#krt

The Korn shell RayTracer

#Contents

1. Synopsis
2. Install
3. Tests
4. Contributing
5. License

#Synopsis

krt [-s sqrt] [-n nearest]

krt is the beginning of a raytracer written in pure shell. There is actually nothing particularly korny about it, this is just a reference to my other project kbf. It is currently compatible with ksh and bash, and probably with any shell implementing the local keyword.

The option -s allows to select among three algorithms to calculate the square root of a given number: heron, newton and bakhshali. All three are implemented in sqrt.sh. The default algorithm is newton and was picked at random.

The option -n allows to select two methods of finding the nearest approximation of square root: dynamic and fixed. The first method, dynamic, is extremely slow and should not be used. The second, fixed, is the default but required a pre-generated list of squares named perfect_squares.txt.

Such a list can be generated beforehand using this helper script:

$ perfect_squares.sh > perfect_squares.txt

For now there are no scene, no floor, no lights, just a hanging red sphere on a blue background. This is the same as section 5 of Ray Tracing in One Weekend.

Here it is:

It took my laptop 47 minutes to generate it.

#Install

#Requires

• Any a-bit-more-than-POSIX shell.

#Build

There is a makefile available, just run make. Note that there are no install rule.

#Contributing

Either send send GitHub pull requests or send patches on SourceHut.

#License

All the code is licensed under the ISC License.