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