SCI: kRandom now exactly behaving like sierra sci

hoyle4 and lsl5 door code work now

svn-id: r52244
This commit is contained in:
Martin Kiewitz 2010-08-20 21:59:14 +00:00
parent 769ad3109d
commit 1b9d95e43c

@ -35,41 +35,19 @@ reg_t kRandom(EngineState *s, int argc, reg_t *argv) {
return NULL_REG;
case 2: { // get random number
// These are unsigned (e.g. in LSL5, this is used for the 5-digit
// door access code with Patty at k rap)
int fromNumber = argv[0].toUint16();
int toNumber = argv[1].toUint16();
// numbers are definitely unsigned, for example lsl5 door code in k rap radio is random
// and 5-digit - we get called kRandom(10000, 65000)
// some codes in sq4 are also random and 5 digit (if i remember correctly)
const uint16 fromNumber = argv[0].toUint16();
const uint16 toNumber = argv[1].toUint16();
uint16 range = toNumber - fromNumber + 1;
// calculating range is exactly how sierra sci did it and is required for hoyle 4
// where we get called with kRandom(0, -1) and we are supposed to give back values from 0 to 0
// the returned value will be used as displace-offset for a background cel
if (range)
range--; // the range value was never returned, our random generator gets 0->range, so fix it
// HACK: Hoyle 4 calls this with (0x0, 0xFFFF) in some dialogs for x,
// then it calls it with (0x0, 0x40) and puts x plus the result in y
// to displace view 924 in kDrawCel right afterwards and create a
// semi-random background in those dialogs. With the current code,
// this case isn't handled properly, and the dialog background is
// drawn off-screen. -1 seems to be incorrect here (probably a newly
// added special case), so we just return a 0 for now, till we
// figure out how to handle this.
if (fromNumber == 0 && toNumber == 0xFFFF) {
if (g_sci->getGameId() == GID_HOYLE4) {
warning("HACK: Special case for Hoyle 4 dialogs in kRandom");
return NULL_REG;
} else {
// Just throw a warning in other games for now, but don't modify
// the result...
warning("kRandom(0x0, 0xFFFF) called - special case?");
}
}
// TODO/CHECKME: It is probably not required to check whether
// toNumber is greater than fromNumber, at least not when one
// goes by their names, but let us be on the safe side and
// allow toNumber to be smaller than fromNumber too.
if (fromNumber > toNumber)
SWAP(fromNumber, toNumber);
const uint diff = (uint)(toNumber - fromNumber);
const int randomNumber = fromNumber + (int)g_sci->getRNG().getRandomNumber(diff);
const int randomNumber = fromNumber + (int)g_sci->getRNG().getRandomNumber(range);
return make_reg(0, randomNumber);
}