feat(player) Implement key event handling.

Adds keyboard input handling to control the "player".

src/bettola.cpp

@@ -41,10 +41,10 @@ Bettola::~Bettola(void) {
 }
 
 int Bettola::run(void) {
-  if(!init_sdl()) return -1;
-  if(!create_window()) return -1;
-  if(!create_gl_context()) return -1;
-  if(!init_glew()) return -1;
+  if(!init_sdl())           return -1;
+  if(!create_window())      return -1;
+  if(!create_gl_context())  return -1;
+  if(!init_glew())          return -1;
 
   if(!_shader.load_from_files("assets/shaders/simple.vert",
                              "assets/shaders/simple.frag")) {
@@ -84,11 +84,31 @@ void Bettola::process_events(void) {
   while(SDL_PollEvent(&event)) {
     if(event.type == SDL_EVENT_QUIT) {
       _is_running = false;
+    } else if(event.type == SDL_EVENT_KEY_DOWN) {
+      switch(event.key.key) {
+        case SDLK_W: _player.move_up(); break;
+        case SDLK_S: _player.move_down(); break;
+        case SDLK_A: _player.move_left(); break;
+        case SDLK_D: _player.move_right(); break;
+      }
+    } else if(event.type == SDL_EVENT_KEY_UP) {
+      switch(event.key.key) {
+        case SDLK_W:
+        case SDLK_S:
+          _player.stop_vertical();
+          break;
+        case SDLK_A:
+        case SDLK_D:
+          _player.stop_horizontal();
+          break;
+      }
     }
   }
 }
 
 void Bettola::update(double dt) {
+  _player.update(dt);
+
   static char window_title[256];
   static double time_since_title_update = 0.0;
 

src/game/player.cpp

@@ -4,8 +4,25 @@ Player::Player(void) :
     _x(400.0f),
     _y(300.0f),
     _width(50.0f),
-    _height(50.0f) {}
+    _height(50.0f),
+    _vx(0.0f),
+    _vy(0.0f),
+    _speed(200.0f) {}
 
 void Player::update(double dt) {
-  /* Do some shit? */
+  _x += _vx * dt;
+  _y += _vy * dt;
+}
+
+void Player::move_up(void)    { _vy = -_speed; }
+void Player::move_down(void)  { _vy =  _speed; }
+void Player::move_left(void)  { _vx = -_speed; }
+void Player::move_right(void) { _vx =  _speed; }
+
+void Player::stop_vertical(void) {
+  _vy = 0.0f;
+}
+
+void Player::stop_horizontal(void) {
+  _vx = 0.0f;
 }

src/game/player.h

@@ -6,6 +6,13 @@ public:
 
   void update(double dt);
 
+  void move_up(void);
+  void move_down(void);
+  void move_left(void);
+  void move_right(void);
+  void stop_vertical(void);
+  void stop_horizontal(void);
+
   float get_x() const       { return _x; }
   float get_y() const       { return _y; }
   float get_width() const   { return _width; }
@@ -16,4 +23,8 @@ private:
   float _y;
   float _width;
   float _height;
+
+  float _vx;
+  float _vy;
+  float _speed;
 };