Add a new API to create a surfaceless GLSurface for Ozone

ui/gl/gl_surface_ozone.cc

 // Copyright 2014 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "ui/gl/gl_surface.h"
 
 #include "base/logging.h"
 #include "base/memory/ref_counted.h"
 #include "ui/gfx/native_widget_types.h"
 #include "ui/gl/gl_context.h"
 #include "ui/gl/gl_image.h"
+#include "ui/gl/gl_image_egl.h"
 #include "ui/gl/gl_implementation.h"
 #include "ui/gl/gl_surface_egl.h"
 #include "ui/gl/gl_surface_osmesa.h"
 #include "ui/gl/gl_surface_stub.h"
 #include "ui/gl/scoped_make_current.h"
+#include "ui/ozone/public/native_pixmap.h"
 #include "ui/ozone/public/surface_factory_ozone.h"
 #include "ui/ozone/public/surface_ozone_egl.h"
 
 namespace gfx {
 
 namespace {
 
 // A thin wrapper around GLSurfaceEGL that owns the EGLNativeWindow
 class GL_EXPORT GLSurfaceOzoneEGL : public NativeViewGLSurfaceEGL {
  public:
@@ skipping 123 matching lines @@
     return ozone_surface_->OnSwapBuffersAsync(callback);
   }
   bool PostSubBufferAsync(int x,
                           int y,
                           int width,
                           int height,
                           const SwapCompletionCallback& callback) override {
     return SwapBuffersAsync(callback);
   }
 
- private:
+ protected:
   ~GLSurfaceOzoneSurfaceless() override {
     Destroy();  // EGL surface must be destroyed before SurfaceOzone
   }
 
   bool Flush() {
     glFlush();
     // TODO: the following should be replaced by a per surface flush as it gets
     // implemented in GL drivers.
     if (has_implicit_external_sync_) {
       const EGLint attrib_list[] = {
@@ skipping 16 matching lines @@
   }
 
   // The native surface. Deleting this is allowed to free the EGLNativeWindow.
   scoped_ptr<ui::SurfaceOzoneEGL> ozone_surface_;
   AcceleratedWidget widget_;
   scoped_ptr<VSyncProvider> vsync_provider_;
   bool has_implicit_external_sync_;
   DISALLOW_COPY_AND_ASSIGN(GLSurfaceOzoneSurfaceless);
 };
 
+// This provides surface-like semantics implemented through surfaceless.
+// A framebuffer is bound automatically and re-bound at each swap.
+class GL_EXPORT GLSurfaceOzoneSurfacelessSurfaceImpl
+    : public GLSurfaceOzoneSurfaceless {
+ public:
+  GLSurfaceOzoneSurfacelessSurfaceImpl(
+      scoped_ptr<ui::SurfaceOzoneEGL> ozone_surface,
+      AcceleratedWidget widget)
+      : GLSurfaceOzoneSurfaceless(ozone_surface.Pass(), widget),
+        fbo_(0),
+        current_surface_(0) {
+    textures_[0] = 0;
+    textures_[1] = 0;
+  }
+
+  unsigned int GetBackingFrameBufferObject() override { return fbo_; }
+
+  bool OnMakeCurrent(GLContext* context) override {
+    if (!fbo_) {
+      glGenFramebuffersEXT(1, &fbo_);
+      if (!fbo_)
+        return false;
+      glGenTextures(2, textures_);
+      // Create and bind our pixmaps.
+      if (!ResizePixmaps())
+        return false;
+    }
+    BindFramebuffer();
+    return SurfacelessEGL::OnMakeCurrent(context);
+  }
+
+  bool Resize(const gfx::Size& size) override {
+    return GLSurfaceOzoneSurfaceless::Resize(size) && ResizePixmaps();
+  }
+
+  bool SupportsPostSubBuffer() override { return false; }
+
+  bool SwapBuffers() override {
+    bool ret = images_[current_surface_]->ScheduleOverlayPlane(
+                   widget_, 0, OverlayTransform::OVERLAY_TRANSFORM_NONE,
+                   gfx::Rect(GetSize()), gfx::RectF(1, 1)) &&
+               GLSurfaceOzoneSurfaceless::SwapBuffers();
+    current_surface_ ^= 1;
+    BindFramebuffer();
+    return ret;
+  }
+
+ private:
+  ~GLSurfaceOzoneSurfacelessSurfaceImpl() override {
+    glBindFramebufferEXT(GL_FRAMEBUFFER, 0);

[piman, 2015/02/19 23:21:19]

This is too late to do GL calls, the context is not current any more.
I think you can do this at Destroy time, though it's worth it to DCHECK that the
context that was passed to OnMakeCurrent is still current.

[achaulk, 2015/02/23 20:43:09]

Done.

+    glDeleteTextures(2, textures_);
+    glDeleteFramebuffersEXT(1, &fbo_);
+  }
+
+  void BindFramebuffer() {
+    glBindFramebufferEXT(GL_FRAMEBUFFER, fbo_);
+    glFramebufferTexture2DEXT(GL_FRAMEBUFFER, GL_COLOR_ATTACHMENT0,
+                              GL_TEXTURE_2D, textures_[current_surface_], 0);
+  }
+
+  bool ResizePixmaps() {
+    if (!fbo_)
+      return true;
+    for (int i = 0; i < 2; i++) {
+      scoped_refptr<ui::NativePixmap> pixmap =
+          ui::SurfaceFactoryOzone::GetInstance()->CreateNativePixmap(
+              widget_, GetSize(), ui::SurfaceFactoryOzone::RGBA_8888,
+              ui::SurfaceFactoryOzone::SCANOUT);
+      if (!pixmap)
+        return false;
+      scoped_refptr<GLImageEGL> image = new GLImageEGL(GetSize());
+      EGLint attrs[] = {EGL_IMAGE_PRESERVED_KHR, EGL_TRUE, EGL_NONE};
+      if (!image->Initialize(EGL_NATIVE_PIXMAP_KHR,
+                             pixmap->GetEGLClientBuffer(), attrs))
+        return false;
+      images_[i] = image;
+      pixmaps_[i] = pixmap;
+      // Bind image to texture.
+      glBindTexture(GL_TEXTURE_EXTERNAL_OES, textures_[i]);
+      if (!images_[i]->BindTexImage(GL_TEXTURE_EXTERNAL_OES))
+        return false;
+    }
+    return true;
+  }
+
+  GLuint fbo_;
+  GLuint textures_[2];
+  scoped_refptr<GLImage> images_[2];
+  scoped_refptr<ui::NativePixmap> pixmaps_[2];
+  int current_surface_;
+  DISALLOW_COPY_AND_ASSIGN(GLSurfaceOzoneSurfacelessSurfaceImpl);
+};
+
 }  // namespace
 
 // static
 bool GLSurface::InitializeOneOffInternal() {
   switch (GetGLImplementation()) {
     case kGLImplementationEGLGLES2:
       if (!GLSurfaceEGL::InitializeOneOff()) {
         LOG(ERROR) << "GLSurfaceEGL::InitializeOneOff failed.";
         return false;
       }
 
       return true;
     case kGLImplementationOSMesaGL:
     case kGLImplementationMockGL:
       return true;
     default:
       return false;
   }
 }
 
 // static
+scoped_refptr<GLSurface> GLSurface::CreateSurfacelessViewGLSurface(
+    gfx::AcceleratedWidget window) {
+  if (GetGLImplementation() == kGLImplementationEGLGLES2 &&
+      window != kNullAcceleratedWidget &&
+      GLSurfaceEGL::IsEGLSurfacelessContextSupported() &&
+      ui::SurfaceFactoryOzone::GetInstance()->CanShowPrimaryPlaneAsOverlay()) {
+    scoped_ptr<ui::SurfaceOzoneEGL> surface_ozone =
+        ui::SurfaceFactoryOzone::GetInstance()
+            ->CreateSurfacelessEGLSurfaceForWidget(window);
+    if (!surface_ozone)
+      return NULL;

[piman, 2015/02/19 23:21:19]

nit: nullptr for consistency

[achaulk, 2015/02/23 20:43:09]

Done.

+    scoped_refptr<GLSurface> surface;
+    surface = new GLSurfaceOzoneSurfaceless(surface_ozone.Pass(), window);
+    if (surface->Initialize())
+      return surface;
+  }
+
+  return nullptr;
+}
+
+// static
 scoped_refptr<GLSurface> GLSurface::CreateViewGLSurface(
     gfx::AcceleratedWidget window) {
   if (GetGLImplementation() == kGLImplementationOSMesaGL) {
     scoped_refptr<GLSurface> surface(new GLSurfaceOSMesaHeadless());
     if (!surface->Initialize())
       return NULL;
     return surface;
   }
   DCHECK(GetGLImplementation() == kGLImplementationEGLGLES2);
   if (window != kNullAcceleratedWidget) {
     scoped_refptr<GLSurface> surface;
     if (GLSurfaceEGL::IsEGLSurfacelessContextSupported() &&
         ui::SurfaceFactoryOzone::GetInstance()
             ->CanShowPrimaryPlaneAsOverlay()) {
       scoped_ptr<ui::SurfaceOzoneEGL> surface_ozone =
           ui::SurfaceFactoryOzone::GetInstance()
               ->CreateSurfacelessEGLSurfaceForWidget(window);
       if (!surface_ozone)
         return NULL;
-      surface = new GLSurfaceOzoneSurfaceless(surface_ozone.Pass(), window);
+      surface = new GLSurfaceOzoneSurfacelessSurfaceImpl(surface_ozone.Pass(),
+                                                         window);
     } else {
       scoped_ptr<ui::SurfaceOzoneEGL> surface_ozone =
           ui::SurfaceFactoryOzone::GetInstance()->CreateEGLSurfaceForWidget(
               window);
       if (!surface_ozone)
         return NULL;
 
       surface = new GLSurfaceOzoneEGL(surface_ozone.Pass(), window);
     }
     if (!surface->Initialize())
@@ skipping 35 matching lines @@
       NOTREACHED();
       return NULL;
   }
 }
 
 EGLNativeDisplayType GetPlatformDefaultEGLNativeDisplay() {
   return ui::SurfaceFactoryOzone::GetInstance()->GetNativeDisplay();
 }
 
 }  // namespace gfx