Check collision

This is a discussion on Check collision within the C++ Programming forums, part of the General Programming Boards category; >> Why? I was just going by past experiences mixed with exaggeration....

  1. #16
    Registered User Queatrix's Avatar
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    >> Why?

    I was just going by past experiences mixed with exaggeration.

  2. #17
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    Ok, but now back to topic!

  3. #18
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    Grrrrrr! Im getting angry! Why aint this working... I only won't 1 random number...

    Code:
    //Check if there is a collision
    int check_coll( int sX, int sY, int pX, int pY )
    {
        //Square's position
        int sXl = sX;
        int sXr = sX + 29;
        int sYl = sY;
        int sYr = sY + 29;
        
        //Piece's position
        int pXl = pX;
        int pXr = pX + 75;
        int pYl = pY;
        int pYr = pY + 148;
        
        //Check if you hit the square
        int n  = sXl;
        if (sXl == pXr || sXr == pXl) 
        {
                //New position for the square
                n = GetRand(0, 640);
                
                SDL_FillRect( screen, NULL, SDL_MapRGB(screen->format, 0x00, 0x00, 0x00) );
                apply_surface( 0, 0, background, screen );
                piece = load_image( "piece.png" ); 
                apply_surface( pXl, pYl, piece, screen ); 
        }
        
        //Apply the square
        apply_surface( n, sYl, square, screen );
    }

  4. #19
    and the hat of wrongness Salem's Avatar
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    > n = GetRand(0, 640);
    If the condition is not met to set the value of n here

    > apply_surface( n, sYl, square, screen );
    What value of n gets used here?
    If you dance barefoot on the broken glass of undefined behaviour, you've got to expect the occasional cut.
    If at first you don't succeed, try writing your phone number on the exam paper.
    I support http://www.ukip.org/ as the first necessary step to a free Europe.

  5. #20
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    Code:
    //Random number
    int GetRand(int min, int max)
    {
      static int Init = 0;
      int rc;
      
      if (Init == 0)
      {
        srand(time(NULL));
        Init = 1;
      }
      
      rc = (rand() % (max - min + 1) + min);
      
      return (rc);
    }
    Sorry

  6. #21
    and the hat of wrongness Salem's Avatar
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    You posted that already in an earlier thread.

    But that wasn't the question.

    Code:
     /* what value is 'n' here? */
        if (sXl == pXr || sXr == pXl) 
        {
                //New position for the square
                n = GetRand(0, 640);
                
                SDL_FillRect( screen, NULL, SDL_MapRGB(screen->format, 0x00, 0x00, 0x00) );
                apply_surface( 0, 0, background, screen );
                piece = load_image( "piece.png" ); 
                apply_surface( pXl, pYl, piece, screen ); 
        }
        
        //Apply the square
        apply_surface( n, sYl, square, screen );
    Sometimes you get the old value, sometimes the new one.
    Now where does the old value come from?
    If you dance barefoot on the broken glass of undefined behaviour, you've got to expect the occasional cut.
    If at first you don't succeed, try writing your phone number on the exam paper.
    I support http://www.ukip.org/ as the first necessary step to a free Europe.

  7. #22
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    Outside the if i got int n = sXl; you can see that earlier in my post. 2 post before this!

  8. #23
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    Hmmmm... This is no bump!
    Last edited by Livijn; 05-13-2007 at 08:51 AM.

  9. #24
    Registered User Queatrix's Avatar
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    That is you'r 6th time!
    Last edited by Queatrix; 05-13-2007 at 09:01 AM.

  10. #25
    and the hat of wrongness Salem's Avatar
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    Well I've had enough of this bumping.
    If you dance barefoot on the broken glass of undefined behaviour, you've got to expect the occasional cut.
    If at first you don't succeed, try writing your phone number on the exam paper.
    I support http://www.ukip.org/ as the first necessary step to a free Europe.

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