*mix.Chunk.setVolume() fails on Windows 7 about go-sdl2

[akovaski]

Your LoadWAV calls are probably failing (at least it is for your project on my machine). Check that gameAudio.enemyHit et al. are not nil.

I suspect that your sdl_mixer installation is not built with ogg support.

That being said, perhaps some changes should be made to the sdl_mixer library:

• This is an unpleasant way to crash... a nil check in the Chunk methods might be a worthwhile investment

  • This version of SetVolume() would result in a nil-pointer panic instead of the somewhat cryptic panic it currently does

  func (chunk Chunk) SetVolume(volume int) int {
      _chunk := (*C.Mix_Chunk)(unsafe.Pointer(&chunk))
      _volume := (C.int)(volume)
      return (int)(C.Mix_VolumeChunk(_chunk, _volume))
  }

• It's hard to tell what's wrong with loading the file (can it not find the file? is the filetype not supported?) without Mix_GetError

  • What LoadWav() with error checking could look like

  func LoadWAV(file string) (c *Chunk, err error) {
      _file := C.CString(file)
      defer C.free(unsafe.Pointer(_file))
      _rb := C.CString("rb")
      defer C.free(unsafe.Pointer(_rb))
  
      rwFile := C.SDL_RWFromFile(_file, _rb)
      if rwFile == nil {
          return nil, errors.New(C.GoString(C.Mix_GetError()))
      }
  
      c = (*Chunk)(unsafe.Pointer(C.Mix_LoadWAV_RW(rwFile, 1)))
      if c == nil {
          return nil, errors.New(C.GoString(C.Mix_GetError()))
      }
      return c, nil
  }

Please try using this version of LoadWAV to see if your files are not being loaded. (the "errors" package must also be imported in sdl_mixer.go)

Sorry, I screwed up. I built the game with go run outside the game folder... and then it couldn't find the asset files and threw this exception.

More idiomatic error handling for sdl_mixer would be a nice thing though :)

I implemented your loadWav function and got this output:
2015/03/03 19:38:40 Couldn't open assets/SFX_Explosion_01.ogg
exit status 1

Which of course make sense since the application is run from outside the intended folder.

I'm closing this issue as "error exists between keyboard and chair".

[krux02]

actually I am writing at the moment more ideomatic error for the mixer. But it's a compatibility changing. Especially SetVolume is now called like the original function just Volume, because it's also the getter.