Botón para anular/activar la gravedad

source/ball.cpp

@@ -115,4 +115,10 @@ void Ball::modVel(float vx, float vy)
     this->vy = this->vy + vy;
     onFloor = false;
     stopped = false;
+}
+
+// Cambia la gravedad
+void Ball::switchGravity()
+{
+    g = g == 0.0f ? GRAVITY : 0.0f;
 }

source/ball.h

@@ -34,4 +34,7 @@ public:
 
     // Modifica la velocidad
     void modVel(float vx, float vy);
+
+    // Cambia la gravedad
+    void switchGravity();
 };

source/main.cpp

@@ -6,8 +6,8 @@
 #include <iostream>
 #include <vector>
 
-SDL_Window *window = NULL;
-SDL_Renderer *renderer = NULL;
+SDL_Window *window = nullptr;
+SDL_Renderer *renderer = nullptr;
 SDL_Event *event;
 Texture *texture = nullptr;
 std::vector<Ball *> balls;
@@ -47,6 +47,7 @@ void initBalls(int value)
 		Ball *b = new Ball(x, vx, vy, color, texture);
 		balls.push_back(b);
 	}
+	setText();
 }
 
 void pushUpBalls()
@@ -60,6 +61,18 @@ void pushUpBalls()
 	}
 }
 
+void switchBallsGravity()
+{
+	for (auto ball : balls)
+	{
+		if (ball)
+		{
+			ball->switchGravity();
+			;
+		}
+	}
+}
+
 void deleteBalls()
 {
 	for (auto ball : balls)
@@ -88,7 +101,7 @@ bool init()
 	{
 		// Create window
 		window = SDL_CreateWindow(WINDOW_CAPTION, SDL_WINDOWPOS_UNDEFINED, SDL_WINDOWPOS_UNDEFINED, SCREEN_WIDTH * 2, SCREEN_HEIGHT * 2, SDL_WINDOW_SHOWN);
-		if (window == NULL)
+		if (window == nullptr)
 		{
 			printf("Window could not be created! SDL Error: %s\n", SDL_GetError());
 			success = false;
@@ -97,7 +110,7 @@ bool init()
 		{
 			// Create renderer for window
 			renderer = SDL_CreateRenderer(window, -1, SDL_RENDERER_ACCELERATED);
-			if (renderer == NULL)
+			if (renderer == nullptr)
 			{
 				printf("Renderer could not be created! SDL Error: %s\n", SDL_GetError());
 				success = false;
@@ -117,10 +130,9 @@ bool init()
 
 	texture = new Texture(renderer, "resources/pelota.png");
 	ticks = SDL_GetTicks();
-	srand(time(NULL));
+	srand(time(nullptr));
 	dbg_init(renderer);
 	initBalls(index);
-	setText();
 
 	return success;
 }
@@ -165,60 +177,82 @@ void checkEvents()
 
 		if (event->type == SDL_KEYDOWN && event->key.repeat == 0)
 		{
-			if (event->key.keysym.sym == SDLK_SPACE)
+			switch (event->key.keysym.sym)
 			{
-				pushUpBalls();
+			case SDLK_ESCAPE:
+			{
+				shouldExit = true;
+				break;
 			}
 
-			if (event->key.keysym.sym == SDLK_1)
+			case SDLK_SPACE:
+			{
+				pushUpBalls();
+				break;
+			}
+
+			case SDLK_g:
+			{
+				switchBallsGravity();
+				break;
+			}
+
+			case SDLK_1:
 			{
 				index = 0;
 				initBalls(index);
+				break;
 			}
 
-			if (event->key.keysym.sym == SDLK_2)
+			case SDLK_2:
 			{
 				index = 1;
 				initBalls(index);
+				break;
 			}
 
-			if (event->key.keysym.sym == SDLK_3)
+			case SDLK_3:
 			{
 				index = 2;
 				initBalls(index);
+				break;
 			}
 
-			if (event->key.keysym.sym == SDLK_4)
+			case SDLK_4:
 			{
 				index = 3;
 				initBalls(index);
+				break;
 			}
 
-			if (event->key.keysym.sym == SDLK_5)
+			case SDLK_5:
 			{
 				index = 4;
 				initBalls(index);
+				break;
 			}
 
-			if (event->key.keysym.sym == SDLK_6)
+			case SDLK_6:
 			{
 				index = 5;
 				initBalls(index);
+				break;
 			}
 
-			if (event->key.keysym.sym == SDLK_7)
+			case SDLK_7:
 			{
 				index = 6;
 				initBalls(index);
+				break;
 			}
 
-			if (event->key.keysym.sym == SDLK_8)
+			case SDLK_8:
 			{
 				index = 7;
 				initBalls(index);
+				break;
+			}
 			}
-
-			setText();
 		}
 	}
 }