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3511 :: Error on runtime (SFML/CSFML related)

• erasmo85 (orginal) [2018-01-29T03:59:34+01:00] view original

  Hi everyone, I'm trying to compile the game that Dominik made for the Ludum Dare 40, and I got two errors (of which I solved one):

  1) Error on the line

  if game.music.status() == Playing:
  Run

  which I solved it with:

  if game.music.status() == SoundStatus.Playing:
  Run

  2) SIGSEGV: Illegal storage access. (Attempt to read from nil?) on the line

  result.titleText.localBounds.width / 2,
  Run

  I understand that localBounds is null, but why?? I am using Nim 0.17.2 on Ubuntu 16.04 64bit, with SFML/CFSML 2.3. @dom96 any ideas?

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• dom96 (orginal) [2018-01-29T10:37:45+01:00] view original

  I was using 0.17.3 to develop this, so you might want to try the same.

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• twetzel59 (orginal) [2018-02-01T18:03:40+01:00] view original

  I'll look at this more in depth later today. Currently at lunch.

  Anyway, I am a big fan of SFML, and I'm wondering if localBounds is even supposed to ever be null...

  Maybe the rectangle was never set.

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• twetzel59 (orginal) [2018-02-01T18:08:35+01:00] view original

  Are you sure it's localBounds... maybe the Text itself is null?

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• twetzel59 (orginal) [2018-02-01T20:19:44+01:00] view original

  Now looking at the repo. If it segfaults there exactly, then it probably isn't the text that is null.

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• twetzel59 (orginal) [2018-02-01T20:25:52+01:00] view original

  That's weird. I wonder if it's really nil, or if it's an invalid memory location. It is a segfault, so... could be either.

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• twetzel59 (orginal) [2018-02-01T21:52:34+01:00] view original

  I've been looking into this for a while, and I can't seem to come across the culprit. localBounds returns a FloatRect, which is a {.bycopy.} object. It is not a ptr object. I am a bit confused myself.

  Here's what I think I've deduced so far:

  • viewport(view: View): FloatRect is another function that returns a FloatRect, and it seems to work properly when tested with the game window's view...
  • globalBounds crashes as well.
  • color(text: Text): Color doesn't. So I believe that the SFML object is still valid. However, unsafe pointers are in use, so it is hard to tell. The binding homepage warns of deconstructions troubles with the binding. I wonder if this is a use-after free error, honestly. But then again, some additional careful testing will be needed to figure this one out.

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