Print Page - Vertex array and drawElements

Title: Vertex array and drawElements
Post by: tetedane on April 24, 2011, 13:27:17

Hi,

I'm developing a small game and trying to make Vertex Array work (I was using basic rendering until now).
If I put vertices for cubes in an buffer and use these commands, it works fine:
GL11.glVertexPointer(3, 0, verticles);
GL11.glDrawArrays(GL11.GL_QUADS, 0,numberElementVerticles);

But if I want to use an index array (to minimize the number of vertex), i use this command:
GL11.glDrawElements(GL11.GL_QUADS, index);

and I only get a few cubes drawn. Maybe the 12 first cubes (out of 250~260).
I think it is weird I don't have to give this function a size of buffer.
I really don't get it...

Thanks.

Title: Re: Vertex array and drawElements
Post by: Matthias on April 24, 2011, 14:02:06

Every buffer has a position and a limit. The elements between position and limit are used.

Title: Re: Vertex array and drawElements
Post by: tetedane on April 24, 2011, 16:14:29

So, what have I to do? set the position to 0? (I think it already is at 0 because I used buffer.rewind()).

Title: Re: Vertex array and drawElements
Post by: tetedane on April 25, 2011, 16:27:15

Solved! I had badly filled my index buffer: it referenced the wrong vertices... I'm so stupid :/

LWJGL Forum

Programming => OpenGL => Topic started by: tetedane on April 24, 2011, 13:27:17