Cmd line and output compatibility with go version.

[tkalbitz]

This pull request updates the command line options and the output file to mimic the Go version. Also you can have more than one render run in an program invocation

Here is an example:

java -Xms4096m -Xmx8192m -XX:+AggressiveOpts javarays/Raycaster 0.05 5
Starting render#1 of size 0.05 MP (223x223) with 8 threads. Completed in 1708 ms
Starting render#2 of size 0.05 MP (223x223) with 8 threads. Completed in 1711 ms
Starting render#3 of size 0.05 MP (223x223) with 8 threads. Completed in 1740 ms
Starting render#4 of size 0.05 MP (223x223) with 8 threads. Completed in 1714 ms
Starting render#5 of size 0.05 MP (223x223) with 8 threads. Completed in 1714 ms
Average time for rendering: 1718 ms

[kidoman]

Hey Tobias,

Have a look at https://github.com/kid0m4n/rays/commit/eb78a3e6b806a667787f1247fb97ad1029188e8e

@t-mat and I were both talking about hardcoding "render.ppm" is a smell which will probably haunt us in near future. Hence, I really like the idea of small wrapper shell scripts which have the responsibility of running their respective benchmark by invoking the command in an appropriate manner.

This will not only allow us to capture details like "-XX:+AggressiveOpts" (as in the example you showed above), it will also allow us to leverage the best each platform has to offer (command line parsing, for eg.)

To that effect, I have implemented a bunch of changes to the Go version. Summary:

• The results are now written to a .json file so that we can easily read and parse it (vs having to grep for results from STDOUT)
• The Go version uses the flag package to accept all options now (vs sequence sensitive command line arguments)
• The ART file externalizes the actual render image. Its a smell to have to go and change n files every time we need to make a correction (the frequency of which should obviously be very low)

I know these changes are massive and will take time to replicate across all programs (and now we already have 5) but the earlier to answer some of these issues, the better off we will be

What do you reckon?

[kidoman]

I am merging this in... it is a small change to get the desired state from here