Lab B04 Axis-Aligned Bounding Box, Texture Mapping and Light Sources

From this lab, we are going to work on Prof. Shirley's second tutorial in the series: Ray Tacing the Next Week.

https://raytracing.github.io/books/RayTracingTheNextWeek.htmlraytracing.github.io

Note - Skip Motion Blur and Perlin Noise

We are skipping Chapter 2 Motion Blur and Chapter 5 Perlin Noise as they are not essential to the project.

As we are not using Motion Blur, take care of the sphere constructor code: not use static_center but stick to center in Task 1.

As we are not using Perlin Noise, use our earthmap texture instead of the Perlin noise texture in Task 5.

They are marked in my source code in T1 and T5.