Added the desktop shape fields to VideoPacket.

If the host passes the desktop shape region in a VideoPacket the client will use it to draw transparent regions. The client also informs the web-app of the desktop shape changes, so it can set the input passthrough region correctly.

Review URL: https://chromiumcodereview.appspot.com/17511004

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@207789 0039d316-1c4b-4281-b951-d872f2087c98

5 files changed, 112 insertions, 0 deletions

diff --git a/remoting/codec/video_decoder.h b/remoting/codec/video_decoder.h
index f1eb650..4e1d39f 100644
--- a/remoting/codec/video_decoder.h
+++ b/remoting/codec/video_decoder.h
@@ -68,6 +68,10 @@ class VideoDecoder {
                            uint8* image_buffer,
                            int image_stride,
                            SkRegion* output_region) = 0;
+
+  // Returns the "shape", if any, of the most recently rendered frame.
+  // The shape is returned in source dimensions.
+  virtual const SkRegion* GetImageShape() = 0;
 };
 
 }  // namespace remoting
diff --git a/remoting/codec/video_decoder_verbatim.cc b/remoting/codec/video_decoder_verbatim.cc
index 56b116f..fa36690 100644
--- a/remoting/codec/video_decoder_verbatim.cc
+++ b/remoting/codec/video_decoder_verbatim.cc
@@ -203,4 +203,8 @@ void VideoDecoderVerbatim::RenderFrame(const SkISize& view_size,
   updated_region_.setEmpty();
 }
 
+const SkRegion* VideoDecoderVerbatim::GetImageShape() {
+  return NULL;
+}
+
 }  // namespace remoting
diff --git a/remoting/codec/video_decoder_verbatim.h b/remoting/codec/video_decoder_verbatim.h
index 46c7069..f058a7e 100644
--- a/remoting/codec/video_decoder_verbatim.h
+++ b/remoting/codec/video_decoder_verbatim.h
@@ -32,6 +32,7 @@ class VideoDecoderVerbatim : public VideoDecoder {
                            uint8* image_buffer,
                            int image_stride,
                            SkRegion* output_region) OVERRIDE;
+  virtual const SkRegion* GetImageShape() OVERRIDE;
 
  private:
   enum State {
diff --git a/remoting/codec/video_decoder_vp8.cc b/remoting/codec/video_decoder_vp8.cc
index d871542..33896fb 100644
--- a/remoting/codec/video_decoder_vp8.cc
+++ b/remoting/codec/video_decoder_vp8.cc
@@ -6,6 +6,8 @@
 
 #include <math.h>
 
+#include <algorithm>
+
 #include "base/logging.h"
 #include "media/base/media.h"
 #include "media/base/yuv_convert.h"
@@ -19,6 +21,10 @@ extern "C" {
 
 namespace remoting {
 
+enum { kBytesPerPixelRGB32 = 4 };
+
+const uint32 kTransparent = 0;
+
 VideoDecoderVp8::VideoDecoderVp8()
     : state_(kUninitialized),
       codec_(NULL),
@@ -39,6 +45,8 @@ void VideoDecoderVp8::Initialize(const SkISize& screen_size) {
 
   screen_size_ = screen_size;
   state_ = kReady;
+
+  transparent_region_.setRect(SkIRect::MakeSize(screen_size_));
 }
 
 VideoDecoder::DecodeResult VideoDecoderVp8::DecodePacket(
@@ -98,6 +106,26 @@ VideoDecoder::DecodeResult VideoDecoderVp8::DecodePacket(
   }
 
   updated_region_.op(region, SkRegion::kUnion_Op);
+
+  // Update the desktop shape region.
+  SkRegion desktop_shape_region;
+  if (packet->has_use_desktop_shape()) {
+    for (int i = 0; i < packet->desktop_shape_rects_size(); ++i) {
+      Rect remoting_rect = packet->desktop_shape_rects(i);
+      SkIRect rect = SkIRect::MakeXYWH(remoting_rect.x(),
+                                       remoting_rect.y(),
+                                       remoting_rect.width(),
+                                       remoting_rect.height());
+      desktop_shape_region.op(rect, SkRegion::kUnion_Op);
+    }
+  } else {
+    // Fallback for the case when the host didn't include the desktop shape
+    // region.
+    desktop_shape_region = SkRegion(SkIRect::MakeSize(screen_size_));
+  }
+
+  UpdateImageShapeRegion(&desktop_shape_region);
+
   return DECODE_DONE;
 }
 
@@ -119,6 +147,13 @@ void VideoDecoderVp8::Invalidate(const SkISize& view_size,
     rect = ScaleRect(rect, view_size, screen_size_);
     updated_region_.op(rect, SkRegion::kUnion_Op);
   }
+
+  // Updated areas outside of the new desktop shape region should be made
+  // transparent, not repainted.
+  SkRegion difference = updated_region_;
+  difference.op(desktop_shape_, SkRegion::kDifference_Op);
+  updated_region_.op(difference, SkRegion::kDifference_Op);
+  transparent_region_.op(difference, SkRegion::kUnion_Op);
 }
 
 void VideoDecoderVp8::RenderFrame(const SkISize& view_size,
@@ -208,6 +243,59 @@ void VideoDecoderVp8::RenderFrame(const SkISize& view_size,
 
   updated_region_.op(ScaleRect(clip_area, view_size, screen_size_),
                      SkRegion::kDifference_Op);
+
+  for (SkRegion::Iterator i(transparent_region_); !i.done(); i.next()) {
+    // Determine the scaled area affected by this rectangle changing.
+    SkIRect rect = i.rect();
+    if (!rect.intersect(source_clip))
+      continue;
+    rect = ScaleRect(rect, screen_size_, view_size);
+    if (!rect.intersect(clip_area))
+      continue;
+
+    // Fill the rectange with transparent pixels.
+    FillRect(image_buffer, image_stride, rect, kTransparent);
+    output_region->op(rect, SkRegion::kUnion_Op);
+  }
+
+  SkIRect scaled_clip_area = ScaleRect(clip_area, view_size, screen_size_);
+  updated_region_.op(scaled_clip_area, SkRegion::kDifference_Op);
+  transparent_region_.op(scaled_clip_area, SkRegion::kDifference_Op);
+}
+
+const SkRegion* VideoDecoderVp8::GetImageShape() {
+  return &desktop_shape_;
+}
+
+void VideoDecoderVp8::FillRect(uint8* buffer,
+                               int stride,
+                               const SkIRect& rect,
+                               uint32 color) {
+  uint32* ptr = reinterpret_cast<uint32*>(buffer + (rect.top() * stride) +
+      (rect.left() * kBytesPerPixelRGB32));
+  int width = rect.width();
+  for (int height = rect.height(); height > 0; --height) {
+    std::fill(ptr, ptr + width, color);
+    ptr += stride / kBytesPerPixelRGB32;
+  }
+}
+
+void VideoDecoderVp8::UpdateImageShapeRegion(SkRegion* new_desktop_shape) {
+  // Add all areas that have been updated or become transparent to the
+  // transparent region. Exclude anything within the new desktop shape.
+  transparent_region_.op(desktop_shape_, SkRegion::kUnion_Op);
+  transparent_region_.op(updated_region_, SkRegion::kUnion_Op);
+  transparent_region_.op(*new_desktop_shape, SkRegion::kDifference_Op);
+
+  // Add newly exposed areas to the update region and limit updates to the new
+  // desktop shape.
+  SkRegion difference = *new_desktop_shape;
+  difference.op(desktop_shape_, SkRegion::kDifference_Op);
+  updated_region_.op(difference, SkRegion::kUnion_Op);
+  updated_region_.op(*new_desktop_shape, SkRegion::kIntersect_Op);
+
+  // Set the new desktop shape region.
+  desktop_shape_.swap(*new_desktop_shape);
 }
 
 }  // namespace remoting
diff --git a/remoting/codec/video_decoder_vp8.h b/remoting/codec/video_decoder_vp8.h
index 53a720b..2efbd22 100644
--- a/remoting/codec/video_decoder_vp8.h
+++ b/remoting/codec/video_decoder_vp8.h
@@ -30,6 +30,7 @@ class VideoDecoderVp8 : public VideoDecoder {
                            uint8* image_buffer,
                            int image_stride,
                            SkRegion* output_region) OVERRIDE;
+  virtual const SkRegion* GetImageShape() OVERRIDE;
 
  private:
   enum State {
@@ -38,6 +39,14 @@ class VideoDecoderVp8 : public VideoDecoder {
     kError,
   };
 
+  // Fills the rectangle |rect| with the given ARGB color |color| in |buffer|.
+  void FillRect(uint8* buffer, int stride, const SkIRect& rect, uint32 color);
+
+  // Calculates the difference between the desktop shape regions in two
+  // consecutive frames and updates |updated_region_| and |transparent_region_|
+  // accordingly.
+  void UpdateImageShapeRegion(SkRegion* new_desktop_shape);
+
   // The internal state of the decoder.
   State state_;
 
@@ -52,6 +61,12 @@ class VideoDecoderVp8 : public VideoDecoder {
   // Output dimensions.
   SkISize screen_size_;
 
+  // The region occupied by the top level windows.
+  SkRegion desktop_shape_;
+
+  // The region that should be make transparent.
+  SkRegion transparent_region_;
+
   DISALLOW_COPY_AND_ASSIGN(VideoDecoderVp8);
 };