Ray picking taking account of my pitch and yaw

[poo2thegeek]

I have been googling this for about two days. I have got to a point where I can find a direction based on my mouse position on screen, but it seems to not be affected by the yaw or pitch of my camera.

        IntBuffer viewport = ByteBuffer.allocateDirect((Integer.SIZE/8)*16).order(ByteOrder.nativeOrder()).asIntBuffer();
		        FloatBuffer modelview = ByteBuffer.allocateDirect((Float.SIZE/8)*16).order(ByteOrder.nativeOrder()).asFloatBuffer();
		        FloatBuffer projection = ByteBuffer.allocateDirect((Float.SIZE/8)*16).order(ByteOrder.nativeOrder()).asFloatBuffer();
		        FloatBuffer pickingRayBuffer = ByteBuffer.allocateDirect((Float.SIZE/8)*3).order(ByteOrder.nativeOrder()).asFloatBuffer();
		        
		        GL11.glGetFloat(GL11.GL_MODELVIEW_MATRIX, modelview);
		        GL11.glGetFloat(GL11.GL_PROJECTION_MATRIX, projection);
		        GL11.glGetInteger(GL11.GL_VIEWPORT, viewport);
		        float winX = (float) Mouse.getX();
		        // convert window coordinates to opengl coordinates (top left to bottom left for (0,0)
		        float winY = (float) viewport.get(3) -(float) Mouse.getX();
		        
		        // now unproject this to get the  vector in to the screen
		        // take the frustrm and unproject in to the screen
		        // frustrum has a near plane and a far plane
		        
		        // first the near vector
		        GLU.gluUnProject(winX, winY,  0, modelview, projection, viewport, pickingRayBuffer);        
		        Vector3f nearVector = new Vector3f(pickingRayBuffer.get(0),pickingRayBuffer.get(1),pickingRayBuffer.get(2));
		        
		        pickingRayBuffer.rewind();
		        
		        // now the far vector
		        GLU.gluUnProject(winX, winY,  1, modelview, projection, viewport, pickingRayBuffer);
		        Vector3f farVector = new Vector3f(pickingRayBuffer.get(0),pickingRayBuffer.get(1),pickingRayBuffer.get(2));

This is my current code, now what do I add to find what part of the world my mouse is clicking on?

I need to be able to find the xz coordinates when a cirtain y value is inputted.
Ie, a method in a similar format to this:

public static Vector2f getCoordAtY(Ray ray, float y)...

Thanks in advance!