Camera mouse

mouse.cpp

void mouseMotion(int x, int y) {
  // calculate the origin point (shifting right divides by two, remember!)
  int halfWidth = windowWidth >> 1;
  int halfHeight = windowHeight >> 1;

  // calculate how far we deviated from the origin point and deaden this
  // by a factor of 20
  float deltaX = (halfWidth - x) / 20.0f;
  float deltaY = (halfHeight - y) / 20.0f;

  // don't do anything if there wasn't any movement to report
  if ((deltaX == 0.0f) && (deltaY == 0.0f)) {
    return ;
  }

  // set the camera's orientation
  cam.yaw(deltaX);
  cam.pitch(deltaY);

  // reset the mouse pointer back to the origin point
  glutWarpPointer(halfWidth, halfHeight);
}