[Mesa-dev] [PATCH] intel: Track the miptree layer wrapped by a renderbuffer [v2]

[Chad Versace]

Add two fields to intel_renderbuffer:
    mt_level
    mt_layer

Multiple renderbuffers may simultaneously wrap a single texture and each
provide a different view into that texture. [Consider
glFramebufferTextureLayer()].  The new fields indicate which slice of the
miptree is wrapped by the renderbuffer.

The buffer resolve operations, to be introduced in the future, require
these fields in order to resolve the correct slice in the miptree.

v2:
   - [kwg] Replace bizarre condition `CubeMapFace > 0` with the more
     sensible `Target == GL_TEXTURE_CUBE_MAP`.

CC: Kenneth Graunke <kenneth at whitecape.org>
Reviewed-by: Eric Anholt <eric at anholt.net>
Signed-off-by: Chad Versace <chad.versace at linux.intel.com>
---
 src/mesa/drivers/dri/intel/intel_fbo.c |   37 +++++++++++++++++++++++++++----
 src/mesa/drivers/dri/intel/intel_fbo.h |   17 ++++++++++++++
 2 files changed, 49 insertions(+), 5 deletions(-)

diff --git a/src/mesa/drivers/dri/intel/intel_fbo.c b/src/mesa/drivers/dri/intel/intel_fbo.c
index 30a42ba..ef74647 100644
--- a/src/mesa/drivers/dri/intel/intel_fbo.c
+++ b/src/mesa/drivers/dri/intel/intel_fbo.c
@@ -948,8 +948,9 @@ intel_framebuffer_renderbuffer(struct gl_context * ctx,
 
 static bool
 intel_update_wrapper(struct gl_context *ctx, struct intel_renderbuffer *irb, 
-		     struct gl_texture_image *texImage)
+		     struct gl_renderbuffer_attachment *att)
 {
+   struct gl_texture_image *texImage = _mesa_get_attachment_teximage(att);
    struct intel_texture_image *intel_image = intel_texture_image(texImage);
    int width, height, depth;
 
@@ -973,15 +974,40 @@ intel_update_wrapper(struct gl_context *ctx, struct intel_renderbuffer *irb,
    irb->Base.Delete = intel_delete_renderbuffer;
    irb->Base.AllocStorage = intel_nop_alloc_storage;
 
+   irb->mt_level = att->TextureLevel;
+   if (texImage->TexObject->Target == GL_TEXTURE_CUBE_MAP) {
+      assert(att->Zoffset == 0);
+      irb->mt_layer = att->CubeMapFace;
+   } else {
+      assert(att->CubeMapFace == 0);
+      irb->mt_layer= att->Zoffset;
+   }
+
    if (intel_image->stencil_rb) {
       /*  The tex image has packed depth/stencil format, but is using separate
        *  stencil. It shares its embedded depth and stencil renderbuffers with
        *  the renderbuffer wrapper.
+       *
+       *  FIXME: glFramebufferTexture*() is broken for depthstencil textures
+       *  FIXME: with separate stencil. To fix this, we must create a separate
+       *  FIXME: pair of depth/stencil renderbuffers for each attached slice
+       *  FIXME: of the miptree.
        */
+      struct intel_renderbuffer *depth_irb;
+      struct intel_renderbuffer *stencil_irb;
+
       _mesa_reference_renderbuffer(&irb->wrapped_depth,
 				   intel_image->depth_rb);
       _mesa_reference_renderbuffer(&irb->wrapped_stencil,
 				   intel_image->stencil_rb);
+
+      depth_irb = intel_renderbuffer(intel_image->depth_rb);
+      depth_irb->mt_level = irb->mt_level;
+      depth_irb->mt_layer = irb->mt_layer;
+
+      stencil_irb = intel_renderbuffer(intel_image->stencil_rb);
+      stencil_irb->mt_level = irb->mt_level;
+      stencil_irb->mt_layer = irb->mt_layer;
    } else {
       intel_miptree_reference(&irb->mt, intel_image->mt);
    }
@@ -994,7 +1020,8 @@ intel_update_wrapper(struct gl_context *ctx, struct intel_renderbuffer *irb,
  * This will have the region info needed for hardware rendering.
  */
 static struct intel_renderbuffer *
-intel_wrap_texture(struct gl_context * ctx, struct gl_texture_image *texImage)
+intel_wrap_texture(struct gl_context * ctx,
+                   struct gl_renderbuffer_attachment *att)
 {
    const GLuint name = ~0;   /* not significant, but distinct for debugging */
    struct intel_renderbuffer *irb;
@@ -1009,7 +1036,7 @@ intel_wrap_texture(struct gl_context * ctx, struct gl_texture_image *texImage)
    _mesa_init_renderbuffer(&irb->Base, name);
    irb->Base.ClassID = INTEL_RB_CLASS;
 
-   if (!intel_update_wrapper(ctx, irb, texImage)) {
+   if (!intel_update_wrapper(ctx, irb, att)) {
       free(irb);
       return NULL;
    }
@@ -1114,7 +1141,7 @@ intel_render_texture(struct gl_context * ctx,
       return;
    }
    else if (!irb) {
-      irb = intel_wrap_texture(ctx, image);
+      irb = intel_wrap_texture(ctx, att);
       if (irb) {
          /* bind the wrapper to the attachment point */
          _mesa_reference_renderbuffer(&att->Renderbuffer, &irb->Base);
@@ -1126,7 +1153,7 @@ intel_render_texture(struct gl_context * ctx,
       }
    }
 
-   if (!intel_update_wrapper(ctx, irb, image)) {
+   if (!intel_update_wrapper(ctx, irb, att)) {
        _mesa_reference_renderbuffer(&att->Renderbuffer, NULL);
        _swrast_render_texture(ctx, fb, att);
        return;
diff --git a/src/mesa/drivers/dri/intel/intel_fbo.h b/src/mesa/drivers/dri/intel/intel_fbo.h
index 34d2f9a..3a21374 100644
--- a/src/mesa/drivers/dri/intel/intel_fbo.h
+++ b/src/mesa/drivers/dri/intel/intel_fbo.h
@@ -52,6 +52,23 @@ struct intel_renderbuffer
    GLbitfield map_mode;
 
    /**
+    * \name Miptree view
+    * \{
+    *
+    * Multiple renderbuffers may simultaneously wrap a single texture and each
+    * provide a different view into that texture. The fields below indicate
+    * which miptree slice is wrapped by this renderbuffer.  The fields' values
+    * are consistent with the 'level' and 'layer' parameters of
+    * glFramebufferTextureLayer().
+    *
+    * For renderbuffers not created with glFramebufferTexture*(), mt_level and
+    * mt_layer are 0.
+    */
+   unsigned int mt_level;
+   unsigned int mt_layer;
+   /** \} */
+
+   /**
     * \name Packed depth/stencil unwrappers
     *
     * If the intel_context is using separate stencil and this renderbuffer has
-- 
1.7.7.1