Move OpenGL context management to FlOpenGLManager (#166025)

This helps to make a non-OpenGL FlRenderer

Author: robert-ancell

engine/src/flutter/ci/licenses_golden/licenses_flutter

@@ -53264,6 +53264,8 @@ ORIGIN: ../../../flutter/shell/platform/linux/fl_mouse_cursor_channel.cc + ../..
 ORIGIN: ../../../flutter/shell/platform/linux/fl_mouse_cursor_channel.h + ../../../flutter/LICENSE
 ORIGIN: ../../../flutter/shell/platform/linux/fl_mouse_cursor_handler.cc + ../../../flutter/LICENSE
 ORIGIN: ../../../flutter/shell/platform/linux/fl_mouse_cursor_handler.h + ../../../flutter/LICENSE
+ORIGIN: ../../../flutter/shell/platform/linux/fl_opengl_manager.cc + ../../../flutter/LICENSE
+ORIGIN: ../../../flutter/shell/platform/linux/fl_opengl_manager.h + ../../../flutter/LICENSE
 ORIGIN: ../../../flutter/shell/platform/linux/fl_pixel_buffer_texture.cc + ../../../flutter/LICENSE
 ORIGIN: ../../../flutter/shell/platform/linux/fl_pixel_buffer_texture_private.h + ../../../flutter/LICENSE
 ORIGIN: ../../../flutter/shell/platform/linux/fl_pixel_buffer_texture_test.cc + ../../../flutter/LICENSE
@@ -53284,10 +53286,6 @@ ORIGIN: ../../../flutter/shell/platform/linux/fl_renderable.cc + ../../../flutte
 ORIGIN: ../../../flutter/shell/platform/linux/fl_renderable.h + ../../../flutter/LICENSE
 ORIGIN: ../../../flutter/shell/platform/linux/fl_renderer.cc + ../../../flutter/LICENSE
 ORIGIN: ../../../flutter/shell/platform/linux/fl_renderer.h + ../../../flutter/LICENSE
-ORIGIN: ../../../flutter/shell/platform/linux/fl_renderer_gdk.cc + ../../../flutter/LICENSE
-ORIGIN: ../../../flutter/shell/platform/linux/fl_renderer_gdk.h + ../../../flutter/LICENSE
-ORIGIN: ../../../flutter/shell/platform/linux/fl_renderer_headless.cc + ../../../flutter/LICENSE
-ORIGIN: ../../../flutter/shell/platform/linux/fl_renderer_headless.h + ../../../flutter/LICENSE
 ORIGIN: ../../../flutter/shell/platform/linux/fl_renderer_test.cc + ../../../flutter/LICENSE
 ORIGIN: ../../../flutter/shell/platform/linux/fl_scrolling_manager.cc + ../../../flutter/LICENSE
 ORIGIN: ../../../flutter/shell/platform/linux/fl_scrolling_manager.h + ../../../flutter/LICENSE
@@ -56281,6 +56279,8 @@ FILE: ../../../flutter/shell/platform/linux/fl_mouse_cursor_channel.cc
 FILE: ../../../flutter/shell/platform/linux/fl_mouse_cursor_channel.h
 FILE: ../../../flutter/shell/platform/linux/fl_mouse_cursor_handler.cc
 FILE: ../../../flutter/shell/platform/linux/fl_mouse_cursor_handler.h
+FILE: ../../../flutter/shell/platform/linux/fl_opengl_manager.cc
+FILE: ../../../flutter/shell/platform/linux/fl_opengl_manager.h
 FILE: ../../../flutter/shell/platform/linux/fl_pixel_buffer_texture.cc
 FILE: ../../../flutter/shell/platform/linux/fl_pixel_buffer_texture_private.h
 FILE: ../../../flutter/shell/platform/linux/fl_pixel_buffer_texture_test.cc
@@ -56301,10 +56301,6 @@ FILE: ../../../flutter/shell/platform/linux/fl_renderable.cc
 FILE: ../../../flutter/shell/platform/linux/fl_renderable.h
 FILE: ../../../flutter/shell/platform/linux/fl_renderer.cc
 FILE: ../../../flutter/shell/platform/linux/fl_renderer.h
-FILE: ../../../flutter/shell/platform/linux/fl_renderer_gdk.cc
-FILE: ../../../flutter/shell/platform/linux/fl_renderer_gdk.h
-FILE: ../../../flutter/shell/platform/linux/fl_renderer_headless.cc
-FILE: ../../../flutter/shell/platform/linux/fl_renderer_headless.h
 FILE: ../../../flutter/shell/platform/linux/fl_renderer_test.cc
 FILE: ../../../flutter/shell/platform/linux/fl_scrolling_manager.cc
 FILE: ../../../flutter/shell/platform/linux/fl_scrolling_manager.h

engine/src/flutter/shell/platform/linux/BUILD.gn

@@ -128,6 +128,7 @@ source_set("flutter_linux_sources") {
     "fl_method_response.cc",
     "fl_mouse_cursor_channel.cc",
     "fl_mouse_cursor_handler.cc",
+    "fl_opengl_manager.cc",
     "fl_pixel_buffer_texture.cc",
     "fl_platform_channel.cc",
     "fl_platform_handler.cc",
@@ -136,8 +137,6 @@ source_set("flutter_linux_sources") {
     "fl_pointer_manager.cc",
     "fl_renderable.cc",
     "fl_renderer.cc",
-    "fl_renderer_gdk.cc",
-    "fl_renderer_headless.cc",
     "fl_scrolling_manager.cc",
     "fl_settings.cc",
     "fl_settings_channel.cc",
@@ -261,7 +260,7 @@ executable("flutter_linux_unittests") {
     "testing/mock_epoxy.cc",
     "testing/mock_gtk.cc",
     "testing/mock_plugin_registrar.cc",
-    "testing/mock_renderer.cc",
+    "testing/mock_renderable.cc",
     "testing/mock_settings.cc",
     "testing/mock_signal_handler.cc",
     "testing/mock_texture_registrar.cc",

engine/src/flutter/shell/platform/linux/fl_engine.cc

@@ -4,6 +4,7 @@
 
 #include "flutter/shell/platform/linux/public/flutter_linux/fl_engine.h"
 
+#include <epoxy/egl.h>
 #include <gmodule.h>
 
 #include <cstring>
@@ -16,12 +17,11 @@
 #include "flutter/shell/platform/linux/fl_display_monitor.h"
 #include "flutter/shell/platform/linux/fl_engine_private.h"
 #include "flutter/shell/platform/linux/fl_keyboard_handler.h"
+#include "flutter/shell/platform/linux/fl_opengl_manager.h"
 #include "flutter/shell/platform/linux/fl_pixel_buffer_texture_private.h"
 #include "flutter/shell/platform/linux/fl_platform_handler.h"
 #include "flutter/shell/platform/linux/fl_plugin_registrar_private.h"
 #include "flutter/shell/platform/linux/fl_renderer.h"
-#include "flutter/shell/platform/linux/fl_renderer_gdk.h"
-#include "flutter/shell/platform/linux/fl_renderer_headless.h"
 #include "flutter/shell/platform/linux/fl_settings_handler.h"
 #include "flutter/shell/platform/linux/fl_texture_gl_private.h"
 #include "flutter/shell/platform/linux/fl_texture_registrar_private.h"
@@ -51,6 +51,9 @@ struct _FlEngine {
   // Renders the Flutter app.
   FlRenderer* renderer;
 
+  // Manages OpenGL contexts.
+  FlOpenGLManager* opengl_manager;
+
   // Messenger used to send and receive platform messages.
   FlBinaryMessenger* binary_messenger;
 
@@ -274,25 +277,24 @@ static bool compositor_present_view_callback(
 // Flutter engine rendering callbacks.
 
 static void* fl_engine_gl_proc_resolver(void* user_data, const char* name) {
-  FlEngine* self = static_cast<FlEngine*>(user_data);
-  return fl_renderer_get_proc_address(self->renderer, name);
+  return reinterpret_cast<void*>(eglGetProcAddress(name));
 }
 
 static bool fl_engine_gl_make_current(void* user_data) {
   FlEngine* self = static_cast<FlEngine*>(user_data);
-  fl_renderer_make_current(self->renderer);
+  fl_opengl_manager_make_current(self->opengl_manager);
   return true;
 }
 
 static bool fl_engine_gl_clear_current(void* user_data) {
   FlEngine* self = static_cast<FlEngine*>(user_data);
-  fl_renderer_clear_current(self->renderer);
+  fl_opengl_manager_clear_current(self->opengl_manager);
   return true;
 }
 
 static uint32_t fl_engine_gl_get_fbo(void* user_data) {
-  FlEngine* self = static_cast<FlEngine*>(user_data);
-  return fl_renderer_get_fbo(self->renderer);
+  // There is only one frame buffer object - always return that.
+  return 0;
 }
 
 static bool fl_engine_gl_present(void* user_data) {
@@ -303,7 +305,7 @@ static bool fl_engine_gl_present(void* user_data) {
 
 static bool fl_engine_gl_make_resource_current(void* user_data) {
   FlEngine* self = static_cast<FlEngine*>(user_data);
-  fl_renderer_make_resource_current(self->renderer);
+  fl_opengl_manager_make_resource_current(self->opengl_manager);
   return true;
 }
 
@@ -483,6 +485,7 @@ static void fl_engine_dispose(GObject* object) {
   g_clear_object(&self->project);
   g_clear_object(&self->display_monitor);
   g_clear_object(&self->renderer);
+  g_clear_object(&self->opengl_manager);
   g_clear_object(&self->texture_registrar);
   g_clear_object(&self->binary_messenger);
   g_clear_object(&self->settings_handler);
@@ -533,6 +536,8 @@ static void fl_engine_init(FlEngine* self) {
     g_warning("Failed get get engine function pointers");
   }
 
+  self->opengl_manager = fl_opengl_manager_new();
+
   self->display_monitor =
       fl_display_monitor_new(self, gdk_display_get_default());
   self->task_runner = fl_task_runner_new(self);
@@ -550,15 +555,13 @@ static void fl_engine_init(FlEngine* self) {
 }
 
 static FlEngine* fl_engine_new_full(FlDartProject* project,
-                                    FlRenderer* renderer,
                                     FlBinaryMessenger* binary_messenger) {
   g_return_val_if_fail(FL_IS_DART_PROJECT(project), nullptr);
-  g_return_val_if_fail(FL_IS_RENDERER(renderer), nullptr);
 
   FlEngine* self = FL_ENGINE(g_object_new(fl_engine_get_type(), nullptr));
 
   self->project = FL_DART_PROJECT(g_object_ref(project));
-  self->renderer = FL_RENDERER(g_object_ref(renderer));
+  self->renderer = fl_renderer_new(self);
   if (binary_messenger != nullptr) {
     self->binary_messenger =
         FL_BINARY_MESSENGER(g_object_ref(binary_messenger));
@@ -570,8 +573,6 @@ static FlEngine* fl_engine_new_full(FlDartProject* project,
       fl_mouse_cursor_handler_new(self->binary_messenger);
   self->windowing_handler = fl_windowing_handler_new(self);
 
-  fl_renderer_set_engine(self->renderer, self);
-
   return self;
 }
 
@@ -581,35 +582,30 @@ FlEngine* fl_engine_for_id(int64_t id) {
   return FL_ENGINE(engine);
 }
 
-FlEngine* fl_engine_new_with_renderer(FlDartProject* project,
-                                      FlRenderer* renderer) {
-  g_return_val_if_fail(FL_IS_DART_PROJECT(project), nullptr);
-  g_return_val_if_fail(FL_IS_RENDERER(renderer), nullptr);
-  return fl_engine_new_full(project, renderer, nullptr);
-}
-
 G_MODULE_EXPORT FlEngine* fl_engine_new(FlDartProject* project) {
-  g_autoptr(FlRendererGdk) renderer = fl_renderer_gdk_new();
-  return fl_engine_new_with_renderer(project, FL_RENDERER(renderer));
+  return fl_engine_new_full(project, nullptr);
 }
 
 FlEngine* fl_engine_new_with_binary_messenger(
     FlBinaryMessenger* binary_messenger) {
   g_autoptr(FlDartProject) project = fl_dart_project_new();
-  g_autoptr(FlRendererGdk) renderer = fl_renderer_gdk_new();
-  return fl_engine_new_full(project, FL_RENDERER(renderer), binary_messenger);
+  return fl_engine_new_full(project, binary_messenger);
 }
 
 G_MODULE_EXPORT FlEngine* fl_engine_new_headless(FlDartProject* project) {
-  g_autoptr(FlRendererHeadless) renderer = fl_renderer_headless_new();
-  return fl_engine_new_with_renderer(project, FL_RENDERER(renderer));
+  return fl_engine_new(project);
 }
 
 FlRenderer* fl_engine_get_renderer(FlEngine* self) {
   g_return_val_if_fail(FL_IS_ENGINE(self), nullptr);
   return self->renderer;
 }
 
+FlOpenGLManager* fl_engine_get_opengl_manager(FlEngine* self) {
+  g_return_val_if_fail(FL_IS_ENGINE(self), nullptr);
+  return self->opengl_manager;
+}
+
 FlDisplayMonitor* fl_engine_get_display_monitor(FlEngine* self) {
   g_return_val_if_fail(FL_IS_ENGINE(self), nullptr);
   return self->display_monitor;

engine/src/flutter/shell/platform/linux/fl_engine_private.h

@@ -11,6 +11,7 @@
 #include "flutter/shell/platform/linux/fl_display_monitor.h"
 #include "flutter/shell/platform/linux/fl_keyboard_manager.h"
 #include "flutter/shell/platform/linux/fl_mouse_cursor_handler.h"
+#include "flutter/shell/platform/linux/fl_opengl_manager.h"
 #include "flutter/shell/platform/linux/fl_renderable.h"
 #include "flutter/shell/platform/linux/fl_renderer.h"
 #include "flutter/shell/platform/linux/fl_task_runner.h"
@@ -63,26 +64,24 @@ FlEngine* fl_engine_new_with_binary_messenger(
     FlBinaryMessenger* binary_messenger);
 
 /**
- * fl_engine_new_with_renderer:
- * @project: an #FlDartProject.
- * @renderer: an #FlRenderer.
+ * fl_engine_get_renderer:
+ * @engine: an #FlEngine.
  *
- * Creates new Flutter engine.
+ * Gets the renderer used by this engine.
  *
- * Returns: a new #FlEngine.
+ * Returns: an #FlRenderer.
  */
-FlEngine* fl_engine_new_with_renderer(FlDartProject* project,
-                                      FlRenderer* renderer);
+FlRenderer* fl_engine_get_renderer(FlEngine* engine);
 
 /**
- * fl_engine_get_renderer:
+ * fl_engine_get_opengl_manager:
  * @engine: an #FlEngine.
  *
- * Gets the renderer used by this engine.
+ * Gets the OpenGL manager used by this engine.
  *
- * Returns: an #FlRenderer.
+ * Returns: an #FlOpenGLManager.
  */
-FlRenderer* fl_engine_get_renderer(FlEngine* engine);
+FlOpenGLManager* fl_engine_get_opengl_manager(FlEngine* engine);
 
 /**
  * fl_engine_get_display_monitor:

engine/src/flutter/shell/platform/linux/fl_engine_test.cc

@@ -10,7 +10,7 @@
 #include "flutter/shell/platform/linux/public/flutter_linux/fl_engine.h"
 #include "flutter/shell/platform/linux/public/flutter_linux/fl_json_message_codec.h"
 #include "flutter/shell/platform/linux/public/flutter_linux/fl_string_codec.h"
-#include "flutter/shell/platform/linux/testing/mock_renderer.h"
+#include "flutter/shell/platform/linux/testing/mock_renderable.h"
 
 // MOCK_ENGINE_PROC is leaky by design
 // NOLINTBEGIN(clang-analyzer-core.StackAddressEscape)

engine/src/flutter/shell/platform/linux/fl_opengl_manager.cc

@@ -0,0 +1,92 @@
+// Copyright 2013 The Flutter Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#include "flutter/shell/platform/linux/fl_opengl_manager.h"
+
+struct _FlOpenGLManager {
+  GObject parent_instance;
+
+  // OpenGL rendering context used by GDK.
+  GdkGLContext* gdk_context;
+
+  // Main OpenGL rendering context used by Flutter.
+  GdkGLContext* main_context;
+
+  // OpenGL rendering context used by a Flutter background thread for
+  // asynchronous texture uploads.
+  GdkGLContext* resource_context;
+};
+
+G_DEFINE_TYPE(FlOpenGLManager, fl_opengl_manager, G_TYPE_OBJECT)
+
+static void fl_opengl_manager_dispose(GObject* object) {
+  FlOpenGLManager* self = FL_OPENGL_MANAGER(object);
+
+  g_clear_object(&self->gdk_context);
+  g_clear_object(&self->main_context);
+  g_clear_object(&self->resource_context);
+
+  G_OBJECT_CLASS(fl_opengl_manager_parent_class)->dispose(object);
+}
+
+static void fl_opengl_manager_class_init(FlOpenGLManagerClass* klass) {
+  G_OBJECT_CLASS(klass)->dispose = fl_opengl_manager_dispose;
+}
+
+static void fl_opengl_manager_init(FlOpenGLManager* self) {}
+
+FlOpenGLManager* fl_opengl_manager_new() {
+  FlOpenGLManager* self =
+      FL_OPENGL_MANAGER(g_object_new(fl_opengl_manager_get_type(), nullptr));
+  return self;
+}
+
+gboolean fl_opengl_manager_create_contexts(FlOpenGLManager* self,
+                                           GdkWindow* window,
+                                           GError** error) {
+  g_return_val_if_fail(FL_IS_OPENGL_MANAGER(self), FALSE);
+
+  self->gdk_context = gdk_window_create_gl_context(window, error);
+  if (self->gdk_context == nullptr) {
+    return FALSE;
+  }
+  if (!gdk_gl_context_realize(self->gdk_context, error)) {
+    return FALSE;
+  }
+
+  self->main_context = gdk_window_create_gl_context(window, error);
+  if (self->main_context == nullptr) {
+    return FALSE;
+  }
+  if (!gdk_gl_context_realize(self->main_context, error)) {
+    return FALSE;
+  }
+
+  self->resource_context = gdk_window_create_gl_context(window, error);
+  if (self->resource_context == nullptr) {
+    return FALSE;
+  }
+  if (!gdk_gl_context_realize(self->resource_context, error)) {
+    return FALSE;
+  }
+
+  return TRUE;
+}
+
+GdkGLContext* fl_opengl_manager_get_context(FlOpenGLManager* self) {
+  g_return_val_if_fail(FL_IS_OPENGL_MANAGER(self), nullptr);
+  return self->gdk_context;
+}
+
+void fl_opengl_manager_make_current(FlOpenGLManager* self) {
+  gdk_gl_context_make_current(self->main_context);
+}
+
+void fl_opengl_manager_make_resource_current(FlOpenGLManager* self) {
+  gdk_gl_context_make_current(self->resource_context);
+}
+
+void fl_opengl_manager_clear_current(FlOpenGLManager* self) {
+  gdk_gl_context_clear_current();
+}