CODEWITHSUNDEEP
c++sdlkeypress
lewisjb
lewisjb

Reputation: 686

SDL Keypressing

I am trying to make a program that will be able to detect key-presses with SDL.

My current code is a modified version of somebody elses (trying to get it to work before making my own version).

#include "SDL/SDL.h"
#include <iostream>
using namespace std;

int main(int argc, char* argv[]) {
    //Start SDL
    if(0 != SDL_Init(SDL_INIT_EVERYTHING)) {
            std::cout << "Well I'm screwed\n";
            return EXIT_FAILURE;
    }
    SDL_Surface* display;
    display = SDL_SetVideoMode(640, 480, 32, SDL_HWSURFACE | SDL_DOUBLEBUF);
    SDL_Event event;
    bool running = true;
    std::cout << "Cake"; //Testing output (doesn't work)
    while(running) {
            std::cout << "Pie"; //Again, testing output and again doesn't work
            if(SDL_PollEvent(&event)) { //I have tried this is a while statement
                    switch(event.type) {
                            case SDL_KEYDOWN:
                                    std::cout << "Down\n"; // Have tried "<< std::endl" instead of "\n"
                                    break;
                            case SDL_KEYUP:
                                    std::cout << "Up\n";
                                    break;
                            case SDL_QUIT:
                                    running = false;
                                    break;
                            default:
                                    break;
                    }
            }
    }
    //Quit SDL
    SDL_Quit();

    return 0;
}

This code is supposed to detect any key-down/up and output it, but it doesn't output anything.

My ultimate goal is to make it detect the konami code and then do something.

I constantly update the code above making it identical to the one I am using (except with added comments of what people have suggested).

Also if it helps: g++ -o myprogram.exe mysource.cpp -lmingw32 -lSDLmain -lSDL is the command I am using to compile. (If you didn't figure it out from the command, I am running windows (7).) No errors occur when compiling

I am getting now output whatsoever, which leads me to believe that my probs has nothing to do with the key-checking; however there is a chance that is incorrect.

Upvotes: 0

Views: 490

Answers (4)

djgL
djgL

Reputation: 34

hey there i think you should go to your "project properties" then "linker settings" and "Subsystem" then choose "Console (/SUBSYSTEM:CONSOLE)" Otherwise you can't see what you typed in cout and in visual studio you cant use #include"SDL/SDL.h" you should type #include<SDL.h>

Upvotes: 0

lewisjb
lewisjb

Reputation: 686

SDL By default redirects output to stdout.txt

Upvotes: 2

genpfault
genpfault

Reputation: 52165

SDL needs a window to receive events.

Uncomment your SDL_SetVideoMode() call:

#include <SDL/SDL.h>
#include <iostream>
using namespace std;

int main( int argc, char* argv[] ) 
{
    if( 0 != SDL_Init(SDL_INIT_EVERYTHING) ) 
    {
        std::cout << "Well I'm screwed\n";
        return EXIT_FAILURE;
    }

    SDL_Surface* display;
    display = SDL_SetVideoMode(640, 480, 32, SDL_HWSURFACE | SDL_DOUBLEBUF);

    SDL_Event event;
    bool running = true;
    while(running) 
    {
        if(SDL_PollEvent(&event)) 
        {
            switch(event.type) 
            {
            case SDL_KEYDOWN:
                std::cout << "Down" << endl;
                break;
            case SDL_KEYUP:
                std::cout << "Up" << endl;
                break;
            case SDL_QUIT:
                running = false;
                break;
            default:
                break;
            }
        }
    }

    SDL_Quit();
    return 0;
}

Upvotes: 3

Zhen
Zhen

Reputation: 4283

You should query for all the SDL events in the loop, not just the first one. Try this one to check all the events:

while( SDL_PollEvent( &event ) ){
    ...
}

also you can try to update the screen in the loop with:

SDL_Flip( display );

Upvotes: 0

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