sdl getting continuously key pressing - c

Question

I am currently programming a simple game in SDL (PONG clone) where i must have a continuously key pressing.
The problem I have is that when i press a button it reacts, waits a short period and then continues to continuously key pressing.
I wonder how i get that little delay to go away.
Here is my code:
while (running)
{
while (SDL_PollEvent(&event))
{
//update the game
if (event.type == SDL_QUIT)
{
quit_game();
running = false;
}
if(event.type == SDL_KEYDOWN)
{
switch (event.key.keysym.sym)
{
case SDLK_DOWN:
move_paddle(UP);
break;
case SDLK_UP:
move_paddle(DOWN);
break;
default:
break;
}
}
}
draw_game();
move_ball();
SDL_Delay(15);
}

Answer 1

The first thing i did was i wanted to remove the small delay and get the movement of the paddle smoother. I introduced 2 new global bool variables to keep track on which key that was pressed down.
bool key_up = false;
bool key_down = false;
I initiate them with the value false because no key is currently pressed.
In my switch I set the value for these boolean variables to match what is currently pressed down.
if(event.type == SDL_KEYDOWN)
{
switch (event.key.keysym.sym)
{
case SDLK_DOWN:
key_up = true;
key_down = false;
break;
case SDLK_UP:
key_down = true;
key_up = false;
break;
default:
break;
}
}
Then in the first while-loop i make two if-cases for the two keys that can be pressed and call the movement function in these if-cases.
if (key_up)
move_paddle(UP);
else if (key_down)
move_paddle(DOWN);
When i did this the delay disappeared and the paddle movement was smooth but it also generated another probelm, the paddle could not stay still in one place (except the boundraries). I then realised that the code is only looking for a key that is pressed down and does not react to a key that is released.
I then figured out that if a key is released (in this case the UP key or the DOWN key) the two boolean values had to be set to false because no key was pressed down.
What I did was that I made another if-statement after the if(event.type == SDL_KEYDOWN) that would disable the movement of the paddle if no key was pressed down.
if (event.type == SDL_KEYUP)
{
key_down = false;
key_up = false;
}
When I implemented all of this in my code the game worked like a charm.
For those who are interested, here is my new final code:
int gameloop()
{
SDL_Event event;
bool running = true;
bool key_up = false;
bool key_down = false;
while (running)
{
while (SDL_PollEvent(&event))
{
//update the game
if (event.type == SDL_QUIT)
{
quit_game();
running = false;
}
if(event.type == SDL_KEYDOWN)
{
switch (event.key.keysym.sym)
{
case SDLK_DOWN:
key_up = true;
key_down = false;
break;
case SDLK_UP:
key_down = true;
key_up = false;
break;
default:
break;
}
}
if (event.type == SDL_KEYUP)
{
key_down = false;
key_up = false;
}
}
if (key_up)
move_paddle(UP);
else if (key_down)
move_paddle(DOWN);
move_ball();
ai_paddle_move();
draw_game();
printf("Player: %d | AI: %d\n", player, ai);
SDL_Delay(15);
}
return 1;
}