Add texture support for macOS shell.

ci/licenses_golden/licenses_flutter

@@ -718,6 +718,7 @@ FILE: ../../../flutter/shell/platform/darwin/common/framework/Headers/FlutterBin
 FILE: ../../../flutter/shell/platform/darwin/common/framework/Headers/FlutterChannels.h
 FILE: ../../../flutter/shell/platform/darwin/common/framework/Headers/FlutterCodecs.h
 FILE: ../../../flutter/shell/platform/darwin/common/framework/Headers/FlutterMacros.h
+FILE: ../../../flutter/shell/platform/darwin/common/framework/Headers/FlutterTexture.h
 FILE: ../../../flutter/shell/platform/darwin/common/framework/Source/FlutterChannels.mm
 FILE: ../../../flutter/shell/platform/darwin/common/framework/Source/FlutterChannelsTest.m
 FILE: ../../../flutter/shell/platform/darwin/common/framework/Source/FlutterCodecs.mm
@@ -735,7 +736,6 @@ FILE: ../../../flutter/shell/platform/darwin/ios/framework/Headers/FlutterHeadle
 FILE: ../../../flutter/shell/platform/darwin/ios/framework/Headers/FlutterPlatformViews.h
 FILE: ../../../flutter/shell/platform/darwin/ios/framework/Headers/FlutterPlugin.h
 FILE: ../../../flutter/shell/platform/darwin/ios/framework/Headers/FlutterPluginAppLifeCycleDelegate.h
-FILE: ../../../flutter/shell/platform/darwin/ios/framework/Headers/FlutterTexture.h
 FILE: ../../../flutter/shell/platform/darwin/ios/framework/Headers/FlutterViewController.h
 FILE: ../../../flutter/shell/platform/darwin/ios/framework/Info.plist
 FILE: ../../../flutter/shell/platform/darwin/ios/framework/Source/FlutterAppDelegate.mm
@@ -813,6 +813,8 @@ FILE: ../../../flutter/shell/platform/darwin/macos/framework/Source/FlutterDartP
 FILE: ../../../flutter/shell/platform/darwin/macos/framework/Source/FlutterDartProject_Internal.h
 FILE: ../../../flutter/shell/platform/darwin/macos/framework/Source/FlutterEngine.mm
 FILE: ../../../flutter/shell/platform/darwin/macos/framework/Source/FlutterEngine_Internal.h
+FILE: ../../../flutter/shell/platform/darwin/macos/framework/Source/FlutterExternalTextureGL.h
+FILE: ../../../flutter/shell/platform/darwin/macos/framework/Source/FlutterExternalTextureGL.mm
 FILE: ../../../flutter/shell/platform/darwin/macos/framework/Source/FlutterTextInputModel.h
 FILE: ../../../flutter/shell/platform/darwin/macos/framework/Source/FlutterTextInputModel.mm
 FILE: ../../../flutter/shell/platform/darwin/macos/framework/Source/FlutterTextInputPlugin.h

shell/platform/darwin/common/framework_shared.gni

@@ -8,5 +8,6 @@ framework_shared_headers =
                     "framework/Headers/FlutterBinaryMessenger.h",
                     "framework/Headers/FlutterChannels.h",
                     "framework/Headers/FlutterCodecs.h",
+                    "framework/Headers/FlutterTexture.h",
                   ],
                   "abspath")

shell/platform/darwin/ios/BUILD.gn

@@ -30,7 +30,6 @@ _flutter_framework_headers = [
   "framework/Headers/FlutterPlatformViews.h",
   "framework/Headers/FlutterPlugin.h",
   "framework/Headers/FlutterPluginAppLifeCycleDelegate.h",
-  "framework/Headers/FlutterTexture.h",
   "framework/Headers/FlutterViewController.h",
 ]
 

shell/platform/darwin/ios/ios_external_texture_gl.h

@@ -8,7 +8,7 @@
 #include "flutter/flow/texture.h"
 #include "flutter/fml/platform/darwin/cf_utils.h"
 #include "flutter/fml/platform/darwin/scoped_nsobject.h"
-#include "flutter/shell/platform/darwin/ios/framework/Headers/FlutterTexture.h"
+#include "flutter/shell/platform/darwin/common/framework/Headers/FlutterTexture.h"
 
 namespace flutter {
 

shell/platform/darwin/ios/platform_view_ios.h

@@ -12,7 +12,7 @@
 #include "flutter/fml/memory/weak_ptr.h"
 #include "flutter/fml/platform/darwin/scoped_nsobject.h"
 #include "flutter/shell/common/platform_view.h"
-#include "flutter/shell/platform/darwin/ios/framework/Headers/FlutterTexture.h"
+#include "flutter/shell/platform/darwin/common/framework/Headers/FlutterTexture.h"
 #include "flutter/shell/platform/darwin/ios/framework/Headers/FlutterViewController.h"
 #include "flutter/shell/platform/darwin/ios/framework/Source/FlutterView.h"
 #include "flutter/shell/platform/darwin/ios/framework/Source/accessibility_bridge.h"

shell/platform/darwin/macos/BUILD.gn

@@ -52,6 +52,8 @@ shared_library("create_flutter_framework_dylib") {
     "framework/Source/FlutterDartProject_Internal.h",
     "framework/Source/FlutterEngine.mm",
     "framework/Source/FlutterEngine_Internal.h",
+    "framework/Source/FlutterExternalTextureGL.h",
+    "framework/Source/FlutterExternalTextureGL.mm",
     "framework/Source/FlutterTextInputModel.h",
     "framework/Source/FlutterTextInputModel.mm",
     "framework/Source/FlutterTextInputPlugin.h",
@@ -75,7 +77,10 @@ shared_library("create_flutter_framework_dylib") {
 
   cflags_objcc = [ "-fobjc-arc" ]
 
-  libs = [ "Cocoa.framework" ]
+  libs = [
+    "Cocoa.framework",
+    "CoreVideo.framework",
+  ]
 }
 
 action("copy_dylib_and_update_framework_install_name") {

shell/platform/darwin/macos/framework/Headers/FlutterEngine.h

@@ -11,6 +11,7 @@
 #include "FlutterDartProject.h"
 #include "FlutterMacros.h"
 #include "FlutterPluginRegistrarMacOS.h"
+#include "FlutterTexture.h"
 
 // TODO: Merge this file with the iOS FlutterEngine.h.
 
@@ -20,7 +21,7 @@
  * Coordinates a single instance of execution of a Flutter engine.
  */
 FLUTTER_EXPORT
-@interface FlutterEngine : NSObject <FlutterPluginRegistry>
+@interface FlutterEngine : NSObject <FlutterTextureRegistry, FlutterPluginRegistry>
 
 /**
  * Initializes an engine with the given viewController.

shell/platform/darwin/macos/framework/Headers/FlutterMacOS.h

@@ -11,4 +11,5 @@
 #import "FlutterMacros.h"
 #import "FlutterPluginMacOS.h"
 #import "FlutterPluginRegistrarMacOS.h"
+#import "FlutterTexture.h"
 #import "FlutterViewController.h"

shell/platform/darwin/macos/framework/Headers/FlutterPluginRegistrarMacOS.h

@@ -9,6 +9,7 @@
 #import "FlutterBinaryMessenger.h"
 #import "FlutterChannels.h"
 #import "FlutterMacros.h"
+#import "FlutterTexture.h"
 
 // TODO: Merge this file and FlutterPluginMacOS.h with the iOS FlutterPlugin.h, sharing all but
 // the platform-specific methods.
@@ -28,6 +29,12 @@ FLUTTER_EXPORT
  */
 @property(nonnull, readonly) id<FlutterBinaryMessenger> messenger;
 
+/**
+ * Returns a `FlutterTextureRegistry` for registering textures
+ * provided by the plugin.
+ */
+@property(nonnull, readonly) id<FlutterTextureRegistry> textures;
+
 /**
  * The view displaying Flutter content. May return |nil|, for instance in a headless environment.
  *

shell/platform/darwin/macos/framework/Source/FlutterEngine.mm

@@ -8,6 +8,7 @@
 #include <vector>
 
 #import "flutter/shell/platform/darwin/macos/framework/Source/FlutterDartProject_Internal.h"
+#import "flutter/shell/platform/darwin/macos/framework/Source/FlutterExternalTextureGL.h"
 #import "flutter/shell/platform/darwin/macos/framework/Source/FlutterViewController_Internal.h"
 #import "flutter/shell/platform/embedder/embedder.h"
 
@@ -46,6 +47,12 @@ - (void)engineCallbackOnPlatformMessage:(const FlutterPlatformMessage*)message;
  */
 - (void)shutDownEngine;
 
+/**
+ * Forwards texture copy request to the corresponding texture via |textureID|.
+ */
+- (BOOL)populateTextureWithIdentifier:(int64_t)textureID
+                        openGLTexture:(FlutterOpenGLTexture*)openGLTexture;
+
 @end
 
 #pragma mark -
@@ -78,6 +85,10 @@ - (instancetype)initWithPlugin:(NSString*)pluginKey flutterEngine:(FlutterEngine
   return _flutterEngine.binaryMessenger;
 }
 
+- (id<FlutterTextureRegistry>)textures {
+  return _flutterEngine;
+}
+
 - (NSView*)view {
   return _flutterEngine.viewController.view;
 }
@@ -119,6 +130,15 @@ static void OnPlatformMessage(const FlutterPlatformMessage* message, FlutterEngi
   [engine engineCallbackOnPlatformMessage:message];
 }
 
+static bool OnAcquireExternalTexture(FlutterEngine* engine,
+                                     int64_t texture_identifier,
+                                     size_t width,
+                                     size_t height,
+                                     FlutterOpenGLTexture* open_gl_texture) {
+  return [engine populateTextureWithIdentifier:texture_identifier
+                                 openGLTexture:open_gl_texture];
+}
+
 #pragma mark -
 
 @implementation FlutterEngine {
@@ -136,6 +156,9 @@ @implementation FlutterEngine {
 
   // Whether the engine can continue running after the view controller is removed.
   BOOL _allowHeadlessExecution;
+
+  // A mapping of textureID to internal FlutterExternalTextureGL adapter.
+  NSMutableDictionary<NSNumber*, FlutterExternalTextureGL*>* _textures;
 }
 
 - (instancetype)initWithName:(NSString*)labelPrefix project:(FlutterDartProject*)project {
@@ -150,6 +173,7 @@ - (instancetype)initWithName:(NSString*)labelPrefix
 
   _project = project ?: [[FlutterDartProject alloc] init];
   _messageHandlers = [[NSMutableDictionary alloc] init];
+  _textures = [[NSMutableDictionary alloc] init];
   _allowHeadlessExecution = allowHeadlessExecution;
 
   return self;
@@ -177,6 +201,7 @@ - (BOOL)runWithEntrypoint:(NSString*)entrypoint {
       .open_gl.present = (BoolCallback)OnPresent,
       .open_gl.fbo_callback = (UIntCallback)OnFBO,
       .open_gl.make_resource_current = (BoolCallback)OnMakeResourceCurrent,
+      .open_gl.gl_external_texture_frame_callback = (TextureFrameCallback)OnAcquireExternalTexture,
   };
 
   // TODO(stuartmorgan): Move internal channel registration from FlutterViewController to here.
@@ -398,4 +423,29 @@ - (void)setMessageHandlerOnChannel:(nonnull NSString*)channel
   return [[FlutterEngineRegistrar alloc] initWithPlugin:pluginName flutterEngine:self];
 }
 
+#pragma mark - FlutterTextureRegistrar
+
+- (BOOL)populateTextureWithIdentifier:(int64_t)textureID
+                        openGLTexture:(FlutterOpenGLTexture*)openGLTexture {
+  return [_textures[@(textureID)] populateTexture:openGLTexture];
+}
+
+- (int64_t)registerTexture:(id<FlutterTexture>)texture {
+  FlutterExternalTextureGL* FlutterTexture =
+      [[FlutterExternalTextureGL alloc] initWithFlutterTexture:texture];
+  int64_t textureID = [FlutterTexture textureID];
+  FlutterEngineRegisterExternalTexture(_engine, textureID);
+  _textures[@(textureID)] = FlutterTexture;
+  return textureID;
+}
+
+- (void)textureFrameAvailable:(int64_t)textureID {
+  FlutterEngineMarkExternalTextureFrameAvailable(_engine, textureID);
+}
+
+- (void)unregisterTexture:(int64_t)textureID {
+  FlutterEngineUnregisterExternalTexture(_engine, textureID);
+  [_textures removeObjectForKey:@(textureID)];
+}
+
 @end

shell/platform/darwin/macos/framework/Source/FlutterExternalTextureGL.h

@@ -0,0 +1,34 @@
+// 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.
+
+#import <Foundation/Foundation.h>
+
+#import "flutter/shell/platform/darwin/common/framework/Headers/FlutterTexture.h"
+#import "flutter/shell/platform/embedder/embedder.h"
+
+/**
+ * Used to bridge FlutterTexture object and handle the texture copy request the
+ * Flutter engine.
+ */
+@interface FlutterExternalTextureGL : NSObject
+
+/**
+ * Initializes a texture adapter with |texture| return a instance.
+ */
+- (nonnull instancetype)initWithFlutterTexture:(nonnull id<FlutterTexture>)texture;
+
+/**
+ * Accepts texture buffer copy request from the Flutter engine.
+ * When the user side marks the textureID as available, the Flutter engine will
+ * callback to this method and ask for populate the |openGLTexture| object,
+ * such as the texture type and the format of the pixel buffer and the texture object.
+ */
+- (BOOL)populateTexture:(nonnull FlutterOpenGLTexture*)openGLTexture;
+
+/**
+ * Returns the ID for the FlutterTexture instance.
+ */
+- (int64_t)textureID;
+
+@end

shell/platform/darwin/macos/framework/Source/FlutterExternalTextureGL.mm

@@ -0,0 +1,85 @@
+// 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.
+
+#import "flutter/shell/platform/darwin/macos/framework/Source/FlutterExternalTextureGL.h"
+
+#import <AppKit/AppKit.h>
+#import <CoreVideo/CoreVideo.h>
+#import <OpenGL/gl.h>
+
+static void OnCVOpenGLTextureRelease(CVOpenGLTextureRef cvOpenGLTexture) {
+  CVOpenGLTextureRelease(cvOpenGLTexture);
+}
+
+@implementation FlutterExternalTextureGL {
+  /**
+   * OpenGL texture cache.
+   */
+  CVOpenGLTextureCacheRef _openGLTextureCache;
+  /**
+   * User side texture object, used to copy pixel buffer.
+   */
+  id<FlutterTexture> _texture;
+}
+
+- (instancetype)initWithFlutterTexture:(id<FlutterTexture>)texture {
+  self = [super init];
+  if (self) {
+    _texture = texture;
+  }
+  return self;
+}
+
+- (int64_t)textureID {
+  return reinterpret_cast<int64_t>(self);
+}
+
+- (BOOL)populateTexture:(FlutterOpenGLTexture*)openGLTexture {
+  // Copy the pixel buffer from the FlutterTexture instance implemented on the user side.
+  CVPixelBufferRef pixelBuffer = [_texture copyPixelBuffer];
+
+  if (!pixelBuffer) {
+    return NO;
+  }
+
+  // Create the opengl texture cache if necessary.
+  if (!_openGLTextureCache) {
+    CGLContextObj context = [NSOpenGLContext currentContext].CGLContextObj;
+    CGLPixelFormatObj format = CGLGetPixelFormat(context);
+    if (CVOpenGLTextureCacheCreate(kCFAllocatorDefault, NULL, context, format, NULL,
+                                   &_openGLTextureCache) != kCVReturnSuccess) {
+      NSLog(@"Could not create texture cache.");
+      CVPixelBufferRelease(pixelBuffer);
+      return NO;
+    }
+  }
+
+  // Try to clear the cache of OpenGL textures to save memory.
+  CVOpenGLTextureCacheFlush(_openGLTextureCache, 0);
+
+  CVOpenGLTextureRef cvOpenGLTexture = NULL;
+  if (CVOpenGLTextureCacheCreateTextureFromImage(kCFAllocatorDefault, _openGLTextureCache,
+                                                 pixelBuffer, NULL,
+                                                 &cvOpenGLTexture) != kCVReturnSuccess) {
+    CVPixelBufferRelease(pixelBuffer);
+    return NO;
+  }
+
+  openGLTexture->target = static_cast<uint32_t>(CVOpenGLTextureGetTarget(cvOpenGLTexture));
+  openGLTexture->name = static_cast<uint32_t>(CVOpenGLTextureGetName(cvOpenGLTexture));
+  openGLTexture->format = static_cast<uint32_t>(GL_RGBA8);
+  openGLTexture->destruction_callback = (VoidCallback)OnCVOpenGLTextureRelease;
+  openGLTexture->user_data = cvOpenGLTexture;
+  openGLTexture->width = CVPixelBufferGetWidth(pixelBuffer);
+  openGLTexture->height = CVPixelBufferGetHeight(pixelBuffer);
+
+  CVPixelBufferRelease(pixelBuffer);
+  return YES;
+}
+
+- (void)dealloc {
+  CVOpenGLTextureCacheRelease(_openGLTextureCache);
+}
+
+@end

shell/platform/embedder/embedder.cc

@@ -807,8 +807,16 @@ FlutterEngineResult FlutterEngineRun(size_t version,
         GrGLTextureInfo gr_texture_info = {texture.target, texture.name,
                                            texture.format};
 
-        GrBackendTexture gr_backend_texture(size.width(), size.height(),
-                                            GrMipMapped::kNo, gr_texture_info);
+        size_t width = size.width();
+        size_t height = size.height();
+
+        if (texture.width != 0 && texture.height != 0) {
+          width = texture.width;
+          height = texture.height;
+        }
+
+        GrBackendTexture gr_backend_texture(width, height, GrMipMapped::kNo,
+                                            gr_texture_info);
         SkImage::TextureReleaseProc release_proc = texture.destruction_callback;
         auto image = SkImage::MakeFromTexture(
             context,                   // context

shell/platform/embedder/embedder.h

@@ -218,7 +218,8 @@ typedef enum {
 } FlutterOpenGLTargetType;
 
 typedef struct {
-  /// Target texture of the active texture unit (example GL_TEXTURE_2D).
+  /// Target texture of the active texture unit (example GL_TEXTURE_2D or
+  /// GL_TEXTURE_RECTANGLE).
   uint32_t target;
   /// The name of the texture.
   uint32_t name;
@@ -229,6 +230,14 @@ typedef struct {
   /// Callback invoked (on an engine managed thread) that asks the embedder to
   /// collect the texture.
   VoidCallback destruction_callback;
+  /// Optional parameters for texture height/width, default is 0, non-zero means
+  /// the texture has the specified width/height. Usually, when the texture type
+  /// is GL_TEXTURE_RECTANGLE, we need to specify the texture width/height to
+  /// tell the embedder to scale when rendering.
+  /// Width of the texture.
+  size_t width;
+  /// Height of the texture.
+  size_t height;
 } FlutterOpenGLTexture;
 
 typedef struct {