function phongShade(surfaceType, lightColor, ka, kd, ks, ke, scr)
% function phongShade(surfaceType, lightColor, ka, kd, ks, ke, scr)
%   surfaceType: calling program denotes the material used
%   lightColor : illuminant color. 2 lights are defined at infinity.
%          ka  : ambient  reflection coefficient [0, 1]
%          kd  : diffuse  reflection coefficient [0, 1]
%          ks  : specular reflection coefficient [0, 1]
%          ke  : spectral exponent
%          scr : reflected light a combination of illuminant
%                and surface color
%
% Authors: ADJ CSC
% Fall 2001
    
  % copper color map
  copperCM   = copper(64);
  copperRGB  = copperCM(52, :); 

  figure;
  
  % graphics rendering set up
  set(gcf, 'RendererMode', 'manual'); 
  set(gcf, 'Renderer',    'zbuffer'); 
  %set(gcf, 'Renderer', 'OpenGL'); 
  
  % define a spherical object
  [xSphere, ySphere, zSphere] = sphere(180); 
  
  % object handle for sphere 1
  hSphere1 = surf(xSphere, ySphere, zSphere); 
  hold on; 
  % object handle for sphere 2
  hSphere2 = surf(xSphere -2, ySphere+2, zSphere); 
  
  % light 1
  hL1 = light('Position', [1 -1 1], 'Color', lightColor); 
  % light 2
  hL2 = light('Position', [-3 0 3], 'Color', lightColor); 
  
  
  set(hSphere1, 'FaceLighting', 'phong',... 
		'FaceColor', copperRGB,... 
		'EdgeColor', 'none',... 
		'AmbientStrength',  ka, ...   
		'DiffuseStrength',  kd, ... 
		'SpecularStrength', ks,... 
		'SpecularExponent', ke, ... 
		'SpecularColorReflectance', scr, ... 
		'BackFaceLighting', 'unlit'); 
  
  set(hSphere2, 'FaceLighting', 'phong',... 
		'FaceColor', 'r',... 
		'EdgeColor', 'none',... 
		'AmbientStrength',  ka, ...   
		'DiffuseStrength',  kd, ... 
		'SpecularStrength', ks,... 
		'SpecularExponent', ke, ... 
		'SpecularColorReflectance', scr, ... 
		'BackFaceLighting', 'lit'); 
  
  axis equal vis3d; 
  view([20 25]); 
  axis off; 
  
  set(gca,'Fontsize',20);
  title(sprintf('Surfaces: %s \n ka=%1.2f kd=%1.2f ks=%1.2f ke=%1.2f scr=%1.2f',surfaceType, ka, kd, ks, ke, scr));