Current Progress

• The library is able to render primitives such as textured cube or sphere on a scene, utilizing blinn-phong shading.
• Lambertian shading is ported, however it seems like Three.js' lambertian model is more of gourad / vertex shading(?)
• Normal mapping and texture mapping are implemented
• Shader is now one per configuration, e.g. if there are 2 meshes in the scene, one uses phong lighting and normal map, while the others only have texture mapping, then 2 shaders are created for the purposes.
• Shadow mapping is implemented, you can now cast shadow using directional and spot lights (cascade shadow is still pending though)
• Integrated with FontStash, thus three.cpp is able to show texts now.