Merge pull request #581 from Local-Trash/master

Added a Note about the Index buffer

docs/beginner/tutorial4-buffer/README.md

@@ -360,7 +360,7 @@ const INDICES: &[u16] = &[
 ];
 ```
 
-Now, with this setup, our `VERTICES` take up about 120 bytes and `INDICES` is just 18 bytes, given that `u16` is 2 bytes wide. In this case, wgpu automatically adds 2 extra bytes of padding to make sure the buffer is aligned to 4 bytes, but it's still just 20 bytes. Altogether, our pentagon is 140 bytes in total. That means we saved 76 bytes! It may not seem like much, but when dealing with tri counts in the hundreds of thousands, indexing saves a lot of memory.
+Now, with this setup, our `VERTICES` take up about 120 bytes and `INDICES` is just 18 bytes, given that `u16` is 2 bytes wide. In this case, wgpu automatically adds 2 extra bytes of padding to make sure the buffer is aligned to 4 bytes, but it's still just 20 bytes. Altogether, our pentagon is 140 bytes in total. That means we saved 76 bytes! It may not seem like much, but when dealing with tri counts in the hundreds of thousands, indexing saves a lot of memory. Please note, that the order of the indices matters. In the example above, the triangles are created counterclockwise. If you want to change it to clockwise, go to your render pipeline and change the `front_face` to `Cw`.  
 
 There are a couple of things we need to change in order to use indexing. The first is we need to create a buffer to store the indices. In `State`'s `new()` method, create the `index_buffer` after you create the `vertex_buffer`. Also, change `num_vertices` to `num_indices` and set it equal to `INDICES.len()`.