[Mesa-stable] [PATCH 3/3] mesa: Use _mesa_detach_renderbuffer when deleting a texture

[Ian Romanick]

From: Ian Romanick <ian.d.romanick at intel.com>

The functional change is that now invalidate_framebuffer is called if
the texture is actually detached from one of the currently bound FBOs.
Previously this was only done for renderbuffers.

The remaining changes make the texture delete path look more similar to
the renderbuffer delete path.  This includes adding relevant spec
quotations to justify the behavior.

Fixes piglit fbo-incomplete "delete texture of bound FBO" test.

Signed-off-by: Ian Romanick <ian.d.romanick at intel.com>
Cc: "9.2" mesa-stable at lists.freedesktop.org
---
 src/mesa/main/fbobject.c | 23 +++++++++++++++++++----
 src/mesa/main/texobj.c   | 42 +++++++++++++++++++++++++++---------------
 2 files changed, 46 insertions(+), 19 deletions(-)

diff --git a/src/mesa/main/fbobject.c b/src/mesa/main/fbobject.c
index d121167..1034c7a 100644
--- a/src/mesa/main/fbobject.c
+++ b/src/mesa/main/fbobject.c
@@ -1223,10 +1223,8 @@ _mesa_BindRenderbufferEXT(GLenum target, GLuint renderbuffer)
 
 
 /**
- * If the given renderbuffer is anywhere attached to the framebuffer, detach
- * the renderbuffer.
- * This is used when a renderbuffer object is deleted.
- * The spec calls for unbinding.
+ * Remove the specified renderbuffer or texture from any attachment point in
+ * the framebuffer.
  *
  * \returns
  * \c true if the renderbuffer was detached from an attachment point.  \c
@@ -1287,6 +1285,23 @@ _mesa_DeleteRenderbuffers(GLsizei n, const GLuint *renderbuffers)
                _mesa_BindRenderbuffer(GL_RENDERBUFFER_EXT, 0);
             }
 
+            /* Section 4.4.2 (Attaching Images to Framebuffer Objects),
+             * subsection "Attaching Renderbuffer Images to a Framebuffer," of
+             * the OpenGL 3.1 spec says:
+             *
+             *     "If a renderbuffer object is deleted while its image is
+             *     attached to one or more attachment points in the currently
+             *     bound framebuffer, then it is as if FramebufferRenderbuffer
+             *     had been called, with a renderbuffer of 0, for each
+             *     attachment point to which this image was attached in the
+             *     currently bound framebuffer. In other words, this
+             *     renderbuffer image is first detached from all attachment
+             *     points in the currently bound framebuffer. Note that the
+             *     renderbuffer image is specifically not detached from any
+             *     non-bound framebuffers. Detaching the image from any
+             *     non-bound framebuffers is the responsibility of the
+             *     application.
+             */
             if (_mesa_is_user_fbo(ctx->DrawBuffer)) {
                _mesa_detach_renderbuffer(ctx, ctx->DrawBuffer, rb);
             }
diff --git a/src/mesa/main/texobj.c b/src/mesa/main/texobj.c
index 1666a66..7c8f04d 100644
--- a/src/mesa/main/texobj.c
+++ b/src/mesa/main/texobj.c
@@ -1041,23 +1041,35 @@ static void
 unbind_texobj_from_fbo(struct gl_context *ctx,
                        struct gl_texture_object *texObj)
 {
-   const GLuint n = (ctx->DrawBuffer == ctx->ReadBuffer) ? 1 : 2;
-   GLuint i;
+   bool progress = false;
 
-   for (i = 0; i < n; i++) {
-      struct gl_framebuffer *fb = (i == 0) ? ctx->DrawBuffer : ctx->ReadBuffer;
-      if (_mesa_is_user_fbo(fb)) {
-         GLuint j;
-         for (j = 0; j < BUFFER_COUNT; j++) {
-            if (fb->Attachment[j].Type == GL_TEXTURE &&
-                fb->Attachment[j].Texture == texObj) {
-	       /* Vertices are already flushed by _mesa_DeleteTextures */
-	       ctx->NewState |= _NEW_BUFFERS;
-               _mesa_remove_attachment(ctx, fb->Attachment + j);         
-            }
-         }
-      }
+   /* Section 4.4.2 (Attaching Images to Framebuffer Objects), subsection
+    * "Attaching Texture Images to a Framebuffer," of the OpenGL 3.1 spec
+    * says:
+    *
+    *     "If a texture object is deleted while its image is attached to one
+    *     or more attachment points in the currently bound framebuffer, then
+    *     it is as if FramebufferTexture* had been called, with a texture of
+    *     zero, for each attachment point to which this image was attached in
+    *     the currently bound framebuffer. In other words, this texture image
+    *     is first detached from all attachment points in the currently bound
+    *     framebuffer. Note that the texture image is specifically not
+    *     detached from any other framebuffer objects. Detaching the texture
+    *     image from any other framebuffer objects is the responsibility of
+    *     the application."
+    */
+   if (_mesa_is_user_fbo(ctx->DrawBuffer)) {
+      progress = _mesa_detach_renderbuffer(ctx, ctx->DrawBuffer, texObj);
    }
+   if (_mesa_is_user_fbo(ctx->ReadBuffer)
+       && ctx->ReadBuffer != ctx->DrawBuffer) {
+      progress = _mesa_detach_renderbuffer(ctx, ctx->ReadBuffer, texObj)
+         || progress;
+   }
+
+   if (progress)
+      /* Vertices are already flushed by _mesa_DeleteTextures */
+      ctx->NewState |= _NEW_BUFFERS;
 }
 
 
-- 
1.8.1.4