Rotating -1 to bigger number

[TehKyle]

Modulus operator works fine if you add up, but how do you deal with -1 going back to 7 without special case code line (if possible)

Code: [Select]

               if (Event.Key.Code == sf::Key::Z){
                    TileSelect--;
                    TileSelect = TileSelect % 7;
                }
                if (Event.Key.Code == sf::Key::X){
                    TileSelect++;
                    TileSelect = TileSelect % 7;
                }


[Walker]

I'm not certain on what you're trying to do. Can't you just do "IF num > 0 THEN num--"?

[Disch]

Code: [Select]

if (Event.Key.Code == sf::Key::Z){
//                    TileSelect--;
                    TileSelect += 7 - 1;
                    TileSelect = TileSelect % 7;
                }


[Jove]

A bitwise AND (& 7) would keep the value at 0-7, if I'm understanding you correctly.

[TehKyle]

Code: [Select]

if (Event.Key.Code == sf::Key::Z){
//                    TileSelect--;
                    TileSelect += 7 - 1;
                    TileSelect = TileSelect % 7;
                }


Thanks, I totally forgot about that. Your code was off by one though, I don't know why you added -1. I used const int MAX_TILE which contained 7 and now it works as intended.

[Disch]

A bitwise AND (& 7) would keep the value at 0-7, if I'm understanding you correctly.

& 7 is equivilent to %8

He wants % 7 which does not have a & equivilent.

Thanks, I totally forgot about that. Your code was off by one though, I don't know why you added -1.

I added the -1 because you wanted to subtract 1:

Code: [Select]

x = (x + 7) % 7;  // does not change x:
// ex:  x=2
//  (2 + 7) % 7
//  9 % 7
//  2