Wayfire display recovery attempt; for track-wlroots 0.18 branch

wayfire-display-recovery.patch

diff --git a/src/core/core-impl.hpp b/src/core/core-impl.hpp
index 8c31dfe6..1b4a6212 100644
--- a/src/core/core-impl.hpp
+++ b/src/core/core-impl.hpp
@@ -38,6 +38,8 @@ class compositor_core_impl_t : public compositor_core_t
     void disconnect_signals();
     void fini();
 
+    void reconfigure_outputs();
+
     static compositor_core_impl_t& get();
     static compositor_core_impl_t& allocate_core();
     static void deallocate_core();
diff --git a/src/core/core.cpp b/src/core/core.cpp
index fa35b895..b9dbb052 100644
--- a/src/core/core.cpp
+++ b/src/core/core.cpp
@@ -229,6 +229,19 @@ void wf::compositor_core_impl_t::post_init()
     this->emit(&startup_ev);
 }
 
+void wf::compositor_core_impl_t::reconfigure_outputs()
+{
+    output_layout = std::make_unique<wf::output_layout_t>(backend);
+    protocols.output_manager->layout = output_layout->get_handle();
+
+    // Move pointer to the middle of the leftmost, topmost output
+    wf::pointf_t p;
+    wf::output_t *wo = wf::get_core().output_layout->get_output_coords_at({FLT_MIN, FLT_MIN}, p);
+    // Output might be noop but guaranteed to not be null
+    wo->ensure_pointer(true);
+    seat->focus_output(wo);
+}
+
 void wf::compositor_core_impl_t::shutdown()
 {
     // We might get multiple signals in some scenarios. Shutdown only on the first instance.
diff --git a/src/main.cpp b/src/main.cpp
index 7cb23e1d..bbb6c5f9 100644
--- a/src/main.cpp
+++ b/src/main.cpp
@@ -401,6 +401,67 @@ int main(int argc, char *argv[])
     core.egl = wlr_gles2_renderer_get_egl(core.renderer);
     assert(core.egl);
 
+    wf::wl_listener_wrapper on_renderer_lost;
+    on_renderer_lost.set_callback([&] (void *data)
+    {
+        drm_fd = wlr_backend_get_drm_fd(core.backend);
+        if (drm_fd < 0)
+        {
+            char *drm_device = getenv("WLR_RENDER_DRM_DEVICE");
+            if (drm_device)
+            {
+                drm_fd = open(drm_device, O_RDWR | O_CLOEXEC);
+            }
+
+            if (drm_fd < 0)
+            {
+                LOGE("Failed to get DRM file descriptor,",
+                    " try specifying a valid WLR_RENDER_DRM_DEVICE!");
+                wl_display_destroy_clients(core.display);
+                wl_display_destroy(core.display);
+                return;
+            }
+        }
+
+        struct wlr_renderer *renderer = wlr_gles2_renderer_create_with_drm_fd(drm_fd);
+        if (!renderer)
+        {
+            LOGE("Failed to create new renderer");
+            return;
+        }
+        struct wlr_allocator *allocator = wlr_allocator_autocreate(core.backend, renderer);
+        if (!allocator)
+        {
+            LOGE("Failed to create new allocator");
+            return;
+        }
+        struct wlr_egl *egl = wlr_gles2_renderer_get_egl(renderer);
+        if (!egl)
+        {
+            LOGE("Failed to get new EGL");
+            return;
+        }
+
+        struct wlr_renderer *old_renderer = core.renderer;
+        struct wlr_allocator *old_allocator = core.allocator;
+        struct wlr_egl *old_egl = core.egl;
+
+        core.renderer = renderer;
+        core.allocator = allocator;
+        core.egl = egl;
+
+        on_renderer_lost.disconnect();
+        on_renderer_lost.connect(&renderer->events.lost);
+
+        wlr_compositor_set_renderer(core.compositor, renderer);
+
+        core.reconfigure_outputs();
+
+        wlr_allocator_destroy(old_allocator);
+        wlr_renderer_destroy(old_renderer);
+    });
+    on_renderer_lost.connect(&core.renderer->events.lost);
+
     if (!drop_permissions())
     {
         wl_display_destroy_clients(core.display);