Comments on: OpenGL ES Tutorial for Android – Part IV – Adding colors

By: OpenGL ES Tutorial for Android – Part IV – Adding colors | Per-Erik Bergman

Wed, 01 Feb 2012 09:31:02 +0000

[...] (function() { var s = document.createElement('SCRIPT'), s1 = document.getElementsByTagName('SCRIPT')[0]; s.type = 'text/javascript'; s.async = true; s.src = 'http://widgets.digg.com/buttons.js'; s1.parentNode.insertBefore(s, s1); })(); TweetThis tutorial is original posted at Jayway’s Developer Blog and can be found here: Jayway’s Developer Blog [...]

By: Karthik

Karthik — Sun, 04 Dec 2011 10:32:31 +0000

Excellent tutorial, read line by line and understood like a teacher teaching the content in person. Hats off!

By: Harry

Harry — Wed, 09 Nov 2011 13:23:39 +0000

You must disable color array to apply colors to all vertex with “glColor4f”
like this:
glColor4f(1.0f, 1.0f, 1.0f, 1.0f);
glDisableClientState(GL_COLOR_ARRAY);
glEnableClientState(GL_VERTEX_ARRAY);

By: Ricky

Ricky — Thu, 13 Oct 2011 11:35:17 +0000

A Great Tutorial!
Thank you so much!!!!

By: Research (Done by Lai Chin Wang) « ifyp

Research (Done by Lai Chin Wang) « ifyp — Fri, 16 Sep 2011 11:17:47 +0000

[...] http://blog.jayway.com/2010/01/14/opengl-es-tutorial-for-android-%E2%80%93-part-iv-adding-colors/ [...]

By: John

John — Mon, 29 Aug 2011 17:05:57 +0000

Question is how do I use the previous sample where the 3 boxes are rotating around but make square A a Square(), square B a FlatColoredSquare() and square c a SmoothColoredSquare()? I tried just initiating the classes and then replace square.draw(gl) with flatSquare.draw(gl) and smoothSquare.draw(gl)…only problem is all the squares end up being rainbow colored.

By: CP Gangstaz

CP Gangstaz — Tue, 14 Jun 2011 15:36:46 +0000

Now I’ve got colors in tha hood! CP Gangstaz represening the red ones, aight. No flue trespass here. Them crabs better stay away…

By: lattimore

lattimore — Thu, 14 Apr 2011 06:52:06 +0000

Great Tutorial!

By: dirhem

dirhem — Tue, 15 Feb 2011 15:02:44 +0000

Thanks for great tutorials, i have a question , how can i color different faces of a cube with different colors ?

By: Peter

Peter — Fri, 28 Jan 2011 23:57:36 +0000

Great tutorial. Have you any plans on one for 2d collision detection with opengl es or do you have any advice on how I would try this?

By: OpenGL ES Tutorial for Android – Part III – Transformations | Jayway Team Blog - Sharing Experience

Thu, 13 Jan 2011 17:58:21 +0000

[...] Previous tutorial: OpenGL ES Tutorial for Android – Part II – Building a polygon Next tutorial: OpenGL ES Tutorial for Android – Part IV – Adding colors [...]

By: RGB

RGB — Wed, 15 Dec 2010 00:44:39 +0000

I’m enjoying and learning your tutorials, Per-Erik.

Reading this article regarding colors, I got an idea that I’d like to share with all of you, since you might find it useful. I added a new functionality to my site http://www.rgbtool.com, so now it is possible to get float RGB colors from the color picker.

I really don’t want to do SPAM with this. But if we need to use float colors in OpenGL ES, my conversion tool will be useful for you.

By: Adrian

Adrian — Sat, 13 Nov 2010 23:10:26 +0000

Great Tutorial,
When can we expect the 2d texturing tutorial?

By: Bernard Segonnes

Bernard Segonnes — Mon, 18 Oct 2010 09:06:43 +0000

Great tutorial pages !

Could you add another tutorial : how to display bitmaps ? as texture, or (for me needs as 2D bitmap displayed only once, without stretching. For instance to display something in 2D for an AR application.

Thanks.

By: vinpa

vinpa — Wed, 17 Mar 2010 15:56:40 +0000

Per-Erik:

Very nice tutorials; I have followed all of them up to this point. I just wanted to say thanks for the nice documentation on the fundamentals of 3D programming using OpenGL. The illustrations are a very nice touch to understanding the whole idea of a matrix.

One thing I found helpful when completing this tutorial was the use of glPushMatrix() and glPopMatrix() to make both squares appear:

@Override public void onDrawFrame(GL10 gl) { // Clear the screen and depth buffer. gl.glClear(GL10.GL_COLOR_BUFFER_BIT | GL10.GL_DEPTH_BUFFER_BIT); // Replace current matrix with the identity matrix. gl.glLoadIdentity();


		// FLAT SQUARE

		// Save current matrix.

		gl.glPushMatrix();

		// Translate -10 units into screen, 1.5 units up.

		gl.glTranslatef(0, 1.5f, depth);

		// Draw our flat square.

		flatSquare.draw(gl);

		// ...then restore previous matrix.

		gl.glPopMatrix();
		// SMOOTH SQUARE

		// Save current matrix.

		gl.glPushMatrix();

		// Translate smoothSquare to end up under flatSquare.

		gl.glTranslatef(0, -1.5f, depth);

		// Draw our smooth square.

		smoothSquare.draw(gl);

		// ...then restore previous matrix.

		gl.glPopMatrix();

}

Again, many thanks! I will continue to read through the rest of your posts and look forward to many more! : )

VP.

By: Per-Erik Bergman

Per-Erik Bergman — Thu, 28 Jan 2010 21:36:10 +0000

Yes, I have started on the next tutorial. It will be about more meshes, but 3D meshes so that we get some real 3D objects on the screen.

By: Sam

Sam — Thu, 28 Jan 2010 06:57:26 +0000

All tutorials are really awesome.By now you must have started preparing the next tutorial, can you please tell which topics will be covered in next tutorial.
thanks.

By: arn.zhan

arn.zhan — Tue, 26 Jan 2010 07:49:56 +0000

Mr Bergman , after seeing your tutorials I want to say , this is the best I have ever seen , even better than NeHe’s. If some day you’ve written a book , I will certainly buy one .

By: Al

Al — Sat, 23 Jan 2010 20:12:52 +0000

Excellent tutorials, they have explained a lot of things for me, looking forward to the next one!

By: Per-Erik Bergman

Per-Erik Bergman — Tue, 19 Jan 2010 06:25:04 +0000

Jen: Glad you like my tutorial. About face picking or mesh picking it’s a bit much to share as a comment. But there is two basic ways of doing this;
1. Sending a ray into the screen and calculate which mesh you clicked on,
2. Rendering all meshes with a unique color and when you pick just check for the color. I recommend for beginners since it’s a bit easier.

By: jen

jen — Sun, 17 Jan 2010 15:04:04 +0000

Thank you verry much. This is the best 3d tutorials I’ve found.

There’s something I would like to know. Hope you will help me.

Is there any way to capture touch events on 3D objects drawn in a space?

I just want to select a object or know where I have clicked.

Is it possible?

Thanks.