c++ - Unable to move character to right position using SDL? -

i having problem moving character right , showing him he's running after press right key moves right 1 time , when enter left goes left again pressing right again doesn't make go right again. here code using :

#include <sdl2/sdl.h>  #include "game.h" #include "graphics.h" #include "input.h"  /* game class *  class holds information our game loop */  namespace {     const int fps = 50;     const int max_frame_time = 5 * 1000/ fps; } game::game() {     sdl_init(sdl_init_everything);     this->gameloop(); } game::~game() {  } void game::gameloop() {     graphics graphics;     input input;     sdl_event event;      this->_player = player(graphics, 100, 100);      int last_update_time = sdl_getticks();     //start game loop     while(true){         input.beginnewframe();          if(sdl_pollevent(&event)){             if(event.type == sdl_keydown){                 if(event.key.repeat == 0){                     input.keydownevent(event);                 }             }             else if(event.type == sdl_keyup){                 input.keyupevent(event);             }             else if(event.type == sdl_quit){                 return;             }         }         if(input.waskeypressed(sdl_scancode_escape) == true){             return;         }         else if(input.iskeyheld(sdl_scancode_left) == true) {             this->_player.moveleft();         }         else if(input.iskeyheld(sdl_scancode_right) == true) {             this->_player.moveright();         }          if(!input.iskeyheld(sdl_scancode_left) && !input.iskeyheld(sdl_scancode_right)){             this->_player.stopmoving();         }      const int current_time_ms = sdl_getticks();     int elapsed_time_ms = current_time_ms - last_update_time;     this->update(std::min(elapsed_time_ms, max_frame_time));     last_update_time = current_time_ms; this->draw(graphics); }  } void game::draw(graphics &graphics){     graphics.clear();      this->_player.draw(graphics);      graphics.flip();  } void game::update(float elapsedtime){     this->_player.update(elapsedtime); } 

and player.cpp

#include "player.h" #include "graphics.h"  namespace player_constants {     const float walk_speed = 0.2f; }  player::player() {}  player::player(graphics &graphics, float x, float y) :     animatedsprite(graphics, "mychar.png", 0, 0, 16, 16, x, y, 100)     {         graphics.loadimage("mychar.png");          this->setupanimations();         this->playanimation("runright");     } void player::setupanimations() {     this->addanimation(1, 0, 0, "idleleft", 16, 16, vector2(0,0));     this->addanimation(1, 0, 16, "idleright", 16, 16, vector2(0,0));     this->addanimation(3, 0, 0, "runleft", 16, 16, vector2(0,0));     this->addanimation(3, 0, 16, "runright", 16, 16, vector2(0,0)); }  void player::animationdone(std::string currentanimation) {}  void player::moveleft(){     this->_dx = -player_constants::walk_speed;     this->playanimation("runleft");     this->_facing = left;  } void player::moveright(){     this->_dx = player_constants::walk_speed;     this->playanimation("runright");     this->_facing = right;  }  void player::stopmoving() {     this->_dx = 0.0f;     this->playanimation(this->_facing == right ? "idleright" : "idleleft"); } void player::update(float elapsedtime) {     //move dx     this->_x += this->_dx * elapsedtime;      animatedsprite::update(elapsedtime); }  void player::draw(graphics &graphics) {     animatedsprite::draw(graphics, this->_x, this->_y); } 

the main functions 'moveleft()', 'moveright()' , 'stopmoving()' in player.cpp file above.

i think there's problem in player.cpp file, can me have been trying fix problem more 3 hours. thank you.

the problem caused polling 1 event on each loop meaning events won't processed. should continue polling events until there no more events queued. see sdl docs bonus details.

in case, need this:

while(sdl_pollevent(&event)){      if(event.type == sdl_keydown){          if(event.key.repeat == 0){              input.keydownevent(event);          }      }      else if(event.type == sdl_keyup){          input.keyupevent(event);      }      else if(event.type == sdl_quit){         return;      } }