8 uniform mat4 perspective;
13 mat4 modelview = view * model;
14 mat4 m = perspective * modelview;
15 vec3 dark = vec3(0.0, 0.0, 0.1);
16 vec3 bright = vec3(0.0, 0.0, 0.9);
17 vec3 u_light = vec3(-0.5, -0.7, -0.6);
18 vec3 v_normal = transpose(inverse(mat3(model))) * normal;
19 float brightness = max(dot(normalize(v_normal), normalize(u_light)), 0.0);
20 color = vec4(mix(dark, bright, brightness), 1.0);
21 gl_Position = m * vec4(position, 1.0);