reg_t reg_t::operator+(const reg_t right) const {
if (isPointer() && right.isNumber()) {
// Pointer arithmetics. Only some pointer types make sense here
SegmentObj *mobj = g_sci->getEngineState()->_segMan->getSegmentObj(getSegment());
if (!mobj)
error("[VM]: Attempt to add %d to invalid pointer %04x:%04x", right.getOffset(), PRINT_REG(*this));
switch (mobj->getType()) {
case SEG_TYPE_LOCALS:
case SEG_TYPE_SCRIPT:
case SEG_TYPE_STACK:
case SEG_TYPE_DYNMEM:
return make_reg(getSegment(), getOffset() + right.toSint16());
default:
return lookForWorkaround(right, "addition");
}
} else if (isNumber() && right.isPointer()) {
// Adding a pointer to a number, flip the order
return right + *this;
} else if (isNumber() && right.isNumber()) {
// Normal arithmetics
return make_reg(0, toSint16() + right.toSint16());
} else {
return lookForWorkaround(right, "addition");
}
}
reg_t reg_t::operator%(const reg_t right) const {
if (isNumber() && right.isNumber() && !right.isNull()) {
// Support for negative numbers was added in Iceman, and perhaps in
// SCI0 0.000.685 and later. Theoretically, this wasn't really used
// in SCI0, so the result is probably unpredictable. Such a case
// would indicate either a script bug, or a modulo on an unsigned
// integer larger than 32767. In any case, such a case should be
// investigated, instead of being silently accepted.
if (getSciVersion() <= SCI_VERSION_0_LATE && (toSint16() < 0 || right.toSint16() < 0))
warning("Modulo of a negative number has been requested for SCI0. This *could* lead to issues");
int16 value = toSint16();
int16 modulo = ABS(right.toSint16());
int16 result = value % modulo;
if (result < 0)
result += modulo;
return make_reg(0, result);
} else
return lookForWorkaround(right, "modulo");
}
reg_t reg_t::operator/(const reg_t right) const {
if (isNumber() && right.isNumber() && !right.isNull())
return make_reg(0, toSint16() / right.toSint16());
else
return lookForWorkaround(right, "division");
}
reg_t reg_t::operator*(const reg_t right) const {
if (isNumber() && right.isNumber())
return make_reg(0, toSint16() * right.toSint16());
else
return lookForWorkaround(right, "multiplication");
}