gotrace

gotrace is a Golang implementation of Peter Shirley's excellent books on raytracing.

I used it as a way to better understand Go interfaces. Being more familiar with object-oriented languages, I wondered how polymorphism behaviour could be implemented without inheritance. Turns out it is pretty awesome !

Pros

• Strong concurrency primitives. Using weighted semaphores is a very intuitive way to create a workgroup.
• Interfaces feels like more natural way to provide polymorphism behaviour at runtime, compared to inheritance.
• Awesome self-documentation

Cons

• No operator overloading

corner := lookFrom.Sub(u.Scale(width * focusDist)).Sub(v.Scale(height * focusDist)).Sub(w.Scale(focusDist))

would have been clearer as

corner := lookfrom - u*width*focusDist - v*height*focusDist - w*focusDist

• No forward declarations

Actor needs to know about Shape, Material and Ray, but Shape also has to know about Ray, so they can't live in different packages without having to add unecessary complexity, because Go doesn't support forward declarations and can't resolve "circular" dependencies.

Credits

• NASA Blue Marble
• Peter Shirley's original work