; else if (opcode >= OP_XNLIT && opcode < 256) *sp = OP_XNLIT - opcode; else trm_str("Bad opcode\n"); break; } } /* getboperand - get data byte */ int getboperand() { int data; data = getcbyte(pc); pc += 1; return (data); } /* getwoperand - get data word */ int getwoperand() { int data; data = getcword(pc); pc += 2; return (data); } /* print - print a message */ print(msg) int msg; { int ch; msg_open(msg); while (ch = msg_byte()) trm_chr(ch); } /* vowel - check for vowel */ // patch for smart articles by MRP vowel(msg) // patch for smart articles by MRP int msg; // patch for smart articles by MRP { // patch for smart articles by MRP int ch,r; // patch for smart articles by MRP // patch for smart articles by MRP msg_open(msg); // patch for smart articles by MRP ch = msg_byte(); // patch for smart articles by MRP if (ch=='a'||ch=='e'||ch=='i'||ch=='o'||ch=='u') // patch by MRP r = T; // patch for smart articles by MRP else // patch for smart articles by MRP r = NIL; // patch for smart articles by MRP while (ch) // patch for smart articles by MRP ch = msg_byte(); // patch for smart articles by MRP return (r); // patch for smart articles by MRP } // patch for smart articles by MRP /* pnumber - print a number */ pnumber(n) int n; { char buf[10]; sprintf(buf,"%d",n); trm_str(buf); } /* getrand - get a random number between 0 and n-1 */ int getrand(n) int n; { long k1; /* make sure we don't get stuck at zero */ if (rseed == 0L) rseed = 1L; /* algorithm taken from Dr. Dobbs Journal, November 1985, page 91 */ k1 = rseed / 127773L; if ((rseed = 16807L * (rseed - k1 * 127773L) - k1 * 2836L) < 0L) rseed += 2147483647L; /* return a random number between 0 and n-1 */ return ((int)(rseed % (long)n)); } /* setrand - set the random number seed */ setrand(n) long n; { rseed = n; }