Can VBOs be used at the same time as Vertex Arrays?

OpenGL Development JOGL Development
#1

Hi All,

Well my problem is simple but i can not figure out some workaround, or the reason of the problem.
I have a scene in which i have a parchment unscrolling itself. Therefore i have kept its data in vertex arrays to be able to modify it dynamically to produce the unscrolling effect.
Once unscrolled i am draying fixed objects on it (trees cows etc…) which are completely fixed and therefore i am keeping them in VBOs.
Now the problem is, when i draw my VBO, my vertex array do not redraw anymore. Below you can find the bits of code used to draw the map and its objects:

 
public void Draw(GL gl)
	{
	gl.glVertexPointer(3, GL.GL_FLOAT, 0, verticesB); 
	gl.glTexCoordPointer(2, GL.GL_FLOAT, 0, texCoords); 
	gl.glNormalPointer(GL.GL_FLOAT, 0, normalsB);
	gl.glBindTexture(GL.GL_TEXTURE_2D,textures[empire]);
	gl.glPushMatrix();
	gl.glTranslatef(0.75f,0.5f+pos,0);
	gl.glRotatef(angle,0,0,1);
	gl.glTranslatef(-0.75f,-0.5f,0);
	gl.glDrawArrays(GL.GL_QUADS, 0, 592);
	gl.glFrontFace(GL.GL_CW);
	gl.glBindTexture(GL.GL_TEXTURE_2D,textures[3]);
	gl.glDrawArrays(GL.GL_QUADS, 0, 592);
	gl.glFrontFace(GL.GL_CCW);
	gl.glDisable(GL.GL_TEXTURE_2D);
	for(int i=0;i<size[empire];i++)
		{
		gl.glPushMatrix();
		gl.glTranslatef(fiefs[empire][i][0],fiefs[empire][i][1],0);
		if(ressources[empire][i].equals("bois"))
			{
			gl.glScalef(0.08f,0.08f,0.08f);
			gl.glRotatef(90,1,0,0);
			Objets.arbre(gl);
			}
		if(ressources[empire][i].equals("betail"))
			{
			gl.glScalef(0.06f,0.06f,0.06f);
			gl.glRotatef(90,1,0,0);
			Objets.betail(gl);
			}
		if(ressources[empire][i].equals("cereales"))
			{
			gl.glScalef(0.03f,0.03f,0.02f);
			gl.glRotatef(90,1,0,0);
			Objets.cereales(gl);
			}
		if(ressources[empire][i].equals("roche"))
			{
			gl.glScalef(0.04f,0.04f,0.04f);
			gl.glRotatef(90,1,0,0);
			Objets.roche(gl);
			}
		gl.glPopMatrix();
		}
	gl.glEnable(GL.GL_TEXTURE_2D);

In turn each Objets.* will call a drawing method looking like this one.

	if(VBOs!=null)
		{
		gl.glBindBufferARB(GL.GL_ARRAY_BUFFER_ARB, VBOs[0]);
		gl.glVertexPointer(3, GL.GL_FLOAT, 0, null);
		gl.glBindBufferARB(GL.GL_ARRAY_BUFFER_ARB, VBOs[1]);
		gl.glTexCoordPointer(2, GL.GL_FLOAT, 0, null);	
		gl.glBindBufferARB(GL.GL_ARRAY_BUFFER_ARB, VBOs[2]);
		gl.glNormalPointer(GL.GL_FLOAT, 0, null);	
		}
	else
		{
		gl.glVertexPointer(3, GL.GL_FLOAT, 0, vertices); 
		gl.glTexCoordPointer(2, GL.GL_FLOAT, 0, texCoords); coordonees de texture
		gl.glNormalPointer(GL.GL_FLOAT, 0, normals); 
		}
          ...   Draw stuff ....

So each times i am turning my pointers to the vertex arrays before drawing the vertex array and to the VBOs before drawing VBOs, so i am not clear to why my the content of my vertex arrays is not drawn anymore. Is there a need for me to “unbind the buffer” before drawing a vertex array structure? If so how?

Thanks for your help

#2

LWJGL has some nice checks for this, but JOGL appearantly don’t force you to release your VBOs before doing VA calls.

To unset the VBO:
gl.glBindBufferARB(GL.GL_ARRAY_BUFFER_ARB, 0);
note the zero as last argument.

You might have to reset the GL_ELEMENT_BUFFER_ARB too, incase you’re rendering indexed geometry

#3

The JSR Jogl version generates exceptions if you use VBO and VA calls incorrectly. From your code however it seems like you’re still using a pre JSR version of jogl, that did not have these checks in place yet.
In the JSR version gl*Pointer style methods are overloaded. One version takes a Buffer, the other a long. The Buffer version should be used for VAs, the long version for VBOs.

#4

Yes i am still using the pre JSR one, but i am going to shift to it as soon as next version is out. Mainly because i fancy the FPSanimator :-p

gl.glBindBufferARB(GL.GL_ARRAY_BUFFER_ARB, 0);

It solved it right away, i guessed there was surely a simple way now i know which one :stuck_out_tongue:

Thanks