anchor.diff:  {
       return calcLightColour(light.colour, light.intensity, position, normalize(-light.direction), normal);
   }
  +vec4 calcBaseColour(Material material, vec2 text_coord)
  +{
  +    vec4 baseColour;
  +    if ( material.hasTexture == 1 )
  +    {
  +        baseColour = texture(texture_sampler, text_coord);
  +    }
  +    else
  +    {
  +        baseColour = vec4(material.colour, 1);
  +    }
  +    return baseColour;
  +}
   
   void main()
   {
  -    vec4 baseColour = vec4(material.color, 1);
  -    
  +    vec4 baseColour = calcBaseColour(material, outTexCoord);
  +
       vec4 totalLight = vec4(ambientLight, 1.0);
       totalLight += calcDirectionalLight(directionalLight, vPos, vNorm);
   
  
positive.code: struct Material
  {
      vec3 color;
      float reflectance;
  };
  
  uniform vec3 ambientLight;
  uniform float specularPower;
  uniform Material material;
  
negative.code: const int MAX_POINT_LIGHTS = 5;
  const int MAX_SPOT_LIGHTS = 5;
  
  in vec2 outTexCoord;
  in vec3 vNorm;
  in vec3 vPos;
  
  