intel: Kill intel_mipmap_level::nr_images [v4]

For all texture targets except GL_TEXTURE_CUBE_MAP, the 'nr_images' and
'depth' fields of intel_mipmap_level were identical.  In the exceptional
case, nr_images == 6 and depth == 1.

It is simple to determine if a texture is a cube or not, so the presence
of two fields here was not helpful. Worse, it was confusing. When we
eventually implement GL_ARB_texture_cube_map_array, this mess would have
become even more confusing.

This patch removes 'nr_images' and assigns to 'depth' a consistent
meaning: depth is the number of 2D slices at each miplevel.  The exact
semantics of depth varies according to the texture target:
   - For GL_TEXTURE_CUBE_MAP, depth is 6.
   - For GL_TEXTURE_2D_ARRAY, depth is the number of array slices. It is
     identical for all miplevels in the texture.
   - For GL_TEXTURE_3D, it is the texture's depth at each miplevel. Its
     value, like width and height, varies with miplevel.
   - For other texture types, depth is 1.

As a consequence, parameters were removed from the following function
signatures:
    intel_miptree_set_level_info
        Remove 'nr_images'.

    i945_miptree_layout
    brw_miptree_layout_texture
    brw_miptree_layout_texture_array
        Remove 'slices'.

v2:
   - Replace "It's" with "Its".
   - Remove all hunks in intel_fbo.c. The hunks were spurious and sneaked
     in during a rebase.
   - Remove unneeded hunk in intel_tex_map_image_for_swrast(). It was
     a little refactor of the for-loop's upper bound.

v4:
   In intel_miptree_get_image_offset(), document the conditions under
   which different if-branches are taken.

Reviewed-by: Eric Anholt <eric@anholt.net>
Signed-off-by: Chad Versace <chad.versace@linux.intel.com>

src/mesa/drivers/dri/i965/brw_tex_layout.c

@@ -41,8 +41,7 @@
 
 static void
 brw_miptree_layout_texture_array(struct intel_context *intel,
-				 struct intel_mipmap_tree *mt,
-				 int slices)
+				 struct intel_mipmap_tree *mt)
 {
    GLuint align_w;
    GLuint align_h;
@@ -58,14 +57,14 @@ brw_miptree_layout_texture_array(struct intel_context *intel,
    if (mt->compressed)
       qpitch /= 4;
 
-   i945_miptree_layout_2d(mt, slices);
+   i945_miptree_layout_2d(mt);
 
    for (level = mt->first_level; level <= mt->last_level; level++) {
-      for (q = 0; q < slices; q++) {
+      for (q = 0; q < mt->depth0; q++) {
 	 intel_miptree_set_image_offset(mt, level, q, 0, q * qpitch);
       }
    }
-   mt->total_height = qpitch * slices;
+   mt->total_height = qpitch * mt->depth0;
 }
 
 void
@@ -82,7 +81,7 @@ brw_miptree_layout(struct intel_context *intel, struct intel_mipmap_tree *mt)
 	  * pitch of qpitch rows, where qpitch is defined by the equation given
 	  * in Volume 1 of the BSpec.
 	  */
-	 brw_miptree_layout_texture_array(intel, mt, 6);
+	 brw_miptree_layout_texture_array(intel, mt);
 	 break;
       }
       /* FALLTHROUGH */
@@ -117,7 +116,7 @@ brw_miptree_layout(struct intel_context *intel, struct intel_mipmap_tree *mt)
 	 GLint y = 0;
 	 GLint q, j;
 
-	 intel_miptree_set_level_info(mt, level, nr_images,
+	 intel_miptree_set_level_info(mt, level,
 				      0, mt->total_height,
 				      width, height, depth);
 
@@ -170,11 +169,11 @@ brw_miptree_layout(struct intel_context *intel, struct intel_mipmap_tree *mt)
 
    case GL_TEXTURE_2D_ARRAY:
    case GL_TEXTURE_1D_ARRAY:
-      brw_miptree_layout_texture_array(intel, mt, mt->depth0);
+      brw_miptree_layout_texture_array(intel, mt);
       break;
 
    default:
-      i945_miptree_layout_2d(mt, 1);
+      i945_miptree_layout_2d(mt);
       break;
    }
    DBG("%s: %dx%dx%d\n", __FUNCTION__,

src/mesa/drivers/dri/intel/intel_mipmap_tree.c

@@ -82,11 +82,17 @@ intel_miptree_create_internal(struct intel_context *intel,
    mt->last_level = last_level;
    mt->width0 = width0;
    mt->height0 = height0;
-   mt->depth0 = depth0;
    mt->cpp = compress_byte ? compress_byte : _mesa_get_format_bytes(mt->format);
    mt->compressed = compress_byte ? 1 : 0;
    mt->refcount = 1; 
 
+   if (target == GL_TEXTURE_CUBE_MAP) {
+      assert(depth0 == 1);
+      mt->depth0 = 6;
+   } else {
+      mt->depth0 = depth0;
+   }
+
 #ifdef I915
    (void) intel;
    if (intel->is_945)
@@ -287,7 +293,6 @@ intel_miptree_match_image(struct intel_mipmap_tree *mt,
 void
 intel_miptree_set_level_info(struct intel_mipmap_tree *mt,
 			     GLuint level,
-			     GLuint nr_images,
 			     GLuint x, GLuint y,
 			     GLuint w, GLuint h, GLuint d)
 {
@@ -296,15 +301,13 @@ intel_miptree_set_level_info(struct intel_mipmap_tree *mt,
    mt->level[level].depth = d;
    mt->level[level].level_x = x;
    mt->level[level].level_y = y;
-   mt->level[level].nr_images = nr_images;
 
    DBG("%s level %d size: %d,%d,%d offset %d,%d\n", __FUNCTION__,
        level, w, h, d, x, y);
 
-   assert(nr_images);
    assert(mt->level[level].slice == NULL);
 
-   mt->level[level].slice = malloc(nr_images * sizeof(*mt->level[0].slice));
+   mt->level[level].slice = malloc(d * sizeof(*mt->level[0].slice));
    mt->level[level].slice[0].x_offset = mt->level[level].level_x;
    mt->level[level].slice[0].y_offset = mt->level[level].level_y;
 }
@@ -318,7 +321,7 @@ intel_miptree_set_image_offset(struct intel_mipmap_tree *mt,
    if (img == 0 && level == 0)
       assert(x == 0 && y == 0);
 
-   assert(img < mt->level[level].nr_images);
+   assert(img < mt->level[level].depth);
 
    mt->level[level].slice[img].x_offset = mt->level[level].level_x + x;
    mt->level[level].slice[img].y_offset = mt->level[level].level_y + y;
@@ -330,28 +333,33 @@ intel_miptree_set_image_offset(struct intel_mipmap_tree *mt,
 }
 
 
+/**
+ * For cube map textures, either the \c face parameter can be used, of course,
+ * or the cube face can be interpreted as a depth layer and the \c layer
+ * parameter used.
+ */
 void
 intel_miptree_get_image_offset(struct intel_mipmap_tree *mt,
-			       GLuint level, GLuint face, GLuint depth,
+			       GLuint level, GLuint face, GLuint layer,
 			       GLuint *x, GLuint *y)
 {
-   switch (mt->target) {
-   case GL_TEXTURE_CUBE_MAP_ARB:
-      *x = mt->level[level].slice[face].x_offset;
-      *y = mt->level[level].slice[face].y_offset;
-      break;
-   case GL_TEXTURE_3D:
-   case GL_TEXTURE_2D_ARRAY_EXT:
-   case GL_TEXTURE_1D_ARRAY_EXT:
-      assert(depth < mt->level[level].nr_images);
-      *x = mt->level[level].slice[depth].x_offset;
-      *y = mt->level[level].slice[depth].y_offset;
-      break;
-   default:
-      *x = mt->level[level].slice[0].x_offset;
-      *y = mt->level[level].slice[0].y_offset;
-      break;
+   int slice;
+
+   if (face > 0) {
+      assert(mt->target == GL_TEXTURE_CUBE_MAP);
+      assert(face < 6);
+      assert(layer == 0);
+      slice = face;
+   } else {
+      /* This branch may be taken even if the texture target is a cube map. In
+       * that case, the caller chose to interpret each cube face as a layer.
+       */
+      assert(face == 0);
+      slice = layer;
    }
+
+   *x = mt->level[level].slice[slice].x_offset;
+   *y = mt->level[level].slice[slice].y_offset;
 }
 
 static void
@@ -429,7 +437,7 @@ intel_miptree_copy_teximage(struct intel_context *intel,
    struct intel_mipmap_tree *src_mt = intelImage->mt;
    int level = intelImage->base.Base.Level;
    int face = intelImage->base.Base.Face;
-   GLuint depth = src_mt->level[level].depth;
+   GLuint depth = intelImage->base.Base.Depth;
 
    for (int slice = 0; slice < depth; slice++) {
       intel_miptree_copy_slice(intel, dst_mt, src_mt, level, face, slice);

src/mesa/drivers/dri/intel/intel_mipmap_tree.h

@@ -69,16 +69,25 @@ struct intel_mipmap_level
    GLuint level_y;
    GLuint width;
    GLuint height;
-   /** Depth of the mipmap at this level: 1 for 1D/2D/CUBE, n for 3D. */
+
+   /**
+    * \brief Number of 2D slices in this miplevel.
+    *
+    * The exact semantics of depth varies according to the texture target:
+    *    - For GL_TEXTURE_CUBE_MAP, depth is 6.
+    *    - For GL_TEXTURE_2D_ARRAY, depth is the number of array slices. It is
+    *      identical for all miplevels in the texture.
+    *    - For GL_TEXTURE_3D, it is the texture's depth at this miplevel. Its
+    *      value, like width and height, varies with miplevel.
+    *    - For other texture types, depth is 1.
+    */
    GLuint depth;
-   /** Number of images at this level: 1 for 1D/2D, 6 for CUBE, depth for 3D */
-   GLuint nr_images;
 
    /**
     * \brief List of 2D images in this mipmap level.
     *
     * This may be a list of cube faces, array slices in 2D array texture, or
-    * layers in a 3D texture. The list's length is \c nr_images.
+    * layers in a 3D texture. The list's length is \c depth.
     */
    struct intel_mipmap_slice {
       /**
@@ -205,7 +214,6 @@ intel_miptree_get_dimensions_for_image(struct gl_texture_image *image,
 
 void intel_miptree_set_level_info(struct intel_mipmap_tree *mt,
                                   GLuint level,
-                                  GLuint nr_images,
                                   GLuint x, GLuint y,
                                   GLuint w, GLuint h, GLuint d);
 

src/mesa/drivers/dri/intel/intel_tex_layout.c

@@ -50,7 +50,7 @@ intel_get_texture_alignment_unit(gl_format format,
    }
 }
 
-void i945_miptree_layout_2d(struct intel_mipmap_tree *mt, int nr_images)
+void i945_miptree_layout_2d(struct intel_mipmap_tree *mt)
 {
    GLuint align_h, align_w;
    GLuint level;
@@ -93,7 +93,7 @@ void i945_miptree_layout_2d(struct intel_mipmap_tree *mt, int nr_images)
    for ( level = mt->first_level ; level <= mt->last_level ; level++ ) {
       GLuint img_height;
 
-      intel_miptree_set_level_info(mt, level, nr_images, x, y, width,
+      intel_miptree_set_level_info(mt, level, x, y, width,
 				   height, depth);
 
       img_height = ALIGN(height, align_h);

src/mesa/drivers/dri/intel/intel_tex_layout.h

@@ -38,7 +38,6 @@ static INLINE GLuint minify( GLuint d )
    return MAX2(1, d>>1);
 }
 
-extern void i945_miptree_layout_2d(struct intel_mipmap_tree *mt,
-				   int nr_images);
+extern void i945_miptree_layout_2d(struct intel_mipmap_tree *mt);
 void intel_get_texture_alignment_unit(gl_format format,
 				      unsigned int *w, unsigned int *h);

src/mesa/drivers/dri/intel/intel_tex_validate.c

@@ -154,7 +154,7 @@ intel_tex_map_image_for_swrast(struct intel_context *intel,
 
       intel_image->base.Data = intel_region_map(intel, mt->region, mode);
    } else {
-      assert(mt->level[level].depth == 1);
+      assert(intel_image->base.Base.Depth == 1);
       intel_miptree_get_image_offset(mt, level, face, 0, &x, &y);
 
       DBG("%s: (%d,%d) -> (%d, %d)/%d\n",