mesa: Identify packed depth/stencil buffers using the Format field.

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@draconx.ca>
Signed-off-by: Brian Paul <brianp@vmware.com>

1 files changed, 16 insertions, 0 deletions

diff --git a/src/mesa/main/formats.c b/src/mesa/main/formats.c
index 90449cc04f..c5f3e0b21d 100644
--- a/src/mesa/main/formats.c
+++ b/src/mesa/main/formats.c
@@ -940,6 +940,22 @@ _mesa_is_format_compressed(gl_format format)
 
 
 /**
+ * Determine if the given format represents a packed depth/stencil buffer.
+ */
+GLboolean
+_mesa_is_format_packed_depth_stencil(gl_format format)
+{
+   if (format == MESA_FORMAT_Z24_S8
+       || format == MESA_FORMAT_Z24_X8
+       || format == MESA_FORMAT_S8_Z24
+       || format == MESA_FORMAT_X8_Z24)
+      return GL_TRUE;
+
+   return GL_FALSE;
+}
+
+
+/**
  * Return color encoding for given format.
  * \return GL_LINEAR or GL_SRGB
  */