[Mesa-dev] [RFC PATCH 13/16] i965: Support array_spacing_lod0 for multiple miplevels

[Jordan Justen]

Previously array spacing lod0 was only used with a single mip level.

It indicated that no mip level spacing should be used between array
slices.

gen6 stencil only support LOD0, so we need to allocate the miptree
similar to array spacing lod0, except we also need space for more
than just one mip level.

So, the miptree is allocated with tightly packed array slice spacing,
but we still also pack the miplevels into the region similar to a
normal multi mip level packing.

Essentially, the miptree is set up as if the texture slices formed
one tall 2D texture, rather than a 2D array.

Signed-off-by: Jordan Justen <jordan.l.justen at intel.com>
---
 src/mesa/drivers/dri/i965/brw_tex_layout.c | 21 +++++++++++++++++++--
 1 file changed, 19 insertions(+), 2 deletions(-)

diff --git a/src/mesa/drivers/dri/i965/brw_tex_layout.c b/src/mesa/drivers/dri/i965/brw_tex_layout.c
index 76044b2..8a0912d 100644
--- a/src/mesa/drivers/dri/i965/brw_tex_layout.c
+++ b/src/mesa/drivers/dri/i965/brw_tex_layout.c
@@ -203,6 +203,11 @@ brw_miptree_layout_2d(struct intel_mipmap_tree *mt)
       if (mt->compressed)
 	 img_height /= mt->align_h;
 
+      if (mt->array_spacing_lod0) {
+         /* Compact arrays with separated miplevels */
+	 img_height *= depth;
+      }
+
       /* Because the images are packed better, the final offset
        * might not be the maximal one:
        */
@@ -238,6 +243,7 @@ brw_miptree_layout_texture_array(struct brw_context *brw,
 				 struct intel_mipmap_tree *mt)
 {
    int h0, h1;
+   unsigned height = mt->physical_height0;
 
    h0 = ALIGN(mt->physical_height0, mt->align_h);
    h1 = ALIGN(minify(mt->physical_height0, 1), mt->align_h);
@@ -251,11 +257,22 @@ brw_miptree_layout_texture_array(struct brw_context *brw,
    brw_miptree_layout_2d(mt);
 
    for (unsigned level = mt->first_level; level <= mt->last_level; level++) {
+      unsigned img_height;
+      img_height = ALIGN(height, mt->align_h);
+      if (mt->compressed)
+         img_height /= mt->align_h;
+
       for (int q = 0; q < mt->physical_depth0; q++) {
-	 intel_miptree_set_image_offset(mt, level, q, 0, q * physical_qpitch);
+         if (mt->array_spacing_lod0) {
+            intel_miptree_set_image_offset(mt, level, q, 0, q * img_height);
+         } else {
+            intel_miptree_set_image_offset(mt, level, q, 0, q * physical_qpitch);
+         }
       }
+      height = minify(height, 1);
    }
-   mt->total_height = physical_qpitch * mt->physical_depth0;
+   if (!mt->array_spacing_lod0)
+      mt->total_height = physical_qpitch * mt->physical_depth0;
 
    align_cube(mt);
 }
-- 
2.0.0.rc4