You will again have to implement 3 functions.

1) Phong lighting

Your task is to compute 3D lighting by implementing Phong lighting model.

2) Cube UVs

Here you get a vertex and a normal and your task is to return correct UV coordinates. See the slides for more details.

3) UV-mapped texture fill

You are asked to correctly color texture, which is than automatically mapped to the cube using the previously implemented function for mapping cube UVs. You need to go through all the pixels in the texture and based on the pixel's position you need to set the color accordingly.