flutter::CompositorOpenGL Class Reference

#include <compositor_opengl.h>

Inheritance diagram for flutter::CompositorOpenGL:

Public Member Functions
	CompositorOpenGL (FlutterWindowsEngine *engine, impeller::ProcTableGLES::Resolver resolver, bool enable_impeller)
bool	CreateBackingStore (const FlutterBackingStoreConfig &config, FlutterBackingStore *result) override
	|Compositor|
bool	CollectBackingStore (const FlutterBackingStore *store) override
	|Compositor|
bool	Present (FlutterWindowsView *view, const FlutterLayer **layers, size_t layers_count) override
	|Compositor|
Public Member Functions inherited from flutter::Compositor
virtual	~Compositor ()=default

Detailed Description

Definition at line 19 of file compositor_opengl.h.

Constructor & Destructor Documentation

CompositorOpenGL()

flutter::CompositorOpenGL::CompositorOpenGL	(	FlutterWindowsEngine *	engine,
		impeller::ProcTableGLES::Resolver	resolver,
		bool	enable_impeller
	)

Definition at line 39 of file compositor_opengl.cc.

    : engine_(engine), resolver_(resolver), enable_impeller_(enable_impeller) {}

Member Function Documentation

CollectBackingStore()

bool flutter::CompositorOpenGL::CollectBackingStore ( const FlutterBackingStore *  store )

overridevirtual

|Compositor|

Implements flutter::Compositor.

Definition at line 108 of file compositor_opengl.cc.

                                                                           {
  FML_DCHECK(is_initialized_);
  FML_DCHECK(store->type == kFlutterBackingStoreTypeOpenGL);
  FML_DCHECK(store->open_gl.type == kFlutterOpenGLTargetTypeFramebuffer);
 
  auto user_data = static_cast<FramebufferBackingStore*>(
      store->open_gl.framebuffer.user_data);
 
  gl_->DeleteFramebuffers(1, &user_data->framebuffer_id);
  gl_->DeleteTextures(1, &user_data->texture_id);
 
  delete user_data;
  return true;
}

References FML_DCHECK, FlutterOpenGLBackingStore::framebuffer, kFlutterBackingStoreTypeOpenGL, kFlutterOpenGLTargetTypeFramebuffer, FlutterBackingStore::open_gl, FlutterOpenGLBackingStore::type, FlutterBackingStore::type, user_data, and FlutterOpenGLFramebuffer::user_data.

CreateBackingStore()

bool flutter::CompositorOpenGL::CreateBackingStore ( const FlutterBackingStoreConfig &  config, FlutterBackingStore *  result  )

overridevirtual

|Compositor|

Implements flutter::Compositor.

Definition at line 44 of file compositor_opengl.cc.

                                 {
  if (!is_initialized_ && !Initialize()) {
    return false;
  }
 
  auto store = std::make_unique<FramebufferBackingStore>();
 
  gl_->GenTextures(1, &store->texture_id);
  gl_->GenFramebuffers(1, &store->framebuffer_id);
 
  gl_->BindFramebuffer(GL_FRAMEBUFFER, store->framebuffer_id);
 
  gl_->BindTexture(GL_TEXTURE_2D, store->texture_id);
  gl_->TexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_NEAREST);
  gl_->TexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_NEAREST);
  gl_->TexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_CLAMP_TO_EDGE);
  gl_->TexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_CLAMP_TO_EDGE);
  gl_->TexImage2D(GL_TEXTURE_2D, 0, format_.general_format, config.size.width,
                  config.size.height, 0, format_.general_format,
                  GL_UNSIGNED_BYTE, nullptr);
  gl_->BindTexture(GL_TEXTURE_2D, 0);
 
  if (enable_impeller_) {
    // Impeller requries that its onscreen surface is Multisampled and already
    // has depth/stencil attached in order for anti-aliasing to work.
    gl_->FramebufferTexture2DMultisampleEXT(GL_FRAMEBUFFER,
                                            GL_COLOR_ATTACHMENT0, GL_TEXTURE_2D,
                                            store->texture_id, 0, 4);
 
    // Set up depth/stencil attachment for impeller renderer.
    GLuint depth_stencil;
    gl_->GenRenderbuffers(1, &depth_stencil);
    gl_->BindRenderbuffer(GL_RENDERBUFFER, depth_stencil);
    gl_->RenderbufferStorageMultisampleEXT(
        GL_RENDERBUFFER,      // target
        4,                    // samples
        GL_DEPTH24_STENCIL8,  // internal format
        config.size.width,    // width
        config.size.height    // height
    );
    gl_->FramebufferRenderbuffer(GL_FRAMEBUFFER, GL_DEPTH_ATTACHMENT,
                                 GL_RENDERBUFFER, depth_stencil);
    gl_->FramebufferRenderbuffer(GL_FRAMEBUFFER, GL_STENCIL_ATTACHMENT,
                                 GL_RENDERBUFFER, depth_stencil);
 
  } else {
    gl_->FramebufferTexture2D(GL_FRAMEBUFFER, GL_COLOR_ATTACHMENT0,
                              GL_TEXTURE_2D, store->texture_id, 0);
  }
 
  result->type = kFlutterBackingStoreTypeOpenGL;
  result->open_gl.type = kFlutterOpenGLTargetTypeFramebuffer;
  result->open_gl.framebuffer.name = store->framebuffer_id;
  result->open_gl.framebuffer.target = format_.sized_format;
  result->open_gl.framebuffer.user_data = store.release();
  result->open_gl.framebuffer.destruction_callback = [](void* user_data) {
    // Backing store destroyed in `CompositorOpenGL::CollectBackingStore`, set
    // on FlutterCompositor.collect_backing_store_callback during engine start.
  };
  return true;
}

References FlutterOpenGLFramebuffer::destruction_callback, FlutterOpenGLBackingStore::framebuffer, FlutterSize::height, kFlutterBackingStoreTypeOpenGL, kFlutterOpenGLTargetTypeFramebuffer, FlutterOpenGLFramebuffer::name, FlutterBackingStore::open_gl, FlutterBackingStoreConfig::size, FlutterOpenGLFramebuffer::target, FlutterOpenGLBackingStore::type, FlutterBackingStore::type, user_data, FlutterOpenGLFramebuffer::user_data, and FlutterSize::width.

Present()

bool flutter::CompositorOpenGL::Present ( FlutterWindowsView *  view, const FlutterLayer **  layers, size_t  layers_count  )

overridevirtual

|Compositor|

Implements flutter::Compositor.

Definition at line 123 of file compositor_opengl.cc.

                                                    {
  FML_DCHECK(view != nullptr);
 
  // Clear the view if there are no layers to present.
  if (layers_count == 0) {
    // Normally the compositor is initialized when the first backing store is
    // created. However, on an empty frame no backing stores are created and
    // the present needs to initialize the compositor.
    if (!is_initialized_ && !Initialize()) {
      return false;
    }
 
    return Clear(view);
  }
 
  // TODO: Support compositing layers and platform views.
  // See: https://github.com/flutter/flutter/issues/31713
  FML_DCHECK(is_initialized_);
  FML_DCHECK(layers_count == 1);
  FML_DCHECK(layers[0]->offset.x == 0 && layers[0]->offset.y == 0);
  FML_DCHECK(layers[0]->type == kFlutterLayerContentTypeBackingStore);
  FML_DCHECK(layers[0]->backing_store->type == kFlutterBackingStoreTypeOpenGL);
  FML_DCHECK(layers[0]->backing_store->open_gl.type ==
             kFlutterOpenGLTargetTypeFramebuffer);
 
  auto width = layers[0]->size.width;
  auto height = layers[0]->size.height;
 
  // Check if this frame can be presented. This resizes the surface if a resize
  // is pending and |width| and |height| match the target size.
  if (!view->OnFrameGenerated(width, height)) {
    return false;
  }
 
  // |OnFrameGenerated| should return false if the surface isn't valid.
  FML_DCHECK(view->surface() != nullptr);
  FML_DCHECK(view->surface()->IsValid());
 
  egl::WindowSurface* surface = view->surface();
  if (!surface->MakeCurrent()) {
    return false;
  }
 
  auto source_id = layers[0]->backing_store->open_gl.framebuffer.name;
 
  // Disable the scissor test as it can affect blit operations.
  // Prevents regressions like: https://github.com/flutter/flutter/issues/140828
  // See OpenGL specification version 4.6, section 18.3.1.
  gl_->Disable(GL_SCISSOR_TEST);
  gl_->BindFramebuffer(GL_READ_FRAMEBUFFER, source_id);
  gl_->BindFramebuffer(GL_DRAW_FRAMEBUFFER, kWindowFrameBufferId);
 
  auto blitFramebuffer = GetBlitFramebufferProc(*gl_);
  blitFramebuffer(0,                    // srcX0
                  0,                    // srcY0
                  width,                // srcX1
                  height,               // srcY1
                  0,                    // dstX0
                  0,                    // dstY0
                  width,                // dstX1
                  height,               // dstY1
                  GL_COLOR_BUFFER_BIT,  // mask
                  GL_NEAREST            // filter
  );
 
  if (!surface->SwapBuffers()) {
    return false;
  }
 
  view->OnFramePresented();
  return true;
}

References FlutterLayer::backing_store, FML_DCHECK, FlutterOpenGLBackingStore::framebuffer, height, FlutterSize::height, kFlutterBackingStoreTypeOpenGL, kFlutterLayerContentTypeBackingStore, kFlutterOpenGLTargetTypeFramebuffer, layers, layers_count, FlutterOpenGLFramebuffer::name, FlutterLayer::offset, FlutterBackingStore::open_gl, FlutterLayer::size, surface, type, FlutterLayer::type, view, width, FlutterSize::width, and FlutterPoint::y.

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The documentation for this class was generated from the following files:

• shell/platform/windows/compositor_opengl.h
• shell/platform/windows/compositor_opengl.cc