Method AdjustViewport

Common/Transforms/vtkPerspectiveTransform.cxx:215–228

------------------------------------------------------------------------------ Utility for adjusting the window range to a new one. Usually the previous range was ([-1,+1],[-1,+1]) as per Ortho and Frustum, and you are mapping to the display coordinate range ([0,width-1],[0,height-1]).

// previous range was ([-1,+1],[-1,+1]) as per Ortho and Frustum, and you
// are mapping to the display coordinate range ([0,width-1],[0,height-1]).
void vtkPerspectiveTransform::AdjustViewport(double oldXMin, double oldXMax, double oldYMin,
  double oldYMax, double newXMin, double newXMax, double newYMin, double newYMax)
{
  double matrix[4][4];
  vtkMatrix4x4::Identity(*matrix);

  matrix[0][0] = (newXMax - newXMin) / (oldXMax - oldXMin);
  matrix[1][1] = (newYMax - newYMin) / (oldYMax - oldYMin);

  matrix[0][3] = (newXMin * oldXMax - newXMax * oldXMin) / (oldXMax - oldXMin);
  matrix[1][3] = (newYMin * oldYMax - newYMax * oldYMin) / (oldYMax - oldYMin);

  this->Concatenate(*matrix);
}

//------------------------------------------------------------------------------
// Utility for adjusting the min/max range of the Z buffer.  Usually