Hello world - Game Loop

// Ver.1 - Easy Loop
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while( true )
{
  processInput();
  update();
  render();
}


// Ver. 2 - Add Time and FPS
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MS_PER_FRAME 16 //60 FPS == 16 millisecondi per frame
 
while( true )
{
  double  start  =  getCurrentTime();
  processInput();
  update();
  render();

  sleep( start  +  MS_PER_FRAME  -  getCurrentTime ());
}





// Ver. 3 - elapsedTime and Update
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double lastTime = getCurrentTime();
 
while (true)
{
  double current = getCurrentTime();
  double elapsed = current - lastTime;
  processInput();
  update(elapsed);
  render();
  lastTime = current;
}



// Ver. 4 - Fix Update and Render
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FPS 60
double lastTime = getCurrentTime();
bool redraw = true;

while (true)
{
  double current = getCurrentTime();
  double elapsed = current - lastTime;
  processInput();

 // Wait until 1/60th of a second has passed,
 // then update everything
 if (elapsed  >= 1.0f / FPS)
 {
   update(elapsed);
   redraw = true;
 }

 // Draw stuff if ready
 if (redraw)
 {
   render();
   redraw = false;
 }

  lastTime = current;
}

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