function render(Constr, varargin)
%RENDER   Sets the vertices, X and Y data properties of the patch and markers.

%   Author(s): Bora Eryilmaz
%   Revised: A. Stothert
%   Copyright 1986-2004 The MathWorks, Inc. 
%   $Revision: 1.1.6.3.2.1 $ $Date: 2005/01/18 16:06:58 $

% Set number of points in rendered line
nP = 5;

% Get axes info
HostAx = handle(Constr.Parent);
HostFig  = HostAx.Parent;

if ~Constr.Activated
  % Initialize when constraint is not activated yet (preset for Activated=1)
  % Construct the constraint patch
  Patch = patch( ...
      'Parent', double(Constr), ...
      'XlimInclude','off',...
      'YlimInclude','off',...        
      'LineStyle', 'none', ...
      'CDataMapping', 'Direct', ...
      'FaceColor', Constr.PatchColor, ...
      'FaceAlpha', 0.75, ...
      'HelpTopicKey', 'gainmarginconstraint', ...
      'UIContextMenu', Constr.addmenu(HostFig), ...
      'ButtonDownFcn',Constr.ButtonDownFcn,...
      'Tag','ConstraintPatch');
  
  % Constraint 'inside edge'
   EdgeInfeasible = line(...
      'Parent', double(Constr), ...
      'Color', Constr.EdgeColor, ...
      'LineWidth', 2, ...
      'Tag','ConstraintInfeasibleEdge', ...
      'Visible','on',...
      'XlimInclude','on',...
      'YlimInclude','on',...
      'HitTest', 'on',...
      'ButtonDownFcn',Constr.ButtonDownFcn);
  
  % Construct the constraint patch end markers
  Markers = line(...
      'Parent', double(Constr),...
      'XlimInclude','off',...
      'YlimInclude','off',...        
      'LineStyle','none', ...
      'Marker','s', ...
      'MarkerSize',4, ... 
      'MarkerFaceColor','k', ...
      'MarkerEdgeColor','k', ...
      'HitTest','on',...
      'Visible',Constr.Selected,...
      'ButtonDownFcn',Constr.ButtonDownFcn,...
      'Tag', 'ConstraintMarkers');
end

% Get margin info
Margin = Constr.MarginGain; % in dB
Origin = Constr.OriginPha;  % in deg

% Create a multi-point line for curved constraint boundaries
XData = linspace( Origin, Origin, nP);  % Phase in deg
YData = linspace(-Margin, Margin, nP);  % Magnitude in dB
XData = unitconv(XData, Constr.PhaseUnits, Constr.xDisplayUnits);
YData = unitconv(YData, Constr.MagnitudeUnits, Constr.yDisplayUnits);

% X-thickness is already in XScale units, so do not reconvert
XLims = HostAx.Xlim;
XDataL = XData - (XLims(2) - XLims(1)) / 2 * 0.01;
XDataR = XData + (XLims(2) - XLims(1)) / 2 * 0.01;

% Construct new X, Y and Z data for the patch
PatchXData = [XDataL  XData  XDataR];
PatchYData = [YData  fliplr(YData)  YData];
PatchZData = Constr.Zlevel(ones(3*nP,1),:);

% Set the new patch data values
Vertices = [PatchXData(:) PatchYData(:) PatchZData(:)];
Faces1 = [1:nP-1 ; 2:nP ; 2*nP-1:-1:nP+1 ; 2*nP:-1:nP+2]';
Faces2 = [nP+1:2*nP-1 ; nP+2:2*nP ; 3*nP-1:-1:2*nP+1 ; 3*nP:-1:2*nP+2]';
Faces = [Faces1 ; Faces2];

hChildren = Constr.Children;
Tags = get(hChildren,'Tag');
idx = strcmp(Tags,'ConstraintPatch');
set(hChildren(idx), 'Faces', Faces, 'Vertices', Vertices, ...
   'FaceColor',Constr.PatchColor);

% Plot top and bottom constraint selection markers in new position
idx = strcmp(Tags,'ConstraintInfeasibleEdge');
set(hChildren(idx),...
   'XData',[XDataR XDataL],'YData', [YData fliplr(YData)],...
   'Zdata',Constr.Zlevel(ones(size(YData,2)*2,1))+0.1,...
   'color',Constr.EdgeColor,...
   'LineWidth', Constr.Weight(1)*2+eps)
idx = strcmp(Tags,'ConstraintMarkers');
set(hChildren(idx), 'XData', [XData(nP) XData(1)], ...
   'YData', [YData(nP) YData(1)], ...
    'Zdata', Constr.Zlevel([1 1])+0.1);