[Mesa-dev] [PATCH] mesa/fbobject: Update CubeMapFace when reusing textures

[Nanley Chery]

Framebuffer attachments can be specified through FramebufferTexture*
calls. Upon specifying a depth (or stencil) framebuffer attachment that
internally reuses a texture, the cube map face of the new attachment
would not be updated (defaulting to TEXTURE_CUBE_MAP_POSITIVE_X).
Fix this issue by actually updating the CubeMapFace field.

This bug manifested itself in BindFramebuffer calls performed on
framebuffers whose stencil attachments internally reused a depth
texture.  When binding a framebuffer, we walk through the framebuffer's
attachments and update each one's corresponding gl_renderbuffer. Since
the framebuffer's depth and stencil attachments may share a
gl_renderbuffer and the walk visits the stencil attachment after
the depth attachment, the uninitialized CubeMapFace forced rendering
to TEXTURE_CUBE_MAP_POSITIVE_X.

Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=77662
Signed-off-by: Nanley Chery <nanley.g.chery at intel.com>
Cc: "12.0 13.0" <mesa-stable at lists.freedesktop.org>

---

This piglit patch will help catch this error in the future:
https://lists.freedesktop.org/archives/piglit/2016-November/021480.html

 src/mesa/main/fbobject.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/src/mesa/main/fbobject.c b/src/mesa/main/fbobject.c
index 9204606..64c4ab5 100644
--- a/src/mesa/main/fbobject.c
+++ b/src/mesa/main/fbobject.c
@@ -2850,6 +2850,7 @@ reuse_framebuffer_texture_attachment(struct gl_framebuffer *fb,
    dst_att->Type = src_att->Type;
    dst_att->Complete = src_att->Complete;
    dst_att->TextureLevel = src_att->TextureLevel;
+   dst_att->CubeMapFace = src_att->CubeMapFace;
    dst_att->Zoffset = src_att->Zoffset;
    dst_att->Layered = src_att->Layered;
 }
-- 
2.10.2