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hairycoconuts

.jam file extensions?

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hairycoconuts    122
I have been browsing through the projects on the nehe website and have noticed that there are alot of .jam files. 1) What are they? 2) What do they do? 3) Have they got ne relevence to OpenGL programming? 4) Are they commonly used? 5) Are there any tutorials telling you how to use them? Thankz alot guys been a great help ----------------------- This space is for sale -----------------------

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Ken Fitlike    123
They are bitmaps with the extensions changed. Get a hexviewer/editor to look at new file types or just change their extensions to recognised ones like bmp or txt. The first two bytes of bitmaps are ''BM''. Change the extensions of the *.jam files to *.bmp and open them with any image viewer capable of handling bitmaps (just about everything) and you''ll see what I mean. *.dat is another popular renaming notation.

I imagine it is a crude way of protecting your artwork but it may be that by doing this it is easier to know which files are meant for which projects - finding and recognising *.jam files, especially when they have numerical names is probably a lot simpler than *.bmp

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feagle814    122
Any file can be saved as a .jam -- remember the filename (including extension) has no bearing on the contents of a file... a .bmp extension is most likely a bitmap, but it could be anything (perhaps a Blue Man Productions data file?).

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Cobra    122
Okay.... this has been asked before.

.jam files are simply bitmap files renamed by nehe for no particular reason other than j.a.m are his initials.

Jeff A Molofee

They are no different from bitmap files.... they simply have the extension changed.
(Most programmers do this at one time or another.. like when u make your first program that can read in zip files, and you rename the zip extension to your initials or the first 3 letters in your name.. its just for fun.. nothing major.. just adds a little extra bit of uniqueness to say its yours.)

As for your question

"is it possible to save a jpg as a .jam?"
The answer is YES. BUT.
Yes.. its possible to save any file as a .jam file.
BUT.. programs that currently read in bmp files using .jam extensions wont obviously be able to read in a jpg posing as a jam file. ( unless u add some code getting it to read in the header, then allocate the texture appropriately ).

Hope this helped.....

~Cobra~

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hairycoconuts    122
U guys are so cleaver!

Thankz a bunch! Can i ask another stupid question?


Would it be possible to code a whole game out of c++, graphics and opengl? (As well as a few music files)

could you tell me averagly how much a game programmer would get paid?

AND...
What is a *.tga file. I heard it was a graphics file but can''t seen to find a program that creates them or presentes them?


Thankz a buch for your help, one day i hope to be dealing out the solutions.

Cheers


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hairycoconuts    122
Why even bother trying to convert .jpg or bmp files to .tga?

Are they smaller and is it that they can only be used in .exe programs?


Very confused!


Cheerse




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Cobra    122
quote:
Would it be possible to code a whole game out of c++, graphics and opengl? (As well as a few music files)



Ummm yes
You''ll find that''s generally how its done *grin*

Just grab urself a copy of MSVC++ 6.0 , Learn the C and C++ programming languages, and get an art/modelling program and you can make a whole game.

All u need is 1) code 2) media ( media = music/graphics/models/maps ) and ur done

quote:
Why even bother trying to convert .jpg or bmp files to .tga?



Well... .tga files are actually normally bigger than .jpg files. but they have the added bonus of having the ability to add alpha channels or masks right into the files themselves. (instead of having to mask a certain colour in code e.t.c which isnt nearly as nice).

Hope this cleared something up for ya

~Cobra~

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Cyberdrek    100
quote:
Original post by hairycoconuts
Would it be possible to code a whole game out of c++, graphics and opengl? (As well as a few music files)

AND...
What is a *.tga file. I heard it was a graphics file but can''t seen to find a program that creates them or presentes them?




Let me answer the first question verry simply, what do you think some of the games you buy at a store are made out of? Yes, you heard right, actually alot of newer games support both OGL and DX... ( That means that OGL code needed to be done programmed in order for the game to render in OGL.. )

Anyhow, that''s what I think about that question, as for *.tga, yes, it''s a graphics format, it''s real name is targa and there aren''t alot of paint program that save in targa anymore. Deluxe Paint II had it as one of it''s export options I think...




"And that''s the bottom line cause I said so!"

Cyberdrek
Headhunter Soft
A division of DLC Multimedia

Resist Windows XP''s Invasive Production Activation Technology!

"gitty up" -- Kramer

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xill    122
Hi 14 year old guy (im 16 :D)

You can see the alpha channel as a layer on top of the normal colormap.
If you''d have an image of 3 pixels, the first had an alpha value of 0, the second 100 and the last 255 (=max), then in your game you would see the first pixel normal, the second pixel would be half transparent and the last one would be completely transparent (invisible), so say you want to draw a text WITHOUT stupid black rectangles around it, you would give those black pixels an alpha value of 255 so they would beocme invisible in the game

clear?? :DDD

i hope so !

cya

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hairycoconuts    122
Too good! now it''s all clear! Thankz alot. If it wasn''t for this message board then i would be stuck!!!

I am hoping to start properly learing it solid but my coursework is getting in the way and have n time i apprieciate all your help mind!

Keep up the good work




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