Demonstração das funções para lidar com eventos de teclado usando SDL 2 com logs no console

test.c

// Testado no MinGW64
// gcc -Wall -Wextra -Wpedantic -Wno-unused-parameter game.c `sdl2-config --cflags --libs`
#include <SDL.h>

SDL_bool quit = SDL_FALSE;

// A tecla está pressionada?
SDL_bool isKeyPressed(int key) {
    return SDL_GetKeyboardState(NULL) [key];
}

// Variável global
Uint8 keyStates[SDL_NUM_SCANCODES];

// Reinicia estados
void resetKeyStates() {
    for (size_t i = 0; i < SDL_NUM_SCANCODES; i++)
        keyStates[i] = 0;
}

// A tecla foi pressinada?
Uint8 wasKeyPressed(int key) {
    return keyStates[key] == 1;
}

// A tecla foi liberada?
Uint8 wasKeyReleased(int key) {
    return keyStates[key] == 2;
}

void handleInput() {
    resetKeyStates();
    SDL_Event event;
    while (SDL_PollEvent(&event)) {
        switch (event.type) {
            case SDL_QUIT:
                quit = SDL_TRUE;
                break;
            case SDL_KEYDOWN:
                keyStates[event.key.keysym.scancode] = !event.key.repeat;
                break;
            case SDL_KEYUP:
                keyStates[event.key.keysym.scancode] = 2;
                break;
        }
    }
}

int main(int argc, char *argv[]) {
    SDL_Init(SDL_INIT_VIDEO);
    SDL_Window* window = SDL_CreateWindow("Window Title", SDL_WINDOWPOS_CENTERED, SDL_WINDOWPOS_CENTERED, 640, 480, 0);

    while ( !quit ) {
        handleInput();

        if ( isKeyPressed(SDL_SCANCODE_A) )
            SDL_Log("A is pressed!");

        if ( wasKeyPressed(SDL_SCANCODE_SPACE) )
            SDL_Log("Space was pressed!");

        if ( wasKeyReleased(SDL_SCANCODE_SPACE) )
            SDL_Log("Space was released!");
    }

    SDL_DestroyWindow(window);
    SDL_Quit();
    return 0;
}