[gtk/matthiasc/color-profiles: 17/32] wayland: Use EGL_KHR_no_config_context

[Matthias Clasen <matthiasc src gnome org>]

commit 656b9b79c27ab51fb41590b13ad697d6bedfa5d3
Author: Matthias Clasen <mclasen redhat com>
Date:   Fri Oct 1 20:18:18 2021 -0400

    wayland: Use EGL_KHR_no_config_context
    
    Require the EGL_KHR_no_config_context extension and
    create a configless GL context that can be used with
    any surface. This decouples context creation from
    fbconfig setting, and will let us change fbconfigs
    of surfaces on the fly, in the future.

 gdk/wayland/gdkglcontext-wayland.c | 32 +++++++++++++++++++++++---------
 1 file changed, 23 insertions(+), 9 deletions(-)
---
diff --git a/gdk/wayland/gdkglcontext-wayland.c b/gdk/wayland/gdkglcontext-wayland.c
index 4fc946cfab..f47bc0eb69 100644
--- a/gdk/wayland/gdkglcontext-wayland.c
+++ b/gdk/wayland/gdkglcontext-wayland.c
@@ -58,6 +58,7 @@ gdk_wayland_gl_context_realize (GdkGLContext *context,
   GdkGLContext *share = gdk_display_get_gl_context (display);
   GdkWaylandDisplay *display_wayland = GDK_WAYLAND_DISPLAY (display);
   EGLContext ctx;
+  EGLContext shared;
   EGLint context_attribs[N_EGL_ATTRS];
   int major, minor, flags;
   gboolean debug_bit, forward_bit, legacy_bit, use_es;
@@ -121,10 +122,14 @@ gdk_wayland_gl_context_realize (GdkGLContext *context,
                                legacy_bit ? "yes" : "no",
                                use_es ? "yes" : "no"));
 
+  if (share != NULL)
+    shared = GDK_WAYLAND_GL_CONTEXT (share)->egl_context;
+  else
+    shared = EGL_NO_CONTEXT;
+
   ctx = eglCreateContext (display_wayland->egl_display,
-                          display_wayland->egl_config,
-                          share != NULL ? GDK_WAYLAND_GL_CONTEXT (share)->egl_context
-                                        : EGL_NO_CONTEXT,
+                          EGL_NO_CONFIG_KHR,
+                          shared,
                           context_attribs);
 
   /* If context creation failed without the ES bit, let's try again with it */
@@ -147,10 +152,10 @@ gdk_wayland_gl_context_realize (GdkGLContext *context,
 
       GDK_DISPLAY_NOTE (display, OPENGL,
                 g_message ("eglCreateContext failed, switching to OpenGL ES"));
+
       ctx = eglCreateContext (display_wayland->egl_display,
-                              display_wayland->egl_config,
-                              share != NULL ? GDK_WAYLAND_GL_CONTEXT (share)->egl_context
-                                            : EGL_NO_CONTEXT,
+                              EGL_NO_CONFIG_KHR,
+                              shared,
                               context_attribs);
     }
 
@@ -176,10 +181,10 @@ gdk_wayland_gl_context_realize (GdkGLContext *context,
 
       GDK_DISPLAY_NOTE (display, OPENGL,
                 g_message ("eglCreateContext failed, switching to legacy"));
+
       ctx = eglCreateContext (display_wayland->egl_display,
-                              display_wayland->egl_config,
-                              share != NULL ? GDK_WAYLAND_GL_CONTEXT (share)->egl_context
-                                            : EGL_NO_CONTEXT,
+                              EGL_NO_CONFIG_KHR,
+                              shared,
                               context_attribs);
     }
 
@@ -611,6 +616,15 @@ gdk_wayland_display_init_gl (GdkDisplay  *display,
       return NULL;
     }
 
+  if (!epoxy_has_egl_extension (dpy, "EGL_KHR_no_config_context"))
+    {
+      eglTerminate (dpy);
+      g_set_error_literal (error, GDK_GL_ERROR,
+                           GDK_GL_ERROR_UNSUPPORTED_PROFILE,
+                           _("Configless contexts are not supported on this EGL implementation"));
+      return NULL;
+    }
+
   start_time2 = GDK_PROFILER_CURRENT_TIME;
   get_eglconfig (dpy, &display_wayland->egl_config_sdr, &display_wayland->egl_config_hdr);
   gdk_profiler_end_mark (start_time2, "get_eglconfig", NULL);