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oggs91

OpenGL
OpenGL 1,2,3,4 general question

11 posts in this topic

Hello!

Recently i've started to learn OpenGL trough OpenTK (wrapper for c#)
after reading lots of tutorials for OpenGL and DirectX stuff, i realized that all directX tutorials are strongly seperated by the directX version (dx9, dx10, dx10.1, dx11)
why doesn't that happen to opengl?
where should i start to learn about the latest opengl version (i think it's 4, 4.2 ?)

http://www.opengl.org/wiki/History_of_OpenGL
on this site changes to opengl are listed, are there any major changes or just additional functionality added ? (EXT_*, ARB_*) are those, i think it's called, vendor extensions?, the only changes between opengl version or are those just added functionality, not mentioning changed basic features

i'm a bit confused about this whole opengl word :D btw. directx looks somewhat cleaner, wouldn't opengl be easier with an object oriented approach ?!
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You're really risking a huge flame-war here by calling either "cleaner", "better" or anything similar :-)

Truth is that extensions get into OpenGL quicker (in fact you have to wait for Microsoft until they make up their minds to use [b]anything [/b]the new cards support!!!).

Khronos don't change the whole API as much as Microsoft every time, fortunately. New features (functions) become available, some are deprecated, some finally removed. The whole concept persists. Same goes for OpenCL.

Start learning directly OpenGL 4. No mather what, do NOT look at OpenGL 1.x, ever :-) That, unfortunately, disqualifies most of the famous NeHe tutorials, for example, hehe. Start with desktops, learn basics and do not touch OpenGL ES (mobile) before that much, if you plan to.
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[quote name='pcmaster' timestamp='1314866866' post='4856198']
You're really risking a huge flame-war here by calling either "cleaner", "better" or anything similar :-)

Truth is that extensions get into OpenGL quicker (in fact you have to wait for Microsoft until they make up their minds to use [b]anything [/b]the new cards support!!!).

Khronos don't change the whole API as much as Microsoft every time, fortunately. New features (functions) become available, some are deprecated, some finally removed. The whole concept persists. Same goes for OpenCL.

Start learning directly OpenGL 4. No mather what, do NOT look at OpenGL 1.x, ever :-) That, unfortunately, disqualifies most of the famous NeHe tutorials, for example, hehe. Start with desktops, learn basics and do not touch OpenGL ES (mobile) before that much, if you plan to.
[/quote]

:D nehe was the first i had a look at xD looked quite old to me too^^
what tutorial source would you suggest =) ? or are there any recommended books for opengl4 ?
i'd like to have an overview and basic techniques used in opengl beginning with
- viewports over
- view matrices for a camera,
- how to use a fbo,
- different techniques of drawing (read about displaylists, vertex arrays and vertexbuffers, different opinions in every spot i've read)
- usage and need of shaders in opengl4
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OMG you like DX better than GL... Many people in the world of DX (including myself) complained endlessly over features simply removed from the spec without deprecating, consulting or providing support from 7 upwards. OpenGL does provide full easily readable specification, that deprecates and has a wide base of developers, who develop for multiple platforms. Also OpenGL is extremely OOP! Just consider that encapsulation, abstraction, modularity, polymorphism, messaging and inheritance (wikipedias definition of OOP is completely met by OpenGL! Just thought I should point that out

[quote name='oggs91' timestamp='1314867902' post='4856202']
[quote name='pcmaster' timestamp='1314866866' post='4856198']
You're really risking a huge flame-war here by calling either "cleaner", "better" or anything similar :-)

Truth is that extensions get into OpenGL quicker (in fact you have to wait for Microsoft until they make up their minds to use [b]anything [/b]the new cards support!!!).

Khronos don't change the whole API as much as Microsoft every time, fortunately. New features (functions) become available, some are deprecated, some finally removed. The whole concept persists. Same goes for OpenCL.

Start learning directly OpenGL 4. No mather what, do NOT look at OpenGL 1.x, ever :-) That, unfortunately, disqualifies most of the famous NeHe tutorials, for example, hehe. Start with desktops, learn basics and do not touch OpenGL ES (mobile) before that much, if you plan to.
[/quote]

:D nehe was the first i had a look at xD looked quite old to me too^^
what tutorial source would you suggest =) ? or are there any recommended books for opengl4 ?
i'd like to have an overview and basic techniques used in opengl beginning with
- viewports over
- view matrices for a camera,
- how to use a fbo,
- different techniques of drawing (read about displaylists, vertex arrays and vertexbuffers, different opinions in every spot i've read)
- usage and need of shaders in opengl4
[/quote]
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[quote name='oggs91' timestamp='1314867902' post='4856202']
what tutorial source would you suggest =) ? or are there any recommended books for opengl4 ?
[/quote]
The usual recommendation is the latest version of the Big Red Book of OpenGL Programming. Unfortunately the [url="http://www.amazon.com/OpenGL-Programming-Guide-Official-Learning/dp/0321773039/"]latest edition[/url] (8th) isn't out until March 2012, and the [url="http://www.amazon.com/OpenGL-Programming-Guide-Official-Learning/dp/0321552628/"]previous edition[/url] only covers up to 3.1. Plus, the 7th edition still had a lot of depreciated stuff in it, I'm hoping the next will be better!

[quote name='pcmaster' timestamp='1314866866' post='4856198']Start learning directly OpenGL 4. No mather what, do NOT look at OpenGL 1.x, ever :-)[/quote]
Ah, you'd be surprised how many of us are still stuck having to use 1.1 hardware. There's a whole other world out there behind the cutting edge. :)
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[quote name='subi211' timestamp='1314870527' post='4856214']
Big Red Book of OpenGL Programming [...] [url="http://www.amazon.com/OpenGL-Programming-Guide-Official-Learning/dp/0321552628/"]previous edition[/url] only covers up to 3.1.[/quote]
One should note that this edition of the Red Book is misleading (if not fraudulent) in its title's wording. It is really a book about versions 1.x and 2.x with some paragraphs in one or another chapter about 3.0/3.1 features, and a chapter on intro to shaders. There is no easy way of learning from this book what functionality is deprecated and what's not (unless you know before!), and some of it outright wrong. The best hint from the author you get is a "Many of the functions in this chapter" note, at the beginning of nearly every chapter. Reading the specification is a dozen times more instructive, and free.

The only recent book that I've bought which is [i]yet worse [/i]than the OpenGL Red Book is Aaftab Munshi's OpenCL Programming Guide (but at least it wasn't all that expensive...).
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[quote name='samoth' timestamp='1314894856' post='4856360']One should note that this edition of the Red Book is misleading (if not fraudulent) in its title's wording. It is really a book about versions 1.x and 2.x with some paragraphs in one or another chapter about 3.0/3.1 features, and a chapter on intro to shaders. There is no easy way of learning from this book what functionality is deprecated and what's not (unless you know before!), and some of it outright wrong. The best hint from the author you get is a "Many of the functions in this chapter" note, at the beginning of nearly every chapter. Reading the specification is a dozen times more instructive, and free.[/quote]
That's pretty bad, I had no idea. May as well read the [url="http://www.opengl.org/documentation/red_book/"]free 1.1 edition[/url] then. :) The reason it's a bit bare on shaders is probably because there's a [url="http://www.amazon.com/OpenGL-Shading-Language-Randi-Rost/dp/0321637631/"]separate book[/url] on GLSL (disclaimer: Not read it, and it's two years old, so probably worthless). I believe you can get the Cg book free on NVidia's site, depending on your choice of shader language, but that is a bit basic still.
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[quote name='oggs91' timestamp='1314867902' post='4856202']:D nehe was the first i had a look at xD looked quite old to me too^^[/quote]
At this point I think Nehe is actually doing more harm than good for people looking to learn OpenGL. (And it's magnified by the fact that all the search engines love to list that site in their top ten for any search having to do with OpenGL)

[quote name='oggs91' timestamp='1314867902' post='4856202']what tutorial source would you suggest =) ? or are there any recommended books for opengl4 ?[/quote]
In this order:
IMHO, best samples on the web. (They cover all versions all the way up to current)
[url="http://www.g-truc.net/"]http://www.g-truc.net/[/url]

Great site:
[url="http://www.opengl-tutorial.org/"]http://www.opengl-tutorial.org/[/url]

Good online book(but a little old):
[url="http://www.arcsynthesis.org/gltut/index.html"]Learning Modern 3D Graphics Programming[/url]

And get [url="http://glew.sourceforge.net/"]Glew[/url] and [url="http://glm.g-truc.net/"]glm[/url] and the opengl registry files([url="http://www.opengl.org/registry/api/glext.h"]glext.h[/url], [url="http://www.opengl.org/registry/api/glxext.h"]glxext.h[/url], and [url="http://www.opengl.org/registry/api/wglext.h"]wglext.h[/url]) here: [url="http://www.opengl.org/registry/#headers"]header files[/url].
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[quote name='oggs91' timestamp='1314867902' post='4856202']
:D nehe was the first i had a look at xD looked quite old to me too^^
what tutorial source would you suggest =) ? or are there any recommended books for opengl4 ?
[/quote]

Personally, I find using a combination of websites (see the OpenGL forum [url="http://www.gamedev.net/topic/594638-the-forum-faq/"]FAQ[/url] for all the links ), the Superbible 5, the Yellow book (OpenGL Shading Language 3rd Edition), and the OpenGL ES 2.0 programming guide is a good way for learning the basics of modern OpenGL. The Superbible 5 uses the author's GLTools library so you will have to read his source code to learn what's going on and it can be a little challenging to get it working on non-Visual Studio compilers. OpenGL ES 2.0 guide is one of the best books I've ever read and I don't even program in OpenGL ES. The API is very similar to OpenGL 3/4 so it can be used to learn modern OpenGL but it may be difficult to read as a first book. Personally, I think the Red book is not worth getting because of all the deprecated stuff in it. I hope the next edition doesn't include the deprecated functions but they most likely will include them for completeness.
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Yeah I found the OpenGL Super Bible 5th edition is really good for theory and code. It does explain the stuff that is used in the gltools stuff so you should be able you replicate what it does with a bit of help from internet sites and the such. Also if your starting out its quite nice to use the gltools stuff to begin with just to get started as it includes some stock shaders so you can make sure you've got everything set up right and it provides matrix stuff that is similar to the old OpenGL functionality but also explains how it all works and so you can write your own or use a lib such as GLM which is good as it is the same as the GLSL stuff.

x
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