Add Simple Lighting

[Robert42]

• [ ] Diffuse
• [ ] Specular
  • [ ] Phong shading
  • [ ] sphere:
    project the best reflection into an orthogonal plane through the origin. the nearest point on the sphere to that point will be threated as pointlight
    • [ ] still an issue: to small sphere in extreme smooth mirror
  • [ ] rect-area:
    project the best reflection into the plane of the rect. use dot product to project the intersection point on the tangent and bitangent to get a 2d coordinates which can be used to find the nearest point to the rectangle and treat that rectangle as pointlight
    • [ ] still an issue: artefact

[Robert42]

decideded not to implement phong at all