intel/isl: Treat 3-D textures as 2-D arrays for rendering

In particular, this means that isl_view::base_array_layer and
isl_view::array_len get applied to 3-D textures but only when rendering.
We were already applying isl_view::base_array_layer for rendering into 3-D
textures so this isn't a huge deviation.

Signed-off-by: Jason Ekstrand <[email protected]>
Reviewed-by: Kenneth Graunke <[email protected]>

1 files changed, 6 insertions, 0 deletions

diff --git a/src/intel/isl/isl.h b/src/intel/isl/isl.h
index bb20d1772d1..e01624bfae9 100644
--- a/src/intel/isl/isl.h
+++ b/src/intel/isl/isl.h
@@ -879,6 +879,12 @@ struct isl_view {
     *
     * For cube maps, both base_array_layer and array_len should be
     * specified in terms of 2-D layers and must be a multiple of 6.
+    *
+    * 3-D textures are effectively treated as 2-D arrays when used as a
+    * storage image or render target.  If `usage` contains
+    * ISL_SURF_USAGE_RENDER_TARGET_BIT or ISL_SURF_USAGE_STORAGE_BIT then
+    * base_array_layer and array_len are applied.  If the surface is only used
+    * for texturing, they are ignored.
     */
    uint32_t base_array_layer;
    uint32_t array_len;