[RyDeR`]

@cj101:
Try to compile with F7. Otherwise please try again, all steps are correct.

@sciman001:
So you basicaly want to call a function from SA-MP to your plugin? That's not difficult. Here's the way I'm doing:
In your C++, you create a "function" where you push the parameter and execute the function and retrieve the return the value to return.

Example of IsPlayerConnected in C++. (I used __IsPlayerConnected to prevent collisions)

pawn Code:

int __IsPlayerConnected(int playerid, AMX *amx) // AMX *amx must stay but it's just the playerid parameter that counts in his function.
{
    int
        index
    ;
    if(!amx_FindPublic(amx, "__IsPlayerConnected", &index))
    {
        cell
            retVal
        ;
        amx_Push(amx, playerid);
        amx_Exec(amx, &retVal, index);
        return (int)retVal;
    }
    return -1;
}

Now all you have to do is open PAWN and do a public call where you return IsPlayerConnected with public __IsPlayerConnected.

pawn Code:

#define FunctionCall(%0) \
    forward __%0; public __%0 return %0

FunctionCall(IsPlayerConnected(playerid)); // This will automaticly define the public starting with '__' and return the function.

And you can use "__IsPlayerConnected(playerid, amx)" in your C++ script.

pawn Code:

static cell AMX_NATIVE_CALL __PrintPlayerConnect(AMX *amx, cell *params)
{
    if(__IsPlayerConnected(params[1], amx)) // Never forget to add 'amx'!
    {
        printf("Player %d is connected", params[1]);
    }
    else printf("Player %d is NOT connected", params[1]);
    return 1;
}

Now you can call your native to SA-MP, like I explained in my first post and add this for example under OnPlayerSpawn and see the result!.

Note: You can convert float to cell and vice-versa using "amx_ftoc" and "amx_ctof". Can be useful for pushing float variables.