At the risk of sounding stupid, can anyone help me understand this method better?  I have been searching for opengl tutorials and looking through all sorts of code people have in their renderers trying to figure this out.

 

I know the first 3 arguments it takes are x,y,z coordinates of the given vertex, and that the last 2 are u,v for that vertex.  I know, or at least I think I know, that u and v refer to the texture.  What I am really unclear on is how exactly the u and v refer to the texture and how that relates to its vertex.

Essentially, it's UV mapping (google that).

 

What you're basically saying is that "this point in 3D space corresponds to this point on the 2D texture."  For Minecraft it's generally pretty easy: all your sides are squares.

I guess what I am really having a hard time figure out is how the UV numbers are telling the pixel what part of the texture file to render.  Since the UV are floats, are they percentages where .5 .5 would represent half the texture file?  Or maybe 1/4 of the texture file if it is half of the U(x) direction and half of the V(y) direction so the bottom left 1/4th of the texture file?

Yes, the UVs are in percentages of the texture file (a float from 0 to 1).  Which is why Minecraft doesn't give two shits about texture size.

Hi

 

You might find this link helpful

http://greyminecraftcoder.blogspot.com.au/2013/08/the-tessellator.html

 

-TGG

You have both been very helpful, thank you.  I think I have a pretty good idea now how to tackle what I was trying to accomplish.