Texture support for glfw.

ci/licenses_golden/licenses_flutter

@@ -690,6 +690,7 @@ FILE: ../../../flutter/shell/platform/common/cpp/client_wrapper/include/flutter/
 FILE: ../../../flutter/shell/platform/common/cpp/client_wrapper/include/flutter/plugin_registry.h
 FILE: ../../../flutter/shell/platform/common/cpp/client_wrapper/include/flutter/standard_message_codec.h
 FILE: ../../../flutter/shell/platform/common/cpp/client_wrapper/include/flutter/standard_method_codec.h
+FILE: ../../../flutter/shell/platform/common/cpp/client_wrapper/include/flutter/texture_registrar.h
 FILE: ../../../flutter/shell/platform/common/cpp/client_wrapper/json_message_codec.cc
 FILE: ../../../flutter/shell/platform/common/cpp/client_wrapper/json_method_codec.cc
 FILE: ../../../flutter/shell/platform/common/cpp/client_wrapper/method_call_unittests.cc
@@ -704,6 +705,7 @@ FILE: ../../../flutter/shell/platform/common/cpp/incoming_message_dispatcher.h
 FILE: ../../../flutter/shell/platform/common/cpp/public/flutter_export.h
 FILE: ../../../flutter/shell/platform/common/cpp/public/flutter_messenger.h
 FILE: ../../../flutter/shell/platform/common/cpp/public/flutter_plugin_registrar.h
+FILE: ../../../flutter/shell/platform/common/cpp/public/flutter_texture_registrar.h
 FILE: ../../../flutter/shell/platform/common/cpp/text_input_model.cc
 FILE: ../../../flutter/shell/platform/common/cpp/text_input_model.h
 FILE: ../../../flutter/shell/platform/darwin/common/buffer_conversions.h
@@ -993,6 +995,8 @@ FILE: ../../../flutter/shell/platform/glfw/client_wrapper/flutter_window_control
 FILE: ../../../flutter/shell/platform/glfw/client_wrapper/include/flutter/flutter_window.h
 FILE: ../../../flutter/shell/platform/glfw/client_wrapper/include/flutter/flutter_window_controller.h
 FILE: ../../../flutter/shell/platform/glfw/client_wrapper/include/flutter/plugin_registrar_glfw.h
+FILE: ../../../flutter/shell/platform/glfw/external_texture_gl.cc
+FILE: ../../../flutter/shell/platform/glfw/external_texture_gl.h
 FILE: ../../../flutter/shell/platform/glfw/flutter_glfw.cc
 FILE: ../../../flutter/shell/platform/glfw/glfw_event_loop.cc
 FILE: ../../../flutter/shell/platform/glfw/glfw_event_loop.h

shell/platform/common/cpp/BUILD.gn

@@ -10,6 +10,7 @@ _public_headers = [
   "public/flutter_export.h",
   "public/flutter_messenger.h",
   "public/flutter_plugin_registrar.h",
+  "public/flutter_texture_registrar.h",
 ]
 
 # Any files that are built by clients (client_wrapper code, library headers for

shell/platform/common/cpp/client_wrapper/core_wrapper_files.gni

@@ -18,6 +18,7 @@ core_cpp_client_wrapper_includes =
                     "include/flutter/method_result.h",
                     "include/flutter/plugin_registrar.h",
                     "include/flutter/plugin_registry.h",
+                    "include/flutter/texture_registrar.h",
                     "include/flutter/standard_message_codec.h",
                     "include/flutter/standard_method_codec.h",
                   ],

shell/platform/common/cpp/client_wrapper/include/flutter/plugin_registrar.h

@@ -12,6 +12,7 @@
 #include <flutter_plugin_registrar.h>
 
 #include "binary_messenger.h"
+#include "texture_registrar.h"
 
 namespace flutter {
 
@@ -40,6 +41,10 @@ class PluginRegistrar {
   // This pointer will remain valid for the lifetime of this instance.
   BinaryMessenger* messenger() { return messenger_.get(); }
 
+  // Returns the texture registrar to use for the plugin to render a pixel
+  // buffer.
+  TextureRegistrar* textures() { return textures_.get(); }
+
   // Takes ownership of |plugin|.
   //
   // Plugins are not required to call this method if they have other lifetime
@@ -59,6 +64,8 @@ class PluginRegistrar {
 
   std::unique_ptr<BinaryMessenger> messenger_;
 
+  std::unique_ptr<TextureRegistrar> textures_;
+
   // Plugins registered for ownership.
   std::set<std::unique_ptr<Plugin>> plugins_;
 };

shell/platform/common/cpp/client_wrapper/include/flutter/texture_registrar.h

@@ -0,0 +1,48 @@
+// 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.
+
+#ifndef FLUTTER_SHELL_PLATFORM_COMMON_CPP_CLIENT_WRAPPER_INCLUDE_FLUTTER_TEXTURE_REGISTRAR_H_
+#define FLUTTER_SHELL_PLATFORM_COMMON_CPP_CLIENT_WRAPPER_INCLUDE_FLUTTER_TEXTURE_REGISTRAR_H_
+
+#include <flutter_texture_registrar.h>
+
+#include <stdint.h>
+#include <memory>
+
+namespace flutter {
+
+// An external texture interface declaration.
+class Texture {
+ public:
+  virtual ~Texture() {}
+  // This is in response to the texture copy request interface, providing the
+  // |height| and |width| parameters of bounds.
+  // In some cases, we need to scale the texture to the bounds size to reduce
+  // memory usage.
+  virtual const PixelBuffer* CopyPixelBuffer(size_t width, size_t height) = 0;
+};
+
+class TextureRegistrar {
+ public:
+  virtual ~TextureRegistrar() {}
+
+  /**
+   * Registers a |texture| object and return textureId.
+   */
+  virtual int64_t RegisterTexture(Texture* texture) = 0;
+
+  /**
+   * Mark a texture buffer is ready.
+   */
+  virtual void MarkTextureFrameAvailable(int64_t texture_id) = 0;
+
+  /**
+   * Unregisters an existing Texture object.
+   */
+  virtual void UnregisterTexture(int64_t texture_id) = 0;
+};
+
+}  // namespace flutter
+
+#endif  // FLUTTER_SHELL_PLATFORM_COMMON_CPP_CLIENT_WRAPPER_INCLUDE_FLUTTER_TEXTURE_REGISTRAR_H_

shell/platform/common/cpp/client_wrapper/plugin_registrar.cc

@@ -138,12 +138,52 @@ void BinaryMessengerImpl::SetMessageHandler(const std::string& channel,
                                      ForwardToHandler, message_handler);
 }
 
+// Wrapper around a FlutterDesktopTextureRegistrarRef that implements the
+// TextureRegistrar API.
+class TextureRegistrarImpl : public TextureRegistrar {
+ public:
+  explicit TextureRegistrarImpl(
+      FlutterDesktopTextureRegistrarRef texture_registrar_ref)
+      : texture_registrar_ref_(texture_registrar_ref) {}
+
+  virtual ~TextureRegistrarImpl() = default;
+
+  // Prevent copying.
+  TextureRegistrarImpl(TextureRegistrarImpl const&) = delete;
+  TextureRegistrarImpl& operator=(TextureRegistrarImpl const&) = delete;
+
+  virtual int64_t RegisterTexture(Texture* texture) override {
+    FlutterTexutreCallback callback =
+        [](size_t width, size_t height, void* user_data) -> const PixelBuffer* {
+      return static_cast<Texture*>(user_data)->CopyPixelBuffer(width, height);
+    };
+    int64_t texture_id = FlutterDesktopRegisterExternalTexture(
+        texture_registrar_ref_, callback, texture);
+    return texture_id;
+  }
+
+  virtual void MarkTextureFrameAvailable(int64_t texture_id) override {
+    FlutterDesktopMarkExternalTextureFrameAvailable(texture_registrar_ref_,
+                                                    texture_id);
+  }
+
+  virtual void UnregisterTexture(int64_t texture_id) override {
+    FlutterDesktopUnregisterExternalTexture(texture_registrar_ref_, texture_id);
+  }
+
+ private:
+  // Handle for interacting with the C API.
+  FlutterDesktopTextureRegistrarRef texture_registrar_ref_;
+};
+
 // PluginRegistrar:
 
 PluginRegistrar::PluginRegistrar(FlutterDesktopPluginRegistrarRef registrar)
     : registrar_(registrar) {
   auto core_messenger = FlutterDesktopRegistrarGetMessenger(registrar_);
   messenger_ = std::make_unique<BinaryMessengerImpl>(core_messenger);
+  auto texture_registrar = FlutterDesktopGetTextureRegistrar(registrar_);
+  textures_ = std::make_unique<TextureRegistrarImpl>(texture_registrar);
 }
 
 PluginRegistrar::~PluginRegistrar() {}

shell/platform/common/cpp/client_wrapper/plugin_registrar_unittests.cc

@@ -6,6 +6,7 @@
 #include <vector>
 
 #include "flutter/shell/platform/common/cpp/client_wrapper/include/flutter/plugin_registrar.h"
+#include "flutter/shell/platform/common/cpp/client_wrapper/include/flutter/texture_registrar.h"
 #include "flutter/shell/platform/common/cpp/client_wrapper/testing/stub_flutter_api.h"
 #include "gtest/gtest.h"
 
@@ -34,8 +35,34 @@ class TestApi : public testing::StubFlutterApi {
 
   const uint8_t* last_data_sent() { return last_data_sent_; }
 
+  int64_t RegisterExternalTexture(
+    FlutterTexutreCallback texture_callback,
+    void* user_data) override {
+      last_texture_id_ = 1;
+      return last_texture_id_;
+  }
+
+  bool UnregisterExternalTexture(int64_t texture_id) override {
+    if(texture_id == 2) {
+      last_texture_id_ = -2;
+      return true;
+    }
+    return false;
+  }
+
+  bool TextureFrameAvailable(int64_t texture_id) override {
+     if(texture_id == 1) {
+      last_texture_id_ = 2;
+      return true;
+    }
+    return false;
+  }
+
+  int64_t last_texture_id() { return last_texture_id_; }
+
  private:
   const uint8_t* last_data_sent_ = nullptr;
+  int64_t last_texture_id_ = -1;
 };
 
 }  // namespace
@@ -55,4 +82,23 @@ TEST(MethodCallTest, MessengerSend) {
   EXPECT_EQ(test_api->last_data_sent(), &message[0]);
 }
 
+// Tests texture register that calls through to the C API.
+TEST(MethodCallTest, RegisterTexture) {
+  testing::ScopedStubFlutterApi scoped_api_stub(std::make_unique<TestApi>());
+  auto test_api = static_cast<TestApi*>(scoped_api_stub.stub());
+
+  auto dummy_registrar_handle =
+      reinterpret_cast<FlutterDesktopPluginRegistrarRef>(1);
+  PluginRegistrar registrar(dummy_registrar_handle);
+  TextureRegistrar* textures = registrar.textures();
+
+  EXPECT_EQ(test_api->last_texture_id(), -1);
+  int64_t texture_id = textures->RegisterTexture(nullptr);
+  EXPECT_EQ(texture_id, 1);
+  textures->MarkTextureFrameAvailable(texture_id);
+  EXPECT_EQ(test_api->last_texture_id(), 2);
+  textures->UnregisterTexture(2);
+  EXPECT_EQ(test_api->last_texture_id(), -2);
+}
+
 }  // namespace flutter

shell/platform/common/cpp/client_wrapper/testing/stub_flutter_api.cc

@@ -44,6 +44,43 @@ FlutterDesktopMessengerRef FlutterDesktopRegistrarGetMessenger(
   return reinterpret_cast<FlutterDesktopMessengerRef>(1);
 }
 
+FlutterDesktopTextureRegistrarRef FlutterDesktopGetTextureRegistrar(
+    FlutterDesktopPluginRegistrarRef registrar) {
+  return reinterpret_cast<FlutterDesktopTextureRegistrarRef>(1);
+}
+
+int64_t FlutterDesktopRegisterExternalTexture(
+    FlutterDesktopTextureRegistrarRef texture_registrar,
+    FlutterTexutreCallback texture_callback,
+    void* user_data) {
+  uint64_t result = -1;
+  if (s_stub_implementation) {
+    result = s_stub_implementation->RegisterExternalTexture(texture_callback,
+                                                            user_data);
+  }
+  return result;
+}
+
+bool FlutterDesktopUnregisterExternalTexture(
+    FlutterDesktopTextureRegistrarRef texture_registrar,
+    int64_t texture_id) {
+  bool result = false;
+  if (s_stub_implementation) {
+    result = s_stub_implementation->UnregisterExternalTexture(texture_id);
+  }
+  return result;
+}
+
+bool FlutterDesktopMarkExternalTextureFrameAvailable(
+    FlutterDesktopTextureRegistrarRef texture_registrar,
+    int64_t texture_id) {
+  bool result = false;
+  if (s_stub_implementation) {
+    result = s_stub_implementation->TextureFrameAvailable(texture_id);
+  }
+  return result;
+}
+
 void FlutterDesktopRegistrarEnableInputBlocking(
     FlutterDesktopPluginRegistrarRef registrar,
     const char* channel) {

shell/platform/common/cpp/client_wrapper/testing/stub_flutter_api.h

@@ -63,6 +63,19 @@ class StubFlutterApi {
   virtual void MessengerSetCallback(const char* channel,
                                     FlutterDesktopMessageCallback callback,
                                     void* user_data) {}
+
+  // Called for FlutterDesktopRegisterExternalTexture.
+  virtual int64_t RegisterExternalTexture(
+    FlutterTexutreCallback texture_callback,
+    void* user_data) {
+      return -1;
+  }
+
+  // Called for FlutterDesktopUnregisterExternalTexture.
+  virtual bool UnregisterExternalTexture(int64_t texture_id) { return false; }
+
+  // Called for FlutterDesktopMarkExternalTextureFrameAvailable.
+  virtual bool TextureFrameAvailable(int64_t texture_id) { return false; }
 };
 
 // A test helper that owns a stub implementation, making it the test stub for

shell/platform/common/cpp/public/flutter_plugin_registrar.h

@@ -10,6 +10,7 @@
 
 #include "flutter_export.h"
 #include "flutter_messenger.h"
+#include "flutter_texture_registrar.h"
 
 #if defined(__cplusplus)
 extern "C" {
@@ -22,6 +23,10 @@ typedef struct FlutterDesktopPluginRegistrar* FlutterDesktopPluginRegistrarRef;
 FLUTTER_EXPORT FlutterDesktopMessengerRef
 FlutterDesktopRegistrarGetMessenger(FlutterDesktopPluginRegistrarRef registrar);
 
+// Returns the texture registrar associated with this registrar.
+FLUTTER_EXPORT FlutterDesktopTextureRegistrarRef
+FlutterDesktopGetTextureRegistrar(FlutterDesktopPluginRegistrarRef registrar);
+
 // Enables input blocking on the given channel.
 //
 // If set, then the Flutter window will disable input callbacks

shell/platform/common/cpp/public/flutter_texture_registrar.h

@@ -0,0 +1,60 @@
+// 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.
+
+#ifndef FLUTTER_SHELL_PLATFORM_COMMON_CPP_PUBLIC_FLUTTER_TEXTURE_REGISTRAR_H_
+#define FLUTTER_SHELL_PLATFORM_COMMON_CPP_PUBLIC_FLUTTER_TEXTURE_REGISTRAR_H_
+
+#include <stddef.h>
+#include <stdint.h>
+
+#include "flutter_export.h"
+
+#if defined(__cplusplus)
+extern "C" {
+#endif
+
+// Opaque reference to a texture registrar.
+typedef struct FlutterDesktopTextureRegistrar*
+    FlutterDesktopTextureRegistrarRef;
+
+// Constructs a pixel buffer object for the plugin side, providing
+// height/width and buffer pointers.
+typedef struct {
+  // Bitmap buffer pointer, currently only supports RGBA.
+  const uint8_t* buffer;
+  // Width of the pixel buffer.
+  size_t width;
+  // Height of the pixel buffer.
+  size_t height;
+} PixelBuffer;
+
+// The pixel buffer copy callback definition is provided to
+// the Flutter engine to copy the texture.
+typedef const PixelBuffer* (*FlutterTexutreCallback)(size_t width,
+                                                     size_t height,
+                                                     void* user_data);
+
+// Registers a new texture with the Flutter engine and returns the texture ID,
+// The engine will use the |texture_callback|
+// function to copy the pixel buffer from the plugin caller.
+FLUTTER_EXPORT int64_t FlutterDesktopRegisterExternalTexture(
+    FlutterDesktopTextureRegistrarRef texture_registrar,
+    FlutterTexutreCallback texture_callback,
+    void* user_data);
+
+// Unregisters an existing texture from the Flutter engine for a |texture_id|.
+FLUTTER_EXPORT bool FlutterDesktopUnregisterExternalTexture(
+    FlutterDesktopTextureRegistrarRef texture_registrar,
+    int64_t texture_id);
+
+// Marks that a new texture frame is available for a given |texture_id|.
+FLUTTER_EXPORT bool FlutterDesktopMarkExternalTextureFrameAvailable(
+    FlutterDesktopTextureRegistrarRef texture_registrar,
+    int64_t texture_id);
+
+#if defined(__cplusplus)
+}  // extern "C"
+#endif
+
+#endif  // FLUTTER_SHELL_PLATFORM_COMMON_CPP_PUBLIC_FLUTTER_TEXTURE_REGISTRAR_H_