Comments on: 4. OpenGL Primitives – Square (Version 2.0)

By: demonindark

demonindark — Tue, 02 Aug 2011 13:10:31 +0000

For the different drawing types here is a quick image that can explain any person without reading tons of text ….

http://www.cs.uregina.ca/Links/class-info/405/WWW/Lab2/glPrimitives.png

By: Bill

Bill — Sat, 26 Mar 2011 19:27:12 +0000

Thanks, I am getting started with OpenGL. I have bookmarked this site for reference. Btw – The colors and they way you layed it out makes it easy to read.

Thank you very much for putting up this site and the time you put into it.

By: Matt

Matt — Thu, 17 Mar 2011 22:18:44 +0000

Well I decided to go with learning the older versions because there seems to be more info and I’m sure when I decide to convert to the newer versions, it won’t be as hard.

By: Swiftless

Swiftless — Thu, 17 Mar 2011 05:32:02 +0000

Hi Matt,

I’m glad it could help. This site started off back in the day as a means to show how to achieve certain effects, and has since grown into full fledged tutorials to show how to use the actual OpenGL code. In these tutorials, GLUT allows that, but in the OpenGL 3.x and 4.x tutorials, there is no GLUT equivalent at the time of writing (If there was, I simply didn’t hear of it).

Cheers,
Swiftless

By: Matt

Matt — Wed, 16 Mar 2011 20:55:42 +0000

Hello, these tutorials have been a big help! I didn’t feel like going through nehe’s window framework so I just read the lessons and apply them to projects. Some of his projects are converted to glut to which helps. Anyways, having some tutorials using glut makes it much easier to learn actual OpenGL code. I can always learn how to make my own window framework later.

I’ll hopefully get some working OpenGL games by the end of the week, I’ll post my progress if I have time. Thanks!

By: Swiftless

Swiftless — Thu, 03 Mar 2011 05:32:23 +0000

Hi Michael,

At the end of your keypress function, you could include a call to tell OpenGL to update, possibly add glutPostRedisplay().

If that doesn’t work, is your window constantly losing focus?

Thanks,
Swiftless

By: Michael

Michael — Thu, 17 Feb 2011 06:30:14 +0000

Hey, want to say that I’ve been reading a book on OpenGL programming but your tutorials are much better.

I’ve also got a question: I wanted to test changing one of the coordinates of a vertex of the quad, so I declared the global variable ‘corner’. I set it to change when the key ‘a’ was pressed (add 0.01f to ‘corner’).

I’m getting unexpected behavior; the quad only changes if I click on the window (???). I tried eliminating the key presses and put the line “corner += 0.01f;” in the renderPrimitive function but the quad only changes when I rapidly click on the window. Any idea what the issue might be? Thanks.

By: Daniel

Daniel — Sat, 02 Oct 2010 14:34:51 +0000

It seems like it had something to do with the positions. I edited the translate values a bit and got the cube visible.

By: Swiftless

Swiftless — Wed, 29 Sep 2010 11:49:32 +0000

Hi Daniel,

It sounds like something is missing. The code I have provided, *will* show a quad, no matter what system you are on, as long as it supports OpenGL.

Cheers,
Swiftless

By: Daniel

Daniel — Tue, 28 Sep 2010 17:59:35 +0000

I can’t see any quad there. O.o I did everything just as you did but I just can’t see any quads.