[SDL] Help with getting user input for controls with SDL

[Ryan C. Gordon]

> The only difficulty left is SAVING this choice and reloading it when  
> your app loads.  The nearest I can come to this being easy is what  
> you feared: a long list of cases...  Is there an easier way to get a  
> keysym from a character and vice-versa?

Is there any reason you can't just write out the keysym?

[keyboard_settings]
jump=182
fire=188

(so you read your config file in as a text file, convert the values to 
ints and store them in an array, and then in your mainloop do something 
like...)

typedef enum {
     JUMP,
     FIRE,
     // etc.
     total_actions
} Actions;

// This gets filled in with the data from the config file, so
//  actions[JUMP] will be the keysym for jumping, etc...
static SDL_keysym actions[total_actions];


    //checking for events...
    case SDL_KEYDOWN:
        if (event.key.keysym.sym == actions[JUMP])
            make_player_jump();
        else if (event.key.keysym.sym == actions[FIRE])
            make_player_shoot();
        else {
            // not a key player has configured to do something, ignore.
        }
        break;



(or something like that.)

You could go a step further and have an array of structs that contain a 
function pointer:

      // however you want to set this up...
      actions[JUMP].sym = 188;
      actions[JUMP].func = make_player_jump;


So your event loop looks like this:

    //checking for events...
    case SDL_KEYDOWN:
        for (int i = 0; i < total_actions; i++) {
            if actions[i].sym == event.key.keysym.sym)
                actions[i].func();
        }
        break;

Extra credit for restructuring the data to not need a for loop on each 
keypress.

(but really, the big block of if-statements are probably just as good. 
Even in something with as many buttons as a flight simulator, you aren't 
going to check _that_ many actions.)

--ryan.