Add reference code for Lights, Camera

[gaocegege]

ref #80

Signed-off-by: Ce Gao ce.gao@outlook.com

[jeremydouglass]

Excellent.

Things from this commit that could also be applied to all other examples/references in master:

1. 0-indexed filenames/paths
2. PI <- pi

[jeremydouglass]

Good -- PI <- pi is better than PI <- 3.141592 -- but still a placeholder until PConstants are defined and loaded outside the example sketches.

In the meantime perhaps all examples using PI, HALF_PI, TWO_PI etc. should be updated to be defined in terms of the R built-in pi.

[gaocegege]

I think it is not what we need. In GSoC we will support the variables so it is only temporary. Both pi and 3.1415 are fine, IMO.

[gaocegege]

And in August we will remove all this tricks from example code.

[jeremydouglass]

As long as they are temporary and all get cleaned up later the inconsistency now is fine.

[jeremydouglass]

I notice that the original Processing reference example images are zero-indexed, so the reference directory names and .rpde files are zero-indexed. I believe that the first batch of examples were 1-indexed, like:

examples/reference/bezierTangent/bezierTangent1/bezierTangent1.rpde

examples/reference/bezierTangent/bezierTangent2/bezierTangent2.rpde

Should all these old files / paths be renamed to match the pattern?

[gaocegege]

I think it doesn't matter since it works well now :)

[jeremydouglass]

I took another look at the original Processing reference and it is not consistent either -- some end in _, some end in _0, and some have numbers in the middle of the name... some are 0-indexed and some are (implicitly) 1-indexed.

• https://processing.org/reference/images/

For example, the reference images for arc() are arc_.png, arc_2.png, arc_3.png etc....

Given that the original material isn't consistent we don't need to worry right now about the new material being consistent -- it won't help us automate. So let's leave things as they are.

[gaocegege]

😄 Yeah, it can't be automated, so we need to write .test.yml manually.