Mesa (10.2): i965/Gen7: Set up layer constraints properly for depth buffers

[Jordan Justen]

Module: Mesa
Branch: 10.2
Commit: af228e999cb86c02060748c396e1237472055aed
URL:    http://cgit.freedesktop.org/mesa/mesa/commit/?id=af228e999cb86c02060748c396e1237472055aed

Author: Chris Forbes <chrisf at ijw.co.nz>
Date:   Thu May  8 16:29:41 2014 +1200

i965/Gen7: Set up layer constraints properly for depth buffers

Again, a few problems:
- Layered attachments did not honor MinLayer.
- Non-layered MSAA attachments rendered to the wrong layer due to
  dividing by the layer count. All depth buffers use the IMS layout, so
  the physical layer count == logical layer count.
- Layered attachments were not limited to irb->layer_count, so we could
  render off the end of the texture.

V2: Restore the MAX2() to account for zero depth/layer_count.

Signed-off-by: Chris Forbes <chrisf at ijw.co.nz>
Reviewed-by: Kenneth Graunke <kenneth at whitecape.org>
(cherry picked from commit 77d55ef4819436ebbf9786a1e720ec00707bbb19)

---

 src/mesa/drivers/dri/i965/gen7_misc_state.c |   15 ++++++---------
 1 file changed, 6 insertions(+), 9 deletions(-)

diff --git a/src/mesa/drivers/dri/i965/gen7_misc_state.c b/src/mesa/drivers/dri/i965/gen7_misc_state.c
index b6759f1..d8efa76 100644
--- a/src/mesa/drivers/dri/i965/gen7_misc_state.c
+++ b/src/mesa/drivers/dri/i965/gen7_misc_state.c
@@ -65,7 +65,7 @@ gen7_emit_depth_stencil_hiz(struct brw_context *brw,
    rb = (struct gl_renderbuffer*) irb;
 
    if (rb) {
-      depth = MAX2(rb->Depth, 1);
+      depth = MAX2(irb->layer_count, 1);
       if (rb->TexImage)
          gl_target = rb->TexImage->TexObject->Target;
    }
@@ -81,19 +81,16 @@ gen7_emit_depth_stencil_hiz(struct brw_context *brw,
       surftype = BRW_SURFACE_2D;
       depth *= 6;
       break;
+   case GL_TEXTURE_3D:
+      assert(rb);
+      depth = MAX2(rb->Depth, 1);
+      /* fallthrough */
    default:
       surftype = translate_tex_target(gl_target);
       break;
    }
 
-   if (fb->MaxNumLayers > 0 || !irb) {
-      min_array_element = 0;
-   } else if (irb->mt->num_samples > 1) {
-      /* Convert physical layer to logical layer. */
-      min_array_element = irb->mt_layer / irb->mt->num_samples;
-   } else {
-      min_array_element = irb->mt_layer;
-   }
+   min_array_element = irb ? irb->mt_layer : 0;
 
    lod = irb ? irb->mt_level - irb->mt->first_level : 0;