c++ - 3D / FPS Camera Issues - SDL2 -

i got problem code, i'm trying make first person 3d camera. use sdl_getkeyboardstate(null) pressed keys.

when press 1 of defined keys nothing happens, why?

camera (controll):

void control(float movevel, float mousevel, bool mi, sdl_window* window) { if (mi)  //if mouse in screen {     int midx = 640 / 2;   //middle of screen     int midy = 480 / 2;     sdl_showcursor(sdl_disable);    //we don't show cursor     int tmpx, tmpy;     sdl_getmousestate(&tmpx, &tmpy); //get current position of cursor     camyaw += mousevel*(midx - tmpx);   //get rotation, example, if mouse current position 315, 5*0.2, y     campitch += mousevel*(midy - tmpy); //this x     lockcamera();     //sdl_warpmouse(midx, midy);       //move cursor center of screen     sdl_warpmouseinwindow(window, midx, midy);      const uint8* kstate = sdl_getkeyboardstate(null);      if (kstate[sdlk_w])     {         if (campitch != 90 && campitch != -90)         {       //if facing directly or down, don't go forward, commented out, when there gravity             movecamera(movevel, 0.0);        //move forward         }          movecameraup(movevel, 0.0);      //move up/down     }      if (kstate[sdlk_s])     {         //same, use 180 degrees, move @ different direction (move back)         if (campitch != 90 && campitch != -90)         {             movecamera(movevel, 180.0);         }          movecameraup(movevel, 180.0);     }      if (kstate[sdlk_a])     {       //move left         movecamera(movevel, 90.0);     }      if (kstate[sdlk_d])     {  //move right         movecamera(movevel, 270);     } }  glrotatef(-campitch, 1.0, 0.0, 0.0); glrotatef(-camyaw, 0.0, 1.0, 0.0); } 

main (loop)

while (running) {     glclear(gl_color_buffer_bit | gl_depth_buffer_bit);     glloadidentity();      sdl_event ev;     while (sdl_pollevent(&ev))     {         switch (ev.type)         {             case sdl_quit:                 running = false;                 break;             case sdl_keydown:                 int x, y;                  sdl_getmousestate(&x, &y);                 main::handlekeys(ev.key.keysym.scancode, x, y);                 break;         }     }      main::update(window);     main::render(window);      sdl_gl_swapwindow(window); } 

main (update):

void main::update(sdl_window* window) { control(0.2, 0.2, mousein, window); updatecamera(0.2); //move camera new location } 

use sdl_pumpevents() update state array. (from sdl_getkeyboardstate() wiki). believe if do:

sdl_pumpevents(); sdl_getkeyboardstate(null); 

you should results looking for. (you need sdl_pumpevents every loop sdl_getkeyboardstate obviously)

(edit) option:

    case sdl_keydown:         switch(event.key.keysym.sym){             case sdlk_w                 (... code)                 break;             case sdlk_s:                 (... code)                 break;             case sdlk_a:                 (... code)                 break;             case sdlk_d:                 (... code)                 break; 

you can send event.key.keysym.sym function , use ofcourse.