EXC_BAD_ACCESS when simply casting a pointer in Obj-C
- by AlexChilcott
Hi all,
Frequent visitor but first post here on StackOverflow, I'm hoping that you guys might be able to help me out with this. I'm fairly new to Obj-C and XCode, and I'm faced with this really... weird... problem. Googling hasn't turned up anything whatsoever. Basically, I get an EXC_BAD_ACCESS signal on a line that doesn't do any dereferencing or anything like that that I can see. Wondering if you guys have any idea where to look for this. I've found a work around, but no idea why this works... The line the broken version barfs out on is the line:
LevelEntity *le = entity;
where I get my bad access signal.
Here goes:
THIS VERSION WORKS
NSArray *contacts = [self.body getContacts];
for (PhysicsContact *contact in contacts)
{
PhysicsBody *otherBody;
if (contact.bodyA == self.body)
{
otherBody = contact.bodyB;
}
if (contact.bodyB == self.body)
{
otherBody = contact.bodyA;
}
id entity = [otherBody userData];
if (entity != nil)
{
LevelEntity *le = entity;
CGPoint point = [contact contactPointOnBody:otherBody];
}
}
THIS VERSION DOESNT WORK
NSArray *contacts = [self.body getContacts];
for (NSUInteger i = 0; i < [contacts count]; i++)
{
PhysicsContact *contact = [contacts objectAtIndex:i];
PhysicsBody *otherBody;
if (contact.bodyA == self.body)
{
otherBody = contact.bodyB;
}
if (contact.bodyB == self.body)
{
otherBody = contact.bodyA;
}
id entity = [otherBody userData];
if (entity != nil)
{
LevelEntity *le = entity;
CGPoint point = [contact contactPointOnBody:otherBody];
}
}
Here, the only difference between the two examples is the way I enumerate through my array. In the first version (which works) I use for (... in ...), where as in the second I use for (...; ...; ...). As far as I can see, these should be the same.
This is seriously weirding me out. Anyone have any similar experience or idea whats going on here? Would be really great :)
Cheers,
Alex
