procedure UpdatePosition;

 glViewport (0, 0, Panel1.ClientWidth, Panel1.ClientHeight);

glMatrixMode(GL_PROJECTION);
  glLoadIdentity();
 sBoundingBox.fMaxX:=100.0;
 sBoundingBox.fMaxY:=100.0;
 sBoundingBox.fMinX:=-100.0;
 sBoundingBox.fMinY:=-100.0;
  glOrtho(
    sBoundingBox.fMinX,
    sBoundingBox.fMaxX,
    sBoundingBox.fMinY,
    sBoundingBox.fMaxY,-1,1);
  glMatrixMode(GL_MODELVIEW);
  glLoadIdentity;

  glScalef( Scale, Scale, 1);
  glTranslatef( XPosition , YPosition , 0 );

GetRealPosition(const X, Y: Integer; out RealX,
  RealY: Extended);
var
    Viewport:TGLVectori4;
    mvMatrix,ProjMatrix: TGLMatrixd4;
    Ytemp:GLInt;
    wx,wy,wz:TGLdouble;
    ZVal:GLFloat;
begin
    glGetIntegerV(GL_ViewPort,@Viewport);
    glGetDoubleV(GL_ModelView_Matrix,@mvMatrix);
    glGetDoubleV(GL_Projection_Matrix,@ProjMatrix);
    Ytemp:=ViewPort[3]-Y-1;
    glReadPixels(X,Ytemp,1,1,GL_Depth_Component,GL_Float,@ZVal);
    gluUnProject(X,Ytemp,ZVal,mvMatrix,ProjMatrix,Viewport,@wx,@wy,@wz);
    RealX := wx;
    RealY := wy;
    // wx,wy,wz - искомые пространственные координаты
end;

UpdatePosition(AResized: Boolean = False);
var
  XLow, YLow, XLow1, YLow1: Extended;
  XHigh, YHigh: Extended;
  nRange: GLfloat;
  w, h: Integer;
begin
  glViewport (0, 0, Panel1.ClientWidth, Panel1.ClientHeight);
  glLoadIdentity();
  glMatrixMode(GL_PROJECTION);
  glLoadIdentity();
  nRange := 100.0;
  w := ClientWidth;      // check new client width of the main window
  h := ClientHeight;     // check new client height of the main window
  if(h = 0) then            // prevent a division by zero, by making sure that
    h := 1;               // windows height is at least 1
  glViewport(0, 0, w, h);         // reset viewport
  glMatrixMode(GL_PROJECTION);    // add perspective to scene
  glLoadIdentity();               // restore matrix to original state

  if (w <= h) then
      glOrtho (-nRange, nRange, -nRange, nRange*(h/w), -nRange, nRange)
  else
	  glOrtho (-nRange*w/h, nRange*w/h, -nRange, nRange, -nRange, nRange);
  glMatrixMode(GL_MODELVIEW);
  glLoadIdentity;
  glScalef( 1 , 1, 1);
  GetRealPosition(0,0,XLow,YLow);
  GetRealPosition(1,1,XLow1,YLow1);
  XHigh := XLow1 - XLow;
  YHigh := YLow1 - YLow;
  glScalef( Scale*XHigh , Scale *YHigh, 1);
  glTranslatef( XPosition , YPosition , 0 );