intel: Replace intel_renderbuffer::region with a miptree [v3]

Essentially, this patch just globally substitutes `irb->region` with
`irb->mt->region` and then does some minor cleanups to avoid segfaults
and other problems.

This is in preparation for
  1. Fixing scatter/gather for mipmapped separate stencil textures.
  2. Supporting HiZ for mipmapped depth textures.

As a nice benefit, this lays down some preliminary groundwork for easily
texturing from any renderbuffer, even those of the window system.

A future commit will replace intel_mipmap_tree::hiz_region with a miptree.

v2:
   - Return early in intel_process_dri2_buffer_*() if region allocation
     fails.
   - Fix double semicolon.
   - Fix miptree reference leaks in the following functions:
       intel_process_dri2_buffer_with_separate_stencil()
       intel_image_target_renderbuffer_storage()

v3:
   - [anholt] Fix check for hiz allocation failure. Replace
     ``if (!irb->mt)` with ``if(!irb->mt->hiz_region)``.

Reviewed-by: Eric Anholt <[email protected]>
Reviewed-by: Kenneth Graunke <[email protected]>
Signed-off-by: Chad Versace <[email protected]>

1 files changed, 3 insertions, 2 deletions

diff --git a/src/mesa/drivers/dri/intel/intel_pixel_copy.c b/src/mesa/drivers/dri/intel/intel_pixel_copy.c
index 89d5c51ef15..2682e152abc 100644
--- a/src/mesa/drivers/dri/intel/intel_pixel_copy.c
+++ b/src/mesa/drivers/dri/intel/intel_pixel_copy.c
@@ -34,6 +34,7 @@
 
 #include "intel_context.h"
 #include "intel_buffers.h"
+#include "intel_mipmap_tree.h"
 #include "intel_regions.h"
 #include "intel_pixel.h"
 #include "intel_fbo.h"
@@ -188,8 +189,8 @@ do_blit_copypixels(struct gl_context * ctx,
    dsty += draw_irb->draw_y;
 
    if (!intel_region_copy(intel,
-			  draw_irb->region, 0, dstx, dsty,
-			  read_irb->region, 0, srcx, srcy,
+			  draw_irb->mt->region, 0, dstx, dsty,
+			  read_irb->mt->region, 0, srcx, srcy,
 			  width, height, flip,
 			  ctx->Color.ColorLogicOpEnabled ?
 			  ctx->Color.LogicOp : GL_COPY)) {