[SOLVED] Preceding VBO render call

Newbie & Debugging Questions
#1

So whenever you render anything in OpenGL, sticking a glColor3f or 4f call in front of it will change it’s colour e.g:


@@glColor3f(1.0f, 0.0f, 0.0f);

glBegin(GL_QUADS);
glVertex2f(0, 0);
glVertex2f(10, 0);
glVertex2f(10, 10);
glVertex2f(0, 10);
glEnd();

produces a red square.

In my buffer object class, I have a function to render to vbo:


	public void render() {
		if (editing)
			throw new RuntimeException("Buffer is still being edited!");
		
		if (hasTexture);
			img.bindGLTexture();

		if (useVBO) {
			GL11.glEnableClientState(GL11.GL_VERTEX_ARRAY);
			GL11.glEnableClientState(GL11.GL_COLOR_ARRAY);
			GL11.glEnableClientState(GL11.GL_TEXTURE_COORD_ARRAY);

			GL15.glBindBuffer(GL15.GL_ARRAY_BUFFER, ID);
			GL11.glVertexPointer(3, GL11.GL_FLOAT, 4 * 8, 0);
			GL11.glColorPointer(3, GL11.GL_FLOAT, 4 * 8, 4 * 3);
			GL11.glTexCoordPointer(2, GL11.GL_FLOAT, 4 * 8, 4 * 6);
			GL11.glDrawArrays(GL11.GL_QUADS, 0, vertexCount);
			GL15.glBindBuffer(GL15.GL_ARRAY_BUFFER, 0);

			GL11.glDisableClientState(GL11.GL_TEXTURE_COORD_ARRAY);
			GL11.glDisableClientState(GL11.GL_COLOR_ARRAY);
			GL11.glDisableClientState(GL11.GL_VERTEX_ARRAY);
		} else {
			GL11.glCallList(ID);
		}
	}

I recently discovered i cannot precede this with a glColor3f call to change the colour e.g:


BufferObject bo = new BufferObject();
//Generate object

@@glColor3f(1.0f, 0.0f, 0.0f);
bo.render();

will not work. Is there something I’m doing wrong to make this work? If not, how could I emulate an effect like this without having to make a seperate VBO for each colour?

(Please note, none of this code is copy and pasted so spelling or syntax errors are not the issue)

Thanks :smiley:

#2

Why do you pass GL11.glColorPointer(3, GL11.GL_FLOAT, 4 * 8, 4 * 3);, if youre going to change the color anyways?

But to anwer your question, Shaders!

#3

Yes, this is the exact answer i came up with when writing the question, haha!

I guess that was a bit dumb of me, thanks for the reply though!