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, 5 insertions, 4 deletions

diff --git a/src/mesa/drivers/dri/intel/intel_buffers.c b/src/mesa/drivers/dri/intel/intel_buffers.c
index 08f5c4decd3..4632751935a 100644
--- a/src/mesa/drivers/dri/intel/intel_buffers.c
+++ b/src/mesa/drivers/dri/intel/intel_buffers.c
@@ -28,6 +28,7 @@
 #include "intel_context.h"
 #include "intel_buffers.h"
 #include "intel_fbo.h"
+#include "intel_mipmap_tree.h"
 
 #include "main/framebuffer.h"
 #include "main/renderbuffer.h"
@@ -40,8 +41,8 @@ intel_drawbuf_region(struct intel_context *intel)
 {
    struct intel_renderbuffer *irbColor =
       intel_renderbuffer(intel->ctx.DrawBuffer->_ColorDrawBuffers[0]);
-   if (irbColor)
-      return irbColor->region;
+   if (irbColor && irbColor->mt)
+      return irbColor->mt->region;
    else
       return NULL;
 }
@@ -54,8 +55,8 @@ intel_readbuf_region(struct intel_context *intel)
 {
    struct intel_renderbuffer *irb
       = intel_renderbuffer(intel->ctx.ReadBuffer->_ColorReadBuffer);
-   if (irb)
-      return irb->region;
+   if (irb && irb->mt)
+      return irb->mt->region;
    else
       return NULL;
 }