Weird SDL problem.

Sage
Posts: 1,482
Joined: 2002.09
Post: #1
So I'm programming along, and all of a sudden, some of my data structures are getting corrupted. So I run it step by step in the debugger to find where things are going awry. I finally tracked it down to a call to SDL_PollEvent().
????
It doesn't scramble it, or crash the program, just writes the same corrupt data in each time. Any possible ideas of what this might be? I can't possibly be getting overlaping memory sections between restarts and everything eles, can I?

I'd post source code, but I don't know where to start. The functions are completely unrelated. I'm even still using the example SDL event handling and initialization code.

Scott Lembcke - Howling Moon Software
Author of Chipmunk Physics - A fast and simple rigid body physics library in C.
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Luminary
Posts: 5,143
Joined: 2002.04
Post: #2
The obvious thing to check is that the pointer you pass to SDL_PollEvent really is valid.

Yes, if nothing random has happened, memory will usually be allocated in exactly the same place each run.
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Member
Posts: 156
Joined: 2002.10
Post: #3
As well as what OSC already said, I found that most of my memory trashing errors were related to accidentally releasing CoreFoundation variables that I had no right to release! Try commenting out all irrelevant code before the SDL_PollEvent call, and see when it stops breaking!!

Good luck

- Iain
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Sage
Posts: 1,482
Joined: 2002.09
Post: #4
Well it works somewhat like this:
I've got some arrays with vertices and associated properties for a physics system. Specific elements of the arrays keep getting changed when I call SDL_PollEvents.

My function that handles events has a static variable defined in it, I just pass the address of that.

IBethune: My physics code has no dependencies outside of the standard C libraries, and everything else is SDL code. Most of that is still untouched from the template. I'm not quite sure what else I can disable and still have it work. Very frustrating when your code is only a hundred lines long, and you still have problems.

Scott Lembcke - Howling Moon Software
Author of Chipmunk Physics - A fast and simple rigid body physics library in C.
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