gallium/docs: document new vertex element cso interface

src/gallium/docs/source/context.rst

@@ -24,6 +24,7 @@ CSO objects handled by the context object:
 * :ref:`Depth, Stencil, & Alpha`: ``*_depth_stencil_alpha_state``
 * :ref:`Shader`: These have two sets of methods. ``*_fs_state`` is for
   fragment shaders, and ``*_vs_state`` is for vertex shaders.
+* :ref:`Vertex Elements`: ``*_vertex_elements_state``
 
 
 Resource Binding State
@@ -60,7 +61,6 @@ objects. They all follow simple, one-method binding calls, e.g.
   not have the scissor test enabled, then the scissor bounds never need to
   be set since they will not be used.
 * ``set_viewport_state``
-* ``set_vertex_elements``
 
 
 Clearing

src/gallium/docs/source/cso/velems.rst

@@ -0,0 +1,24 @@
+.. _vertex,elements
+
+Vertex Elements
+===============
+
+This state controls format etc. of the input attributes contained
+in the pipe_vertex_buffer(s). There's one pipe_vertex_element array member
+for each input attribute.
+
+Members
+-------
+
+src_offset
+    The byte offset of the attribute in the buffer given by
+    vertex_buffer_index for the first vertex.
+instance_divisor
+    The instance data rate divisor, used for instancing.
+    0 means this is per-vertex data, n means per-instance data used for
+    n consecutive instances (n > 0).
+vertex_buffer_index
+    The vertex buffer this attribute lives in. Several attributes may
+    live in the same vertex buffer.
+src_format
+    The format of the attribute data. One of the PIPE_FORMAT tokens.