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2286 :: Help with SDL2's blitScaled

• hcorion (orginal) [2016-05-29T07:40:40+02:00] view original

  Hi all, I'm back again! I'm trying to follow Lesson 05 of Lazy Foo's C++ sdl2 tutorial. Right now in the tutorial the C++ code looks like:

  SDL_Rect stretchRect;
  stretchRect.x = 0;
  stretchRect.y = 0;
  stretchRect.w = SCREEN_WIDTH;
  stretchRect.h = SCREEN_HEIGHT;
  SDL_BlitScaled( gStretchedSurface, NULL, gScreenSurface, &stretchRect );
  Run

  And my Nim code looks (roughly) like this:

  var stretchRect: Rect
  stretchRect.x = 0;
  stretchRect.y = 0;
  stretchRect.w = screenWidth
  stretchRect.h = screenHeight
  blitScaled(stretchedSurface, nil, surface, stretchRect)
  Run

  but it doesn't like that because blitScaled last value takes a ptr Rect:

  proc blitScaled*(src: SurfacePtr; srcrect: ptr Rect; dst: SurfacePtr;
    dstrect: ptr Rect): SDL_Return {.inline, discardable.} = upperBlitScaled(src, srcrect, dst, dstrect)
  Run

  However, if I change my

  var stretchRect: Rect
  Run

  to

  var stretchRect: ptr Rect
  Run

  I get SIGSEGV: Illegal storage access. (Attempt to read from nil?) with the most recent call being on the following line:

  stretchRect.x = 0;
  Run

  Help? The tutorial uses &stretchRect in the BlitScaled function, but I don't how to do that in Nim. Thanks, hcorion

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• Araq (orginal) [2016-05-29T11:29:51+02:00] view original

  &stretchRect is addr stretchRect in Nim or if stretchRect is a parameter, unsafeAddr stretchRect.

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