SFML and Box2D Demo

gistfile1.cpp

#include <Box2D/Box2D.h>
#include <SFML/Audio.hpp>
#include <SFML/Graphics.hpp>
#include <stdio.h>
#include <cstring>
#include "DebugDraw.h"

#define kBodies 5

b2Body* CreateBody(b2World& world, int32 index) {
   // Define the dynamic body. We set its position and call the body factory.
   b2BodyDef bodyDef;
   bodyDef.type = b2_dynamicBody;
   bodyDef.position.Set(10.0f, index * 4.0f);
   bodyDef.angle = rand() * 3.14;
   b2Body* body = world.CreateBody(&bodyDef);

   // Define another box shape for our dynamic body.
   b2PolygonShape dynamicBox;
   dynamicBox.SetAsBox(1.0f, 1.0f);

   // Define the dynamic body fixture.
   b2FixtureDef fixtureDef;
   fixtureDef.shape = &dynamicBox;

   // Set the box density to be non-zero, so it will be dynamic.
   fixtureDef.density = 0.3f;
   fixtureDef.restitution = 0.4f;

   // Override the default friction.
   fixtureDef.friction = 0.3f;

   // Add the shape to the body.
   body->CreateFixture(&fixtureDef);
   return body;
}
 
int main() {
   b2Vec2 gravity(0.0f, -5.0f);
   b2World world(gravity);
   world.SetAllowSleeping(true);
     
   b2BodyDef groundBodyDef;
   groundBodyDef.position.Set(10.0f, -30.0f);
   b2Body* groundBody = world.CreateBody(&groundBodyDef);

   // Define the ground box shape.
   b2PolygonShape groundBox;

   // The extents are the half-widths of the box.
   groundBox.SetAsBox(40.0f, 1.0f);

   // Add the ground fixture to the ground body.
   groundBody->CreateFixture(&groundBox, 0.0f);

   b2BodyDef groundBodyDef2;
   groundBodyDef2.position.Set(-10.0f, 0.0f);
   b2Body* groundBody2 = world.CreateBody(&groundBodyDef2);

   // Define the ground box shape.
   b2PolygonShape groundBox2;

   // The extents are the half-widths of the box.
   groundBox2.SetAsBox(1.0f, 40.0f);

   // Add the ground fixture to the ground body.
   groundBody2->CreateFixture(&groundBox2, 0.0f);

   b2Body* body[kBodies + 10];
   for (int i = 0; i < kBodies; ++i) {
     body[i] = CreateBody(world, i);
   }

   float32 timeStep = 1.0f / 60.0f;
   int32 velocityIterations = 15;
   int32 positionIterations = 15;
 
   // Create the main window
   bool use_vsync = true; 
   sf::RenderWindow App(sf::VideoMode(924, 704), "SFML window");
   App.UseVerticalSync(use_vsync);
    
   DebugDraw draw(App);
   world.SetDebugDraw(&draw);
    
   uint32 flags = 0;
   flags += b2Draw::e_shapeBit;
   draw.SetFlags(flags);
 
   // Create a graphical string to display
   sf::Font Arial;
   if (!Arial.LoadFromFile("Vera.ttf")) return EXIT_FAILURE;
   sf::String Text("Hello SFML", Arial, 25);
   Text.SetX(700);
   Text.SetY(600);
     
   // FPS as a string.
   char fps_string[25];

   // Start the game loop
  while (App.IsOpened()) {
    sf::Event Event;
    while (App.GetEvent(Event)) {
      // Did someone close the application?
      if (Event.Type == sf::Event::Closed) {
        App.Close();
      }

      // Did someone press V to toggle vsync? 
      if (Event.Type == sf::Event::KeyPressed && Event.Key.Code == sf::Key::V) {
        use_vsync = !use_vsync;
        App.UseVerticalSync(use_vsync);
      }
    }
    
    // Clear screen
    App.Clear();
        
    world.Step(timeStep, velocityIterations, positionIterations);
    world.DrawDebugData();

    // Draw the current framerate.
    float Framerate = 1.f / App.GetFrameTime(); 
    sprintf(fps_string, "%f", Framerate);
    Text.SetText(fps_string);
    App.Draw(Text);

    // Update the window
    App.Display();
  }
  
  return EXIT_SUCCESS;
}