[Ozone] Adding a software surface implementation

ui/gfx/ozone/impl/software_surface_ozone.cc

+// Copyright (c) 2013 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/gfx/ozone/impl/software_surface_ozone.h"
+
+#include <errno.h>
+#include <sys/mman.h>
+#include <sys/types.h>
+#include <xf86drm.h>
+
+#include "base/logging.h"
+#include "base/memory/scoped_vector.h"
+#include "third_party/skia/include/core/SkBitmap.h"
+#include "third_party/skia/include/core/SkBitmapDevice.h"
+#include "third_party/skia/include/core/SkCanvas.h"
+#include "ui/gfx/ozone/impl/buffer_generator_ozone.h"
+#include "ui/gfx/ozone/impl/drm_skbitmap_ozone.h"
+#include "ui/gfx/ozone/impl/hardware_display_controller_ozone.h"
+#include "ui/gfx/skia_util.h"
+
+namespace gfx {
+
+namespace {
+
+// Extends the SkBitmapDevice to allow setting the SkPixelRef. We use the setter
+// to change the SkPixelRef such that the device always points to the
+// backbuffer.
+class CustomSkBitmapDevice : public SkBitmapDevice {
+ public:
+  CustomSkBitmapDevice(const SkBitmap& bitmap) : SkBitmapDevice(bitmap) {}
+  virtual ~CustomSkBitmapDevice() {}
+
+  void SetPixelRef(SkPixelRef* pixel_ref) { setPixelRef(pixel_ref, 0); }
+
+ private:
+  DISALLOW_COPY_AND_ASSIGN(CustomSkBitmapDevice);
+};
+
+}  // namespace
+
+////////////////////////////////////////////////////////////////////////////////
+// SoftwareSurfaceOzone implementation
+
+SoftwareSurfaceOzone::SoftwareSurfaceOzone(
+    HardwareDisplayControllerOzone* controller,
+    BufferGeneratorOzone* buffer_generator)

[rjkroege, 2013/10/11 17:26:51]

rather than having a buffer generator class, why not just pass in the bitmap?
that will permit providing a mock for tests?

or just make "CreateBuffer" a virtual method and override it in a test? it's
reasonable to make testing subclasses be friends.

[dnicoara, 2013/10/11 19:20:07]

Done.

+    : buffer_generator_(buffer_generator),
+      controller_(controller),
+      bitmaps_(),
+      front_buffer_(0) {
+}
+
+SoftwareSurfaceOzone::~SoftwareSurfaceOzone() {
+}
+
+bool SoftwareSurfaceOzone::Initialize() {
+  for (int i = 0; i < 2; ++i) {
+    DrmSkBitmapOzone* bitmap = buffer_generator_->CreateBuffer(
+        controller_->get_fd());
+    // TODO(dnicoara) Should select the configuration based on what the
+    // underlying system supports.
+    bitmap->setConfig(SkBitmap::kARGB_8888_Config,
+                      controller_->get_mode().hdisplay,
+                      controller_->get_mode().vdisplay);
+
+    if (!bitmap->Initialize()) {
+      delete bitmap;
+      return false;
+    }
+
+    bitmaps_.push_back(bitmap);
+  }
+
+  skia_device_ = skia::AdoptRef(
+      new SkBitmapDevice(*bitmaps_[front_buffer_ ^ 1]));
+  skia_canvas_ = skia::AdoptRef(new SkCanvas(skia_device_.get()));
+
+  return true;
+}
+
+uint32_t SoftwareSurfaceOzone::GetFramebufferId() const {
+  return bitmaps_[front_buffer_ ^ 1]->get_framebuffer();
+}
+
+// This call is made after the hardware just started displaying our back buffer.
+// We need to update our pointer reference and synchronize the two buffers.
+void SoftwareSurfaceOzone::SwapBuffers() {
+  // Update our front buffer pointer.
+  front_buffer_ ^= 1;

[rjkroege, 2013/10/11 17:26:51]

either the vector is unnecessary or this will be sad in 97 if one bitmap
couldn't be initialized.

[dnicoara, 2013/10/11 19:20:07]

Changed how the bitmaps are stored and added CHECK.

+
+  // Unlocking will unset the pixel pointer, so it won't be pointing to the old
+  // PixelRef.
+  skia_device_->accessBitmap(false).unlockPixels();
+  // Update the backing pixels for the bitmap device.
+  static_cast<CustomSkBitmapDevice*>(skia_device_.get())->SetPixelRef(
+      bitmaps_[front_buffer_ ^ 1]->pixelRef());
+  // Locking the pixels will set the pixel pointer based on the PixelRef value.
+  skia_device_->accessBitmap(false).lockPixels();
+
+  SkIRect device_damage;
+  skia_canvas_->getClipDeviceBounds(&device_damage);
+  SkRect damage = SkRect::Make(device_damage);
+
+  skia_canvas_->drawBitmapRectToRect(*bitmaps_[front_buffer_], &damage, damage);
+}
+
+SkCanvas* SoftwareSurfaceOzone::GetDrawableForWidget() {
+  return skia_canvas_.get();
+}
+
+}  // namespace gfx