Celestia Forums

This is sort of a minor point, but it's something that needs to be resolved before 1.5.0 final . . .

At the moment, rotation files (as used for SampledRotation) have the extension .q, for quaternion. But, while this is appropriate now, I have visions of extending the format to also handle Euler angles. Thus, something more generic seems better . . . I've considered .celatt (Celestia attitude), .celrot (Celestia rotation), .rot, and others. Anyone have an opinion on this that they'd care to share?

--Chris

chris wrote:This is sort of a minor point, but it's something that needs to be resolved before 1.5.0 final . . .

At the moment, rotation files (as used for SampledRotation) have the extension .q, for quaternion. But, while this is appropriate now, I have visions of extending the format to also handle Euler angles. Thus, something more generic seems better . . . I've considered .celatt (Celestia attitude), .celrot (Celestia rotation), .rot, and others. Anyone have an opinion on this that they'd care to share?

--Chris

.rot


Bye Fridger

PS: Moreover: the cel part of .celxyz seems unnecessary, since throughout we are talking about Celestia...

I think that, to the greatest extent possible, filetypes used only by Celestia should be unique and not be the same as filetypes used by other programs. Including "cel" in the filetype may one way to ensure that is the case. Not having unique file extensions already is causing problems. .stc, for example, is used by OpenOffice, which registers that filetype for its own use when OO is installed on a Windows system.

I personally don't like the .rot extension because it immediately makes me think it's a file created by a rot-13 "encryption" program.

FWIW, http://filext.com/ claims that the .rot filetype is used by Homeworld and Rotator 3D.

How about .celo for "Celestia orientation"?

For a future release of Celestia I suggest to have only two file extensions. I suggest ced (Celestia Data) for all the data and ces for all the scripts. So why not starting right now?
Kind regards

Different types of data files require different formats. I think it's best that the filetypes be self-documenting.

selden wrote:Different types of data files require different formats. I think it's best that the filetypes be self-documenting.

I agree . . . So far, I like .celo the best--it makes it clear that the data file is for Celestia, and it's not too long.

--Chris

If this is a postfix for a generic rotation file then .rot seems best to me. The reason is that "rotation" is currently being used in the documentation as an alias for a quaternion, so this would be a generalization of the term rotation in that quaternion becomes only one instance of the type Celestia rotation.

type rotation = { quaternion, euler angle ?€¦.. }

Henry

selden wrote:Different types of data files require different formats. I think it's best that the filetypes be self-documenting.

I like the .rot extension, since either quaternion or euler angles are both just rotations. However, as Selden mentions, it's best for the file to be self documenting, i.e. you know what you have solely by looking at the file contents and extension.

Perhaps a several line ascii header would work. Things like the rotation sequence and ref frame could be contained and make the file usable by someone that may not know exactly how it was generated. Guess we're approaching a spice ck file here--that's my 2 cts.

Scott

Whatever the considerations with other competing formats (outside Celestia) are, .celo sounds just funny to me and does not carry any mnemonic properties at all . I had checked before that my favorite (.rot) does neither occur as a /standard/, i.e. preassigned , format in Linux AND Windows XP. If .rot occurs in some specialized other application,...so what.

Bye Fridger

My 'four' cents:

QOF = Quaternion Orientation File
QOC = Quaternion Orientation of Celestia
CQF = Celestia Quaternion File
CQO = Celestia Quaternion for Orientation

Adirondack

.celo or .celr or .cela all OK by me.

I like Selden's idea of including .cel in all of them, and 4 characters would give 26 possible filetypes (some more meaningful than others).

in fact if you weren't worried about backward compatibility:
.stc could become .cels (Celestia Stars) to avoid conflict with OpenOffice
.ssc could be .celp (Celestia Planets) [ and Moons ]
or a separate type for Moons: .celm
and even a separate type for spacecraft : .celc (Celestia Craft)
.dsc could be .celg (Celestia Galaxies) [ and nebulae ]
or have a separate filetype for nebulae: .celn

etc, etc...

what have I missed?


At the end of the day, a naming convention which has some connection/meaning associated with it's purpose would be nice, but less important than ensuring lack of conflict with other apps (which is why I like Selden's idea in principle)

Another advantage of prefixing the suffixes with .cel is that they will all appear together in the Folder Options > Filetypes list in Windows.

t00fri wrote:Whatever the considerations with other competing formats (outside Celestia) are, .celo sounds just funny to me (...)

It also sounds funny to a Spanish-speaking person
I liked more the simplicity of original proposition:
.xyz
.xyzq
.xyze
.q
.e

Toti wrote:

t00fri wrote:Whatever the considerations with other competing formats (outside Celestia) are, .celo sounds just funny to me (...)

It also sounds funny to a Spanish-speaking person
I liked more the simplicity of original proposition:
.xyz
.xyzq
.xyze
.q
.e

The .e file, .q file, and .xyz file are already used by other applications, but not for .xyze file or .xyzq file

I think .rot would be good, since it is nearly selfexplaining what the file is for.

@Selden:
Is the .stc still an issue with Oo version 2? Didn't they switch to the ODF Data format with other extensions as standard?
Have to check and install it on my new machine.

Just my 2 cents

I'll try to check the status of .stc this evening. I really don't recall if I updated to OO v2 or not.

(I changed the association of .stc to be with Notepad long ago but the icon didn't change: it still claims incorrectly to be associated with OO.)

And to add to the mix STK uses .a for the attitude file extension--may even be able to use the STK format too.

I had OO v2.02 installed.
STC files displayed an OO icon (it looks like a histogram), but were being opened by Notepad: I had set that association manually.

I deinstalled OO v2.02.
STC files properly displayed the Notepad icon.

I installed OO v2.1
I did not check any of the Office (Word, Excel and Powerpoint) association boxes.
STC files once more improperly display the OO icon, but still are opened by Notepad.

Oh, well.

:3

I would like to point out that the extension of a file usually is associated to the data format. The data format requires a particular algorithm to read the data from disk. This is the reason why new extensions are created. Celestia has already a general purpose algorithm to read structured data from file. So why a new format/extension?

IMHO at present time there are already too much Celestia data formats.
Some time ago there was a discussion about the future data format and the data model. I promoted the necessity of a unified data format (XML, LUA, Celestia own format, whatever else but unified).
This approach should improve greatly expandability of new Celestia data, even through tools for data conversion and data sharing. All of this should be implemented through a unified object serialization system that should work using schemas both for reading and for writing data from file (editors and add-on managers should be possible).

The content of the file should not be defined by the extension but from the name. At the end everything is Celestial Data.
Please take a look at the Celestia's data folder. Everyone can understand the most of the content reading the name of files. The extension should be unified.

But this is a task for Celestia 2.0 because will break the backward compatibility for all the current add-on.

Kind regards

Paolo wrote:I would like to point out that the extension of a file usually is associated to the data format. The data format requires a particular algorithm to read the data from disk. This is the reason why new extensions are created. Celestia has already a general purpose algorithm to read structured data from file. So why a new format/extension?

The orientation files aren't structured, so a different routine is used to load them. I find that the different extensions help me keep the different files organized.

Eventually, I would like to eliminate the distinction between stc, ssc, and dsc files. But cmod, position, and orientation files are different enough that I don't see what benefit there would be to unifying them.

--Chris