1varying vec3 normal;
2uniform float lightFactor;
3
4void main()
5{
6    vec3 lightPosition = vec3(-1.0, 1.0, 1.0);
7    vec3 eyePosition = vec3(0.0, 0.0, 1.0);
8    vec3 halfVector = normalize(lightPosition + eyePosition);
9    float intensity = lightFactor + (1.0 - lightFactor) * dot(normalize(normal), normalize(halfVector));
10    gl_FragColor = gl_Color * vec4(intensity, intensity, intensity, 1.0);
11}
12