vertex3f and vertex3fv

[frannack]

Hello,
This must be a newbie question,but sorry, I could'nt find the answer.
I'm using vertex3f to draw a sphere composed of triangles. I thought using vertex3fv since i have a lot of triangles but I don't know how to put the array in the int attribute of vertex3fv.
Could you tell me How to do that or where can I find an example, plz.
Thks a lot..
Franck

[cfmdobbie]

The int parameter is the address of a buffer, in this case a FloatBuffer.  You'll probably want to read up on them at java.sun.com, but here's a fragment to get you started:

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import org.lwjgl.Sys ; import java.nio.* ; FloatBuffer v1 = ByteBuffer.allocateDirect(4 * 3).order(ByteOrder.nativeOrder()).asFloatBuffer() ; int v1_addr = Sys.getDirectBufferAddress(v1) ; v1.put(10.0f).put(5.0f).put(23.0f) ; gl.vertex3fv(v1_addr) ;

The extra imports you may need are listed.  The size allocated (4 * 3) is because you have three components (it's a vertex3f) and floats are 4 bytes in size.

Most methods called on buffers will return a reference to the buffer itself, so you can chain methods together as above.

Hope that helps.

[frannack]

That's exactly what I was looking for

tks cfmdobbie

Franck

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[princec]

It's also the second slowest way to draw triangles there is :/

Cas

[frannack]

I suppose so.
But i'm just starting to learn opengl, so I think i'll learn more later instead you give me a hint

[princec]

Ok, well don't use glVertex3fv! It's vastly over complicated and very slow. In fact I thought it was so useless I left it out of the first alpha because I didn't think anyone would want to use it!

Stick to glVertex3f, because it's much easier, and approximately the same speed. And it's blindingly fast in a display list. If you're going to muck around with pointers then you've really got to use vertex arrays which are much, much faster for any non-trivial number of polygons, but again, too fiddly for just a few.

Cas