Mesa (master): i915: Fix 945 cube map layout for the small mipmaps along the bottom.

[Eric Anholt]

Module: Mesa
Branch: master
Commit: b197a8ade3e1e6c67743111f12f27e0a4a985cd9
URL:    http://cgit.freedesktop.org/mesa/mesa/commit/?id=b197a8ade3e1e6c67743111f12f27e0a4a985cd9

Author: Steinar H. Gunderson <sgunderson at bigfoot.com>
Date:   Tue May 12 11:32:03 2009 -0700

i915: Fix 945 cube map layout for the small mipmaps along the bottom.

Bug #21691.

---

 src/mesa/drivers/dri/i915/i915_tex_layout.c |   16 ++++++++++++++--
 1 files changed, 14 insertions(+), 2 deletions(-)

diff --git a/src/mesa/drivers/dri/i915/i915_tex_layout.c b/src/mesa/drivers/dri/i915/i915_tex_layout.c
index 7cc1c09..40bcf7a 100644
--- a/src/mesa/drivers/dri/i915/i915_tex_layout.c
+++ b/src/mesa/drivers/dri/i915/i915_tex_layout.c
@@ -55,6 +55,17 @@ static GLint step_offsets[6][2] = {
    [FACE_NEG_Z] = {-1, 1},
 };
 
+
+static GLint bottom_offsets[6] = {
+   [FACE_POS_X] = 16 + 0 * 8,
+   [FACE_POS_Y] = 16 + 1 * 8,
+   [FACE_POS_Z] = 16 + 2 * 8,
+   [FACE_NEG_X] = 16 + 3 * 8,
+   [FACE_NEG_Y] = 16 + 4 * 8,
+   [FACE_NEG_Z] = 16 + 5 * 8,
+};
+
+
 /**
  * Cube texture map layout for i830M-GM915.
  *
@@ -297,7 +308,7 @@ i915_miptree_layout(struct intel_context *intel, struct intel_mipmap_tree * mt)
  * +---+   +---+   +---+   +---+   +---+   +---+
  *
  * The bottom row continues with the remaining 2x2 then the 1x1 mip contents
- * in order, with each of them aligned to a 4x4 block boundary.  Thus, for
+ * in order, with each of them aligned to a 8x8 block boundary.  Thus, for
  * 32x32 cube maps and smaller, the bottom row layout is going to dictate the
  * pitch of the tree.  For a tree with 4x4 images, the pitch is at least
  * 14 * 8 = 112 texels, for 2x2 it is at least 12 * 8 texels, and for 1x1
@@ -375,10 +386,11 @@ i945_miptree_layout_cube(struct intel_context *intel,
 	       x = (face - 4) * 8;
 	       break;
 	    }
+	    break;
 
 	 case 2:
 	    y = mt->total_height - 4;
-	    x = 16 + face * 8;
+	    x = bottom_offsets[face];
 	    break;
 
 	 case 1: