asahi: Identify the separate varying count fields

Flat/goraud/linear and 32/16 need to be specified separately. This
change identifies the new fields but should be a functional no-op.

Signed-off-by: Asahi Lina <lina@asahilina.net>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/23998>

docs/drivers/asahi.rst

@@ -39,41 +39,66 @@ of the shader in the "Bind Vertex Pipeline" packet. The value may be interpreted
 consist of a single 32-bit value or an aligned 16-bit register pair, depending
 on whether interpolation should happen at 32-bit or 16-bit. Vertex outputs are
 indexed starting from 0, with the *vertex position* always coming first, the
-32-bit user varyings coming next, then 16-bit user varyings, and finally *point
-size* and *clip distances* at the end if present. Note that *clip distances* are
-not accessible from the fragment shader; if the fragment shader needs to read
-the interpolated clip distance, the vertex shader must *also* write the clip
-distance values to a user varying for the fragment shader to interpolate. Also
-note there is no clip plane enable mask anywhere; that must lowered for APIs
-that require this (OpenGL but not Vulkan).
+32-bit user varyings coming next with perspective, flat, and linear interpolated
+varyings grouped in that order, then 16-bit user varyings with the same groupings,
+and finally *point size* and *clip distances* at the end if present. Note that
+*clip distances* are not accessible from the fragment shader; if the fragment
+shader needs to read the interpolated clip distance, the vertex shader must
+*also* write the clip distance values to a user varying for the fragment shader
+to interpolate. Also note there is no clip plane enable mask anywhere; that must
+lowered for APIs that require this (OpenGL but not Vulkan).
 
 .. list-table:: Ordering of vertex outputs with all outputs used
    :widths: 25 75
    :header-rows: 1
 
-   * - Index
+   * - Size (words)
      - Value
-   * - 0
-     - Vertex position
    * - 4
-     - 32-bit varying 0
+     - Vertex position
+   * - 1
+     - 32-bit smooth varying 0
    * -
      - ...
-   * - 4 + m
-     - 32-bit varying m
-   * - 4 + m + 1
-     - Packed pair of 16-bit varyings 0
+   * - 1
+     - 32-bit smooth varying m
+   * - 1
+     - 32-bit flat varying 0
    * -
      - ...
-   * - 4 + m + 1 + n
-     - Packed pair of 16-bit varyings n
-   * - 4 + m + 1 + n + 1
+   * - 1
+     - 32-bit flat varying n
+   * - 1
+     - 32-bit linear varying 0
+   * -
+     - ...
+   * - 1
+     - 32-bit linear varying o
+   * - 1
+     - Packed pair of 16-bit smooth varyings 0
+   * -
+     - ...
+   * - 1
+     - Packed pair of 16-bit smooth varyings p
+   * - 1
+     - Packed pair of 16-bit flat varyings 0
+   * -
+     - ...
+   * - 1
+     - Packed pair of 16-bit flat varyings q
+   * - 1
+     - Packed pair of 16-bit linear varyings 0
+   * -
+     - ...
+   * - 1
+     - Packed pair of 16-bit linear varyings r
+   * - 1
      - Point size
-   * - 4 + m + 1 + n + 2 + 0
+   * - 1
      - Clip distance for plane 0
    * -
      - ...
-   * - 4 + m + 1 + n + 2 + 15
+   * - 1
      - Clip distance for plane 15
 
 Remapping