Key input in SDL

cunnins4

Hey guys, i've a project in C++ in college to make a retro game through SDL such as space invaders or similar. I'm trying to take an input from the keyboard to make the ship move.

I can get it to move, but it's really slow in reacting and most of the time doesn't at all.

I'm using a class and loading a sprite to the screen and using the usual x and y position and velocity variables and updated them everytime the screen refreshes. I'm using a function called keyinput() to take the input from the keyboard, then update the velocity variables. This then updates the position of the image and it moves.

I got the code from a tutorial on the web, but i'm having trouble with it. Our lecturer is going to give us material on this next week, but i'm trying to get it out of the way so i can move onto other parts of the game.

It does work, but not very well.

Here's a snippet of code:


Uint8* keys;
keys = SDL_GetKeyState(NULL);

SDL_Event event;


bool move=true;

while (move)
{
if (SDL_PollEvent(&event))
{

if (event.type == SDL_KEYDOWN)
{

SDLKey keyPressed = event.key.keysym.sym;


switch (keyPressed)
{
case SDLK_UP:
ship_vy=-1;
move= false;
break;
case SDLK_DOWN:
ship_vy=1;
move= false;
break;
case SDLK_RIGHT:
ship_vx=1;
move= false;
break;
case SDLK_LEFT:
ship_vx=-1;
move= false;
break;
}

}
}


cheers for any advice.