#include "TPad.h"

/*  Set aspect of pad
   *pad   = TPad pad to be altered
   aspect = aspect ratio X:Y
*/
void SetAspect( TPad *pad, double aspect ) {
  double xlo, ylo, xup, yup;
  double xmid, ymid, xwid, xwid2, ywid, ywid2;
//  Check for valid aspect ratio
  if( aspect <= 0. ) {
    printf("aspad: ERROR Invalid aspect ratio %lf\n",aspect);
    return;
  }
//  Get originial pad coordinates
  pad->GetPadPar( xlo, ylo, xup, yup );
  xwid = (xup - xlo)/2.;
  ywid = (yup - ylo)/2.;
  xmid = (xlo + xup)/2.;
  ymid = (ylo + yup)/2.;
//  Set pad to size of smaller width, being careful not to overstep bounds
  if( xwid < ywid ) {
    xwid2 = xwid;
    ywid2 = aspect/xwid2;
    if( ywid2 > ywid ) {
      ywid2 = ywid;
      xwid2 = ywid2*aspect;
    }
  } else {
    ywid2 = ywid;
    xwid2 = aspect*ywid2;
    if( xwid2 > xwid ) {
      xwid2 = xwid;
      ywid2 = xwid2/aspect;
    }
  }
  xlo = xmid - xwid2;
  xup = xmid + xwid2;
  ylo = ymid - ywid2;
  yup = ymid + ywid2;
  pad->SetPad( xlo, ylo, xup, yup );
}