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compositor_opengl.cc
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1 // Copyright 2013 The Flutter Authors. All rights reserved.
2 // Use of this source code is governed by a BSD-style license that can be
3 // found in the LICENSE file.
4
5 #include "flutter/shell/platform/windows/compositor_opengl.h"
6
7 #include "GLES3/gl3.h"
8 #include "flutter/shell/platform/windows/flutter_windows_engine.h"
9 #include "flutter/shell/platform/windows/flutter_windows_view.h"
10
11 namespace flutter {
12
13 namespace {
14
15 constexpr uint32_t kWindowFrameBufferId = 0;
16
17 // The metadata for an OpenGL framebuffer backing store.
18 struct FramebufferBackingStore {
19 uint32_t framebuffer_id;
20 uint32_t texture_id;
21 };
22
23 } // namespace
24
25 CompositorOpenGL::CompositorOpenGL(FlutterWindowsEngine* engine,
26 impeller::ProcTableGLES::Resolver resolver,
27 bool enable_impeller)
28 : engine_(engine), resolver_(resolver), enable_impeller_(enable_impeller) {}
29
30 bool CompositorOpenGL::CreateBackingStore(
31 const FlutterBackingStoreConfig& config,
32 FlutterBackingStore* result) {
33 if (!is_initialized_ && !Initialize()) {
34 return false;
35 }
36
37 auto store = std::make_unique<FramebufferBackingStore>();
38
39 gl_->GenTextures(1, &store->texture_id);
40 gl_->GenFramebuffers(1, &store->framebuffer_id);
41
42 gl_->BindFramebuffer(GL_FRAMEBUFFER, store->framebuffer_id);
43
44 gl_->BindTexture(GL_TEXTURE_2D, store->texture_id);
45 gl_->TexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_NEAREST);
46 gl_->TexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_NEAREST);
47 gl_->TexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_CLAMP_TO_EDGE);
48 gl_->TexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_CLAMP_TO_EDGE);
49 gl_->TexImage2D(GL_TEXTURE_2D, 0, format_.general_format, config.size.width,
50 config.size.height, 0, format_.general_format,
51 GL_UNSIGNED_BYTE, nullptr);
52 gl_->BindTexture(GL_TEXTURE_2D, 0);
53
54 if (enable_impeller_) {
55 // Impeller requries that its onscreen surface is Multisampled and already
56 // has depth/stencil attached in order for anti-aliasing to work.
57 gl_->FramebufferTexture2DMultisampleEXT(GL_FRAMEBUFFER,
58 GL_COLOR_ATTACHMENT0, GL_TEXTURE_2D,
59 store->texture_id, 0, 4);
60
61 // Set up depth/stencil attachment for impeller renderer.
62 GLuint depth_stencil;
63 gl_->GenRenderbuffers(1, &depth_stencil);
64 gl_->BindRenderbuffer(GL_RENDERBUFFER, depth_stencil);
65 gl_->RenderbufferStorageMultisampleEXT(
66 GL_RENDERBUFFER, // target
67 4, // samples
68 GL_DEPTH24_STENCIL8, // internal format
69 config.size.width, // width
70 config.size.height // height
71 );
72 gl_->FramebufferRenderbuffer(GL_FRAMEBUFFER, GL_DEPTH_ATTACHMENT,
73 GL_RENDERBUFFER, depth_stencil);
74 gl_->FramebufferRenderbuffer(GL_FRAMEBUFFER, GL_STENCIL_ATTACHMENT,
75 GL_RENDERBUFFER, depth_stencil);
76
77 } else {
78 gl_->FramebufferTexture2D(GL_FRAMEBUFFER, GL_COLOR_ATTACHMENT0,
79 GL_TEXTURE_2D, store->texture_id, 0);
80 }
81
82 result->type = kFlutterBackingStoreTypeOpenGL;
83 result->open_gl.type = kFlutterOpenGLTargetTypeFramebuffer;
84 result->open_gl.framebuffer.name = store->framebuffer_id;
85 result->open_gl.framebuffer.target = format_.sized_format;
86 result->open_gl.framebuffer.user_data = store.release();
87 result->open_gl.framebuffer.destruction_callback = [](void* user_data) {
88 // Backing store destroyed in `CompositorOpenGL::CollectBackingStore`, set
89 // on FlutterCompositor.collect_backing_store_callback during engine start.
90 };
91 return true;
92 }
93
94 bool CompositorOpenGL::CollectBackingStore(const FlutterBackingStore* store) {
95 FML_DCHECK(is_initialized_);
96 FML_DCHECK(store->type == kFlutterBackingStoreTypeOpenGL);
97 FML_DCHECK(store->open_gl.type == kFlutterOpenGLTargetTypeFramebuffer);
98
99 auto user_data = static_cast<FramebufferBackingStore*>(
100 store->open_gl.framebuffer.user_data);
101
102 gl_->DeleteFramebuffers(1, &user_data->framebuffer_id);
103 gl_->DeleteTextures(1, &user_data->texture_id);
104
105 delete user_data;
106 return true;
107 }
108
109 bool CompositorOpenGL::Present(FlutterWindowsView* view,
110 const FlutterLayer** layers,
111 size_t layers_count) {
112 FML_DCHECK(view != nullptr);
113
114 // Clear the view if there are no layers to present.
115 if (layers_count == 0) {
116 // Normally the compositor is initialized when the first backing store is
117 // created. However, on an empty frame no backing stores are created and
118 // the present needs to initialize the compositor.
119 if (!is_initialized_ && !Initialize()) {
120 return false;
121 }
122
123 return Clear(view);
124 }
125
126 // TODO: Support compositing layers and platform views.
127 // See: https://github.com/flutter/flutter/issues/31713
128 FML_DCHECK(is_initialized_);
129 FML_DCHECK(layers_count == 1);
130 FML_DCHECK(layers[0]->offset.x == 0 && layers[0]->offset.y == 0);
131 FML_DCHECK(layers[0]->type == kFlutterLayerContentTypeBackingStore);
132 FML_DCHECK(layers[0]->backing_store->type == kFlutterBackingStoreTypeOpenGL);
133 FML_DCHECK(layers[0]->backing_store->open_gl.type ==
134 kFlutterOpenGLTargetTypeFramebuffer);
135
136 auto width = layers[0]->size.width;
137 auto height = layers[0]->size.height;
138
139 // Check if this frame can be presented. This resizes the surface if a resize
140 // is pending and |width| and |height| match the target size.
141 if (!view->OnFrameGenerated(width, height)) {
142 return false;
143 }
144
145 // |OnFrameGenerated| should return false if the surface isn't valid.
146 FML_DCHECK(view->surface() != nullptr);
147 FML_DCHECK(view->surface()->IsValid());
148
149 egl::WindowSurface* surface = view->surface();
150 if (!surface->MakeCurrent()) {
151 return false;
152 }
153
154 auto source_id = layers[0]->backing_store->open_gl.framebuffer.name;
155
156 // Disable the scissor test as it can affect blit operations.
157 // Prevents regressions like: https://github.com/flutter/flutter/issues/140828
158 // See OpenGL specification version 4.6, section 18.3.1.
159 gl_->Disable(GL_SCISSOR_TEST);
160 gl_->BindFramebuffer(GL_READ_FRAMEBUFFER, source_id);
161 gl_->BindFramebuffer(GL_DRAW_FRAMEBUFFER, kWindowFrameBufferId);
162
163 gl_->BlitFramebuffer(0, // srcX0
164 0, // srcY0
165 width, // srcX1
166 height, // srcY1
167 0, // dstX0
168 0, // dstY0
169 width, // dstX1
170 height, // dstY1
171 GL_COLOR_BUFFER_BIT, // mask
172 GL_NEAREST // filter
173 );
174
175 if (!surface->SwapBuffers()) {
176 return false;
177 }
178
179 view->OnFramePresented();
180 return true;
181 }
182
183 bool CompositorOpenGL::Initialize() {
184 FML_DCHECK(!is_initialized_);
185
186 egl::Manager* manager = engine_->egl_manager();
187 if (!manager) {
188 return false;
189 }
190
191 if (!manager->render_context()->MakeCurrent()) {
192 return false;
193 }
194
195 gl_ = std::make_unique<impeller::ProcTableGLES>(resolver_);
196 if (!gl_->IsValid()) {
197 gl_.reset();
198 return false;
199 }
200
201 if (gl_->GetDescription()->HasExtension("GL_EXT_texture_format_BGRA8888")) {
202 format_.sized_format = GL_BGRA8_EXT;
203 format_.general_format = GL_BGRA_EXT;
204 } else {
205 format_.sized_format = GL_RGBA8;
206 format_.general_format = GL_RGBA;
207 }
208
209 is_initialized_ = true;
210 return true;
211 }
212
213 bool CompositorOpenGL::Clear(FlutterWindowsView* view) {
214 FML_DCHECK(is_initialized_);
215
216 // Check if this frame can be presented. This resizes the surface if needed.
217 if (!view->OnEmptyFrameGenerated()) {
218 return false;
219 }
220
221 // |OnEmptyFrameGenerated| should return false if the surface isn't valid.
222 FML_DCHECK(view->surface() != nullptr);
223 FML_DCHECK(view->surface()->IsValid());
224
225 egl::WindowSurface* surface = view->surface();
226 if (!surface->MakeCurrent()) {
227 return false;
228 }
229
230 gl_->ClearColor(0.0f, 0.0f, 0.0f, 0.0f);
231 gl_->Clear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT | GL_STENCIL_BUFFER_BIT);
232
233 if (!surface->SwapBuffers()) {
234 return false;
235 }
236
237 view->OnFramePresented();
238 return true;
239 }
240
241 } // namespace flutter
flutter::CompositorOpenGL::Present
bool Present(FlutterWindowsView *view, const FlutterLayer **layers, size_t layers_count) override
|Compositor|
Definition: compositor_opengl.cc:109
flutter::CompositorOpenGL::CreateBackingStore
bool CreateBackingStore(const FlutterBackingStoreConfig &config, FlutterBackingStore *result) override
|Compositor|
Definition: compositor_opengl.cc:30
flutter::CompositorOpenGL::CollectBackingStore
bool CollectBackingStore(const FlutterBackingStore *store) override
|Compositor|
Definition: compositor_opengl.cc:94
flutter::CompositorOpenGL::CompositorOpenGL
CompositorOpenGL(FlutterWindowsEngine *engine, impeller::ProcTableGLES::Resolver resolver, bool enable_impeller)
Definition: compositor_opengl.cc:25
flutter::FlutterWindowsEngine
Definition: flutter_windows_engine.h:90
flutter::FlutterWindowsEngine::egl_manager
egl::Manager * egl_manager() const
Definition: flutter_windows_engine.h:171
flutter::FlutterWindowsView
Definition: flutter_windows_view.h:34
flutter::FlutterWindowsView::OnFramePresented
virtual void OnFramePresented()
Definition: flutter_windows_view.cc:665
flutter::FlutterWindowsView::surface
egl::WindowSurface * surface() const
Definition: flutter_windows_view.cc:770
flutter::FlutterWindowsView::OnFrameGenerated
bool OnFrameGenerated(size_t width, size_t height)
Definition: flutter_windows_view.cc:153
flutter::egl::Context::MakeCurrent
virtual bool MakeCurrent() const
Definition: context.cc:29
flutter::egl::Manager
Definition: manager.h:39
flutter::egl::Manager::render_context
virtual Context * render_context() const
Definition: manager.cc:328
flutter::egl::Surface::SwapBuffers
virtual bool SwapBuffers() const
Definition: surface.cc:59
flutter::egl::Surface::IsValid
virtual bool IsValid() const
Definition: surface.cc:19
flutter::egl::Surface::MakeCurrent
virtual bool MakeCurrent() const
Definition: surface.cc:50
flutter::egl::WindowSurface
Definition: window_surface.h:19
texture_id
uint32_t texture_id
Definition: compositor_opengl.cc:20
framebuffer_id
uint32_t framebuffer_id
Definition: compositor_opengl.cc:19
compositor_opengl.h
flutter_windows_engine.h
flutter_windows_view.h
user_data
void * user_data
Definition: flutter_windows_view_unittests.cc:53
type
enum flutter::testing::@88::KeyboardChange::Type type
flutter
Definition: accessibility_bridge_windows.cc:11