[Mesa-dev] [PATCH 1/3] mesa: Identify packed depth/stencil buffers using the Format field.

[Nick Bowler]

Intel sometimes uses packed depth/stencil buffers even when only a depth
buffer or only a stencil buffer was requested.  Common code currently
uses the _BaseFormat field to determine whether a depth/stencil wrapper
is necessary.  But unless the user explicitly requested a packed
depth/stencil buffer, the _BaseFormat field does not encode this
information, and the required wrappers are not created.

The problem was introduced by commit 45e76d2665b38b ("mesa: remove a
bunch of gl_renderbuffer fields"), which killed off the _ActualFormat
field upon which the decision to create a wrapper used to be made.  This
patch changes the logic to use the Format field instead, which is more
like the old code.

Fixes fdo bug 27590.

Signed-off-by: Nick Bowler <nbowler at draconx.ca>
---
 src/mesa/main/framebuffer.c |   18 ++++++++++++++++--
 1 files changed, 16 insertions(+), 2 deletions(-)

diff --git a/src/mesa/main/framebuffer.c b/src/mesa/main/framebuffer.c
index e0aac26..869401d 100644
--- a/src/mesa/main/framebuffer.c
+++ b/src/mesa/main/framebuffer.c
@@ -588,6 +588,20 @@ _mesa_update_framebuffer_visual(struct gl_framebuffer *fb)
    compute_depth_max(fb);
 }
 
+/**
+ * Determine if a renderbuffer is a packed depth/stencil buffer.
+ */
+static int rb_is_depth_stencil(struct gl_renderbuffer *rb)
+{
+   if (rb->Format == MESA_FORMAT_Z24_S8
+       || rb->Format == MESA_FORMAT_Z24_X8
+       || rb->Format == MESA_FORMAT_S8_Z24
+       || rb->Format == MESA_FORMAT_X8_Z24)
+      return 1;
+
+   return 0;
+}
+
 
 /**
  * Update the framebuffer's _DepthBuffer field using the renderbuffer
@@ -611,7 +625,7 @@ _mesa_update_depth_buffer(GLcontext *ctx,
 
    depthRb = fb->Attachment[attIndex].Renderbuffer;
 
-   if (depthRb && depthRb->_BaseFormat == GL_DEPTH_STENCIL) {
+   if (depthRb && rb_is_depth_stencil(depthRb)) {
       /* The attached depth buffer is a GL_DEPTH_STENCIL renderbuffer */
       if (!fb->_DepthBuffer
           || fb->_DepthBuffer->Wrapped != depthRb
@@ -652,7 +666,7 @@ _mesa_update_stencil_buffer(GLcontext *ctx,
 
    stencilRb = fb->Attachment[attIndex].Renderbuffer;
 
-   if (stencilRb && stencilRb->_BaseFormat == GL_DEPTH_STENCIL) {
+   if (stencilRb && rb_is_depth_stencil(stencilRb)) {
       /* The attached stencil buffer is a GL_DEPTH_STENCIL renderbuffer */
       if (!fb->_StencilBuffer
           || fb->_StencilBuffer->Wrapped != stencilRb
-- 
1.7.1