[mutter] cogl: Rebind the EGL image when handling damage

[Marge Bot <marge-bot src gnome org>]

commit ad071c64f9cfb1d3860a8e9574a9a55c486816e7
Author: Neil Roberts <nroberts igalia com>
Date:   Tue Oct 26 18:19:12 2021 +0200

    cogl: Rebind the EGL image when handling damage
    
    When Cogl gained support for importing pixmaps, I think there was a
    misunderstanding that there is a difference in how it works in GLX and
    EGL where GLX needs to rebind the pixmap in order to guarantee that
    changes are reflected in the texture after it detects damage, whereas
    with EGL it doesn’t. The GLX spec makes it pretty clear that it does
    need to rebind whereas the EGL spec is a bit harder to follow. As a
    fallout from Mesa MR 12869, it seems like the compositor really does
    need to rebind the image to comply with the spec. Notably, in
    OES_EGL_image_external there is:
    
    "Binding (or re-binding if already bound) an external texture by calling
     BindTexture after all modifications are complete guarantees that
     sampling done in future draw calls will return values corresponding to
     the values in the buffer at or after the time that BindTexture is
     called."
    
    So this commit changes the x11_damage_notify handler for EGL to lazily
    queue a rebind like GLX does. The code that binds the image while
    allocating the texture has been moved into a reusable helper function.
    
    It seems like there is a bit of a layering violation when accessing the
    GL driver internals from the EGL winsys code, but I noticed that the GLX
    code also includes the driver GL headers and otherwise it seems pretty
    tricky to do properly.
    
    Part-of: <https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/2062>

 cogl/cogl/driver/gl/cogl-texture-2d-gl-private.h |  7 +++++
 cogl/cogl/driver/gl/cogl-texture-2d-gl.c         | 38 +++++++++++++++++-------
 cogl/cogl/winsys/cogl-winsys-egl-x11.c           | 32 ++++++++++++++++++++
 3 files changed, 67 insertions(+), 10 deletions(-)
---
diff --git a/cogl/cogl/driver/gl/cogl-texture-2d-gl-private.h 
b/cogl/cogl/driver/gl/cogl-texture-2d-gl-private.h
index c106376277..574c10fb0a 100644
--- a/cogl/cogl/driver/gl/cogl-texture-2d-gl-private.h
+++ b/cogl/cogl/driver/gl/cogl-texture-2d-gl-private.h
@@ -60,6 +60,13 @@ _cogl_texture_2d_gl_new_from_bitmap (CoglBitmap *bmp,
                                      gboolean can_convert_in_place,
                                      GError **error);
 
+#if defined (COGL_HAS_EGL_SUPPORT)
+gboolean
+cogl_texture_2d_gl_bind_egl_image (CoglTexture2D *tex_2d,
+                                   EGLImageKHR    image,
+                                   GError       **error);
+#endif
+
 #if defined (COGL_HAS_EGL_SUPPORT) && defined (EGL_KHR_image_base)
 CoglTexture2D *
 _cogl_egl_texture_2d_gl_new_from_image (CoglContext *ctx,
diff --git a/cogl/cogl/driver/gl/cogl-texture-2d-gl.c b/cogl/cogl/driver/gl/cogl-texture-2d-gl.c
index 4862dbe2e6..23111eabfb 100644
--- a/cogl/cogl/driver/gl/cogl-texture-2d-gl.c
+++ b/cogl/cogl/driver/gl/cogl-texture-2d-gl.c
@@ -274,18 +274,11 @@ allocate_from_egl_image (CoglTexture2D *tex_2d,
 
   tex_2d->gl_texture =
     ctx->texture_driver->gen (ctx, GL_TEXTURE_2D, internal_format);
-  _cogl_bind_gl_texture_transient (GL_TEXTURE_2D,
-                                   tex_2d->gl_texture);
-  _cogl_gl_util_clear_gl_errors (ctx);
 
-  ctx->glEGLImageTargetTexture2D (GL_TEXTURE_2D, loader->src.egl_image.image);
-  if (_cogl_gl_util_get_error (ctx) != GL_NO_ERROR)
+  if (!cogl_texture_2d_gl_bind_egl_image (tex_2d,
+                                          loader->src.egl_image.image,
+                                          error))
     {
-      g_set_error_literal (error,
-                           COGL_TEXTURE_ERROR,
-                           COGL_TEXTURE_ERROR_BAD_PARAMETER,
-                           "Could not create a CoglTexture2D from a given "
-                           "EGLImage");
       GE( ctx, glDeleteTextures (1, &tex_2d->gl_texture) );
       return FALSE;
     }
@@ -360,6 +353,31 @@ allocate_custom_egl_image_external (CoglTexture2D *tex_2d,
   return TRUE;
 }
 
+gboolean
+cogl_texture_2d_gl_bind_egl_image (CoglTexture2D *tex_2d,
+                                   EGLImageKHR    image,
+                                   GError       **error)
+{
+  CoglContext *ctx = COGL_TEXTURE (tex_2d)->context;
+
+  _cogl_bind_gl_texture_transient (GL_TEXTURE_2D,
+                                   tex_2d->gl_texture);
+  _cogl_gl_util_clear_gl_errors (ctx);
+
+  ctx->glEGLImageTargetTexture2D (GL_TEXTURE_2D, image);
+  if (_cogl_gl_util_get_error (ctx) != GL_NO_ERROR)
+    {
+      g_set_error_literal (error,
+                           COGL_TEXTURE_ERROR,
+                           COGL_TEXTURE_ERROR_BAD_PARAMETER,
+                           "Could not bind the given EGLImage to a "
+                           "CoglTexture2D");
+      return FALSE;
+    }
+
+  return TRUE;
+}
+
 CoglTexture2D *
 cogl_texture_2d_new_from_egl_image_external (CoglContext *ctx,
                                              int width,
diff --git a/cogl/cogl/winsys/cogl-winsys-egl-x11.c b/cogl/cogl/winsys/cogl-winsys-egl-x11.c
index abe740a210..bef385a55c 100644
--- a/cogl/cogl/winsys/cogl-winsys-egl-x11.c
+++ b/cogl/cogl/winsys/cogl-winsys-egl-x11.c
@@ -43,6 +43,7 @@
 #include "cogl-renderer-private.h"
 #include "cogl-texture-pixmap-x11-private.h"
 #include "cogl-texture-2d-private.h"
+#include "driver/gl/cogl-texture-2d-gl-private.h"
 #include "cogl-texture-2d.h"
 #include "cogl-poll-private.h"
 #include "winsys/cogl-onscreen-egl.h"
@@ -62,6 +63,7 @@ typedef struct _CoglTexturePixmapEGL
 {
   EGLImageKHR image;
   CoglTexture *texture;
+  gboolean bind_tex_image_queued;
 } CoglTexturePixmapEGL;
 #endif
 
@@ -496,6 +498,9 @@ _cogl_winsys_texture_pixmap_x11_create (CoglTexturePixmapX11 *tex_pixmap)
                                         COGL_EGL_IMAGE_FLAG_NONE,
                                         NULL));
 
+  /* The image is initially bound as part of the creation */
+  egl_tex_pixmap->bind_tex_image_queued = FALSE;
+
   tex_pixmap->winsys = egl_tex_pixmap;
 
   return TRUE;
@@ -530,15 +535,42 @@ _cogl_winsys_texture_pixmap_x11_update (CoglTexturePixmapX11 *tex_pixmap,
                                         CoglTexturePixmapStereoMode stereo_mode,
                                         gboolean needs_mipmap)
 {
+  CoglTexturePixmapEGL *egl_tex_pixmap = tex_pixmap->winsys;
+  CoglTexture2D *tex_2d;
+  GError *error = NULL;
+
   if (needs_mipmap)
     return FALSE;
 
+  if (egl_tex_pixmap->bind_tex_image_queued)
+    {
+      COGL_NOTE (TEXTURE_PIXMAP, "Rebinding GLXPixmap for %p", tex_pixmap);
+
+      tex_2d = COGL_TEXTURE_2D (egl_tex_pixmap->texture);
+
+      if (cogl_texture_2d_gl_bind_egl_image (tex_2d,
+                                             egl_tex_pixmap->image,
+                                             &error))
+        {
+          egl_tex_pixmap->bind_tex_image_queued = FALSE;
+        }
+      else
+        {
+          g_warning ("Failed to rebind EGLImage to CoglTexture2D: %s",
+                     error->message);
+          g_error_free (error);
+        }
+    }
+
   return TRUE;
 }
 
 static void
 _cogl_winsys_texture_pixmap_x11_damage_notify (CoglTexturePixmapX11 *tex_pixmap)
 {
+  CoglTexturePixmapEGL *egl_tex_pixmap = tex_pixmap->winsys;
+
+  egl_tex_pixmap->bind_tex_image_queued = TRUE;
 }
 
 static CoglTexture *