How to define a new VertexAttribute ?

tlecoz

Hello !

To create an effect, I need some extra values associated to each vertex, then I would like to define an extra vertexAttributes with my values stored inside.

I saw the LowLevelShader example. It works but if I follow that exemple, it needs to define every vertexAttributes by myself and that's not what I want... I would like to add a custom vertex attribute to the "vertexAttribute-list" not to create all the list...

How can I do that ?

If there is no solution, it's possible to "hack" Processing structure and use "tint" or "normal" to send some values to the shader, but it's really not my favorite solution :)

Thanks !

MenteCode

Processing has a class called PGL, which focuses more in-depth on OpenGL than PGraphics does (what you would normally use). You use it like so, following the PGL javadoc:

PGL pgl; //Processing-OpenGL abstraction class

void setup() {
  size(300, 300, P3D);
  PGraphicsOpenGL pg = (PGraphicsOpenGL) g;
  pgl = pg.beginPGL();
}

void draw() {
  //Your PGL commands below
  //I.e:
  pgl.clear(pgl.COLOR_BUFFER_BIT | pgl.DEPTH_BUFFER_BIT);
}

From here, you can do anything (within OpenGL limits) shown in the doc. You don't seem to have to do anything else, though I could be wrong.

To prove things work, try adding/removing pgl.COLOR_BUFFER_BIT | from pgl.clear(). Everything else can be deduced from the PGL doc.

tlecoz

Thank you for your message, but I don't want to clear the processing buffers, I want to create an additional buffers to the existing ones

MenteCode

I gave you a link to the Javadoc. In case it isn't noticeable, here it is again: http://processing.org/reference/javadoc/core/processing/opengl/PGL.html

Like I said, this contains everything you should need, but I can't help you beyond this.

MenteCode

"I think I should just stop before I cause too much damage."

The more I read your question, the more I realize how true that statement is. Ignore everything I've said in my past 2 comments. I truly can't help you, and I'm not sure why I thought I could. Sorry. :-/

tlecoz

no problem, thanks for your interest :)