flutter::CompositorOpenGL Class Reference

#include <compositor_opengl.h>

Inheritance diagram for flutter::CompositorOpenGL:

Public Member Functions
	CompositorOpenGL (FlutterWindowsEngine *engine, impeller::ProcTableGLES::Resolver resolver)
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
	)

Definition at line 38 of file compositor_opengl.cc.

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

Member Function Documentation

CollectBackingStore()

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

overridevirtual

|Compositor|

Implements flutter::Compositor.

Definition at line 80 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;
}

CreateBackingStore()

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

overridevirtual

|Compositor|

Implements flutter::Compositor.

Definition at line 42 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, GL_RGBA8, config.size.width,
                  config.size.height, 0, GL_RGBA, GL_UNSIGNED_BYTE, nullptr);
  gl_->BindTexture(GL_TEXTURE_2D, 0);
 
  gl_->FramebufferTexture2D(GL_FRAMEBUFFER, GL_COLOR_ATTACHMENT0_EXT,
                            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_;
  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;
}

Present()

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

overridevirtual

|Compositor|

Implements flutter::Compositor.

Definition at line 95 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);
 
  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;
}

---

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

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