function.cc

swf文件查看工具,能够看flash文件的格式

PostScriptFunction::PostScriptFunction(PostScriptFunction *func) {
  memcpy(this, func, sizeof(PostScriptFunction));
  code = (PSObject *)gmallocn(codeSize, sizeof(PSObject));
  memcpy(code, func->code, codeSize * sizeof(PSObject));
  codeString = func->codeString->copy();
}

PostScriptFunction::~PostScriptFunction() {
  gfree(code);
  delete codeString;
}

void PostScriptFunction::transform(double *in, double *out) {
  PSStack *stack;
  int i;

  stack = new PSStack();
  for (i = 0; i < m; ++i) {
    //~ may need to check for integers here
    stack->pushReal(in[i]);
  }
  exec(stack, 0);
  for (i = n - 1; i >= 0; --i) {
    out[i] = stack->popNum();
    if (out[i] < range[i][0]) {
      out[i] = range[i][0];
    } else if (out[i] > range[i][1]) {
      out[i] = range[i][1];
    }
  }
  // if (!stack->empty()) {
  //   error(-1, "Extra values on stack at end of PostScript function");
  // }
  delete stack;
}

GBool PostScriptFunction::parseCode(Stream *str, int *codePtr) {
  GString *tok;
  char *p;
  GBool isReal;
  int opPtr, elsePtr;
  int a, b, mid, cmp;

  while (1) {
    if (!(tok = getToken(str))) {
      error(-1, "Unexpected end of PostScript function stream");
      return gFalse;
    }
    p = tok->getCString();
    if (isdigit(*p) || *p == '.' || *p == '-') {
      isReal = gFalse;
      for (++p; *p; ++p) {
	if (*p == '.') {
	  isReal = gTrue;
	  break;
	}
      }
      resizeCode(*codePtr);
      if (isReal) {
	code[*codePtr].type = psReal;
	code[*codePtr].real = atof(tok->getCString());
      } else {
	code[*codePtr].type = psInt;
	code[*codePtr].intg = atoi(tok->getCString());
      }
      ++*codePtr;
      delete tok;
    } else if (!tok->cmp("{")) {
      delete tok;
      opPtr = *codePtr;
      *codePtr += 3;
      resizeCode(opPtr + 2);
      if (!parseCode(str, codePtr)) {
	return gFalse;
      }
      if (!(tok = getToken(str))) {
	error(-1, "Unexpected end of PostScript function stream");
	return gFalse;
      }
      if (!tok->cmp("{")) {
	elsePtr = *codePtr;
	if (!parseCode(str, codePtr)) {
	  return gFalse;
	}
	delete tok;
	if (!(tok = getToken(str))) {
	  error(-1, "Unexpected end of PostScript function stream");
	  return gFalse;
	}
      } else {
	elsePtr = -1;
      }
      if (!tok->cmp("if")) {
	if (elsePtr >= 0) {
	  error(-1, "Got 'if' operator with two blocks in PostScript function");
	  return gFalse;
	}
	code[opPtr].type = psOperator;
	code[opPtr].op = psOpIf;
	code[opPtr+2].type = psBlock;
	code[opPtr+2].blk = *codePtr;
      } else if (!tok->cmp("ifelse")) {
	if (elsePtr < 0) {
	  error(-1, "Got 'ifelse' operator with one blocks in PostScript function");
	  return gFalse;
	}
	code[opPtr].type = psOperator;
	code[opPtr].op = psOpIfelse;
	code[opPtr+1].type = psBlock;
	code[opPtr+1].blk = elsePtr;
	code[opPtr+2].type = psBlock;
	code[opPtr+2].blk = *codePtr;
      } else {
	error(-1, "Expected if/ifelse operator in PostScript function");
	delete tok;
	return gFalse;
      }
      delete tok;
    } else if (!tok->cmp("}")) {
      delete tok;
      resizeCode(*codePtr);
      code[*codePtr].type = psOperator;
      code[*codePtr].op = psOpReturn;
      ++*codePtr;
      break;
    } else {
      a = -1;
      b = nPSOps;
      // invariant: psOpNames[a] < tok < psOpNames[b]
      while (b - a > 1) {
	mid = (a + b) / 2;
	cmp = tok->cmp(psOpNames[mid]);
	if (cmp > 0) {
	  a = mid;
	} else if (cmp < 0) {
	  b = mid;
	} else {
	  a = b = mid;
	}
      }
      if (cmp != 0) {
	error(-1, "Unknown operator '%s' in PostScript function",
	      tok->getCString());
	delete tok;
	return gFalse;
      }
      delete tok;
      resizeCode(*codePtr);
      code[*codePtr].type = psOperator;
      code[*codePtr].op = (PSOp)a;
      ++*codePtr;
    }
  }
  return gTrue;
}

GString *PostScriptFunction::getToken(Stream *str) {
  GString *s;
  int c;
  GBool comment;

  s = new GString();
  comment = gFalse;
  while (1) {
    if ((c = str->getChar()) == EOF) {
      break;
    }
    codeString->append(c);
    if (comment) {
      if (c == '\x0a' || c == '\x0d') {
	comment = gFalse;
      }
    } else if (c == '%') {
      comment = gTrue;
    } else if (!isspace(c)) {
      break;
    }
  }
  if (c == '{' || c == '}') {
    s->append((char)c);
  } else if (isdigit(c) || c == '.' || c == '-') {
    while (1) {
      s->append((char)c);
      c = str->lookChar();
      if (c == EOF || !(isdigit(c) || c == '.' || c == '-')) {
	break;
      }
      str->getChar();
      codeString->append(c);
    }
  } else {
    while (1) {
      s->append((char)c);
      c = str->lookChar();
      if (c == EOF || !isalnum(c)) {
	break;
      }
      str->getChar();
      codeString->append(c);
    }
  }
  return s;
}

void PostScriptFunction::resizeCode(int newSize) {
  if (newSize >= codeSize) {
    codeSize += 64;
    code = (PSObject *)greallocn(code, codeSize, sizeof(PSObject));
  }
}

void PostScriptFunction::exec(PSStack *stack, int codePtr) {
  int i1, i2;
  double r1, r2;
  GBool b1, b2;

  while (1) {
    switch (code[codePtr].type) {
    case psInt:
      stack->pushInt(code[codePtr++].intg);
      break;
    case psReal:
      stack->pushReal(code[codePtr++].real);
      break;
    case psOperator:
      switch (code[codePtr++].op) {
      case psOpAbs:
	if (stack->topIsInt()) {
	  stack->pushInt(abs(stack->popInt()));
	} else {
	  stack->pushReal(fabs(stack->popNum()));
	}
	break;
      case psOpAdd:
	if (stack->topTwoAreInts()) {
	  i2 = stack->popInt();
	  i1 = stack->popInt();
	  stack->pushInt(i1 + i2);
	} else {
	  r2 = stack->popNum();
	  r1 = stack->popNum();
	  stack->pushReal(r1 + r2);
	}
	break;
      case psOpAnd:
	if (stack->topTwoAreInts()) {
	  i2 = stack->popInt();
	  i1 = stack->popInt();
	  stack->pushInt(i1 & i2);
	} else {
	  b2 = stack->popBool();
	  b1 = stack->popBool();
	  stack->pushBool(b1 && b2);
	}
	break;
      case psOpAtan:
	r2 = stack->popNum();
	r1 = stack->popNum();
	stack->pushReal(atan2(r1, r2));
	break;
      case psOpBitshift:
	i2 = stack->popInt();
	i1 = stack->popInt();
	if (i2 > 0) {
	  stack->pushInt(i1 << i2);
	} else if (i2 < 0) {
	  stack->pushInt((int)((Guint)i1 >> i2));
	} else {
	  stack->pushInt(i1);
	}
	break;
      case psOpCeiling:
	if (!stack->topIsInt()) {
	  stack->pushReal(ceil(stack->popNum()));
	}
	break;
      case psOpCopy:
	stack->copy(stack->popInt());
	break;
      case psOpCos:
	stack->pushReal(cos(stack->popNum()));
	break;
      case psOpCvi:
	if (!stack->topIsInt()) {
	  stack->pushInt((int)stack->popNum());
	}
	break;
      case psOpCvr:
	if (!stack->topIsReal()) {
	  stack->pushReal(stack->popNum());
	}
	break;
      case psOpDiv:
	r2 = stack->popNum();
	r1 = stack->popNum();
	stack->pushReal(r1 / r2);
	break;
      case psOpDup:
	stack->copy(1);
	break;
      case psOpEq:
	if (stack->topTwoAreInts()) {
	  i2 = stack->popInt();
	  i1 = stack->popInt();
	  stack->pushBool(i1 == i2);
	} else if (stack->topTwoAreNums()) {
	  r2 = stack->popNum();
	  r1 = stack->popNum();
	  stack->pushBool(r1 == r2);
	} else {
	  b2 = stack->popBool();
	  b1 = stack->popBool();
	  stack->pushBool(b1 == b2);
	}
	break;
      case psOpExch:
	stack->roll(2, 1);
	break;
      case psOpExp:
	r2 = stack->popNum();
	r1 = stack->popNum();
	stack->pushReal(pow(r1, r2));
	break;
      case psOpFalse:
	stack->pushBool(gFalse);
	break;
      case psOpFloor:
	if (!stack->topIsInt()) {
	  stack->pushReal(floor(stack->popNum()));
	}
	break;
      case psOpGe:
	if (stack->topTwoAreInts()) {
	  i2 = stack->popInt();
	  i1 = stack->popInt();
	  stack->pushBool(i1 >= i2);
	} else {
	  r2 = stack->popNum();
	  r1 = stack->popNum();
	  stack->pushBool(r1 >= r2);
	}
	break;
      case psOpGt:
	if (stack->topTwoAreInts()) {
	  i2 = stack->popInt();
	  i1 = stack->popInt();
	  stack->pushBool(i1 > i2);
	} else {
	  r2 = stack->popNum();
	  r1 = stack->popNum();
	  stack->pushBool(r1 > r2);
	}
	break;
      case psOpIdiv:
	i2 = stack->popInt();
	i1 = stack->popInt();
	stack->pushInt(i1 / i2);
	break;
      case psOpIndex:
	stack->index(stack->popInt());
	break;
      case psOpLe:
	if (stack->topTwoAreInts()) {
	  i2 = stack->popInt();
	  i1 = stack->popInt();
	  stack->pushBool(i1 <= i2);
	} else {
	  r2 = stack->popNum();
	  r1 = stack->popNum();
	  stack->pushBool(r1 <= r2);
	}
	break;
      case psOpLn:
	stack->pushReal(log(stack->popNum()));
	break;
      case psOpLog:
	stack->pushReal(log10(stack->popNum()));
	break;
      case psOpLt:
	if (stack->topTwoAreInts()) {
	  i2 = stack->popInt();
	  i1 = stack->popInt();
	  stack->pushBool(i1 < i2);
	} else {
	  r2 = stack->popNum();
	  r1 = stack->popNum();
	  stack->pushBool(r1 < r2);
	}
	break;
      case psOpMod:
	i2 = stack->popInt();
	i1 = stack->popInt();
	stack->pushInt(i1 % i2);
	break;
      case psOpMul:
	if (stack->topTwoAreInts()) {
	  i2 = stack->popInt();
	  i1 = stack->popInt();
	  //~ should check for out-of-range, and push a real instead
	  stack->pushInt(i1 * i2);
	} else {
	  r2 = stack->popNum();
	  r1 = stack->popNum();
	  stack->pushReal(r1 * r2);
	}
	break;
      case psOpNe:
	if (stack->topTwoAreInts()) {
	  i2 = stack->popInt();
	  i1 = stack->popInt();
	  stack->pushBool(i1 != i2);
	} else if (stack->topTwoAreNums()) {
	  r2 = stack->popNum();
	  r1 = stack->popNum();
	  stack->pushBool(r1 != r2);
	} else {
	  b2 = stack->popBool();
	  b1 = stack->popBool();
	  stack->pushBool(b1 != b2);
	}
	break;
      case psOpNeg:
	if (stack->topIsInt()) {
	  stack->pushInt(-stack->popInt());
	} else {
	  stack->pushReal(-stack->popNum());
	}
	break;
      case psOpNot:
	if (stack->topIsInt()) {
	  stack->pushInt(~stack->popInt());
	} else {
	  stack->pushBool(!stack->popBool());
	}
	break;
      case psOpOr:
	if (stack->topTwoAreInts()) {
	  i2 = stack->popInt();
	  i1 = stack->popInt();
	  stack->pushInt(i1 | i2);
	} else {
	  b2 = stack->popBool();
	  b1 = stack->popBool();
	  stack->pushBool(b1 || b2);
	}
	break;
      case psOpPop:
	stack->pop();
	break;
      case psOpRoll:
	i2 = stack->popInt();
	i1 = stack->popInt();
	stack->roll(i1, i2);
	break;
      case psOpRound:
	if (!stack->topIsInt()) {
	  r1 = stack->popNum();
	  stack->pushReal((r1 >= 0) ? floor(r1 + 0.5) : ceil(r1 - 0.5));
	}
	break;
      case psOpSin:
	stack->pushReal(sin(stack->popNum()));
	break;
      case psOpSqrt:
	stack->pushReal(sqrt(stack->popNum()));
	break;
      case psOpSub:
	if (stack->topTwoAreInts()) {
	  i2 = stack->popInt();
	  i1 = stack->popInt();
	  stack->pushInt(i1 - i2);
	} else {
	  r2 = stack->popNum();
	  r1 = stack->popNum();
	  stack->pushReal(r1 - r2);
	}
	break;
      case psOpTrue:
	stack->pushBool(gTrue);
	break;
      case psOpTruncate:
	if (!stack->topIsInt()) {
	  r1 = stack->popNum();
	  stack->pushReal((r1 >= 0) ? floor(r1) : ceil(r1));
	}
	break;
      case psOpXor:
	if (stack->topTwoAreInts()) {
	  i2 = stack->popInt();
	  i1 = stack->popInt();
	  stack->pushInt(i1 ^ i2);
	} else {
	  b2 = stack->popBool();
	  b1 = stack->popBool();
	  stack->pushBool(b1 ^ b2);
	}
	break;
      case psOpIf:
	b1 = stack->popBool();
	if (b1) {
	  exec(stack, codePtr + 2);
	}
	codePtr = code[codePtr + 1].blk;
	break;
      case psOpIfelse:
	b1 = stack->popBool();
	if (b1) {
	  exec(stack, codePtr + 2);
	} else {
	  exec(stack, code[codePtr].blk);
	}
	codePtr = code[codePtr + 1].blk;
	break;
      case psOpReturn:
	return;
      }
      break;
    default:
      error(-1, "Internal: bad object in PostScript function code");
      break;
    }
  }
}